| 摘要 |
A pump has a pump assembly for pumping fluid. The pump assembly includes a fluid pressure changing mechanism in fluid communication with a valve plate which is in fluid communication with a port plate. A pair of flappers are interposed between and sealable with the valve plate and port plate. A head has a head port, and is in sealed engagement with the port plate, so that, in cooperation with the port plate and the valve plate, the flappers control fluid flowing through the head port and to and from the fluid pressure changing mechanism. Rotation of the port plate and valve plate relative to the head reverses flow of the fluid through the head port. |
