| 摘要 |
A hydraulic pump or motor (50)includes a body (52) having a chamber (54) and a rotor (60) rotatably mounted within the chamber. The chamber (54) and the rotor (60) are shaped to define one or more rise regions (61,63), fall regions (63,65), major dwell regions (62,64) and minor dwell regions (67,69) between walls of the chamber (54) and the rotor (60). The rotor (60) has a plurality of slots (84) and vanes (86) located in each slot (84). Each vane (60) is movable between a retracted position and an extended position. In the retracted position, the vanes (86) are unable to work the hydraulic fluid introduced into the chamber (54). In the extended position the vanes (86) are able to work the hydraulic fluid introduced into the chamber (54). Vane retaining means (88) that are selectively actuable enable the vanes to be retained in the retracted position. |
