Patent GB-919456-A (GB)
Title: Variable-speed transmission
IPC: F16H47/08
Filed: 1961-06-28
Abstract: 919,456. Hydro-mechanical variable-speed gear and control. GENERAL MOTORS CORPORATION. June 28, 1961 [July 18, 1960], No. 23389/61. Class 80 (2). A combined hydrodynamic torque converter and planetary gear for motor vehicles comprises a first planet set having a carrier 48 splined on an output shaft 51, a sun 46 connected to a turbine 33, and a ring 52, a second planet set having a carrier 64 connected to the first set ring 52, a sun 61 connected to an engine-driven impeller 21, and a ring 66, and a reverse planet set having a carrier 89 also splined on the output shaft 51, a sun 87 connected to the first set ring 52, and a ring 91; the first, set ring 52 being friction braked at 53 for low gear by way of a series drive through the converter and the reducing first set, the second set ring 66 being friction braked at 67 for split-torque intermediate gear (60% hydrodynamic, 40% mechanical) by way. of parallel drives through the converter and through the reducing second set to the torque-combining first set, the sun 61 being friction clutched to the carrier 64 at 78 for split-torque high gear (33% hydrodynamic, 67% mechanical) by way of parallel drives through the converter and through the locked -up second set to the torque. combining first set, and the ring 91 being friction braked at 92 for reverse. The brakes and clutch are fluid pressure engaged, the brakes being actuated through Belleville spring levers and the clutch being spring-released. The impeller is connected to the sun 61 through springs 41<SP>1</SP>, streamlined spokes 45<SP>1</SP> and a sleeve 49 journalled on an intermediate shaft 38 connecting the turbine and the sun 46. The converter reactor 32 reacts to the casing 12 through a one-way detent 31. The control system which is manual-hydraulic comprises parallel front and rear pumps 24, 101 respectively driven by the impeller 21 and the output shaft 51, drawing from a sump 106 through a filter 108 by-passed in the event of blockage through a valve 112, and feeding a regulator valve 122 to a main line 121 respectively through a line 116, and a one-way valve 117 and a line 118. The regulator valve comprises a three-land plunger subjected, at its reduced diameter end 129 through a check valve 131 having a return flow orifice, to main line pressure to oppose the bias of a spring 126. The regulator valve first regulates main line pressure and then torque converter pressure in a line 134, to the same value. Exhaust oil from the converter passes through a cooler 137 to a lubrication line 138 having a relief valve 139. A manual distributor valve 146 comprises a bored, three-land plunger 162 which is positioned by spring and ball means 161, blocks throughflow in neutral, and selectively connects main line 121 pressure to lines 159, 158, 157 and 156 for engagement of clutch 78 (high) and brakes 67 (intermediate), 53 (low), and 92 (reverse) respectively. In intermediate and high the valve 146 also connects the main line 121 through a line 133 to the annular face between a land c and the reduced end 129 to reduce main line pressure. Spring-loaded check valves 171, 166 in the low and intermediate lines 157, 158 have orifices 174, 169 to restrict exhaust and thereby retard brake release.