A hydraulic control valve can be one type of a variable characteristic (e.g., coil voltage). A visual identification system is provided to permit the visual identification of the specific type of the variable characteristic that the control valve is to assist in the assembly of systems utilizing such control valves. The visual identification system includes first and second indicator bearing first and second indicia, respectively, configured to indicate a first value and a different second value of a variable characteristic, respectively. The first and second indicator members are configured to be separately removably mounted to the control valve via a mechanical connection substantially without adhesive such that the appropriate indicator member can be selected and mounted to the valve depending upon what type of valve it is.

A spool component for use in a spool valve has a cylindrical body including a first diameter portion and a second diameter portion, the first diameter portion having a diameter that is larger than a diameter of the second diameter portion. A metering notch is cut into the first diameter portion and extends toward the second diameter portion. The metering notch includes a first angle cut and a second angle cut that are sloped at different depth angles toward the first diameter portion. A spool valve assembly includes a housing defining a bore, and the spool component, which is moveable within the bore along a stroke distance comprising a metering band for metering a flow of fluid across the spool component. The metering notch provides precise metering of the flow of fluid across the spool component based on the different depth angles of the cuts in the metering notch.

Systems and methods are provided for enhanced valves. One embodiment is a hydraulic valve that includes a housing that defines a first port, a second port, and a third port for a hydraulic fluid, and a sleeve disposed within the housing that defines openings in fluid communication with the second port and the third port. The valve also includes a slide comprising a head and a shaft. The shaft is disposed within the sleeve and the slide is movable in a lengthwise direction from a closed position to an open position. The head includes a circumferential lip that extends perpendicular to the lengthwise direction, and that abuts the sleeve when the slide is in the closed position to prevent flow of the hydraulic fluid from the first port. The shaft provides a flow path between the second port and the third port when the slide is closed.

A first valve component (10), in particular a pressure compensator component, has a valve slide (16) that can be guided in a valve housing (12) in a longitudinal direction. The valve slide has a control part (34) controlling a fluid-conducting connection (28) between at least two fluid connection points (30, 32) in the valve housing (12). The control part has at least one pocket-shaped recess (38), at least part of which is bordered by a fluid-guiding surface (40) extending at least between two vertices of the recess and extending with increasing inclination from one vertex to another vertex. Starting from a predeterminable distance before the other vertex, the fluid-guiding surface (40) extends from its point of greatest inclination with decreasing inclination in the direction of the other vertex.

A hydraulic driving device includes: a hydraulic motor configured to operate by flushing oil from a hydraulic pump through a high pressure oil passage and a low pressure oil passage; a low pressure selective valve configured to operate in accordance with differential pressure between the high pressure oil passage and the low pressure oil passage, and to discharge the oil in the low pressure oil passage inside a motor case; a tank oil passage configured to connect the inside of the motor case with an oil tank; and a choke throttle provided to the low pressure selective valve or to an oil passage lower than the low pressure selective valve.

A spool valve includes: a valve body that has a spool hole; and a spool disposed in the spool hole and movable in an axial direction, wherein the spool has a first large-diameter portion, and a small-diameter portion provided on one side in the axial direction of the first large-diameter portion, the first large-diameter portion has a first outer surface slidable with an inner surface of the spool hole, an end surface connected to an end portion at the one side in the axial direction of the first outer surface and to an end portion at the other side in the axial direction of an outer surface of the small-diameter portion, and a cutout portion provided on the end surface, and a bottom surface of the cutout portion is inclined toward the one side in the axial direction to approach a central axis of the spool.

A valve includes a pressure limiting flow spool disposed in a valve body. The spool is movable in a first direction from a first position to a second position and in the first direction from the second position to the third position. The valve includes an inlet and a first outlet. The first position is a closed position preventing flow from the inlet to the first outlet, the second position is a maximum flow position having a maximum flow capacity from the inlet to the first outlet, and the third position is a pilot flow position having a reduced flow capacity from the inlet to the first outlet smaller than the maximum flow capacity.

A spool is disclosed for use in a valve. The spool may have an elongated cylindrical body with a first end and a second end. The spool may also have a first land formed at the first end, a second land axially spaced apart from the first land, and a check element located between the first and second lands. The check element may have an outer diameter that is about 0.5-1% greater than an outer diameter of the second land.

A spool component for use in a spool valve has a cylindrical body including a first diameter portion and a second diameter portion, the first diameter portion having a diameter that is larger than a diameter of the second diameter portion. A metering notch is cut into the first diameter portion and extends toward the second diameter portion. The metering notch includes a first angle cut and a second angle cut that are sloped at different depth angles toward the first diameter portion. A spool valve assembly includes a housing defining a bore, and the spool component, which is moveable within the bore along a stroke distance comprising a metering band for metering a flow of fluid across the spool component. The metering notch provides precise metering of the flow of fluid across the spool component based on the different depth angles of the cuts in the metering notch.

A rotary valve subassembly includes a spool and a sleeve. The spool is positioned within the sleeve and rotatable relative to the sleeve. Rotating the spool relative to the sleeve can align a scalloped recess formed into an outer side surface of the spool with an inner circumferential recess formed into an inner side surface of the sleeve to fluidly-connect a pressurized fluid source and a low pressure fluid reservoir with a hydraulic actuator.