摘要:
A valve for controlling flow of hydraulic fluid. The valve includes a valve sleeve (82) and a valve core (80). The core (80) is disposed within the sleeve (82). The core (80) and sleeve (82) are relatively rotatable. Each of said core (80) and sleeve (82) has an axially extending land (192,220) and an axially extending groove (110,122). The core (80) and sleeve (82) have relative rotational positions such that the lands (192,220) overlap to define a flow gap for flow of hydraulic fluid from the groove (110) in the sleeve (82) to the groove (122) in the core (80). The flow gap has a minimum cross-sectional flow area adjacent to the groove (122) in the core (80). The minimum cross-sectional flow area constantly varies as the core (80) and sleeve (82) relatively rotate. The land (192) on the sleeve (82) has a notch (202) immediately adjacent to, and downstream of the minimum cross-sectional flow area which provides an abrupt increase in cross-sectional flow area for suppressing valve noise due to cavitation.