| 摘要 |
A hydraulic actuation system, eg for an automatic transmission, comprises a clutch actuator 22, gear engagement actuators 114, 115, a main control valve 120 and gear engagement control valves 144, 146. The actuators 22, 114, 115 and control valves 120, 144, 146 are mounted in a common housing to form a valve/actuator pack. This construction enables the hydraulic connections between the valves/actuators to be as short as possible and made of a non-compliant nature of the connections, any excess pressure in working chamber 118 will be dissipated by infinitesimal movement of the actuators 114, 115. Main control valve 120 selectively connects the actuator 22 to a pump 275 or to the reservoir 278. Engagement control valves 144, 146 selectively connects working chambers 11, 119 of the actuators 114, 115 to the main control valve 120 or to the reservoir 278. |
