Patent GB-1008674-A (GB)
Title: Hydrodynamic torque converters
IPC: F16H61/58
Filed: 1964-10-27
Abstract: 1,008,674. Hydraulic torque converters; change-speed control; reverse gearing; disc brakes. FORD MOTOR CO. Ltd. Oct. 27, 1964 [Dec. 30, 1963], No. 43749/64. Headings F2C, F2D and F2E. To reduce power losses when a multi-turbined hydrodynamic torque converter is operated at medium and high speeds, an hydraulically controlled friction clutch 90, 92, Fig. 1, between first and second turbines 52, 70, is disengaged. The torque converter comprises an impeller 24 fast with the crank-shaft 10 of a motor car &c. engine, the first turbine 52 journalled by a hub 64 on the end of a driven shaft 84, a first reactor 112 carried by a one-way brake 128, the second turbine 70 fast with the driven shaft, a second reactor 160 mounted through a oneway brake 172 upon a fixed tube 98, a third turbine 150 secured by a connector 158 to the second turbine 70, and a third reactor 134 mounted through a one-way brake 144 upon the fixed tube 98. The one-way brake 128 mounts the first reactor 112 upon the periphery of the third reactor 134. Oil is fed into the torque converter working space from an input driven pump 44 through a space between the tube 98 and a short shaft 28 rotating with the impeller 24. On starting from rest, the three reactors 112, 134, 160 are held by their one-way brakes. Oil circulates in the working space of the converter, and is returned to sump through the space between the shrouds 60, 72 of the first and second turbines, these shrouds also carrying the frusto-conical friction clutch members 90, 92. The pressure drop as the oil passes between the friction clutch members 90, 92 enables the higher pressure within the converter working space to overcome the natural resilience of the turbine shrouds 60, 72 and engage the friction clutch members. The first and second turbines 52, 70 thus rotate together. With increasing speed, the first reactor 112 begins to turn forwardly. The exit blade angle of the first turbine 52 does not now match the entry blade angle of the second turbine 70, and power losses result. To reduce these power losses, oil pressure is applied through a space between the driven shaft 84 and the fixed tube 98 to holes 108, and thence through holes 88 in the hub of the second turbine to radial holes 86 in a thrust washer the radial holes leading into the space between the two shrouds 60, 72. The pressure of the oil in the converter working space is then counterbalanced, and the clutch 90, 92 is disengaged. With further increasing speed the second reactor 160 and later the third reactor 134 rotate forwardly, the converter then acting as a coupling. The clutch 90, 92 is maintained disengaged throughout the higher speed range. In a modified construction, Fig. 4 (not shown), an additional clutch is provided between the impeller 24 and the first reactor 112, for engagement when the latter rotates forwardly, to obtain greater efficiency when the converter is operated at speed. Control.-The clutch 90, 92 is controlled by an output-speed responsive governor 304, Fig. 3, supplying pressure through a pipe 296 to a signal valve and working in opposition to carengine inlet - manifold - depression modulated (TV) pressure in a pipe 294. The signal valve either connects the pump P (44) to a pipe 286 leading to a shift valve 278, or vents the pipe 286 to sump. When the pipe 286 is connected to the pump P, the shift valve 278 is slidden against spring bias to connect a pipe 284, fed with regulated main pressure, to a pipe 276, and thence to the space between the shrouds 60, 72 for disengagement of the clutch 90, 92. When the pipe 286 is connected to sump, the shift valve 278 vents the pipe 276 also to sump, and the friction clutch 90, 92 is engaged, as described above. The pump P supplies a main pressure regulator 260 feeding valves 264 controlling a forward-reverse planetary gear (described below), and also a pressure regulator valve 266 feeding a pipe 270 (which is in part the space between the shaft 28, Fig. 1, and the tube 98) leading to the converter working space. From a shaft bore 272, oil is returned through a cooler 274 to sump. Reverse gear; disc brakes.-The driven shaft 84, Fig. 1A, of the converter is integral with a sun-gear 182 meshing planet pinions 184 journalled in a carrier 186. The planet pinions 184 mesh a ring gear 178 fast with an output shaft 190. Forward drive is established by hydraulic engagement of a multi-disc friction clutch 212 between the sun-gear 182 and the planet carrier 186. Reverse is established by engagement of a multi-disc brake 240 between a clutch sleeve 210 fast for rotation with the planet carrier 186 and a fixed housing 96. Brake engagement is effected when oil under pressure is admitted through a passage 254 in the fixed housing 96 to a short duct 252 in the hub of a ring-shaped piston 244, and thence into a servo space 242. The pressure in the servo space 242 slides the piston 244 rightwards of Fig. 1A, against the bias of brakedisengaging springs 246.