IE B007TWO REPORTS BY KhTsNTEI JSC · TREATMENT 30.11.2004 — 29.03.2005
Lift worm gearboxes: quieter, smoother and more efficient after a major overhaul
Drives of both elevators became quieter and smoother, current draw dropped. 18–23 % — drive current on all three phases, 10.4–11.0 → 8.0–9.0 A; 25–60 % — vibration displacement across housing points, 8.16–77.6 → 4.15–26.6 µm; 2.5–3 dB — gearbox noise level, 78–79.5 → 75.5–76.5 dB (2005).
lift drivesserial no. 746/2 and no. 757/1 · both after a major overhaul
with signatures and stamp
What was repeated on both gearboxes
| GEARBOX | CONDITION AT START | RUNNING TIME TO CONTROL MEASUREMENT | WHAT WAS MEASURED |
|---|---|---|---|
| Lift drive, serial no. 746/2 | After a major overhaul, in intensive service | 451 h | Current on three phases, noise level, vibration at seven points of the housing |
| Lift drive, serial no. 757/1 | After a major overhaul, in intensive service | 437 h | Current on three phases, noise level, vibration at seven points of the housing |
Drive current and gearbox noise
| PARAMETER | GEARBOX No. 746/2, BEFORE → AFTER | GEARBOX No. 757/1, BEFORE → AFTER |
|---|---|---|
| Current, phase A | 10.4 → 8.0 A · −23 % | 10.5 → 8.5 A · −19 % |
| Current, phase B | 10.8 → 8.5 A · −21 % | 10.8 → 8.9 A · −18 % |
| Current, phase C | 10.8 → 8.4 A · −22 % | 11.0 → 9.0 A · −18 % |
| Gearbox noise level | 78 → 75.5 dB | 79.5 → 76.5 dB |
Measurements taken with the lift travelling “up”: current — ATK 2200 clamp meter, noise — 00024 sound level meter.
Vibration displacement at housing points, µm
| MEASUREMENT POINT AND DIRECTION | GEARBOX No. 746/2, BEFORE → AFTER | GEARBOX No. 757/1, BEFORE → AFTER |
|---|---|---|
| Vertical, worm wheel bearing opposite the sheave | 21.7 → 15.2 | 67.2 → 26.6 |
| Vertical, worm wheel bearing away from the sheave | 20.4 → 18.1 | 71.2 → 25.0 |
| Vertical, worm bearing at the front | 14.3 → 8.2 | 77.6 → 13.8 |
| Axial, worm wheel bearing opposite the sheave | 23.3 → 17.4 | 27.5 → 26.1 |
| Axial, worm bearing at the front | 10.0 → 7.9 | 17.6 → 12.3 |
| Horizontal, worm wheel bearing opposite the sheave | 8.16 → 4.15 | 40.3 → 8.62 |
| Horizontal, worm bearing at the front | 17.9 → 12.1 | 25.9 → 12.3 |
SENDIG 911 vibrometer, seven fixed points on the housing of each gearbox. A reduction was recorded at every point on both gearboxes.
Vibration acceleration and velocity — the same seven points
| PARAMETER | GEARBOX No. 746/2, BEFORE → AFTER | GEARBOX No. 757/1, BEFORE → AFTER |
|---|---|---|
| Vibration acceleration, m/s² | 1.21–6.61 → 0.43–4.06 | 2.87–16.1 → 1.43–3.75 |
| Vibration velocity, mm/s | 0.337–0.831 → 0.115–0.492 | 0.688–1.88 → 0.358–1.18 |
The table shows the spread of values across the seven housing points of each gearbox, same SENDIG 911 vibrometer.
Conclusions of the reports
Current equivalent
- Revitalizant gel for gearboxesGearboxes · transmissions · gear drives
- Revitalizant gel for compressors and bearingsCompressors · bearings · spindles
How such units are treated:
About this result:
Limits of this report: The results relate to worm gearboxes of passenger lift drives that have undergone a major overhaul and operate under intensive service; on other units and duty modes the figures may differ. The treatment was performed by, and the measurements were attended by, a representative of the compound supplier.