GB428605A - Improvements in or relating to controlling hydraulic gears - Google Patents

Abstract

428,605. Hydraulic transmission of power. VOITH, W., VOITH, H., and VOITH, H., (trading as VOITH, J. M., [Firm of]), Heidenheim, Brenz, W³rtemberg, Germany. Oct. 11, 1933, No. 28107. Convention date, Jan. 30. [A Specification was laid open to inspection under Sect. 91 of the Acts, April 12, 1934.] [Class 69 (ii)] A hydraulic change-speed gear of the Fottinger type consisting of a hydraulic slipping clutch and one or more hydraulic torque transformers which are put into and out of operation by controlling the flow of liquid to the gear has its control pump in coupling operation run at a substantially lower speed than in transformer operation. In the form shown a motor M drives a hydraulic clutch K and a transformer U. The operating liquid is supplied from a reservoir B by a pump C through a two-way cock f to the gear from which it returns through a pipe a and a cooling device to the reservoir. The cock f is moved by a lever g connected to a servomotor piston h which is actuated by the control pump pressure. When the driven shaft is stationary the gear W is emptied of liquid and the control pump piping is without pressure and the servomotor piston being pressed over to the left by a spring i, opens the cock f to the coupling K. The motor M on being started revolves at noload speed until a switch d, which controls the circuit of an electric motor D driving the pump, is moved out of zero position thus starting the pump and developing a high pressure in the liquid pipe. The piston h moves to the right opening the cock f to the transformer position. The transformer is thus brought into operation and after sufficient speed has developed for a transfer to coupling operation the switch d is moved into position for a lower speed of the control pump : the pressure in the pipes then falls, and the piston h moves the cock f into position to supply the coupling K. When used on an automobile, switches k and m actuated by the accelerator and brake levers l, n, may be arranged in series with the switch d. The Specification as open to inspection under Sect. 91 comprises also arrangements of the gear and the reservoir to which the highest surface level of the liquid in the reservoir is below the lowest point of the revolving parts of the gear and the control pump is arranged at the lowest point of and preferably inside the reservoir : the highest points of the reservoir and the gear casing are connected by an air pipe to equalize air pressures : the control pump is driven from the primary shaft. This subject-matter does not appear in the Specification as accepted.