| 摘要 |
A pump utilizing basically the same pumping elements as currently in use in a slipper-type pump having a rotor rotatable in a cam ring providing a double-lobed working chamber and wherein the rotor carries a plurality of slipper-type pumping elements which are free to move radially and to rock angularly in following the adjoining wall of the bore contour is modified by providing the cam ring and the adjoining pressure plate with two sets of multiple passages, for example, sets of six, and adding a freely rotatable actuator plate movable from a neutral position to either a forward position or a reverse position, thereby to preferentially bias the actuator plate in such a manner as to selectively exclude or include egress holes. |
