.

.

.

.

                                                                               

.

.

.

                         


.

.

PORTABLE BALANCER “Balanset-1A”

.

A Dual-Channel
PC-Based Dynamic Balancing System

.

.

.

OPERATION MANUAL
rev. 1.56 May 2023

.

.

                

.

.

.

.

.

.

.

.

.

2023

Estonia, Narva

.

TABLE OF CONTENTS

.

.

1.

BALANCING SYSTEM OVERVIEW

3

2.

SPECIFICATION

4

3.

COMPONENTS AND DELIVERY SET

5

4.

BALANCE PRINCIPLES

6

5.

SAFETY PRECAUTIONS

9

6.

SOFTWARE AND HARDWARE SETTINGS

8

7.

BALANCING SOFTWARE

13

.

7.1

General

Initial window………………………………………………………..
F1-About»…………………………………………………………..
F2-«Single plane», F3-«Two plane»……………………………….
F4 – «Settings»……………………………………………………..
F5 – «Vibration meter»…………………………………………….
F6 – «Reports».
F7 – «Balancing»
F8 – «Charts»

13

13

15

16

17

18

18

18

18

.

7.2

“Vibration meter” mode

19

.

7.4

Balancing in one plane (static)

27

.

7.5

Balancing in two planes (dynamic)

38

.

7.6

“Charts” mode

49

8.

General instructions on operation and maintenance of the device

55

.

Annex 1 Balancing in operational conditions

61

.

                                                           

.

.

.

.

.

.

1.  BALANCING SYSTEM OVERVIEW

.

Balanset-1A balancer provides single- and twoplane dynamic موازنة services for fans, grinding wheels, spindles, crushers, pumps and other rotating machinery.

.

Balanset-1A balancer includes two vibrosensors (accelerometers), laser phase sensor (tachometer), 2-channels USB interface unit with pre-amplifiers, integrators and ADC acquired module and Windows based balancing software.

Balanset-1A require notebook or other Windows (WinXP…Win11, 32 or 64bit) compatible PC.

Balancing software provides the correct balancing solution for single-plane and two-plane balancing automatically.  Balanset-1A is simple to use for non-vibration experts.

.

All balancing results saved in archive and can be used to create the reports.

.

سمات:

 Easy to use
 Storage of unlimited balancing data
 User selectable trial mass
 Split weight calculation, drill calculation
 Trial mass validity automatically popup message
 Measuring RPM, amplitude and phase of vibrovelocity overall and 1x vibration
 FFT spectrum
 Dual-channel simultaneous data collection
 Waveform and spectrum display
 Storage of vibration values and vibration waveform and spectra
 Balancing using saved influence coefficients
 Trim balancing
 Balancing mandrel eccentricity calculations
 Remove or leave trial weights
 Balancing tolerance calculation (ISO 1940 G-classes)
 Changing correction planes calculations
 الرسم البياني القطبي
 إدخال البيانات يدويا
 RunDown charts (experimental option)
2. SPECIFICATION

Measurement range of the root-mean-square value (RMS) of the vibration velocity, mm/sec (for 1x vibration)  

from 0.02 to 100

The frequency range of the RMS measurement of the vibration velocity, Hz

من 5 إلى 550

Number of the correction planes

.

1 or 2

Range of the frequency of rotation measurement, rpm

100 – 100000

.

.

Range of the vibration phase measurement, angular degrees

from 0 to 360

Error of the vibration phase measurement, angular degrees

± 1

Dimensions (in hard case), جm,

39*33*13

Mass, kg

<5

Overall dimensions of the vibrator sensor, mm, max   

25*25*20

Mass of the vibrator sensor, kg, max

0.04

– Temperature range: from 5°C to 50°C
– Relative humidity: < 85%, unsaturated
– Without strong electric-magnetic field & strong impact

.

.

3. PACKAGE

.

Balanset-1A balancer includes two single-axis accelerometers, laser phase reference marker (digital tachometer), 2-channel USB interface unit with pre-amplifiers, integrators and ADC acquired module and Windows based balancing software.
.

Delivery set

.

وصف

Number

Note

USB interface unit

1

.

Laser phase reference marker (tachometer)

1

.

Single-axis accelerometers

2

.

Magnetic stand

1

.

Digital scales

1

.

Hard case for transportation

1

.

“Balanset-1A”. User’s manual.

1

.

Flash disk with balancing software

1

.

.

.

.

4. BALANCE PRINCIPLES

4.1. “Balanset-1A” include (fig. 4.1) USB interface unit (1), two accelerometers (2) and (3), phase reference marker (4) and portable PC (not supplied) (5).

Delivery set also includes the magnetic stand (6) used for mounting the phase reference marker and digital scales 7.

X1 and X2 connectors intended for connection of the vibration sensors respectively to 1 and 2 measuring channels, and the X3 connector used for connection of the phase reference marker.

The USB cable provides power supply and connection of the USB interface unit to the computer.

.

                                                                 

.

Fig. 4.1. Delivery set of the “Balanset-1A”

.

Mechanical vibrations cause an electrical signal proportional to the vibration acceleration on the output of the vibration sensor. Digitized signals from ADC module transferred via USB to the portable PC (5). Phase reference marker generate the pulse signal used to calculate rotation frequency and vibration phase angle.
Windows based software provides solution for single-plane and two-plane balancing, spectrum analyzing, charts, reports, storage of influence coefficients

                                                                                                                                 

5. SAFETY PRECAUTIONS

.

5.1. Attention! When operating on 220V electrical safety regulations must be observed. It is not allowed to repair the device when connected to 220 V.

5.2. If you use the appliance in a low quality AC power and weights of network interference it is recommended to use a standalone power from computer’s battery pack.

6. SOFTWARE AND HARDWARE SETTINGS.
6.1. USB drivers and balancing software installation

Before working install drivers and balancing software.
.

List of folders and files.

Installation disk (flash drive) contains the following files and folders:

Bs1Av###Setup – folder with “Balanset-1A” balancing software (### – version number)

ArdDrv– USB drivers

EBalancer_manual.pdf – this manual

Bal1Av###Setup.exe – setup file. This file contains all archived files and folders mentioned above. ###– version of “Balanset-1A” software.

Ebalanc.cfg – sensitivity value

Bal.ini – some initialization data
.

برمجة Installation procedure .

For installing drivers and specialized software run file Bal1Av###Setup.exe and follow setup instructions by pressing buttons «Next», «ОК» etc.

.

.

Choose setup folder. Usually the given folder should not be changed.

.

.

.

Then the program requires specifying Program group and desktop folders. Press button Next.

.

.

The window «Ready to Install» appears.

.

.

Press button «Install»

.

.

.

Install Arduino drivers.

Press button “Next”, then “Install” and “Finish”

.

.

And finally press button «Finish»

.

As a result all necessary drivers and the موازنة software are installed on the computer. After that it is possible to connect the USB interface unit to the computer.

.

Finishing installation.

.

 Install sensors on the inspected or balanced mechanism (Detailed information about how to install the sensors is given in Annex 1)
 Connect vibration sensors 2 and 3 to the inputs X1 and X2, and phase angle sensor to the input X3 of USB interface unit.
 Connect USB interface unit to the USB-port of the computer.
  When using the AC power supply connect the computer to the power mains. Connect the power supply to 220 V, 50 Hz.6.3.5. Click shortcut “Balanset-1A” on desktop.

                                                                                                

7 BALANCING SOFTWARE

7.1. General

Initial window.

When running the program “Balanset-1A” the Initial window, shown in Fig. 7.1, appears.

Fig. 7.1. Initial window of the “Balanset-1A”

.

There are 9 buttons in the Initial window with the names of the functions realized when click on them.

.

.

.

.

.

.

.

F1-«About»

.

Fig. 7.2. F1-«About» نافذة او شباك

F2-«Single plane», F3-«Two plane».

Pressing “F2Single-plane” (or F2 function key on the computer keyboard) selects the measurement vibration on thechannel X1.

After clicking this button, the computer display diagram shown in Fig. 7.1 illustrating a process of measuring the vibration only on the first measuring channel (or the balancing process in a single plane).

Pressing the “F3Two-plane” (or F3 function key on the computer keyboard) selects the mode of vibration measurements on two channels X1 and X2 simultaneously. (Fig. 7.3.)

Initial window of the “Balanset-1A”. Two plane balancing.

.

Fig. 7.3. Initial window of the “Balanset-1A”. Two plane balancing.

.

.

.

.

.

.

.

.

.

F4 – «Settings».

In this window you can change some Balanset-1A settings.

In this window you can change some Balanset-1A settings.

Fig. 7.4. “Settings” نافذة او شباك

 Sensitivity. The nominal value is 13 mV / mm/s.

Changing the sensitivity coefficients of sensors is required only when replacing sensors!
.

انتباه!

When you enter a sensitivity coefficient its fractional part is separated from the integer part with the decimal point (the sign “,”).

Averaging – number of averaging (number of revolutions of the rotor over which data is averaged to more accuracy)

Tacho channel# – channel# the Tacho is connected. By default – 3rd channel.

Unevenness – the difference in duration between adjacent tacho pulses, which above gives the warning “Failure of the tachometer

Imperial/Metric – Select the system of units.

Com port number is assigned automatically.
.

F5 – «Vibration meter».

Pressing this button (or a function key of F5 on the computer keyboard) activates the mode of vibration measurement on one or two measuring channels of virtual Vibration meter depending on the buttons condition “F2-single-plane”, “F3-two-plane”.

.

F6 – «Reports».

  Pressing this button (or F6 function key on the computer keyboard) switches on the balancing Archive, from which you can print the report with the results of balancing for a specific mechanism (rotor).

.

F7 – «Balancing».

  Pressing this button (or function key F7 on your keyboard) activates balancing mode in one or two correction planes depending on which measurement mode is selected by pressing the buttons “F2-single-plane”, “F3-two-plane”.

F8 – «Charts».

  Pressing this button (or F8 function key on the computer’s keyboard) enables graphic Vibration meter, the implementation of which displays on a display simultaneously with the digital values of the amplitude and phase of the vibration graphics of its time function.

F10 – «Exit».

  Pressing this button (or F10 function key on the computer’s keyboard) completes the program “Balanset-1A”.
.

.

  7.2. “Vibration meter”.

  Before working in the “ Vibration meter ” mode, install vibration sensors on the machine and connect them respectively to the connectors X1 and X2 of the USB interface unit. Tacho sensor should be connected to the input X3 of the USB interface unit.

.

.

Fig. 7.5 USB interface unit

.

Place reflective type on the surface of a rotor for tacho wotking.

.

Fig. 7.6. Reflective type.

Recommendations for the installation and configuration of sensors are given in Annex 1.
.

  To begin the measurement in the Vibration meter mode click on the button “F5 – Vibration Meter” in the Initial window of the program (see fig. 7.1).

Vibration Meter window appears (see. Fig.7.7)

.

Fig. 7.7. Vibration meter mode. Wave and Spectrum.

                                                                                                                   

  To start vibration measurements click button “F9 – Run” (or press the function key F9 on the keyboard).

  لو Trigger mode  Auto is checked – the results of vibration measurements will be periodically displayed on the screen.

  In case of simultaneous measurement of vibration on the first and second channels, the windows located beneath the words “Plane 1” and “Plane 2” will be filled.
.

Vibration measuring in the “Vibration” mode also may be carried out with disconnected phase angle sensor. In the Initial window of the program the value of the total RMS vibration (V1s, V2s) will only be displayed.

There are next settings in Vibration meter mode

 RMS Low, Hz – lowest frequency to calculate RMS of overall vibration
 Bandwidth – vibration frequency bandwidth in the chart
 Averages – number of average for more measure accuracy

.

To complete the work in the “Vibration meter” mode click button “F10 – Exit” and return to the Initial window.

.

Fig. 7.8. Vibration meter mode. Rotation speed Unevenness, 1x vibration wave form.

                    

  Fig. 7.9. Vibration meter mode. Rundown (beta version, no warranty!).                  

.

    

7.3 التوازن إجراء

يتم إجراء الموازنة للآليات ذات الحالة الفنية الجيدة والمثبتة بشكل صحيح. بخلاف ذلك، قبل إجراء الموازنة، يجب إصلاح الآلية وتركيبها في محامل مناسبة وتثبيتها. يجب تنظيف الدوار من الملوثات التي يمكن أن تعيق عملية التوازن.

.

قبل موازنة الاهتزاز، قم بقياس الاهتزاز في وضع مقياس الاهتزاز (زر F5) للتأكد من أن الاهتزاز بشكل أساسي هو اهتزاز 1x.

.


الشكل 7.10. وضع مقياس الاهتزاز. التحقق من الاهتزاز الشامل (V1s، V2s) و1x (V1o، V2o).

.

إذا كانت قيمة الاهتزاز الكلي V1s (V2s) تساوي تقريبًا حجم الاهتزاز

الاهتزاز عند تردد الدوران (اهتزاز 1x) V1o (V2o) ، يمكن الافتراض أن المساهمة الرئيسية في آلية الاهتزاز تدفع إلى خلل في الدوار. إذا كانت قيمة الاهتزاز الإجمالي V1s (V2s) أعلى بكثير من مكون الاهتزاز 1x V1o (V2o)، فمن المستحسن التحقق من حالة الآلية - حالة المحامل، وتركيبها على القاعدة، وعدم وجود رعي الأجزاء الثابتة من الدوار أثناء الدوران، الخ.

يجب عليك أيضًا الانتباه إلى ثبات القيم المقاسة في وضع مقياس الاهتزاز - يجب ألا يختلف سعة ومرحلة الاهتزاز بأكثر من 10-15% في عملية القياس. وبخلاف ذلك، يمكن الافتراض أن الآلية تعمل بمجال قريب من الرنين. في هذه الحالة، قم بتغيير سرعة دوران الدوار، وإذا لم يكن ذلك ممكنًا - قم بتغيير شروط تثبيت الماكينة على الأساس (على سبيل المثال، التثبيت المؤقت على دعامات الزنبرك).

لموازنة الدوار معامل التأثير طريقة التوازن (طريقة التشغيل 3) يجب أن تؤخذ.

يتم إجراء التجارب التجريبية لتحديد تأثير الكتلة التجريبية على تغير الاهتزازات والكتلة ومكان (زاوية) تركيب أوزان التصحيح.

حدد أولاً الاهتزاز الأصلي للآلية (ابدأ أولاً بدون وزن)، ثم اضبط الوزن التجريبي على المستوى الأول وقم بالبدء الثاني. ثم قم بإزالة الوزن التجريبي من المستوى الأول، ثم ضعه في المستوى الثاني وقم بالبدء الثاني.

يقوم البرنامج بعد ذلك بحساب ويشير على الشاشة إلى الوزن ومكان (زاوية) تركيب أوزان التصحيح.

عند الموازنة في مستوى واحد (ثابت)، لا يلزم البدء الثاني.

يتم ضبط الوزن التجريبي على موقع اختياري على الدوار حيث يكون مناسبًا، ثم يتم إدخال نصف القطر الفعلي في برنامج الإعداد.

(يُستخدم نصف قطر الموضع فقط لحساب كمية عدم الاتزان بالجرام * مم) 

Important!

 يجب إجراء القياسات بسرعة دوران ثابتة للآلية!
 يجب تثبيت أوزان التصحيح على نفس نصف قطر الأوزان التجريبية!
يتم اختيار كتلة الوزن التجريبي بحيث تتغير سعة الاهتزاز بشكل كبير بعد مرحلة التثبيت (> 20-30°) و(20-30%). إذا كانت التغييرات صغيرة جدًا، فسيزداد الخطأ بشكل كبير في الحسابات اللاحقة. قم بتعيين الكتلة التجريبية بشكل ملائم في نفس المكان (نفس الزاوية) مثل علامة الطور.

Important!

بعد كل اختبار تشغيل تتم إزالة الكتلة التجريبية! أثقال التصحيح الموضوعة بزاوية محسوبة من مكان تثبيت الوزن التجريبي في اتجاه دوران الدوار!

الشكل 7.11. تصحيح تركيب الوزن.

.

.

.

مُستَحسَن!

قبل إجراء التوازن الديناميكي، يوصى بالتأكد من أن عدم التوازن الثابت ليس مرتفعًا جدًا. بالنسبة للدوارات ذات المحور الأفقي، يمكن تدوير الدوار يدويًا بزاوية 90 درجة من الموضع الحالي. إذا كان الدوار غير متوازن بشكل ثابت، فسيتم تدويره إلى وضع التوازن. بمجرد أن يتولى الدوار وضع التوازن، فمن الضروري ضبط موازنة الوزن في النقطة العلوية تقريبًا في الجزء الأوسط من طول الدوار. يجب اختيار وزن الوزن بحيث لا يتحرك الدوار في أي موضع.

سيؤدي هذا التوازن المسبق إلى تقليل كمية الاهتزاز عند البداية الأولى للدوار غير المتوازن بشدة.

تركيب وتركيب أجهزة الاستشعار.
الخامسيجب تثبيت مستشعر الاهتزاز على الجهاز في نقطة القياس المحددة وتوصيله بالمدخل X1 لوحدة واجهة USB.
هناك نوعان من تكوينات التركيب
• المغناطيس

ترصيع الخيوط M4

يجب توصيل مستشعر سرعة الدوران البصري بمدخل X3 لوحدة واجهة USB. علاوة على ذلك، لاستخدام هذا المستشعر، يجب وضع علامة عاكسة خاصة على سطح الدوار.

المتطلبات التفصيلية حول اختيار الموقع لأجهزة الاستشعار وربطها بالجسم عند الموازنة موضحة في الملحق 1.    
.

   

7.3.1 موازنة المستوى الفردي.

.

الشكل 7.12. “موازنة طائرة واحدة

.

أرشيف الموازنة.

.

لبدء العمل على البرنامج في "موازنة الطائرة الواحدةالوضع "، انقر على"F2-طائرة واحدة" (أو اضغط على المفتاح F2 على لوحة مفاتيح الكمبيوتر).

.

ثم اضغط على "F7 – التوازن"زر، وبعد ذلك أرشيف موازنة الطائرة الواحدة ستظهر نافذة يتم فيها حفظ بيانات الموازنة (انظر الشكل 7.13).      

                                                                                              

  

الشكل 7.13 نافذة اختيار أرشيف الموازنة في مستوى واحد.

.

      في هذه النافذة، تحتاج إلى إدخال البيانات على اسم الدوار (اسم الدوار) مكان تركيب الدوار (مكان) ، التحمل للاهتزاز وعدم التوازن المتبقي (تسامح)، تاريخ القياس. يتم تخزين هذه البيانات في قاعدة بيانات. أيضًا، يتم إنشاء مجلد Arc###، حيث ### هو رقم الأرشيف الذي سيتم حفظ المخططات وملف التقرير وما إلى ذلك فيه. بعد اكتمال الموازنة، سيتم إنشاء ملف تقرير يمكن تحريره وطباعته في المحرر المدمج.

.

بعد إدخال البيانات اللازمة اضغط على "F10-موافقزر "، وبعد ذلك يظهر زر "موازنة الطائرة الواحدة"ستفتح النافذة (انظر الشكل 7.13)

.

إعدادات الموازنة (طائرة واحدة)

                                                                                                                  

                             

الشكل 7.14. طائرة واحدة. إعدادات التوازن
.

في الجانب الأيسر من هذه النافذة يتم عرض بيانات قياسات الاهتزازات وأزرار التحكم في القياس “تشغيل # 0"،"تشغيل # 1"،"RunTrim".
يوجد في الجانب الأيمن من هذه النافذة ثلاث علامات تبويب

 إعدادات التوازن
 الرسوم البيانية
 نتيجة

.

.

.

.

.

.

.

ال "إعدادات التوازنيتم استخدام علامة التبويب للدخول إلى إعدادات الموازنة:

1. “معامل التأثير” –

    • "روتور جديد"- اختيار موازنة الدوار الجديد، الذي لا توجد معاملات موازنة مخزنة له ويتطلب تشغيلين لتحديد الكتلة وزاوية التثبيت لوزن التصحيح.

    • "معامل محفوظ."- اختيار إعادة موازنة الدوار، حيث توجد معاملات موازنة محفوظة ويتطلب تشغيلًا واحدًا فقط لتحديد الوزن وزاوية تثبيت الوزن التصحيحي.

.

    2. “كتلة الوزن التجريبي” –

     "نسبه مئويه"- يتم حساب الوزن التصحيحي كنسبة مئوية من الوزن التجريبي.

     غرام” – يتم إدخال الكتلة المعروفة للوزن التجريبي ويتم حساب كتلة الوزن التصحيحي بها جرامات أو في أوقية للنظام الامبراطوري.

        انتباه!

        إذا كان من الضروري استخدام "معامل محفوظ."في الوضع لمزيد من العمل أثناء الموازنة الأولية، يجب إدخال كتلة الوزن التجريبي بالجرام أو الأوقية، وليس بـ %. يتم تضمين المقاييس في حزمة التسليم.

.

    3. “طريقة ربط الوزن

     "موقف مجاني"- يمكن تثبيت الأوزان في مواضع زاوية عشوائية على محيط الدوار.

     "موقف ثابت” – يمكن تثبيت الوزن في مواضع زاوية ثابتة على الدوار مثلاً على الشفرات أو الثقوب (مثلاً 12 فتحة – 30 درجة) إلخ. ويجب إدخال عدد المواضع الثابتة في الحقل المناسب. بعد الموازنة، سيقوم البرنامج تلقائيًا بتقسيم الوزن إلى جزأين ويشير إلى عدد المواضع التي من الضروري تحديد الكتل التي تم الحصول عليها.

الشكل 7.15. علامة التبويب النتيجة. موقف ثابت لتركيب الوزن التصحيحي.

Z1 وZ2 - مواضع الأوزان التصحيحية المثبتة، محسوبة من موضع Z1 وفقًا لاتجاه الدوران. Z1 هو موضع الوزن التجريبي الذي تم تثبيته.


.

.

.

الشكل 7.16 المواضع الثابتة. المخطط القطبي.
.

أخدود دائري – تستخدم لموازنة عجلة الطحن في هذه الحالة يتم استخدام 3 أثقال موازنة للتخلص من عدم التوازن


الشكل 7.17 موازنة عجلة الطحن بثلاثة أثقال موازنة

الشكل 7.18 موازنة عجلة الطحن. الرسم البياني القطبي.

.

.

 نصف قطر التركيب الشامل، مم" - "المستوى 1" - نصف قطر الوزن التجريبي في المستوى 1. مطلوب حساب حجم الخلل الأولي والمتبقي لتحديد الامتثال للتسامح مع الخلل المتبقي بعد الموازنة.
 ترك الوزن التجريبي في Plane1.”عادة ما تتم إزالة الوزن التجريبي أثناء عملية الموازنة. ولكن في بعض الحالات يكون من المستحيل إزالته، فأنت بحاجة إلى وضع علامة اختيار في هذا لحساب كتلة الوزن التجريبي في الحسابات.
 "إدخال البيانات يدويا"- يستخدم لإدخال قيمة الاهتزاز ومرحلته يدويًا في الحقول المناسبة على الجانب الأيسر من النافذة وحساب الكتلة وزاوية التثبيت لوزن التصحيح عند التبديل إلى"نتائج" فاتورة غير مدفوعة
 زر "استعادة بيانات الجلسة". أثناء الموازنة، يتم حفظ البيانات المقاسة في ملف session1.ini. إذا تمت مقاطعة عملية القياس بسبب تجميد الكمبيوتر أو لأسباب أخرى، فمن خلال النقر على هذا الزر يمكنك استعادة بيانات القياس ومواصلة الموازنة من لحظة الانقطاع.
 إزالة انحراف الشياق (موازنة الفهرس)
موازنة مع بداية إضافية للقضاء على تأثير الانحراف المركزي للشياق (موازنة الشجرة). قم بتركيب الدوار بالتناوب عند 0 درجة و 180 درجة بالنسبة إلى. قياس عدم التوازن في كلا الموقفين.

.

    • موازنة التسامح

إدخال أو حساب تفاوتات التفاوت المتبقية بـ gx mm (فئات G)

    • استخدم الرسم البياني القطبي

استخدم الرسم البياني القطبي لعرض نتائج الموازنة

.

1-موازنة الطائرة. الدوار الجديد

كما ذكرنا أعلاه "روتر جديد" التوازن يتطلب اثنين امتحان تشغيل وواحد على الأقل رتشغيل حافة آلة الموازنة.

.

Run#0 (التشغيل الأولي)

بعد تثبيت المستشعرات على دوار الموازنة وإدخال معلمات الإعدادات، من الضروري تشغيل دوران الدوار، وعندما يصل إلى سرعة العمل، اضغط على الزر "Run#0زر لبدء القياسات.
ال "الرسوم البيانية" سيتم فتح علامة التبويب في اللوحة اليمنى، حيث سيتم عرض شكل الموجة وطيف الاهتزاز (الشكل 7.18.). في الجزء السفلي من علامة التبويب، يتم الاحتفاظ بملف السجل، حيث يتم حفظ نتائج كل ما يبدأ بمرجع زمني. على القرص، يتم حفظ هذا الملف في مجلد الأرشيف بالاسم memo.txt

       انتباه!

       قبل البدء في القياس، من الضروري تشغيل دوران الدوار لآلة الموازنة (Run#0) وتأكد من استقرار سرعة الدوار.    

     

                                                                                                                                                        

الشكل 7.19. التوازن في مستوى واحد. التشغيل الأولي (Run#0). علامة تبويب الرسوم البيانية

.

بعد الانتهاء من عملية القياس، في Run#0 القسم في اللوحة اليسرى تظهر نتائج القياس - سرعة الدوار (RPM)، RMS (Vo1) والمرحلة (F1) من الاهتزاز 1x.

ال "F5-العودة إلى Run#0يتم استخدام الزر (أو مفتاح الوظيفة F5) للعودة إلى قسم Run#0، وإذا لزم الأمر، لتكرار قياس معلمات الاهتزاز.

.

   Run#1 (الطائرة الجماعية التجريبية 1)

قبل البدء في قياس معلمات الاهتزاز في القسم "Run#1 (الطائرة الجماعية التجريبية 1)، يجب تثبيت الوزن التجريبي حسب "كتلة الوزن التجريبي" مجال. (انظر الشكل 7.10).

   الهدف من تثبيت الوزن التجريبي هو تقييم كيفية تغير اهتزاز الدوار عند تثبيت وزن معروف في مكان (زاوية) معروفة. يجب أن يغير الوزن التجريبي سعة الاهتزاز بمقدار 30% أقل أو أعلى من السعة الأولية أو مرحلة التغيير بمقدار 30 درجة أو أكثر من الطور الأولي.

      2. إذا كان من الضروري استخدام "معامل محفوظ."للموازنة لمزيد من العمل، يجب أن يكون مكان (زاوية) تركيب الوزن التجريبي هو نفس مكان (زاوية) العلامة العاكسة.     

قم بتشغيل دوران الدوار لآلة الموازنة مرة أخرى وتأكد من استقرار تردد الدوران. ثم اضغط على "F7-Run#1" (أو اضغط على المفتاح F7 على لوحة مفاتيح الكمبيوتر). "Run#1 (الطائرة الجماعية التجريبية 1)قسم "(انظر الشكل 7.18)
بعد القياس في النوافذ المقابلة لـ "Run#1 (الطائرة الجماعية التجريبية 1)" تظهر نتائج قياس سرعة الدوار (RPM) وكذلك قيمة مكون RMS (Vо1) والطور (F1) للاهتزاز 1x.

وفي الوقت نفسه، "نتيجةتفتح علامة التبويب على الجانب الأيمن من النافذة (انظر الشكل 7.13).

تعرض علامة التبويب هذه نتائج حساب الكتلة وزاوية الوزن التصحيحي التي يجب تثبيتها على الدوار لتعويض الخلل.

علاوة على ذلك، في حالة استخدام نظام الإحداثيات القطبية، تظهر الشاشة قيمة الكتلة (M1) وزاوية التثبيت (f1) لوزن التصحيح.

في حالة "مواقف ثابتةسيتم عرض أرقام المواضع (Zi، Zj) والكتلة المقسمة للوزن التجريبي.

.

  الشكل 7.20. التوازن في مستوى واحد. Run#1 ونتيجة الموازنة.

.

.

لو الرسم البياني القطبي سيتم عرض الرسم البياني القطبي.

.

الشكل 7.21. نتيجة التوازن. الرسم البياني القطبي.

.

                                                  

الشكل 7.22. نتيجة التوازن. الوزن المقسم (المواضع الثابتة)

أيضا إذا "الرسم البياني القطبي"، وتم فحص سيتم عرض الرسم البياني القطبي.   

       

                    

الشكل 7.23. الوزن مقسم على مواضع ثابتة. الرسم البياني القطبي

.

.

       انتباه!:

    1. بعد الانتهاء من عملية القياس في الجولة الثانية ("Run#1 (الطائرة الجماعية التجريبية 1)") لآلة الموازنة، من الضروري إيقاف الدوران وإزالة الوزن التجريبي المثبت. ثم قم بتثبيت (أو إزالة) الوزن التصحيحي على الدوار وفقًا لبيانات علامة تبويب النتيجة.

إذا لم تتم إزالة الوزن التجريبي، فستحتاج إلى التبديل إلى "إعدادات التوازنعلامة التبويب " وقم بتشغيل مربع الاختيار في "ترك الوزن التجريبي في Plane1". ثم انتقل مرة أخرى إلى "نتيجة" فاتورة غير مدفوعة. يتم إعادة حساب الوزن وزاوية التثبيت لوزن التصحيح تلقائيًا.

.

    2. يتم تنفيذ الوضع الزاوي للوزن التصحيحي من مكان تركيب الوزن التجريبي. يتزامن الاتجاه المرجعي للزاوية مع اتجاه دوران الدوار.

.

    3. في حالة "موقف ثابت" - 1شارع الموضع (Z1) يتزامن مع مكان تركيب الوزن التجريبي. اتجاه العد لرقم الموضع هو في اتجاه دوران الدوار.

  4. بشكل افتراضي، سيتم إضافة الوزن التصحيحي إلى الدوار. يتم الإشارة إلى ذلك من خلال الملصق الموجود في "يضيف" مجال. في حالة إزالة الوزن (على سبيل المثال، عن طريق الحفر)، يجب عليك وضع علامة في "يمسح"، وبعد ذلك سيتغير الموضع الزاوي لوزن التصحيح تلقائيًا بمقدار 180 درجة.

.

   بعد تثبيت وزن التصحيح على دوار الموازنة في نافذة التشغيل (انظر الشكل 7.15)، من الضروري إجراء RunC (التشذيب) وتقييم فعالية الموازنة التي تم إجراؤها.

.

RunC (التحقق من جودة الرصيد)

انتباه!

قبل البدء بالقياس على RunC، من الضروري تشغيل دوران دوار الماكينة والتأكد من دخوله في وضع التشغيل (تردد الدوران المستقر).

لإجراء قياس الاهتزاز في "RunC (التحقق من جودة الرصيد)" (انظر الشكل 7.15)، انقر على "F7 - رنتريم" (أو اضغط على المفتاح F7 على لوحة المفاتيح).

            عند الانتهاء بنجاح من عملية القياس، في "RunC (التحقق من جودة الرصيد)"في اللوحة اليسرى تظهر نتائج قياس سرعة الدوار (RPM) وكذلك قيمة مكون RMS (Vo1) والطور (F1) للاهتزاز 1x.

في ال "نتيجة"، يتم عرض نتائج حساب الكتلة وزاوية تثبيت الوزن التصحيحي الإضافي.

.

الشكل 7.24. التوازن في مستوى واحد. تنفيذ RunTrim. علامة التبويب النتيجة

                                                                     

يمكن إضافة هذا الوزن إلى وزن التصحيح المثبت بالفعل على الدوار للتعويض عن الخلل المتبقي. بالإضافة إلى ذلك، يتم عرض عدم التوازن المتبقي للدوار بعد الموازنة في الجزء السفلي من هذه النافذة.

في حالة استيفاء مقدار الاهتزاز المتبقي و/أو عدم الاتزان المتبقي للدوار المتوازن لمتطلبات التسامح المنصوص عليها في الوثائق الفنية، يمكن إكمال عملية الموازنة.

وإلا فإن عملية التوازن قد تستمر. يتيح ذلك لطريقة التقريبات المتعاقبة تصحيح الأخطاء المحتملة التي قد تحدث أثناء تركيب (إزالة) الوزن التصحيحي على الدوار المتوازن.

عند مواصلة عملية الموازنة على دوار الموازنة، من الضروري تثبيت (إزالة) كتلة تصحيحية إضافية، يشار إلى معلماتها في القسم "تصحيح الكتل والزوايا".

.

معاملات التأثير (طائرة واحدة)

.

ال "F4-Inf.Coeff"زر في"نتيجةتُستخدم علامة التبويب (الشكل 7.23) لعرض وتخزين معاملات موازنة الدوار (معاملات التأثير) المحسوبة من نتائج عمليات المعايرة في ذاكرة الكمبيوتر.

عند الضغط عليه يظهر "معاملات التأثير (طائرة واحدة)تظهر نافذة على شاشة الكمبيوتر (انظر الشكل 7.17)، حيث يتم عرض معاملات الموازنة المحسوبة من نتائج عمليات المعايرة (الاختبار). إذا كان من المفترض أثناء الموازنة اللاحقة لهذا الجهاز استخدام "معامل محفوظ.في الوضع "، يجب تخزين هذه المعاملات في ذاكرة الكمبيوتر.

للقيام بذلك، انقر فوق ""F9 - حفظ" ثم انتقل إلى الصفحة الثانية من "معامل التأثير. أرشيف. طائرة واحدة."(انظر الشكل 7.24)

.

.

                              الشكل 7.25. موازنة المعاملات في المستوى الأول

.

           ثم تحتاج إلى إدخال اسم هذا الجهاز في "الدوار" العمود وانقر فوق "F2-حفظزر لحفظ البيانات المحددة على جهاز الكمبيوتر.

وبعد ذلك يمكنك العودة إلى النافذة السابقة بالضغط على زر "F10-خروج" (أو مفتاح الوظيفة F10 على لوحة مفاتيح الكمبيوتر).      

                                                 

الشكل 7.26. "معامل التأثير. أرشيف. طائرة واحدة. "

تقرير الموازنةبعد موازنة جميع البيانات المحفوظة وإنشاء تقرير الموازنة. يمكنك عرض وتحرير التقرير في المحرر المدمج. في ال نافذة او شباك "موازنة الأرشيف في مستوى واحد" (الشكل 7.9) اضغط على الزر "F9 -تقرير"للوصول إلى محرر تقرير الموازنة.

.

                                                          

الشكل 7.26. تقرير الموازنة.

.

                                                        

          

معامل محفوظ. إجراء الموازنة مع معاملات التأثير المحفوظة في مستوى واحد.
إعداد نظام القياس (إدخال البيانات الأولية).

معامل محفوظ. موازنة يمكن إجراؤها على جهاز تم بالفعل تحديد معاملات موازنة له وإدخالها في ذاكرة الكمبيوتر.

انتباه!

عند الموازنة مع المعاملات المحفوظة، يجب تثبيت مستشعر الاهتزاز ومستشعر زاوية الطور بنفس الطريقة التي تم بها أثناء الموازنة الأولية.

إدخال البيانات الأولية ل معامل محفوظ. موازنة (كما في حالة الابتدائي("الدوار الجديد") التوازن) يبدأ في "موازنة طائرة واحدة. إعدادات التوازن"(انظر الشكل 7.27).

في هذه الحالة، في "معاملات التأثير"القسم، حدد "معامل محفوظ" غرض. في هذه الحالة، الصفحة الثانية من "معامل التأثير. أرشيف. طائرة واحدة"(انظر الشكل 7.27) الذي يخزن أرشيفًا لمعاملات الموازنة المحفوظة.

.

.

الشكل 7.28. الموازنة مع معاملات التأثير المحفوظة في مستوى واحد

.

       من خلال التنقل عبر جدول هذا الأرشيف باستخدام أزرار التحكم "►" أو "◄"، يمكنك تحديد السجل المطلوب مع موازنة معاملات الآلة التي تهمنا. ثم، لاستخدام هذه البيانات في القياسات الحالية، اضغط على زر "F2 - اختر" زر.

وبعد ذلك تظهر محتويات كافة النوافذ الأخرى للـ “موازنة طائرة واحدة. إعدادات التوازن."يتم ملؤها تلقائيًا.

بعد الانتهاء من إدخال البيانات الأولية، يمكنك البدء في القياس.

                         

.

القياسات أثناء الموازنة مع معاملات التأثير المحفوظة.

تتطلب الموازنة باستخدام معاملات التأثير المحفوظة تشغيلًا أوليًا واحدًا فقط وتشغيلًا اختباريًا واحدًا على الأقل لآلة الموازنة.

انتباه!

قبل البدء في القياس، من الضروري تشغيل دوران الدوار والتأكد من استقرار تردد الدوران.

لإجراء قياس معلمات الاهتزاز في "Run#0 (الأولي، لا يوجد كتلة تجريبية)"القسم، اضغط على"F7 - Run#0"(أو اضغط على المفتاح F7 على لوحة مفاتيح الكمبيوتر).

.

   
الشكل 7.29. الموازنة مع معاملات التأثير المحفوظة في مستوى واحد. النتائج بعد تشغيل واحد.

.

في الحقول المقابلة لـ "Run#0" تظهر نتائج قياس سرعة الدوار (RPM) وقيمة مكون RMS (Vо1) والطور (F1) للاهتزاز 1x.

وفي الوقت نفسه، "نتيجةتعرض علامة التبويب نتائج حساب كتلة وزاوية الوزن التصحيحي الذي يجب تثبيته على الدوار لتعويض الخلل.

علاوة على ذلك، في حالة استخدام نظام الإحداثيات القطبية، تظهر الشاشة قيم الكتلة وزاوية تثبيت وزن التصحيح.

في حالة تقسيم الوزن التصحيحي على المواضع الثابتة يتم عرض أرقام مواضع دوار الموازنة وكتلة الوزن المطلوب تثبيتها عليها.

علاوة على ذلك، يتم تنفيذ عملية الموازنة وفقًا للتوصيات الواردة في القسم 7.4.2. للموازنة الأولية.

                                                          

إزالة انحراف الشياق (موازنة الفهرس)إذا تم تثبيت الدوار في شياق أسطواني أثناء الموازنة، فإن انحراف الشياق قد يؤدي إلى حدوث خطأ إضافي. للتخلص من هذا الخطأ، يجب نشر الدوار في الشياق بمقدار 180 درجة وتنفيذ بداية إضافية. وهذا ما يسمى موازنة الفهرس.

لتنفيذ موازنة الفهرس، يتم توفير خيار خاص في برنامج Balanset-1A. عند تحديد إزالة انحراف مغزل الشياق، يظهر قسم RunEcc إضافي في نافذة الموازنة.

.


الشكل 7.30. نافذة العمل لموازنة الفهرس.

.

بعد تشغيل Run # 1 (المستوى التجريبي 1)، ستظهر نافذة

الشكل 7.31 نافذة الانتباه لموازنة الفهرس.
.

بعد تثبيت الدوار بدورة 180، يجب إكمال Run Ecc. سيقوم البرنامج تلقائيًا بحساب الخلل الحقيقي في الجزء الدوار دون التأثير على انحراف مركزية الشياق.

7.3.2 Two plane balancing.

Before starting work in the Two plane balancing mode, it is necessary to install vibration sensors on the machine body at the selected measurement points and connect them to the inputs X1 and X2 of the measuring unit, respectively.

An optical phase angle sensor must be connected to input X3 of the measuring unit. In addition, to use this sensor, a reflective tape must be glued onto the accessible rotor surface of the balancing machine.

.

       Detailed requirements for choosing the installation location of sensors and their mounting at the facility during balancing are set out in Appendix 1.

The work on the program in the “Two plane balancing” mode starts from the Main window of the programs.

Click on the “F3-Two plane” button (or press the F3 key on the computer keyboard).

Further, click on the “F7 – Balancing” button, after which a working window will appear on the computer display (see Fig. 7.13), selection of the archive for saving data when balancing in two planes.

.

.

Fig. 7.32 Two plane balancing archive window.

      

In this window you need to enter the data of the balanced rotor. After pressing the “F10-موافق” button, a balancing window will appear.

.

.

.

.

.

.

.

.

.

.

Balancing settings (2-plane)

.

.

Fig. 7.33. Balancing in two planes window.

.

.

      On the right side of the window is the “إعدادات التوازن” tab for entering settings before balancing.

    • معاملات التأثير

Balancing a new rotor or balancing using stored influence coefficients (balancing coefficients)

    • Mandrel eccentricity elimination

Balancing with additional start to eliminate the influence of the eccentricity of the mandrel

    • طريقة ربط الوزن

Installation of corrective weights in an arbitrary place on the circumference of the rotor or in a fixed position. Calculations for drilling when removing the mass.
"موقف مجاني"- يمكن تثبيت الأوزان في مواضع زاوية عشوائية على محيط الدوار.

     "موقف ثابت” – يمكن تثبيت الوزن في مواضع زاوية ثابتة على الدوار مثلاً على الشفرات أو الثقوب (مثلاً 12 فتحة – 30 درجة) إلخ. ويجب إدخال عدد المواضع الثابتة في الحقل المناسب. بعد الموازنة، سيقوم البرنامج تلقائيًا بتقسيم الوزن إلى جزأين ويشير إلى عدد المواضع التي من الضروري تحديد الكتل التي تم الحصول عليها.

.

.

    • كتلة الوزن التجريبي

Trial weight

    • Leave trial weight in Plane1 / Plane2

Remove or leave trial weight when balancing.

    • نصف قطر التركيب الشامل، مم

Radius of mounting trial and corrective weights

    • موازنة التسامح

Entering or calculating residual imbalance tolerances in g-mm

    • استخدم الرسم البياني القطبي

استخدم الرسم البياني القطبي لعرض نتائج الموازنة

    • إدخال البيانات يدويا

Manual data entry for calculating balancing weights

    • Restore last session data

Recovery of the measurement data of the last session in the event of failure to continue balancing.

.

.

2 planes balancing. New rotor
إعداد نظام القياس (إدخال البيانات الأولية).

Input of the initial data for the New rotor balancing in the “Two plane balancing. Settings”(see Fig. 7.32.).

في هذه الحالة، في "معاملات التأثير"القسم، حدد "الدوار الجديد” item.

Further, in the section “كتلة الوزن التجريبي“, you must select the unit of measurement of the mass of the trial weight – “غرام” or “نسبه مئويه“.

When choosing the unit of measure “نسبه مئويه”, all further calculations of the mass of the corrective weight will be performed as a percentage in relation to the mass of the trial weight.

When choosing the “غرام” unit of measurement, all further calculations of the mass of the corrective weight will be performed in grams. Then enter in the windows located to the right of the inscription “غرام” the mass of trial weights that will be installed on the rotor.

.

انتباه!

إذا كان من الضروري استخدام "معامل محفوظ.” Mode for further work during initial balancing, the mass of trial weights must be entered in جرامات.
Then select “طريقة ربط الوزن” – “Circum” or “موقف ثابت".
If you select “موقف ثابت”, you must enter the number of positions.

.

.

Calculation of tolerance for residual imbalance (Balancing tolerance)

The tolerance for residual imbalance (Balancing tolerance) can be calculated in accordance with the procedure described in ISO 1940 Vibration. Balance quality requirements for rotors in a constant (rigid) state. Part 1. Specification and verification of balance tolerances.   

                                                                   

                             

Fig. 7.34. Balancing tolerance calculation window

.

Initial run (Run#0).

When balancing in two planes in the “الدوار الجديد” mode, balancing requires three calibration runs and at least one test run of the balancing machine.

The vibration measurement at the first start of the machine is performed in the “Two plane balance” working window (see Fig. 7.34) in the “Run#0” section.

.

.

         Fig. 7.35. Measurement results at balancing in two planes after the initial run.

.

انتباه!

       Before starting the measurement, it is necessary to turn on the rotation of the rotor of the balancing machine (first run) and make sure that it has entered the operating mode with a stable speed.

To measure vibration parameters in the Run#0 section, click on the “F7 - Run#0” button (or press the F7 key on a computer keyboard)

           The results of measuring the rotor speed (RPM), the value RMS (VО1, VО2) and phases (F1, F2) of 1x vibration appearing appear in the corresponding windows of the Run#0 section.
.

Run#1.Trial mass in Plane1.

.

Before starting to measure vibration parameters in the “Run#1.Trial mass in Plane1” section, you should stop the rotation of the rotor of the balancing machine and install a trial weight on it, the mass selected in the “كتلة الوزن التجريبي” section.

     انتباه!

      1. The question of choosing the mass of trial weights and their installation places on the rotor of a balancing machine is discussed in detail in Appendix 1.

      2. If it is necessary to use the معامل محفوظ. Mode in future work, the place for installing the trial weight must necessarily coincide with the place for installing the mark used to read the phase angle.

.

After this, it is necessary to turn on the rotation of the rotor of the balancing machine again and make sure that it has entered the operating mode.

To measure vibration parameters in the “Run # 1.Trial mass in Plane1” section (see Fig. 7.25), click on the “F7 – Run#1” button (or press the F7 key on the computer keyboard).

           

          Upon successful completion of the measurement process, you are returned to the tab of measurement results (see Fig. 7.25).

           In this case, in the corresponding windows of the “Run#1. Trial mass in Plane1” section, the results of measuring the rotor speed (RPM), as well as the value of the components of the RMS (Vо1, Vо2) and phases (F1, F2) of 1x vibration.

.

Run # 2.Trial mass in Plane2

.

Before starting to measure vibration parameters in the section “Run # 2.Trial mass in Plane2“, you must perform the following steps:

         – stop the rotation of the rotor of the balancing machine;

         – remove the trial weight installed in plane 1;

         – install on a trial weight in plane 2, the mass selected in the section “كتلة الوزن التجريبي“.

           

After this, turn on the rotation of the rotor of the balancing machine and make sure that it has entered the operating speed.

To begin the measurement of vibration in the “Run # 2.Trial mass in Plane2” section (see Fig. 7.26), click on the “F7 – Run # 2” button (or press the F7 key on the computer keyboard). Then the “نتيجة” tab opens.
.

In the case of using the طريقة ربط الوزن” – "Free positions, the display shows the values ​​of the masses (M1, M2) and installation angles (f1, f2) of the corrective weights.

.

           Fig. 7.36. Results of calculation of corrective weights – free position

.

.

Fig. 7.37. Results of calculation of corrective weights – free position.
Polar diagram

.

In the case of using the Weight Attachment Method” – "مواقف ثابتة


.

Fig. 7.37. Results of calculation of corrective weights – fixed position.

Fig. 7.39. Results of calculation of corrective weights – fixed position.
Polar diagram.
.

In the case of using the Weight Attachment Method” – "Circular groove”

Fig. 7.40. Results of calculation of corrective weights – أخدود دائري.

.

انتباه!:

    1. After completing the measurement process on the RUN#2 of the balancing machine, stop the rotation of the rotor and remove the trial weight previously installed. Then you can to install (or remove) corrective weights.

    2. The angular position of the corrective weights in the polar coordinate system is counted from the place of installation of the trial weight in the direction of rotation of the rotor.

    3. في حالة "موقف ثابت" - 1شارع الموضع (Z1) يتزامن مع مكان تركيب الوزن التجريبي. اتجاه العد لرقم الموضع هو في اتجاه دوران الدوار.

4. بشكل افتراضي، سيتم إضافة الوزن التصحيحي إلى الدوار. يتم الإشارة إلى ذلك من خلال الملصق الموجود في "يضيف" مجال. في حالة إزالة الوزن (على سبيل المثال، عن طريق الحفر)، يجب عليك وضع علامة في "يمسح"، وبعد ذلك سيتغير الموضع الزاوي لوزن التصحيح تلقائيًا بمقدار 180 درجة.

.

RunC (Trim run)

   After installing the correction weight on the balancing rotor it is necessary to carry out a RunC (trim) and evaluate the effectiveness of the performed balancing.

انتباه!

Before starting the measurement at the test run, it is necessary to turn on the rotation of the rotor of the machine and make sure that it has entered the operating speed.

                

To measure vibration parameters in the RunTrim (Check balance quality) section (see Fig. 7.37), click on the “F7 - رنتريم” button (or press the F7 key on the computer keyboard).

       

           The results of measuring the rotor rotation frequency (RPM), as well as the value of the RMS component (Vо1) and phase (F1) of 1x vibration will be shown.

ال "نتيجة” tab appears on right side of the working window with the table of measurement results (see Fig. 7.37), which displays the results of calculating the parameters of additional corrective weights.

           These weights can be added to corrective weights that are already installed on the rotor to compensate for residual imbalance.

In addition, the residual rotor unbalance achieved after balancing is displayed in the lower part of this window.

In the case when the values ​​of the residual vibration and / or residual unbalance of the balanced rotor satisfy the tolerance requirements established in the technical documentation, the balancing process can be completed.

وإلا فإن عملية التوازن قد تستمر. يتيح ذلك لطريقة التقريبات المتعاقبة تصحيح الأخطاء المحتملة التي قد تحدث أثناء تركيب (إزالة) الوزن التصحيحي على الدوار المتوازن.

When continuing the balancing process on the balancing rotor, it is necessary to install (remove) additional corrective mass, the parameters of which are indicated in the “Result” window.

.

في ال "نتيجة” window there are two control buttons can be used – “F4-Inf.Coeff“, “F5 – Change correction planes“.

.

.

Influence coefficients (2 planes)

.

ال "F4-Inf.Coeff” button (or the F4 function key on the computer keyboard) is used to view and save rotor balancing coefficients in the computer memory, calculated from the results of two calibration starts.

عند الضغط عليه يظهر "Influence coefficients (two planes)” working window appears on the computer display (see Fig. 7.40), in which balancing coefficients calculated based on the results of the first three calibration starts are displayed.

.

Fig. 7.41. Working window with balancing coefficients in 2 planes.

.

In the future, when balancing of such type of the machine it is supposed, require to use the “معامل محفوظ.” mode and balancing coefficients stored in the computer memory.

To save coefficients, click the “F9 – Save” button and go to the “Influence coefficients archive (2planes)” windows (see Fig. 7.42)

.

.

Fig. 7.42. The second page of the working window with balancing coefficients in 2 planes.

.

Change correction planes

ال "F5 – Change correction planes” button is used when require change the position of the correction planes, when it is necessary to recalculate the masses and installation angles

corrective weights.

This mode is primarily useful when balancing rotors of complex shape (for example, crankshafts).

When this button is pressed, the working window “Recalculation of correction weights mass and angle to other correction planes” is displayed on the computer display (see Fig. 7.42).

In this working window, you should select one of the 4 possible options by clicking corresponding picture.

The original correction planes (Н1 and Н2) in Fig. 7.29 are marked in green, and new (K1 and K2), for which it recounts, in red.

Then, in the “Calculation data” section, enter the requested data, including:

– the distance between the corresponding correction planes (a, b, c);

– new values ​​of the radii of the installation of corrective weights on the rotor (R1 ’, R2’).

After entering the data, you must press the button “F9-calculate

The calculation results (masses M1, M2 and installation angles of corrective weights f1, f2) are displayed in the corresponding section of this working window (see Fig. 7.42).


Fig. 7.43 Change correction planes. Recalculation of correction mass and angle to other correction planes.

.

.

.

.

Saved coeff. balancing in 2 planes.

                                                                                                                          

معامل محفوظ. موازنة can be performed on a machine for which balancing coefficients have already been determined and saved in the computer memory.

     انتباه!

When re-balancing, the vibration sensors and the phase angle sensor must be installed in the same way as during the initial balancing.

Input of initial data for re-balancing begins in the “Two plane balance. Balancing settings”(see Fig. 7.23).

.

في هذه الحالة، في "معاملات التأثير"القسم، حدد "معامل محفوظ.” Item. In this case, the window “Influence coefficients archive (2planes)” will appear (see Fig. 7.30), in which the archive of the previously determined balancing coefficients is stored.

Moving through the table of this archive using the “►” or “◄” control buttons, you can select the desired record with balancing coefficients of the machine of interest to us. Then, to use this data in current measurements, press the “F2 – OK” button and return to the previous working window.

Fig. 7.44. The second page of the working window with balancing coefficients in 2 planes.

وبعد ذلك تظهر محتويات كافة النوافذ الأخرى للـ “Balancing in 2 pl. Source data” is filled in automatically.

.

Saved coeff. Balancing

.

"معامل محفوظ.” balancing requires only one tuning start and at least one test start of the balancing machine.

Vibration measurement at the tuning start (تشغيل # 0) of the machine is performed in the “Balancing in 2 planes” working window with a table of balancing results (see Fig. 7.14) in the تشغيل # 0 section.

.

انتباه!

       Before starting the measurement, it is necessary to turn on the rotation of the rotor of the balancing machine and make sure that it has entered the operating mode with a stable speed.

To measure vibration parameters in the تشغيل # 0 section, click the “F7 - Run#0” button (or press the F7 key on the computer keyboard).

.

           The results of measuring the rotor speed (RPM), as well as the value of the components of the RMS (VО1, VО2) and phases (F1, F2) of the 1x vibration appear in the corresponding fields of the تشغيل # 0 section.

At the same time, the “نتيجة” tab opens (see Fig. 7.15), which displays the results of calculating the parameters of corrective weights that must be installed on the rotor to compensate for its imbalance.

Moreover, in the case of using the polar coordinate system, the display shows the values ​​of the masses and installation angles of corrective weights.

In the case of decomposition of corrective weights on the blades, the numbers of the blades of the balancing rotor and the mass of weight that need to be installed on them are displayed.

Further, the balancing process is carried out in accordance with the recommendations set out in section 7.6.1.2. for primary balancing.

انتباه!:

1.After completion of the measurement process after the second start of the balanced machine stop the rotation of its rotor and remove the previously set trial weight. Only then you can begin to install (or remove) correction weight on the rotor.
2.Counting the angular position of the place of adding (or removing) of the correction weight from the rotor is carried out on the installation site of trial weight in the polar coordinate system. Counting direction coincides with the direction of the angle of rotor rotation.
3.In case of balancing on the blades – the balanced rotor blade, conditionally accepted for the 1st, coincides with the place of the trial weight installation. Reference number direction of the blade shown on the computer display is performed in the direction of the rotor rotation.
4.In this version of the program it is accepted by default that correction weight will be added on the rotor. The tag established in the field “Addition” testifies to it.

In case of correction of imbalance by removal of a weight (for example by drilling) it is necessary to establish tag in the field “Removal” then the angular position of the correction weight will change automatically on 180º.

إزالة انحراف الشياق (موازنة الفهرس)إذا تم تثبيت الدوار في شياق أسطواني أثناء الموازنة، فإن انحراف الشياق قد يؤدي إلى حدوث خطأ إضافي. للتخلص من هذا الخطأ، يجب نشر الدوار في الشياق بمقدار 180 درجة وتنفيذ بداية إضافية. وهذا ما يسمى موازنة الفهرس.

لتنفيذ موازنة الفهرس، يتم توفير خيار خاص في برنامج Balanset-1A. عند تحديد إزالة انحراف مغزل الشياق، يظهر قسم RunEcc إضافي في نافذة الموازنة.

.


Fig. 7.45. The working window for Index balancing.

.

After running Run # 2 (Trial mass Plane 2), a window will appear


.


Fig. 7.46. Attention windows
.

بعد تثبيت الدوار بدورة 180، يجب إكمال Run Ecc. سيقوم البرنامج تلقائيًا بحساب الخلل الحقيقي في الجزء الدوار دون التأثير على انحراف مركزية الشياق.

  7.4. Charts mode

.

  Working in the “Charts” mode begins from the Initial window (see. Fig. 7.1) by pressing “F8 – Charts”. Then opens a window “Measurement of vibration on two channels. Charts” (see. Fig. 7.19).

.

Fig. 7.47. Operating window “Measurement of vibration on two channels. Charts”.

.

  While working in this mode it is possible to plot four versions of vibration chart.

The first version allows to get a timeline function of the overall vibration (of vibration velocity) on the first and second measuring channels.

The second version allows you to get graphs of vibration (of vibration velocity), which occurs on rotation frequency and its higher harmonical components.

These graphs are obtained as a result of the synchronous filtering of the overall vibration time function.

The third version provides vibration charts with the results of the harmonical analysis.

The fourth version allows to get a vibration chart with the results of the spectrum analysis.  

  

Charts of overall vibration.

To plot a overall vibration chart in the operating window “Measurement of vibration on two channels. Charts” it is necessary to select the operating mode “overall vibration” by clicking the appropriate button. Then set the measurement of vibration in the box “Duration, in seconds,” by clicking on the button «▼» and select from the drop-down list the desired duration of the measurement process, which may be equal to 1, 5, 10, 15 or 20 seconds;

Upon readiness press (click) the “F9-Measure” button then the vibration measurement process begins simultaneously on two channels.

After completion of the measurement process in the operating window appear charts of time function of the overall vibration of the first (red) and the second (green) channels (see. Fig. 7.47).

On these charts time is plotted on X-axis and the amplitude of the vibration velocity (mm/sec) is plotted on Y-axis.

.

Fig. 7.48. Operating window for the output of the time function of the overall vibration charts

.

  There are also marks (blue-colored) in these graphs connecting charts of overall vibration with the rotation frequency of the rotor. In addition, each mark indicates beginning (end) of the next revolution of the rotor.

In need of the scale change of the chart on X-axis the slider, pointed by an arrow on fig. 7.20, can be used.

.

.

Charts of 1x vibration.

To plot a 1x vibration chart in the operating window “Measurement of vibration on two channels. Charts” (see Fig. 7.47) it is necessary to select the operating mode “1x vibration” by clicking the appropriate button.

Then appears operating window “1x vibration” (see Fig. 7.48).

Press (click) the “F9-Measure” button then the vibration measurement process begins simultaneously on two channels.

Fig. 7.49. Operating window for the output of the 1x vibration charts.
.

  After completion of the measurement process and mathematical calculation of results (synchronous filtering of the time function of the overall vibration) on display in the main window on a period equal to one revolution of the rotor appear charts of the 1x vibration on two channels.

In this case, a chart for the first channel is depicted in red and for the second channel in green. On these charts angle of the rotor revolution is plotted (from mark to mark) on X-axis and the amplitude of the vibration velocity (mm/sec) is plotted on Y-axis.

In addition, in the upper part of the working window (to the right of the button “F9 – Measure”) numerical values of vibration measurements of both channels, similar to those we get in the “Vibration meter” mode, are displayed.

In particular: RMS value of the overall vibration (V1s, V2s), the magnitude of RMS (V1o, V2o) and phase (Fi, Fj) of the 1x vibration and rotor speed (Nrev).

.

Vibration charts with the results of harmonical analysis.

.

To plot a chart with the results of harmonical analysis in the operating window “Measurement of vibration on two channels. Charts” (see Fig. 7.47) it is necessary to select the operating mode “Harmonical analysis” by clicking the appropriate button.

Then appears an operating window for simultaneous output of charts of temporary function and of spectrum of vibration harmonical aspects whose period is equal or multiple to the rotor rotation frequency (see Fig. 7.49).  

انتباه!

When operating in this mode it is necessary to use the phase angle sensor which synchronizes the measurement process with the rotor frequency of the machines to which the sensor is set.

.

Fig. 7.50. Operating window harmonics of 1x vibration.

.

Upon readiness press (click) the “F9-Measure” button then the vibration measurement process begins simultaneously on two channels.

After completion of the measurement process in operating window (see Fig. 7.49) appear charts of time function (higher chart) and harmonics of 1x vibration (lower chart).

The number of harmonic components is plotted on X-axis and RMS of the vibration velocity (mm/sec) is plotted on Y-axis.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

Charts of vibration time domen and spectrum.

To plot a spectrum chart use “F5-Spectrum” tab:

Then appears an operating window for simultaneous output of charts of wave and spectrum of vibration (Fig. 7.51).

Fig. 7.51. Operating window for the output of the spectrum of vibration .

Upon readiness press (click) the “F9-Measure” button then the vibration measurement process begins simultaneously on two channels.

After completion of the measurement process in operating window (see Fig. 7.50) appear charts of time function (higher chart) and spectrum of vibration (lower chart).

The vibration frequency is plotted on X-axis and RMS of the vibration velocity (mm/sec) is plotted on Y-axis.

In this case, a chart for the first channel is depicted in red and for the second channel in green.

ANNEX 1 ROTOR   BALANCING.

.

The rotor is a body that rotates around a certain axis and is held by its bearing surfaces in the supports. Bearing surfaces of the rotor transmit weights to the supports through rolling or sliding bearings. While using the term of “bearing surface” we simply refer to the Zapfen* or Zapfen-replacing surfaces.

.

*Zapfen (German for “journal”, “pin”) – is a part of an shaft or an axis, that is being carried by a holder (bearing box).

fig.1 Rotor and centrifugal forces.

.

In a perfectly balanced rotor, its mass is distributed symmetrically regarding the axis of the rotation. This means that any element of the rotor can correspond to another element located symmetrically in a relation to the axis of the rotation. During rotation, each rotor element acts upon by a centrifugal force directed in the radial direction (perpendicular to the axis of the rotor rotation). In a balanced rotor, the centrifugal force influencing any element of the rotor is balanced by the centrifugal force that influences the symmetrical element. For example, elements 1 and 2 (shown in fig.1 and colored in green) are influenced by centrifugal forces F1 and F2: equal in value and absolutely opposite in directions. This is true for all symmetrical elements of the rotor and thus the total centrifugal force influencing the rotor is equal to 0 the rotor is balanced. But if the symmetry of the rotor is broken (in Figure 1, the asymmetric element is marked in red), then the unbalanced centrifugal force F3 begins to act on the rotor.

When rotating, this force changes the direction together with the rotation of the rotor. The dynamic weight resulting from this force is transferred to the bearings, which leads to their accelerated wear. In addition, under the influence of this variable towards the force, there is a cyclic deformation of the supports and of the foundation on which the rotor is fixed, which lets out a vibration. To eliminate the imbalance of the rotor and the accompanying vibration, it is necessary to set balancing masses, that will restore the symmetry of the rotor.

Rotor balancing is an operation to eliminate imbalance by adding balancing masses.

The task of balancing is to find the value and places (angle) of the installation of one or more balancing masses.

.

The types of rotors and imbalance.

Considering the strength of the rotor material and the magnitude of the centrifugal forces influencing it, the rotors can be divided into two types: rigid and flexible.

Rigid rotors at operating conditions under the influence of centrifugal force may get slightly deformed and the influence of this deformation in the calculations may therefore be neglected.

Deformation of flexible rotors on the other hand should never be neglected. The deformation of flexible rotors complicates the solution for the balancing problem and requires the use of some other mathematical models in comparison with the task of balancing rigid rotors. It is important to mention that the same rotor at low speeds of rotation can behave like rigid one and at high speeds it will behave like flexible one. Further on we will consider the balancing of rigid rotors only.

Depending on the distribution of imbalanced masses along the length of the rotor, two types of imbalance can be distinguished – static and dynamic (quick, instant). It works correspondingly same with the static and the dynamic rotor balancing.

The static imbalance of the rotor occurs without the rotation of the rotor. In other words, it is quiescent when the rotor is under the influence of gravity and in addition it turns the “heavy point” down. An example of a rotor with the static imbalance is presented in Fig.2

.

Fig.2

.

The dynamic imbalance occurs only when the rotor spins.

An example of a rotor with the dynamic imbalance is presented in Fig.3.

.

Fig.3. Dynamic imbalance of rotor – couple of the centrifugal forces

.

In this case, imbalanced equal masses M1 and M2 are located in different surfaces – in different places along the length of the rotor. In the static position, i.e. when the rotor does not spin, the rotor may only be influenced by gravity and the masses therefore will balance each other. In dynamics when the rotor is spinning, the masses M1 and M2 start to be influenced by centrifugal forces FЎ1 and FЎ2. These forces are equal in value and are opposite in the direction. However, since they are located in different places along the length of the shaft and are not on the same line, the forces do not compensate each other. The forces of FЎ1 and FЎ2 create a moment impacted to the rotor. That is why this imbalance has another name “momentary”. Accordingly, non-compensated centrifugal forces influence the bearing supports, which can significantly exceed the forces that we relied on and also reduce the service life for the bearings.

Since this type of imbalance occurs only in dynamics during the rotor spinning, thus it is called dynamic. It can not be eliminated in the static balancing (or so called “on the knives”) or in any other similar ways. To eliminate the dynamic imbalance, it is necessary to set two compensating weights that will create a moment equal in value and opposite in direction to the moment arising from the masses of M1 and M2. Compensating masses do not necessarily have to be installed opposite to the masses M1 and M2 and be equal to them in value. The most important thing is that they create a moment that fully compensates right at the moment of imbalance.

In general, the masses M1 and M2 may not be equal to each other, so there will be a combination of static and dynamic imbalance. It is theoretically proved that for a rigid rotor to eliminate its imbalance it is necessary and sufficient to install two weights spaced along the length of the rotor. These weights will compensate both the moment resulting from the dynamic imbalance and the centrifugal force resulting from the asymmetry of the mass relative to the rotor axis (static imbalance). As usual the dynamic imbalance is typical for long rotors, such as shafts, and static – for narrow. However, if the narrow rotor is mounted skewed in reference to the axis, or worse, deformed (the so-called “wheel wobbles”), in this case it will be difficult to eliminate the dynamic imbalance (see Fig.4), due to the fact that it is difficult to set correcting weights, that create the right compensating moment.

.

Fig.4 Dynamic balancing of the wobbling wheel

.

.

Since the narrow rotor shoulder creates a short moment, it may require correcting weights of a large mass. But at the same time there is an additional so-called “induced imbalance” associated with the deformation of the narrow rotor under the influence of centrifugal forces from the correcting masses.

See the example:

” Methodical instructions on rigid rotors balancing” ISO 1940-1:2003 Mechanical vibration – Balance quality requirements for rotors in a constant (rigid) state – Part 1: Specification and verification of balance tolerances

.

This is visible for narrow fan wheels, which, in addition to the power imbalance, also influences an aerodynamic imbalance. And it is important to bear in mind that the aerodynamic imbalance, in fact the aerodynamic force, is directly proportional to the angular velocity of the rotor, and to compensate it, the centrifugal force of the correcting mass is used, which is proportional to the square of the angular velocity. Therefore, the balancing effect may only occur at a specific balancing frequency. At other speeds there would be an additional gap. The same can be said about electromagnetic forces in an electromagnetic motor, which are also proportional to the angular velocity. In other words it is impossible to eliminate all causes of vibration of the mechanism by any means of balancing.

.

.

.

.

.

.

.

.

Fundamentals of Vibration.

Vibration is a reaction of the mechanism design to the effect of cyclic excitation force. This force can may a different nature.

 The centrifugal force arising due to the imbalance of the rotor is an uncompensated force influencing the “heavy point”. Particularly this force and also the vibration caused by it are eliminated by the rotor balancing.
 Interacting forces, that have a “geometric” nature and arise out of errors in the manufacture and installation of mating parts. These forces can occur, for instance, due to the non-roundness of the shaft journal, errors in the tooth profiles in gears, the waviness of the bearing treadmills, misalignment of the mating shafts, etc. in case of non-roundness of the necks, the shaft axis will shift depending on the angle of rotation of the shaft. Although this vibration is manifested at the rotor speed, it is almost impossible to eliminate it with the balancing.
 Aerodynamic forces arising from the rotation of the impeller fans and other blade mechanisms. Hydrodynamic forces arising from the rotation of hydraulic pump impellers, turbines, etc.
 Electromagnetic forces arising from the operation of electric machines as a result, for example, due to the asymmetry of the rotor windings, the presence of short-circuited turns, etc.reasons.

.

The magnitude of vibration (for example, its amplitude AB) depends not only on the magnitude of the excitation force Fт acting on the mechanism with the circular frequency ω, but also on the stiffness k of the structure of the mechanism, its mass m, and damping coefficient C.

Various types of sensors can be used to measure vibration and balance mechanisms, including:

– absolute vibration sensors designed to measure vibration acceleration (accelerometers) and vibration velocity sensors;

– relative vibration sensors eddy-current or capacitive, designed to measure vibration.

In some cases (when the structure of the mechanism allows it) sensors of force can also be used to examine its vibration weight.

Particularly, they are widely used to measure the vibration weight of the supports of hardbearing balancing machines.

.

Therefore vibration is the reaction of the mechanism to the influence of external forces. The amount of vibration depends not only on the magnitude of the force acting on the mechanism, but also on the rigidity of the mechanism. Two forces with the same magnitude can lead to different vibrations. In mechanisms with a rigid support structure, even with the small vibration, the bearing units can be significantly influenced by dynamic weights. Therefore, when balancing mechanisms with stiff legs apply the force sensors, and vibration (vibro accelerometers). Vibration sensors are only used on mechanisms with relatively pliable supports, right when the action of unbalanced centrifugal forces leads to a noticeable deformation of the supports and vibration. Force sensors are used in rigid supports even when significant forces arising from imbalance do not lead to significant vibration.

The resonance of the structure.

We have previously mentioned that rotors are divided into rigid and flexible. The rigidity or flexibility of the rotor should not be confused with the stiffness or mobility of the supports (foundation) on which the rotor is located. The rotor is considered rigid when its deformation (bending) under the action of centrifugal forces can be neglected. The deformation of the flexible rotor is relatively large: it cannot be neglected.

In this article we only study the balancing of rigid rotors. The rigid (non-deformable) rotor in its turn can be located on rigid or movable (malleable) supports. It is clear that this stiffness/mobility of the supports is relative depending on the speed of rotation of the rotor and the magnitude of the resulting centrifugal forces. The conventional border is the frequency of free oscillations of the rotor supports/foundation. For mechanical systems, the shape and frequency of the free oscillations are determined by the mass and elasticity of the elements of the mechanical system. That is, the frequency of natural oscillations is an internal characteristic of the mechanical system and does not depend on external forces. Being deflected from the equilibrium state, supports tend to return to its equilibrium position due to the elasticity. But due to the inertia of the massive rotor, this process is in the nature of damped oscillations. These oscillations are their own oscillations of the rotor-support system. Their frequency depends on the ratio of the rotor mass and the elasticity of the supports.

.

.

.

When the rotor begins to rotate and the frequency of its rotation approaches the frequency of its own oscillations, the vibration amplitude increases sharply, which can even lead to the destruction of the structure.

There is a phenomenon of mechanical resonance. In the resonance region, a change in the speed of rotation by 100 rpm can lead to an increase in a vibration tenfold. In this case (in the resonance region) the vibration phase changes by 180°.

If the design of the mechanism is calculated unsuccessfully, and the operating speed of the rotor is close to the natural frequency of oscillations, the operation of the mechanism becomes impossible due to unacceptably high vibration. Usual balancing way is also impossible, as parameters change dramatically even with a slight change in the speed of rotation. Special methods in the field of resonance balancing are used but they are not well-described in this article. You can determine the frequency of natural oscillations of the mechanism on the run-out (when the rotor is turned off) or by impact with subsequent spectral analysis of the system response to the shock. The “Balanset-1” provides the ability to determine the natural frequencies of mechanical structures by these methods.

For mechanisms whose operating speed is higher than the resonance frequency, that is, operating in the resonant mode, supports are considered as mobile ones and vibration sensors are used to measure, mainly vibration accelerometers that measure the acceleration of structural elements. For mechanisms operating in hard bearing mode, supports are considered as rigid. In this case, force sensors are used.

Linear and nonlinear models of the mechanical system.

Mathematical models (linear) are used for calculations when balancing rigid rotors. The linearity of the model means that one model is directly proportionally (linearly) dependent on the other. For example, if the uncompensated mass on the rotor is doubled, then the vibration value will be doubled correspondingly. For rigid rotors you can use a linear model because such rotors are not deformed. It is no longer possible to use a linear model for flexible rotors. For a flexible rotor, with an increase of the mass of a heavy point during rotation, an additional deformation will occur, and in addition to the mass, the radius of the heavy point will also increase. Therefore, for a flexible rotor, the vibration will more than double, and the usual calculation methods will not work. Also, a violation of the linearity of the model can lead to a change in the elasticity of the supports at their large deformations, for example, when small deformations of the supports work some structural elements, and when large in the work include other structural elements. Therefore it is impossible to balance the mechanisms that are not fixed at the base, and, for example, are simply established on a floor. With significant vibrations, the unbalance force can detach the mechanism from the floor, thereby significantly changing the stiffness characteristics of the system. The engine legs must be securely fastened, bolted fasteners tightened, the thickness of the washers must provide sufficient rigidity, etc. With broken bearings, a significant displacement of the shaft and its impacts is possible, which will also lead to a violation of linearity and the impossibility of carrying out high-quality balancing.

.

Methods and devices for balancing

As mentioned above, balancing is the process of combining the main Central axis of inertia with the axis of rotation of the rotor.

The specified process can be executed in two ways.

The first method involves the processing of the rotor axles, which is performed in such a way that the axis passing through the centers of the section of the axles with the main Central axis of inertia of the rotor. This technique is rarely used in practice and will not be discussed in detail in this article.

The second (most common) method involves moving, installing or removing corrective masses on the rotor, which are placed in such a way that the axis of inertia of the rotor is as close as possible to the axis of its rotation.

Moving, adding or removing corrective masses during balancing can be done using a variety of technological operations, including: drilling, milling, surfacing, welding, screwing or unscrewing screws, burning with a laser beam or electron beam, electrolysis, electromagnetic welding, etc.

The balancing process can be performed in two ways:

– balanced rotors Assembly (in its own bearings);

– balancing of rotors on balancing machines.

To balance the rotors in their own bearings we usually use specialized balancing devices (kits), which allows us to measure the vibration of the balanced rotor at the speed of its rotation in a vector form, i.e. to measure both the amplitude and phase of vibration.

Currently, these devices are manufactured on the basis of microprocessor technology and (in addition to the measurement and analysis of vibration) provide automated calculation of the parameters of corrective weights that must be installed on the rotor to compensate its imbalance.

These devices include:

– measuring and computing unit, made on the basis of a computer or industrial controller;

– two (or more) vibration sensors;

– phase angle sensor;

– equipment for installation of sensors at the facility;

– specialized software designed to perform a full cycle of measurement of rotor unbalance parameters in one, two or more planes of correction.

For balancing rotors on balancing machines in addition to a specialized balancing device (measuring system of the machine) it is required to have an “unwinding mechanism” designed to install the rotor on the supports and ensure its rotation at a fixed speed.

Currently, the most common balancing machines exist in two types:

– over-resonant (with supple supports);

– hard bearing (with rigid supports).

Over-resonant machines have a relatively pliable supports, made, for example, on the basis of the flat springs.

The natural oscillation frequency of these supports is usually 2-3 times lower than the speed of the balanced rotor, which is mounted on them.

Vibration sensors (accelerometers, vibration velocity sensors, etc.) are usually used to measure the vibration of the supports of a resonant machine.

In the hardbearing balancing machines are used relatively-rigid supports, natural oscillation frequencies of which should be 2-3 times higher than the speed of the balanced rotor.

Force sensors are usually used to measure the vibration weight on the supports of the machine.

The advantage of the hard bearing balancing machines is that they can be balanced at relatively low rotor speeds (up to 400-500 rpm), which greatly simplifies the design of the machine and its foundation, as well as increases the productivity and safety of balancing.

.

Balancing technique

Balancing eliminates only the vibration which is caused by the asymmetry of the rotor mass distribution relative to its axis of rotation. Other types of the vibration cannot be eliminated by the balancing!

Balancing is the subject to technically serviceable mechanisms, the design of which ensures the absence of resonances at the operating speed, securely fixed on the foundation, installed in serviceable bearings.

The faulty mechanism is the subject to a repair, and only then – to a balancing. Otherwise, qualitative balancing impossible.

Balancing cannot be a substitute for repair!

.

The main task of balancing is to find the mass and the place (angle) of installation of compensating weights, which are balanced by centrifugal forces.

As mentioned above, for rigid rotors it is generally necessary and sufficient to install two compensating weights. This will eliminate both the static and dynamic rotor imbalance. A general scheme of the vibration measurement during balancing looks like the following:

.

.

fig.5 Dynamic balancing – correction planes and measure points

.

Vibration sensors are installed on the bearing supports at points 1 and 2. The speed mark is fixed right on the rotor, a reflective tape is glued usually. The speed mark is used by the laser tachometer to determine the speed of the rotor and the phase of the vibration signal.

.

.

fig. 6. Installation of sensors during balancing in two planes, using Balanset-1
1,2-vibration sensors, 3-phase, 4- USB measuring unit, 5-laptop

.

.

In most cases, dynamic balancing is carried out by the method of three starts. This method is based on the fact that test weights of an already-known mass are installed on the rotor in series in 1 and 2 planes; so the masses and the place of installation of balancing weights are calculated based on the results of changing the vibration parameters.

The place of installation of the weight is called the correction plane. Usually, the correction planes are selected in the area of the bearing supports on which the rotor is mounted.

The initial vibration is measured at the first start. Then, a trial weight of a known mass is installed on the rotor closer to one of the supports. Then the second start is performed, and we measure the vibration parameters, that should change because of the installation of the trial weight. Then the trial weight in the first plane is removed and installed in the second plane. The third start-up is performed and the vibration parameters are measured. When the trial weight is removed, the program automatically calculates the mass and the place (angles) of the installation of balancing weights.

The point in setting up test weights is to determine how the system responds to the imbalance change. When we know the masses and the location of the sample weights, the program can calculate the so-called influence coefficients, showing how the introduction of a known imbalance affects the vibration parameters. The coefficients of influence are the characteristics of the mechanical system itself and depend on the stiffness of the supports and the mass (inertia) of the rotor-support system.

For the same type of mechanisms of the same design, the coefficients of influence will be similar. You can save them in your computer memory and use them afterwards for balancing the same type of mechanisms without carrying out test runs, which greatly improves the performance of the balancing. We should also note that the mass of test weights should be chosen as such so that the vibration parameters vary markedly when installing test weights. Otherwise, the error in calculating the coefficients of the affect increases and the quality of balancing deteriorates.

1111 A guide to the device Balanset-1 provides a formula by which you can approximately determine the mass of the trial weight, depending on the mass and the speed of the rotation of the balanced rotor. As you can understand from Fig. 1 the centrifugal force acts in the radial direction, i.e. perpendicular to the rotor axis. Therefore, vibration sensors should be installed so that their sensitivity axis is also directed in the radial direction. Usually the rigidity of the foundation in the horizontal direction is less, so the vibration in the horizontal direction is higher. Therefore, to increase the sensitivity of the sensors should be installed so that their axis of sensitivity could also be directed horizontally. Although there is no fundamental difference. In addition to the vibration in the radial direction, it is necessary to control the vibration in the axial direction, along the axis of rotation of the rotor. This vibration is usually caused not by imbalance, but by other reasons, mainly due to misalignment and misalignment of shafts connected through the coupling. This vibration is not eliminated by balancing, in this case alignment is required. In practice, usually in such mechanisms there is an imbalance of the rotor and misalignment of the shafts, which greatly complicates the task of eliminating the vibration. In such cases, you must first align and then balance the mechanism. (Although with a strong torque imbalance, vibration also occurs in the axial direction due to the” twisting ” of the foundation structure).

.

Criteria for assessing the quality of balancing mechanisms.

.

Quality of rotor (mechanisms) balancing can be estimated in two ways. The first method involves comparing the value of the residual imbalance determined during the balancing with the tolerance for the residual imbalance. The specified tolerances for various classes of rotors installed in the standard ISO 1940-1-2007. «Vibration. Requirements for the balancing quality of rigid rotors. Part 1. Determination of permissible imbalance”. 
However, the implementation of these tolerances can not fully guarantee the operational reliability of the mechanism associated with the achievement of a minimum level of vibration. This is due to the fact that the vibration of the mechanism is determined not only by the amount of force associated with the residual imbalance of its rotor, but also depends on a number of other parameters, including: the rigidity K of the structural elements of the mechanism, its mass M, damping coefficient, and the speed. Therefore, to assess the dynamic qualities of the mechanism (including the quality of its balance) in some cases, it is recommended to assess the level of residual vibration of the mechanism, which is regulated by a number of standards. 
The most common standard regulating permissible vibration levels of mechanisms is ISO 10816-3:2009 Preview Mechanical vibration – Evaluation of machine vibration by measurements on non-rotating parts — Part 3: Industrial machines with nominal power above 15 kW and nominal speeds between 120 r/min and 15 000 r/min when measured in situ.» 
With its help, you can set the tolerance on all types of machines, taking into account the power of their electric drive. 
In addition to this universal standard, there are a number of specialized standards developed for specific types of mechanisms. For example, 
ISO 14694:2003 “Industrial fans – Specifications for balance quality and vibration levels”, 
ISO 7919-1-2002 “Vibration of machines without reciprocating motion. Measurements on rotating shafts and evaluation criteria. General guidance.»

arAR