GB885354A - Improved variable-speed power transmission mechanism - Google Patents

Abstract

885,354. Variable-speed gear. GENERAL MOTORS CORPORATION. June 3, 1960 [June 10, 1959], No. 19697/60. Addition to 838,186. Class 80 (2). The variable-speed gear of the parent Specification, comprising first and second turbines 14, 15, Fig. 1, of a hydrodynamic torque converter connected respectively to an outputmounted planet carrier and to a ring gear 29 of planetary gearing having also a sun-gear 28 connected to an input 10 and to the impeller 12, the blade angles (all specified) being such that, with increasing output speed, the torque delivered by the first turbine 14 reduces from a maximum value at stall while that of the second turbine 15 increases, is modified by the provision of additional gearing between the torque converter and the planetary gearing to approximately equalize the speeds of rotation of the two turbines. In one form, the second turbine 15 is fast with a planet carrier 32 upon which are supported planet pinions 33 meshing a reaction sun gear 34 fast upon a casing mounted sleeve 21 also supporting one-way detents 19 on which reactors 17, 18 are carried in the torque converter, the planet pinions also meshing with an extension 30 of the ring gear 29. In this construction, the additional gearing gives a step-up drive. A direct-drive clutch 36 can be engaged between the impeller 12 and the output-shaft-mounted first turbine 14. In a modification in which the additional gearing gives a step-down ratio, a first turbine 54, Fig. 2, is fast with a gear 73 meshing a gear 74 carried by a ratchet clutch 75 on a countershaft 76 driving through a step-down gear train 82, 81 to a final driven shaft 79, a second turbine 55 driving through a sun-planet ring train 65, 66 to a gear 77 meshing a further gear 78 also fast on the countershaft 76. Performance curves are given.