GB729094A - Improvements in or relating to variable speed transmissions - Google Patents

Abstract

729,094. Change-speed gear. BORGWARNER CORPORATION. March 10, 1953 [March 13, 1952], No. 6561/53. Class 80 (2). Three forward ratios comprising hydraulic low, all mechanical second and hydromechanical split-torque one-to-one high, and hydraulic reverse are provided by two planet trains 47, 48, the former acting alone for all forward ratios and compounding with the latter for reverse, a final output shaft 11 being permanently fast with a rear planet-carrier 58 and connected front ring 51, and the remaining connections being as specified in the following. Low ratio (2.428) is by engaging a friction clutch 15 to drive from an input 10 through a hydraulic torque-converter 14 of the overrun-reactor type, a sleeve shaft 18, the friction clutch 15 and an additional shaft 17 to a front sun 49. With a band-brake 21 applied to the front planet carrier 52, a simple countershaft reduced drive is transmitted to the output ring 51 through intermeshed planets 53, 54. Second ratio (1.700) is by releasing the clutch 15 and brake 21, and engaging only a front clutch 13 to drive through an innermost intermediate shaft 16 the front planet-carrier 52. With the front sun 49 reacting on a one-way detent 19, drive is transmitted mechanically to the output ring 51 by the intermeshed planets. For the one-to-one split-torque high ratio, the clutch 15 is engaged additionally to 13, whereupon the detent 19 overruns, the mechanically driven planet-carrier 52 transmits 59 per cent of the power and the hydraulically driven sun 49 the remaining 41 per cent. For reverse (2.469), the clutch 15 is engaged and a rear brake 22 applied to a freely mounted rear ring 57. The hydraulic drive to the front sun 49 is then compounded in the two trains and issues at the rear planet carrier 58. The clutches and brakes are hydraulically engaged by pressure supplied by input and output pumps 68, 70, which also lubricate the gear.