Patent ID: 6179739
Filing Date: 2001-01-30
Classification: B60W,F16H

Abstract:
A continuously variable transmission for transferring drive from an engine to a device to be driven, said transmission comprising a primary pulley for receiving drive from an engine, a belt, a secondary pulley which is coupled over said belt to the primary pulley for transferring drive to a device to be driven that exerts a load on said transmission, said primary an secondary pulleys each having an axially movable sheave and a hydraulically operated actuator therefor to effect ration change of the transmission and to maintain belt tension, a hydraulic pressure control loop for controlling the hydraulic pressure applied to the actuator of said secondary pulley as a function of the load of said device to be driven on said transmission and the pitch radius of the secondary pulley, an output speed control loop for controlling the hydraulic pressure applied to the actuator of said primary pulley and thereby the output speed of said transmission driving said device to be driven, and a torque lagging apparatus in the transmission between the secondary pulley and the device to be driven to insert a lag in the load torque transmission to allow the control loops time to respond to a sudden increase in load torque of said device to be driven on said transmission for preventing transmission belt slippage.