Patent ID: 6684142
Filing Date: 2004-01-27
Classification: F16H,Y10T

Abstract:
A method for protecting a variator in a continuously variable belt-type transmission coupled to an engine of a motor vehicle, the method comprising the steps of:determining an engine torque of the engine and calculating a theoretical contact pressure of the variator based on a magnitude of the engine torque; correcting the theoretical contact pressure value using predetermined safety factors by adding the safety factors to the theoretical pressure value; measuring, simultaneously with calculating the theoretical contact pressure of the variator, an actual contact pressure of the variator via a pressure sensor to obtain a corresponding maximum permissible transmission input torque; determining an anticipated engine torque signal from a driver input and within a delay period less than a period between a change in the driver input and a corresponding change in the actual engine torque in order to calculate a corresponding anticipated theoretical contact pressure of the variator before the anticipated engine torque is imposed on the transmission; and comparing the maximum permissible transmission input torque with the anticipating engine torque to determine a differential value between the maximum permissible transmission input torque and the anticipated engine torque.