ISO 1328-1:2013 defines the ISO flank tolerance classification system for cylindrical gears. Eleven flank tolerance classes are defined, numbered 1 (highest precision) to 11 (lowest). It specifies tolerances for pitch, profile, and helix deviations.

Anong quality class ang kailangan ko?

Class 5-6: precision gearing (machine tools, instruments). Class 6-7: general engineering. Class 8-9: heavy machinery. Class 10-11: rough gearing. Most industrial gearboxes use class 6-8.

Ano ang total pitch deviation (Fp)?

Ang Fp ay ang pinakamataas na pagkakaiba sa pagitan ng aktwal at teoretikal na cumulative pitch sa lahat ng ngipin. Sumasalamin ito sa spacing accuracy ng lahat ng ngipin sa paligid ng gear. Sinusukat gamit ang mga gear measuring machine.

Ano ang profile deviation?

Sinusukat ng profile deviation kung paano naiiba ang aktwal na tooth profile mula sa teoretikal na involute. Kasama dito ang total profile deviation (Fα), profile form deviation (ffα), at profile slope deviation (fHα).

Paano kinakalkula ang mga ISO 1328 tolerance?

Tolerances are calculated with the formulae of ISO 1328-1:2013, clause 5.3, from normal module (mn), reference diameter (d), and facewidth (b). Values are computed for class 5 and scaled by a step factor of √2 per class, so tolerances double every two classes.

Libreng Engineering Tool #095

Gear Accuracy Class Calculator

Mga ISO 1328-1 gear accuracy tolerance. Ilagay ang module, pitch diameter, face width, at quality class upang hanapin ang pitch deviation, profile deviation, at helix deviation tolerance.

ISO 1328-1Classes 1–11Tolerances

Results

Quality Class

—

Total Pitch Deviation F_p

—

Single Pitch Deviation f_pt

—

Total Profile Deviation F_α

—

Total Helix Deviation F_β

—

ISO 1328-1:2013 Tolerance Formulas

Where A is the flank tolerance class (1–11), m_n is the normal module, d the reference diameter and b the facewidth, in mm. Tolerances are calculated for class 5 and scaled by the step factor √2 per class (2^0.5(A−5)), so values double every two classes. Total profile tolerance F_αT and total helix tolerance F_βT are the root-sum-squares of the corresponding slope and form tolerances (clause 5.3). The formulae apply within 5 ≤ z ≤ 1 000, 5 mm ≤ d ≤ 15 000 mm, 0.5 mm ≤ m_n ≤ 70 mm, 4 mm ≤ b ≤ 1 200 mm.

Quality Class Application Guide

Class	Application	Typical Tolerance Scale
3–4	Master gears, measuring instruments	Finest
5–6	Machine tools, precision gearboxes, turbine gears	Precision
7–8	General industrial gearboxes, vehicle transmissions	Standard
9–10	Mabibigat na makinarya, pagmimina, semento	Coarse
11	Rough gearing, agricultural, slow speed	Very coarse