Patent GB-700443-A (GB)
Title: Improvements in hydraulic power transmission devices
IPC: F16H61/62
Filed: 1948-05-25
Abstract: 700,443. Torque converters. SVENSKA ROTOR MASKINER AKTIEBOLAG, and AHLEN, K. G. May 25, 1948, No. 8089/52. Divided out of and addition to 700,342, under which a Specification was laid open to inspection under Sect. 91 of the Acts, Nov. 29, 1948. Class 69 (2) In a hydraulic torque converter consisting of a primary (pump) member, a secondary (turbine) member having two or three stages, and a guide blade (reaction) member having one or two stages with the guide blades operating under some conditions as turbine members rotating in a direction opposite to that of the pump, the blade ring or rings of the guide blade member are arranged wholly in that part of the hydraulic circuit which is inwardly directed. The driving shaft 10 and flywheel 12 drive the pump 24 having blading 28 and an extension 122 carrying discs 270 of a liquid-actuated friction clutch 250 ; the two-stage turbine 42 having blades 34, 36, is attached to the driven shaft 44 carrying a gear wheel 368 of a reversing gear, and the guide member 50 having blades 46 located in the inwardly directed port of the hydraulic circuit 56 has a shaft 48 with an extension 62 mounted on a free-wheel 110 which prevents the guide member from rotating faster than the turbine shaft 44 when the guide and turbine members rotate in the same direction. The extension 62 has a member 252 carrying friction discs 254, a wall 256, a plunger 258 and a valve 350, and is surrounded by a brake band 360 secured to the stationary housing 16a and operated by a servomotor 362. The reversing gear comprises the gear wheel 368, a toothed rim 366 on the extension 62, and gear wheels 370 supported on a ring 376 mounted on the stationary housing by a free-wheel 378 which prevents the ring from rotating opposite to the pump but leaves it free to rotate in the same direction. Liquid to operate the clutch 250 is admitted by the valve 350 from a bore 266 by moving a ring 356 through a lever 354 actuated by a servomotor 352. A pump 380 driven from the extension 122 delivers liquid to a bore 392 communicating via a valve 396 with the servomotors 352, 361, and (preferably with intermediate cooling) to a bore 394 leading to the bore 266 and also via passages 78 and 88 into the hydraulic circuit, excess pressure being exhausted by a relief valve 98. The position of the valve 396 may be controlled automatically from the guide member or manually or by a separate device. With the valve in position a the servomotors 352 and 362 are open to exhaust, disengaging clutch 250 and brake 360 so that the guide member 50 is connected to the turbine shaft 44 by the reversing gear, the blades 46 rotating oppositely to the pump 24 and turbine blades 34, 36; and hence at starting when the speed of the output shaft 44 is much lower than the speed of the input shaft 10, the secondary member of the converter operates as a turbine having a double rotation system, the torque from the guide member being transmitted to the turbine shaft. As the output speed increases the efficiency reaches its peak and the valve 396 is moved to position b in which the servomotor 352 remains open to exhaust but liquid from the bore 392 enters the servomotor 362 via a channel 402 and the brake 360 is applied to lock the guide member to the stationary housing, the secondary member then operating as a turbine having a single rotation svstem, i.e. the converter then orerates as a normal twostage turbine type, with the reversing gear released from the free-wheel 378 and rotating without transmitting any torque. When neak efficiency has been reached under this condition, the valve 396 is moved to position c in which the servomotor 362 is again onen to exhaust, thereby releasing the brake 360, but liquid is admitted to the servomotor 352 which shifts the valve 350 to admit liquid to engage the clutch 250. The guide member is thus connected to the pumn, hence the guide member and. due to the free wheel 110, also the turbine member. rotate with the numn and direct drive is established. In a modification the reversing gear comprises planet gears meshing with a toothed rim formed on the member 252 and supported on the stationary housing 16b, with a sun wheel mounted on a free-wheel on the turbine shaft. Specification 700,342 is referred to.