GB750788A - Improved variable speed power transmission mechanism for motor vehicles - Google Patents

Abstract

750,788. Variable speed gear. GENERAL MOTORS CORPORATION. Dec. 15, 1954 [Jan. 13, 1954], No. 36336/54. Class 80(2) [Also in Groups XXIX and XXXI] A variable-speed power transmission for vehicles comprises a hydrodynamic torque converter including a reactor R having angularly adjustable blades 47 under the control of a device responsive to the operation of the accelerator pedal. An impeller P is fixed to a driving shaft 11, a first turbine T1 is connected to an internal gear 31, a second turbine T2 is fixed to a planet carrier 38 which is splined to the output shaft 15, and the reactor R is mounted on a shaft 19 by a one-way detent 49. The remaining element of the gear train is a sun gear 34 mounted on the shaft 19 by a one-way detent 36. Each blade 47 of the reactor R is secured to a shaft 51 having a crank arm 61 operatively connected to a piston 57. Liquid is supplied to the left hand side of the piston from a gear pump 24, driven by the impeller, through a passage 73<SP>1</SP>, a valve 81 and passages 73, 74, 72. The right hand side of the piston 57 communicates with the working chamber of the torque converter which is supplied by the pump 24 through a pressure reducing valve 100. Depression of the engine accelerator pedal 93 beyond a predetermined point depresses the valve 81 to connect the, passage 73 to exhaust. The piston 57 then moves to the left and the reactor blades are rocked to a high angle position, shown in dotted lines in Fig. 6, in which maximum'torque multiplication is obtained. The blades are prevented from assuming the high angle position at high vehicle speeds by a speed responsive lock-out mechanism (not shown) which closes the passage 73. In the raised position of the valve 81 the differential pressure on the piston 57 shifts the latter to rock the blades 47 to the low angle position, shown in full lines to obtain maximum coupling efficiency.