SYSTEM FOR ACTUATING THE DISPLACEABLE PULLEY IN A CONTINUALLY VARIABLE TRANSMISSION

摘要

In a belt driven continually variable transmission, the drive ratio is changed by varying the radial position of the drive belt by moving displaceable sheaves (52, 78) of a pulley assembly. A system for actuating the displaceable sheaves includes a ratio control valve (320) supplied with pressurized fluid and connected to a source of ratio control pressure produced by a solenoid actuated valve (308). An orifice (330) located between the ratio control valve (320) and the hydraulic cylinder in which the displaceable sheave (52) is located has a feedback line (334) located on opposite sides of the orifice. Pressure in the feedback lines produces a differential force on the ratio control valve (320) tending to increase the flow rate to the cylinder when the pressure drop across the orifice decreases.