Worm & Wheel Reduction Gear Box Project: Taper Roller Bearings- Report Writing Assignment

Internal Code: TV431

Report Writing Assignment:

Task: Speed Reduction is obtained by the action of a 'Worm' as it meshes with a "Worm Wheel" or 'Worm Gear' on which are cut teeth of involute profile. The threads on the worm are machined to the proportions of a rack so that worm and wheel engage in the manner of a spur gear and a rack. In the Gear Box, the worm has 3 threads or 'Starts' and is in effect a 3-toothed gear which engages a 39- toothed wheel so that the speed reduction is 13:1. The worm is made from Case Hardened Steel and the wheel from Phosphor Bronze, i.e. the teeth are cut on a phosphor bronze ring which is 'SHRUNK' onto a cast iron or steel hub and is further locked by a key. Bearings & mounting Both Worm and Wheel are mounted on Taper Roller Bearings. WORM - 33205 (SKF taper roller bearing) - 2 required WHEEL - 32210 (SKF taper roller bearing) - 2 required The Worm & Wheel Gear Box is as shown below: