A hydraulic system for a vehicle includes a hydraulic monitoring control unit configured to receive an operational signal from a sub-system of the vehicle and control flow of hydraulic fluid to actuators of components based on the operational signal. The hydraulic monitoring control unit is configured to bypass the flow of the hydraulic fluid in relation to a subset of the actuators in response to the operational signal indicating an altered operational state of the sub-system.

A distributor (3) of the closed-center, load sensing type, connected to a variable displacement pump (1) comprises a valve device (10, 110), composed of a logic element, which is pilot-operated and configured to bring a high-pressure channel (2) into communication with a low-pressure channel (4), the connection being usually opened by the combined action of an equivalent pressure generated by an elastic member (12) and a counter-pressure which is generated, under operative conditions, in the low-pressure channel (4). The connection is closed in a switching position and it is pilot-operated to a closure position by the combined action of a high-pressure signal (P) and a load sensing signal (LS).

A hydraulic pressure amplifier arrangement (1) is described comprising a supply port (A1), a pressure outlet (A2) connected to the supply port via check valve means (3), a tank port (B1), an intensifier section (5) having a high pressure piston (6) in a high pressure cylinder (7) which is connected to the pressure outlet (A2), a low pressure piston (8) in a low pressure cylinder (9) and connected to the high pressure piston (6), an intermediate space (11) between the high pressure piston (6) and the low pressure piston (8), a control valve (12) controlling a pressure in the low pressure cylinder (9), and a feeder arrangement of the intensifier section (5) including an input connection (19) connected to the supply port (A1) and a return connection (20) connected to the tank port (B1). Such a pressure amplifier arrangement should have a simple construction. To this end the feeder arrangement (19, 20) comprises throttling means (21).

A passive fluidic valve for fixed flow rate distribution comprising: a hollow valve body; a valve member for blocking a passage to one of the two outlets; and communications to impose the pressure of the upstream and downstream cavities at the ends of the valve member. The valve body further comprises: an inlet; a first outlet comprising a first restriction delimiting an upstream cavity and a downstream cavity; a second outlet comprising a second restriction delimiting an upstream cavity and a downstream cavity; and a first and a second cavity. The valve member further comprises: a first end in the first cavity delimiting a first and a third chambers, and a second end in the second cavity delimiting a second and a fourth chambers.

A fluid pressure control device includes a switching valve, a main pilot passage and a sub pilot passage, the switching valve is configured to be switched to the open position when the working fluid is supplied to the pilot chamber, and to be switched to the throttled position with opening on the downstream side of the switching valve in the neutral passage, and the sub pilot passage is provided with a throttle portion and a check valve in parallel in the throttle portion.

A hydraulic system, comprising: a hydraulic pump, a hydraulic load, and an electric machine. The electric machine working as an electric generator and mechanically coupled with said hydraulic pump. A low-pressure fluid tank and a valve assembly comprising one or more valves selectively fluidly connecting the hydraulic load with the low-pressure fluid tank.

A hydraulic system includes a control device to reduce a first movement speed to be lower than a second movement speed, the first movement speed being a speed at which a spool of a first control valve moves from a first supply position to a first stop position under a state where a second control valve is in the second supply position, the second movement speed being a speed at which the spool moves from the first supply position to the first stop position under a state where the second control valve is in the second stop position. The first supply position allows operation fluid to be supplied to a hydraulic actuator. The first stop position prevents the operation fluid from being supplied to the hydraulic actuator. The second stop position prevents the operation fluid from being supplied to a first fluid tube coupling a hydraulic pump to the hydraulic actuator.

A valve includes a valve housing (33), which has at least one service connection (A, B), a pressure supply connection (P) and a return connection (T). In the valve housing (33), a control slide (STS) is guided so as to be movable longitudinally to control these individual connections. The supply pressure, which is applied to the pressure connection (P) to control a consumer (10, 12), connected to the service connection (A; B), is guided across at least one control side (56) of the control slide (STS) via an orifice plate (54) and a control channel (50). The control side (56) is positioned in a control chamber (58) in the valve housing (33) such that it can move. The control chamber (58) is connected to the return connection (T) via an additional orifice plate (59).

A hydraulic system includes a first output fluid tube connecting between a hydraulic pump to output operation fluid and a first operation valve to change a first pilot pressure of the operation fluid, a second output fluid tube connected between the hydraulic pump and a second operation valve to change a second pilot pressure of the operation fluid, a switching valve provided in the second output fluid tube, and a warm-up fluid tube connected between the first operation valve and the switching valve, wherein the switching valve is switched between a first position allowing the operation fluid to be drained through the first output fluid tube, the first operation valve, the warm-up fluid tube and the switching valve, and a second position allowing the operation fluid to be supplied through second output fluid tube to the second operation valve.

A vehicle door positioning holder includes a hydraulic cylinder connected to the door and a vehicle chassis, and a brake hydraulically connected in a loop. The cylinder pushes hydraulic fluid in the loop when the door is moved. The brake includes first and second chambers hydraulically connected to the loop and a third chamber connected in the loop at respective ends to the first and second chambers. The brake has a ball element in the third chamber when the hydraulic fluid is still, moved towards the first chamber as the hydraulic fluid flows in a first direction, and moved towards the second chamber as the hydraulic fluid flows in a second direction. A flow resistance of the hydraulic fluid is larger when the ball is positioned in the third chamber than when the ball is moved towards the first or the second chambers.