Hydraulic clutch and transmission actuating system
AssigneeDana Corporation
InventorKenneth B. Yant
Life of this patent
Estimating the term…
Abstract
A hydraulic actuating system for disengaging a clutch, shifting gears in a transmission and reengaging the clutch for a vehicle. An electric pump delivers hydraulic fluid under pressure to an accumulator. High and low pressure switches control operation of the pump to maintain the hydraulic fluid pressure within a desired range, while limiting operating time of the pump and minimizing energy waste. The pressurized fluid from the accumulator is applied through valves to operate a clutch actuating mechanism and to shift transmission gears. A secondary accumulator is provided at the clutch actuating mechanism to provide smoother clutch reengagement with a low cost valve having a relative coarse modulation capacity.
Claims7
A hydraulic system for operating a vehicle clutch comprising a source of hydraulic fluid having a predetermined high pressure, a hydraulic clutch release cylinder, a first normally closed valve connecting said source to said clutch release cylinder, a hydraulic fluid accumulator connected to said clutch release cylinder, said accumulator filling with hydraulic fluid at a predetermined intermediate pressure less than said predetermined high pressure, said clutch release cylinder and said accumulator receiving predetermined high pressure hydraulic fluid from said source to disengage the clutch when said first valve is opened, a normally closed second valve connected to vent hydraulic fluid from said clutch release cylinder and said accumulator when opened, and means for opening said first valve to disengage said clutch and for closing said first valve and for modulating said second valve to reengage said clutch.
A hydraulic pressure system for operating a clutch and transmission shifting mechanism, comprising an electrically driven hydraulic fluid pump, an accumulator for receiving and storing pressurized hydraulic fluid from said pump, a check valve located between said pump and said accumulator, said check valve preventing a flow of hydraulic fluid from said accumulator to said pump, pressure responsive switch means for turning on said pump when the fluid pressure at said accumulator drops below a predetermined minimum pressure and for turning off said pump when the fluid pressure at said accumulator reaches a predetermined maximum pressure, and means for operating the clutch and the transmission shifting mechanism with hydraulic fluid from said accumulator.
Dependencies are inferred from the claim text.