The present application relates to a switching valve, a switching hydraulic system, and a crane, in which the switching valve having an oil inlet and an oil outlet comprises at least two pairs of valve oil ports, a pair of cartridge valves provided between each pair of valve oil ports, and the oil inlet and the oil outlet are controlled such that the oil inlet and the oil outlet are capable of shifting between communications with the at least two pairs of valve oil ports. The switching valve switches on and off communication between the oil inlet and the oil outlet and the at least two pairs of valve oil ports by controlling opening or closing of the cartridge valves.

A valve assembly includes a valve base having a tubular section with a longitudinal bore formed therein, a fluid inlet port and a common port with an internal passageway therebetween. A solenoid coil is adapted to generate a magnetic flux and includes a longitudinal axis and a bore coaxial therewith. The valve assembly further includes an orifice piece positioned within the longitudinal bore of the valve base. The orifice piece includes a central passageway with a first end and a second end. A plunger is movable within the longitudinal bore between a first de-actuated position and a second actuated position.

A two-position, two-stage servo valve includes a valve body, a valve element, a control pressure chamber, and a control element. The valve body has an inner surface that defines a valve element chamber that includes a first control chamber and a second control chamber. The first control chamber is larger than the second control chamber. The valve element has first and second ends and is disposed within the valve element chamber and is movable between a first valve position and a second valve position. The first end is larger than the second end and is disposed within the first control chamber, and the second end is disposed within the second control chamber. The control pressure chamber includes a control pressure port that is in continuous fluid communication with the first control chamber. The control element is movable between a first control position and a second control position.

A valve assembly including a housing and a first movable member which divides the housing into a control chamber and a main chamber. A second movable member has a first valve part and a second valve part and is movable to engage the first valve part with a corresponding inlet valve part to substantially prevent flow of fluid into the main chamber via an inlet port. The first movable member is provided with an exhaust valve part and is movable to engage the second valve part of the second movable member to substantially prevent flow of pressurized fluid out of the main chamber via an exhaust port. A support part is secured relative to the housing, there being a first seal between the second movable member and the support part and a second seal between the support part and the first movable member.

Apparatus to bias spool valves using supply pressure are disclosed. An example apparatus includes a sleeve of a spool valve, and a spool within the sleeve to control a flow of fluid at a supply pressure through the spool valve as the spool is moved relative to the sleeve in response to a variable input force. A biasing force is to bias the spool opposite the variable input force. The biasing force is to be generated from a biasing pressure of the fluid within a chamber adjacent a biasing end of the spool. The biasing pressure is to be based on the fluid at the supply pressure provided directly to the chamber from a supply of the fluid independent of the flow of the fluid through the spool valve.

A solenoid valve has a housing defining a first axis and second axis, a solenoid which produces a magnetic field along the first axis, a valve shaft movable between a first position and a second position along the second axis, and a manifold mounted to the housing. The valve shaft is biased toward the first position by a spring and mechanical forces sufficient to overcome the force of the spring are transferred from the solenoid to the shaft by a lever to displace the shaft to its second position. A poppet seal affixed to the shaft, which interacts with a portion of the housing to close an outlet port in the housing, and a spool seal, also affixed to the shaft which interacts with a wall of the manifold defining an exhaust port to route fluid to the desired port. An electronic circuit controls delivery of current to the solenoid to shift and hold the shaft in the second position.

A solenoid valve has a housing defining a first axis and second axis, a solenoid which produces a magnetic field along the first axis, a valve shaft movable between open and closed positions along the second axis, and a manifold mounted to the housing. The shaft is biased toward the closed position by a spring and mechanical forces sufficient to overcome the force of the spring are transferred from the solenoid to the shaft by a lever to displace the shaft and then hold a first poppet valve open. The first poppet valve, which interacts with a portion of the housing to close the first valve, and a second poppet valve, which interacts with portions of the manifold to route fluid to the desired port, are mounted to the shaft. An electronic circuit controls delivery of current to the solenoid to shift and hold the shaft in the open position.

A hydraulic suspension system includes a suspension cylinder, a pump, and a control valve therebetween. The control valve includes a spool reciprocally movable between a pump flow position and a tank flow position in which a control port of the control valve is in communication with a pump and a tank, respectively. A piloted logic element in fluid communication with and interposed between the control valve and the suspension cylinder is selectively movable between a through-flow position in which fluid can flow in either direction between a chamber of the suspension cylinder and the control port of the control valve and a blocked position in which fluid is prevented from flowing in or out of the chamber of the suspension cylinder. The logic element is biased to the blocking position, moving to the through-flow position when subjected to a crack pressure delivered from the control port of the control valve.

Hard coated spool valves are disclosed. An example spool valve includes a sleeve and a spool to be positioned within the sleeve. The sleeve and the spool are made of a corrosion resistant material. The spool valve includes a wear resistant coating on at least one of the spool or the sleeve.

An oil control valve assembly includes a valve body and a controller coupled to an exterior end of the valve body. The controller includes a solenoid housing attached to the exterior end of the valve body, and defines an interior region. An encapsulated coil assembly is disposed within the interior region of the solenoid housing. A housing seal is disposed within the interior region of the solenoid housing, in sealing engagement with the solenoid housing, the valve body, and the encapsulated coil assembly. The housing seal is operable to seal the interior region of the solenoid housing to prevent fluid communication between the solenoid housing and the valve body. An adapter assembly is coupled to the valve body to reposition a discharge location of a supply port, a control port, and an exhaust port of the valve body along a longitudinal axis of the valve body.