| 摘要 |
A rotary pump and flow control valve assembly (73) are disclosed. The pump includes a pumping element (17) defining fluid pockets (31), a discharge port (59) and a discharge fluid path (57). The flow control valve assembly is disposed in a valve bore (71) and includes a valve spool (83) having a spool land (105) disposed between the discharge path and a bypass bore (81). The spool land includes a cylindrical wall portion (109) and an annular wall portion (111) extending from the spool to the cylindrical wall portion. The wall portions define an annular fluid chamber (115) in communication with the discharge path. The wall portions are relatively thin such that the cylindrical wall portion expands radially when the annular fluid chamber communicates with fluid at relatively higher fluid pressure. The result is a reduction in the normal clearance between the cylindrical wall portion and the valve bore, reducing leakage past the spool land. |
