EN
Core Selling Points
· Module 8, 20 deg - meshes with standard hoist racks.
· Safety device pinions in the common 15-tooth form; 12-tooth versions to order.
· Drive pinions with bore, keyway or spline to the reducer output shaft.
· Alloy steel with hardened teeth for high contact stress and shock.
Application Scenarios
· Drive units of construction hoists (two or three drive sets per cage)
· Progressive safety devices (anti-fall devices)
· Industrial rack hoists and lifting platforms
Module 8 pinion meshing with a hoist rack
A rack hoist cage normally carries two or three identical drive units - motor, coupling, reducer and pinion - plus a separate safety device with its own pinion. All of them run on the same module 8 rack. The pinions are the fastest-wearing part of the drive, because each pinion tooth meshes once per revolution while each rack tooth meshes only when the cage passes it.
With 15 teeth and module 8, the pitch diameter is 15 x 8 = 120 mm and the pinion travels 15 x pi x 8 = 377 mm along the rack per revolution. At a lifting speed of 40 m/min, a 15-tooth pinion turns at 40 000 / 377 = 106 rpm. This is the relationship to check when a gearbox ratio or pinion tooth count is changed.
Pinion wear is measured as the common normal length over a set number of teeth with a disc micrometer, and compared with the limit in the hoist manual. We supply new pinions with the measured common normal length recorded, so the site team has a baseline.
| Item | Value |
| Module / pressure angle | 8 / 20 deg |
| Safety device pinion teeth | 15 (12 to order) |
| Drive pinion teeth | To gearbox drawing |
| Pitch diameter, 15 teeth | 120 mm |
| Travel per revolution, 15 teeth | 377 mm |
| Material | 20CrMnTi / 42CrMo / 40Cr (to drawing) |
| Heat treatment | Carburised and hardened, or induction hardened |
| Bore | Plain with keyway, spline, or to drawing |
Travel per revolution and tangential force against pinion tooth count
Ordering Notes
· Give module, tooth count, face width, bore or spline data, and the hoist or safety device model plate data.
· Replace pinions in matched sets on multi-drive cages so the drives share load.
· Safety device pinions are part of a certified device: replace them through the device maker's procedure.
· Common normal length recorded on each pinion.
· Spline and bore machined after heat treatment where specified.
· Matching module 8 racks available.
Applicable Industries
Construction hoists, industrial lifts, mast climbing platforms, hoist service and rental companies.
For drawings, samples or a quotation, send us your rack, pinion or gear specification and quantity.
