Abstract: A valve (10) for controlling flow of hydraulic fluid. The valve (10) has first and second valve members (80, 82) which have a plurality of lands and grooves. The valve members (80, 82) are relatively movable from a neutral position to a displaced position in which surface segments (202, 226, 208, 218) of respective pairs of lands overlap to form flow gaps (232, 234) for restricting flow of fluid between respective pairs of grooves. At least one (234) of the flow gaps is divergent by having a cross-sectional flow area which increases along a direction of fluid flow and at least one (232) of the flow gaps is convergent by having a cross-sectional flow area which decreases along a direction of fluid flow. The flow gaps (232, 234) have minimum cross-sectional flow areas (A, B) defined by the surface segments.

Abstract: A valve for controlling flow of hydraulic fluid. The valve includes first and second relatively movable valve members (60 and 62). The valve members (60 and 62) include cooperating surfaces (112, 142, 144) which define first and second orifices for metering fluid from a pressurized fluid source (44) toward first and second locations (22 and 24) in a fluid utilization device (12). The valve members (60 and 62) have a displaced position in which the first orifice is increased in size and the second orifice is decreased in size. The increased size of the first orifice reduces a pressure drop across the first orifice. The decreased size of the second orifices increases a pressure drop across the second orifice. The valve members (60 and 62) include means (114 and 146) for increasing a pressure on a downstream side of the second orifice to reduce the pressure drop for controlling valve noise.

Abstract: A valve for controlling flow of hydraulic fluid. The valve includes a valve sleeve and a valve core. The core is disposed within the sleeve. The core and sleeve are relatively rotatable. Each of said core and sleeve has an axially extending land and an axially extending groove. The core and sleeve have relative rotational positions such that the lands overlap to define a flow gap for flow of hydraulic fluid from the groove in the sleeve to the groove in the core. The flow gap has a minimum cross-sectional flow area adjacent to the groove in the core. The minimum cross-sectional flow area constantly varies as the core and sleeve relatively rotate. The land on the sleeve has a notch 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.

Abstract: A valve for controlling flow of hydraulic fluid. The valve includes a valve sleeve and a valve core. The core is disposed within the sleeve. The core and sleeve are relatively rotatable. The sleeve has grooves connected to a utilization device. The core has grooves connected to a fluid supply and reservoir. The core and sleeve have lands which radially overlap during relative rotation of said core and sleeve to restrict fluid flow from a portion of the grooves in the sleeve to the grooves in the core connected to the reservoir. The lands on the sleeve have chamfered end faces with tapered segments.