Hydraulic emergency control for transmission ratio-dependent variation of the hydraulic oil pressure in the hydraulic conical pulley axial adjustment mechanisms of a continuously variable transmission

摘要

PCT No. PCT/EP96/01947 Sec. 371 Date Nov. 4, 1997 Sec. 102(e) Date Nov. 4, 1997 PCT Filed May 9, 1996 PCT Pub. No. WO96/37717 PCT Pub. Date Nov. 28, 1996A hydraulic emergency control system for a continuous looped gear type continuously variable transmission (10) includes first and second hydraulic beveled conical pulley axial actuators controlling a gear ratio. A pump supplies a first piston chamber (13) of said first axial actuator via a sensor valve (20), wherein the sensor valve (20) is controlled by a flow control valve (73) connected downstream of the pump (80). The pump (80) supplies a second piston chamber (17) of the second axial actuator, with a pressure relief valve (40) limiting fluid pressure in said second piston chamber. Fluid in the second piston chamber (17) is controlled as a function of the fluid pressure in the first piston chamber (13) via a control line (52, 113).