LiftEquip TW160, Operating Manual

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Operating manual Servicing and Maintenance
TW160 drive
TK Aufzugswerke
71
Version 08/2021
8.4 Checking the backlash
If the running performance deteriorates, this might have been caused by excessive
backlash in the worm gear toothing.
Wear on the worm wheel gear teeth changes the existing tooth thickness and this can
be determined using the following measurement of the backlash.
WARNING
Deformation and/or breakage of the teeth on the worm wheel or
worm shaft due to excessive backlash.
The braking effect deteriorates.

Measure the backlash at least every 3 years and/or if running
performance deteriorates (noises, jolting, etc.)

When a wear limit value (backlash) of 1.5 mm is reached, the gear
drive must be replaced.
Measurement possibility:
1. Take load off the ropes: move the counterweight onto the buffers and lift the
elevator car with lifting gear.

The traction sheave must be free to move.
2. Run the measuring operation with the operational brake closed.
3. Release the emergency brake, if present.
4. Fit a measuring attachment to the traction sheave; e.g. screw clamp.
5. Specify the measured radius (M).
6. Mark the measuring point.
The radius (r) for the TW160 = 186 mm.
7. Attach a dial gauge with magnet stator at the gear drive housing and align to
the measuring point (M).
8. Turn the traction sheave by hand until the dial gauge pointer moves.
9. Move the traction sheave back and forth until resistance is felt in both
directions.
10. Read off the movement of the dial gauge.
11. Use the formula below to calculate the backlash.