Besplatan Inženjerski Alat
Kalkulator test-težine za balansiranje rotora
Calculate the recommended trial weight mass for single-plane rotor balancing using an empirical field formula. Accounts for rotor mass, speed, correction radius, support stiffness, and vibration severity — and automatically caps the result so the trial-weight centrifugal force stays below 10% of the rotor weight.
Results
Formula mase pokušajne težine
The trial weight mass is estimated using an empirical field formula (based on Vibromera balancing experience, not derived from ISO 21940) that accounts for support conditions and vibration severity:
- Mt — masa pokušajne težine (g)
- Mr — masa rotora (g) — unesite u kg, interno se pretvara u grame
- Ksupp — koeficijent krutosti oslanjanja (0,5–5,0)
- Kvib — koeficijent nivoa vibracije (0,5–3,0) — izvedeno iz izmjerene vibracije u mm/s
- Rt — radijus postavljanja pokušajne težine (cm) — unesite u mm, interno se pretvara u cm
- N — brzina rotora (RPM)
Koeficijent krutosti oslanjanja (Ksupp)
Ovaj koeficijent uzima u obzir kako struktura oslanjanja mašine utiče na odziv vibracije na neubalansiranstu:
| Ksupp | Support Type | Opis |
|---|---|---|
| 5.0 | Very rigid | Masivni betonski blok, kruta čelična konstrukcija. Vibracija se gotovo ne menja sa neubalansiranošću — potrebna heavier pokušajna težina (visok Ksupp). |
| 4.0 | Rigid | Betonski temelj, kruta postolja. Tipično za velike pumpe i kompresore. |
| 2.0–3.0 | Medium | Standardna industrijska montaža, osnovna ploča na betonu. Najčešća situacija za ventilatore, motore i opštu mašineriju. |
| 1.0 | Flexible | Montaža sa oprugama, gumeni izolatori. Mašina slobodno vibrira — lighter dovoljno je pokušajne težine (nizak Ksupp). |
| 0.5 | Very flexible | Suspenzivna montaža, mekani izolatori, uravnotežavajući nosač/kolica. Maksimalan odziv vibracije — najlakša pokušajna težina. |
Rule of thumb: Rigid supports (Ksupp = 4–5) “absorb” vibration, so you need a heavier trial weight to produce a measurable change. Flexible supports (Ksupp = 0.5–1) amplify the response, so a lighter trial weight works.
Koeficijent nivoa vibracije (Kvib)
Ovaj koeficijent odražava trenutnu ozbiljnost vibracije mašine prije balansiranja:
| Kvib | Nivo Vibracija | Condition |
|---|---|---|
| 0.5 | Dobar (≤ 1 mm/s) | Veoma glatko pokretanje. Koristite laku probnu težinu kako bi se već nizak signal vibracije ne preplavio. |
| 0.8 | Dobar (1–2 mm/s) | Glatko pokretanje. Samo fino usklađivanje. Laka probna težina. |
| 1.0 | Prihvatljiv (2–3 mm/s) | Primetna ali prihvatljiva vibracija. Standardan posao balansiranja. |
| 1.2 | Prihvatljiv (3–4,5 mm/s) | Umjerena nebalansiranost. Tipičan scenarij na terenu. |
| 1.5 | Povećan / Visok (4,5–11 mm/s) | Jasna, značajna nebalansiranost. Najčešće slučaj polnog balansiranja — zadana oblast. |
| 2.0 | Opasno (11–18 mm/s) | Velika nebalansiranost, hitno balansiranje. Teža probna težina je u redu — vibracija je već visoka. |
| 2.5 | Opasno (18–28 mm/s) | Ozbiljna nebalansiranost. Teža probna težina je prihvatljiva kako bi se osigurala merljiva promena vektora. |
| 3.0 | Ekstremno (> 28 mm/s) | Ekstremna vibracija. Pregledajte mašinu prije balansiranja; najpešća grupa probne težine. |
Zašto ova formula radi
The formula Mt = Mr × Ksupp × Kvib / (Rt × (N/100)²) captures the key physics:
- Heavier rotors potrebne veće probne težine (linearno sa Mr)
- Higher speeds generiše veću centrifugalnu silu po gramu, pa je manja pokušajna masa potrebna (inverzni kvadrat od N)
- Larger radius znači veći moment po gramu, pa je manja masa potrebna (inverzno od Rt)
- Čvršće podloge potrebna veća masa da bi se proizvela detektabilna promjena vibracije (viši Ksupp = 4–5)
- Fleksibilne podloge pojačavaju odziv, pa je manja masa potrebna (niži Ksupp = 0,5–1)
- Viša postojeća vibracija znači veću postojeću neubalansenost — proporcionalno veću pokušajnu masu (viši Kvib)
Centrifugal Force Safety Cap
The empirical formula alone can suggest a mass that is unsafe at speed — especially with high Ksupp and Kvib values. That is why the calculator always checks the centrifugal force the trial weight would generate:
- F — centrifugal force of the trial weight (N)
- m — trial weight mass (kg)
- r — installation radius (m)
- ω — angular speed (rad/s), N in RPM
A widely used field-balancing guideline is that this force should not exceed about 10% of the rotor weight (W = Mr × 9.81 N). If the empirical formula suggests a heavier mass, the calculator automatically limits the recommended trial weight to the 10%-of-rotor-weight force level and shows a warning. The centrifugal force of the recommended weight (in newtons and as a percentage of rotor weight) is always displayed in the results.
Praktični primjer
Given: Mr = 111 kg = 111,000 g, N = 1111 RPM, Rt = 111 mm = 11.1 cm, Ksupp = 1.0, Vibration = 11 mm/s → Kvib = 1.5
Step 1: Speed factor: (N/100)² = (1111/100)² = 11.11² = 123.43
Step 2: Denominator: Rt(cm) × (N/100)² = 11.1 × 123.43 = 1,370.1
Step 3: Numerator: Mr(g) × Ksupp × Kvib = 111,000 × 1.0 × 1.5 = 166,500
Step 4: Empirical estimate: Mt = 166,500 / 1,370.1 = 121.5 g
Step 5 — force check: ω = 2π × 1111 / 60 ≈ 116.34 rad/s. For 121.5 g at 0.111 m: F = 0.1215 × 0.111 × 116.34² ≈ 182.6 N — that is ≈ 16.8% of the rotor weight (111 × 9.81 ≈ 1,089 N), above the 10% guideline.
Step 6 — safety cap: Mt(max) = 0.10 × 1,089 / (0.111 × 116.34²) ≈ 0.0725 kg = 72.5 g
Result: Koristite približno 72 g trial weight at 111 mm radius (capped by the 10% force limit; the raw empirical estimate of 121.5 g would create excessive centrifugal force).
⚠️ Napomena o sigurnosti: An excessively heavy trial weight can cause dangerously high vibration. The goal of the trial run is a measurable but safe response — typically a 20–30% change in vibration amplitude or a 20–30° phase shift. Keep the trial-weight centrifugal force below about 10% of the rotor weight (this calculator enforces that limit automatically). If in doubt, start with half the calculated weight and increase gradually. Always ensure the trial weight is securely attached and cannot detach during rotation.
Usporedba s ISO 21940 metodom
The classic ISO approach uses balance grade G to calculate permissible unbalance, then takes 5–10% of it (divided by the correction radius) as trial weight. This Vibromera formula is an empirical field shortcut, not an ISO-derived equation; it gives comparable results while directly accounting for real-world conditions (support stiffness and current vibration level) that the ISO method assumes are ideal. The added centrifugal-force cap keeps its recommendations within safe limits even when the machine is already vibrating heavily.
Profesionalni instrumenti i softver za balansiranje na terenu. Postignite usklađenost s ISO 21940-11 na mjestu s Balanset serijom uređaja. Korišteno u više od 50 zemalja.
