Patent ID: 6875139
Filing Date: 2005-04-05
Classification: F15B,F16D,F16H,Y10T

Abstract:
1. A continuously variable, belt-driven, conical pulley transmission, said transmission comprising: a pair of conical disks; an endless, torque-transmitting member positioned between and in contact with the conical disks in torque-transmitting relationship; and a control system for a working medium pressure for hydraulically controlling a contact pressure of a movable conical disk against the endless torque-transmitting member of the transmission, said control system including one of a pressure control valve and a pressure reduction valve that is operatively connected with the movable conical disk and is controlled via a control means by a control variable in order to adjust a working medium pressure acting on the movable conical disk within a nominal pressure range and a maximum pressure range, wherein the maximum pressure range is between a system pressure value and the nominal pressure range, including an actuation means for the pressure control valve or pressure reduction valve that actuates a valve body member beyond a specified value of the control variable in such a way that with equal changes of the control variable the working medium pressure in the maximum pressure range changes more than in the nominal pressure range, and a control conduit connected with the control means and extending between and operatively connected with the actuation means and with the pressure control valve or pressure reduction valve for conducting a pilot pressure produced by the control means to the actuation means and to the pressure control valve or pressure reduction valve, whereby the control system operates to provide precise control of a contact pressure between the conical disks and the endless torque-transmitting member in the nominal pressure range and in the maximum pressure range, to prevent slippage between the conical disks and the endless torque-transmitting member.