Patent GB-712290-A (GB)
Title: Improvements in or relating to hydraulic power transmissions
IPC: F16H61/62
Filed: 1949-07-21
Abstract: 712,290. Torque converters. SVENSKA ROTOR MASKINER AKTIEBOLAG. July 21, 1949 [July 22, 1948], No. 31835/52. Divided out of 712,231. Class 69 (2) Relates to hydraulic power transmissions embodying a variable speed torque converter producing an increase in the applied torque, the converter having a liquid filled chamber 16 containing impeller, turbine and reaction blades : as shown, the impeller blades 18 are on a rotary casing 12 providing the chamber 16, the turbine blades 28, 32 are supported by a disc 26 secured to a turbine shaft 20 and the reaction blades 34 are carried by a disc 36 mounted on a sleeve 40 surrounding the turbine shaft 20. According to the invention, the converter is constructed for alternative operation as a single rotation or double rotation converter and comprises a rotatably mounted reaction member, releasable means for holding the reaction member rotationally stationary and to release it for rotation in either direction, fluid pressure actuated means for engaging the braking means and including a control valve and means responsive to predetermined variations in the speed ratio between the driving and driven members for moving the valve to effect engagement or release of the braking means. The sleeve portion 40 of the reaction member 36 has a sun gear 110 having planets 112 on a carrier 114 meshing with a ring gear 116 on the turbine shaft 20. An overrunning clutch 118 between a part 10a of the stationary casing 10 of the rotary casing 12, and the carrier 114 permits the latter to rotate freely in the same direction as the pump and prevents its rotation in the counter-direction. A fluid actuated brake 120 having plates splined on the reaction sleeve 40 and the stationary housing part 10a has an operating member 122. Supply of liquid to the brake is controlled by a master valve 94, Fig. 3, via conduits 146, 148 through an automatic shift valve or ratio regulator 124. The latter comprises a valve rod 130 having a recessed portion 138, one end being threaded at 136 in a gear 126 interposed between the pump driving gear 86, Fig. 1, on the rotating casing 12 and the pump gear 88, the other end being connected by spring-loaded friction plates 132 to a gear 128 meshing with teeth 62 on the turbine shaft 20. At starting, the stationary turbine shaft 20 holds the gear 128 so that the plates 132 keep the valve rod 130 from turning while the gear 126 is rotated by the rotating casing, consequently the rod is forced towards the gear 128 until arrested by the collar 130a engaging the housing, and pressure liquid is cut off from the brake 120. As the shaft 20 begins to rotate with increasing speed, the gear 128 rotates until it coincides with the rotation of the gear 126. During this period, the brake is disengaged so that the converter operates as a double rotation converter, the reaction blades 34 rotating counter to the pump and constituting counter rotating turbine blades delivering power through reversing gearing to the output shaft 64. As the speed of the turbine shaft further increases, the speed of the gear 128 will exceed that of the gear 126 and the valve rod 130 will be moved to its opposite limit position in which it places the member 122 in communication with the conduit 146 for engagement of the brake, thus locking the reaction member to the stationary housing and the converter then operates as a single rotation converter with stationary reaction blades. The master valve 94 has a vent port 170 communicating with the conduit 146 when the valve is in the direct drive position so that the brake 120 is automatically disengaged when direct drive is established, regardless of the position of the valve 124. Since under direct drive, the pump and turbine members rotate forwardly at the same speed, the planet carrier must also rotate with them and this is permitted by the overrunning clutch 118.