GB150435A - Improvements in or relating to power transmission for tractors and other motor vehicles - Google Patents

Abstract

150,435. Caterpillar Tractors, Ltd., (Holt Manufacturing Co.). June 4, 1919. Change-speed and reversing gearing; compulsory differential driving and differential braking; driving external machines, adapting vehicle driving-gear for.-A transmission unit for endless-track and other motor-vehicles comprises a changespeed gear, a driving-shaft for the two driven traction members, and positive reduction gear of known worm type between the driving-shaft and the traction members whereby the relative speeds of the latter may be varied for steering. The propeller shaft 20 drives a transverse shaft 39 through two-speed and reversing gearing having independently sliding gear-wheels 31, 32 for the different speeds. The transverse shaft 39 drives the traction pinions 43 through two sets of worm gearing shown in Figs. 4 and 7. Connected to each pinion 43 by a sleeve 46 is a worm-wheel 47 engaged by two worms 48, 49 carried in bearings in a frame 51 fixed to the shaft 39, so that normally as the shaft is rotated the worm-wheels are also rotated at the same rate. The frame 51 also carries shafts 56 geared to the worm shafts 50 and having bevel-pinions 57 which gear with brake drums 61 loose on the shaft 39 and sleeves 46. Normally, the brake drums 61 rotate in unison with the shaft 39 and the sleeve 46, but when a band 62 is applied to either drum, that drum is retarded, and consequently rotates its pinions 57 and worms 48, 49, so retarding the corresponding sleeve 46 and pinion 43. The gearing is enclosed in a single casing having a part A for the change-speed gear, a part B for the reduction gear, and a third part into which the propeller shaft 20 extends to drive gearing for a power pulley.