| 摘要 |
A hydraulic system for a vehicle clutch assembly can include a pump and a purge valve for regulating hydraulic pressure supplied to the clutch. The hydraulic pressure at the pump can be set to a value higher than the operating pressure for the clutch. The purge valve can be configured to purge hydraulic pressure from the hydraulic system so that an optimum, controllable, and/or pre-determined operating pressure can be supplied to the clutch. The system can be configured to provide accurate control of the clutch(es), continuous cooling capacity to the hydraulic system components, lateral torque control when two separate hydraulic circuits are used, weight and cost reduction of the vehicle clutch, as well as other vehicle functions and characteristics. |
| 主权项 |
1. An apparatus for transferring a torque from a vehicle drive train to a wheel of a vehicle, the apparatus comprising:
a first clutch having a first driven part and a first driving part; a second clutch having a second driven part and a second driving part; a hydraulic system configured to actuate the first clutch and the second clutch by placing the first driven part into engagement with the first driving part and by placing the second driven part into engagement with the second driving part, the hydraulic system including:
a first cylinder,a second cylinder,a first piston movably received in the first cylinder and configured to move the first driven part into engagement with the first driving part when an operating hydraulic fluid pressure is supplied to the first piston,a second piston movably received in the second cylinder and configured to move the second driven part into engagement with the second driving part when an operating hydraulic fluid pressure is supplied to the second piston,a pump in fluid communication with the first piston and the second piston and configured to supply an output hydraulic fluid pressure, anda purge valve connected to a junction that is located between the pump and each of the first piston and the second piston and connected to the pump in parallel fluid communication with each of the first piston and the second piston, the purge valve is a variable-type linear solenoid valve that has a fully closed position, a fully open position, and a plurality of intermediate positions such that fluid flow through the purge valve is prevented if the purge valve is in the fully closed position, fluid flows through the purge valve at a first flow rate if the purge valve is in the fully open position, and fluid flows through the purge valve at one of a plurality of intermediate flow rates if the purge valve is in a respective one of the intermediate positions, where each of the intermediate flow rates is less than the first flow rate; and a controller in communication with the hydraulic system and configured to control each of the pump and purge valve to provide a desired hydraulic pressure to the first piston and the second piston. |
