Abstract: The present invention relates to a hydraulic valve arrangement for controlling/regulating at least one hydraulic consumer of a mobile machine, with a summation interconnection of at least two hydraulic valves and at least one consumer interconnection of hydraulic valves, wherein the outputs of the summation interconnection are hydraulically connected with the inputs of the consumer interconnection, wherein at least one backflow valve is provided in the consumer interconnection. According to the invention, the at least one backflow valve for throttling a consumer return volume flow opens or closes in dependence on a consumer inflow pressure and comprises at least one main piston arranged in a bushing and at least two further pistons arranged in a lid separate from the bushing, wherein the main piston and the control piston interact with each other via a compression spring.

Abstract: A hydraulic system and method of controlling such on a machine is disclosed. The hydraulic system may comprise a primary hydraulic circuit that includes a first load sense controlled pump, a secondary hydraulic circuit that includes a second load sense controlled pump, a flow sharing valve, and a load sense arrangement. The load sense arrangement may include a main resolver configured to select a higher pressure signal between the primary and secondary hydraulic circuits, and a load sense valve having an open position at which pressure signal flow between the primary hydraulic circuit and the main resolver is allowed, and a closed position at which pressure signal flow between the primary hydraulic circuit and the main resolver is blocked. In an embodiment, when the load sense valve is in the closed position, the second load sense controlled pump may be controlled only by the secondary hydraulic circuit.

Abstract: In one aspect, a system for controlling the supply of hydraulic fluid to an implement of a work vehicle may generally include a pump, a control valve coupled to the pump and first and second fluid lines provided in flow communication with output ports of the control valve. The system may also include a pressure control valve provided in flow communication with the second fluid line that is configured to regulate a fluid pressure of the hydraulic fluid being supplied to a hydraulic cylinder of the implement. Additionally, the system may include a bypass fluid line configured to provide a flow path for hydraulic fluid between the pump and the second fluid line that is independent of the control valve and a load sensing line configured to provide an indication of the fluid pressure of the hydraulic fluid being supplied to the hydraulic cylinder.

Abstract: A brake booster for a vehicle brake system includes a brake force transmitting element, a booster force transmitting element, a first rotation sensor, and a second rotation sensor. The brake force transmitting element is moveable in an axial direction for transmitting a pedal brake force from a brake pedal to a primary brake cylinder. The booster force transmitting element is moveable in the axial direction for transmitting a booster brake force to the primary brake cylinder. The first rotation sensor is kinematically coupled with the brake force transmitting element via a motion converting mechanism for measuring the axial position of the brake force transmitting element. The second rotation sensor is kinematically coupled with the booster force transmitting element for measuring the axial position of the booster force transmitting element. The measurements of the first and second rotation sensors are used for controlling the generation of the booster brake force.

Abstract: A working machine including a movable implement, a hydraulic actuator for displacing the implement, and a hydraulic control system for enabling an operator to control movement of the implement. The control system allows the implement to be returned to a desired position or state, such as a return to dig position or a return to float state, in a single automated operation that is initiated by the operator actuating a switch at the same time as moving a joystick in a desired direction. A pilot-operated valve is used to supply hydraulic fluid under pressure to the actuator acting on the implement and the operation of the joystick is detected by means of a pressure sensor connected to a control line of the pilot-operated valve.

Abstract: The present disclosure relates to a method, a device, and a system for controlling a hydraulic pump of a construction machine, the system comprising: an engine; an engine control unit configured to control the engine by using engine limit torque information and current engine torque information of the engine; a hydraulic pump operated by power supplied from the engine; at least one actuator driven by a hydraulic pressure discharged from the hydraulic pump; and a hydraulic pump control device configured to control a limited swash plate angle of the hydraulic pump by using a torque of the hydraulic pump and the engine limit torque information received from the engine control unit.

Abstract: A hydraulic cylinder includes: a cylinder tube; a piston; a piston rod; a pair of end covers; and a snubbing mechanism configured to reduce the moving speed of the piston after the piston reaches the vicinity of the end of its stroke. The snubbing mechanism includes: a supply/discharge port formed in an associated one of the end covers; a valve configured to open and close the supply/discharge port; a connector configured to connect the valve and the piston together; and at least one recess extending from the edge of the supply/discharge port. When the piston approaches the end of its stroke, the valve closes the supply/discharge port to form a throttle oil passage, and hydraulic oil is discharged through the throttle oil passage to reduce the moving speed of the piston.

Abstract: The present invention relates to a way of pressurizing a fluid to power a load, by initially pressurizing the fluid in a series of stages to yield a low-pressure fluid and further pressurizing the low-pressure fluid concurrently in parallel stages to yield a high-pressure fluid for supply to the load.

Abstract: An element is provided to maintain a clearance gap between a piston and a cylinder wall. In some embodiments, an element is included that is capable of spatial change. In some embodiments, the element is a component such as a clearance ring, a surface bearing, or a segment of a clearance ring or surface bearing. A clearance gap may be maintained by inward and outward motion of the component with respect to a piston assembly and a cylinder wall, where the motion is determined by a balance of forces acting on the component. In some embodiments, an inward force generated by an external gas pressure source is balanced by an outward preload force generated by, for example, a pneumatic piston. In some embodiments, a clearance gap is maintained based on in part on the ratio of inner to outer surface areas of a clearance ring.

Abstract: A pump-regulator combination includes first and second pumps, a control valve, first orifice, and pilot valve. The first pump is configured to pump fluid from a tank to a first point. The control valve is configured to control pressure and/or delivery flow at the first point by adjusting a displacement volume of the first pump. The second pump is configured to pump fluid from the tank to a second point, through the first orifice, and back to the tank. A highest load pressure of the actuator is connected to a third point. The pilot valve includes an adjustable second orifice connected to the third point, via a fourth point, and the tank to pass fluid from the actuator to the tank. A pressure at the second point acts to close the second orifice. A pressure of the fourth point acts to adjust the control valve.

Abstract: A system may comprise a first sensor; a second sensor; and an electronic control module. The electronic control module may be configured to determine a flow of the fluid based on information regarding the pressure from the first sensor and information regarding the temperature from the second sensor; determine a portion of the flow of the fluid that is directed to a particle counter of the machine; receive, from the particle counter, information identifying a quantity of particles in the portion of the flow of the fluid; determine a quality of the fluid based on the quantity of particles; determine whether the flow of the fluid exceeds a flow threshold or whether the quality of the fluid is less than a quality threshold; and take a remedial action when the flow of the fluid exceeds the flow threshold or the quality of the fluid is less than the quality threshold.

Abstract: A brake apparatus improved in mountability on a vehicle is provided. The apparatus includes a master cylinder 4 that generates hydraulic brake pressure by a driver's brake operation, and a stroke simulator 5 that creates an artificial operation reaction force of a brake operation member when the brake fluid flown out of the master cylinder 4 enters the stroke simulator 5. The master cylinder 4 and the stroke simulator 5 are integrally arranged to overlap each other in a perpendicular direction (as viewed from the perpendicular direction) when installed in the vehicle.

Abstract: The present invention relates to a system preventing the pressured oil leakage in a cylinder line enabling very low leakage rates without using the valve or the system, or without reducing the diametrical space between the housing and spool.

Abstract: A hydraulic drive system (1) including a meter-in compensator (37) and a bleed-off compensator (42) comprises a plurality of sensors (64 to 68), a controller (62), and an outlet pressure switching valve (61). The controller (62) determines whether or not the state of a wheel loader (2) which is detected based on the signals output from the sensors (64 to 68) meets a predetermined steering limiting condition. When the controller (62) determines that the state of the wheel loader (2) meets the steering limiting condition, it outputs a command signal to the outlet pressure switching valve (61). The outlet pressure switching valve (61) reduces the flow rate of the hydraulic oil flowing to steering cylinders (18L, 18R), in response to the command signal in such a manner that the flow rate becomes lower than that corresponding to the operation amount of a handle of a steering device (35).

Abstract: The present disclosure provides a pressure peak reduction valve for an excavator. The pressure peak reduction valve includes at least: a poppet seat which has an inlet port, and at least one communication hole which communicates with a hydraulic tank and is formed in an outer circumferential surface of the poppet seat; a main poppet which slides in the poppet seat; a poppet spring which is provided in the main poppet; a valve seat which has one end portion inserted into the main poppet so as to be in contact with one end portion of the poppet spring; a cone which is provided to be inserted into an openable hole formed at an end portion of the valve seat; an adjustment screw which is provided in the valve seat; and a piston which slides in the adjustment screw.

Abstract: A balance weight includes a main weight portion extending over a range defined by a circular-arc circumferential edge centered at a rotational shaft hole side and a pair of virtual end surfaces located on the circular-arc circumferential edge on both sides of the rotational shaft hole, a pair of extension weight portions extending from the pair of virtual end surfaces to an opposite circular-arc side of the rotational shaft hole from the circular-arc circumferential edge, the rotational shaft hole provided at the main weight portion so as to be located on a central side of the circular-arc circumferential edge, a crank shaft attachment protrusion, a crank shaft hole provided at the crank shaft attachment protrusion radially eccentrically with respect to the rotational shaft hole, and a pair of spaces formed between positions on both sides of the crank shaft attachment protrusion and the pair of extension weight portions, respectively.

Abstract: To keep operability of a hydraulic actuator excellent even in a state pressure has been sufficiently accumulated in a pressure accumulator. In a hydraulic driving device of a work machine including a hydraulic actuator, a tank, a flow control valve, and a pressure accumulator, there are further provided with a first pressure compensation valve that is for controlling difference between front and back pressures of the flow control valve constant and a second pressure compensation valve that is arranged between the pressure accumulator and the tank and is for controlling difference between front and back pressures of the flow control valve and the first pressure compensation valve constant.

Abstract: A hydrostatic drive has a hydrostatic pump (3) driven by a drive motor (2) and connected in a closed circuit with a hydrostatic motor (4). The closed circuit is formed by a first hydraulic connection (6a) and a second hydraulic connection (6b). Each of the hydraulic connections (6a, 6b) can form the high-pressure side or the low-pressure side of the closed circuit. A high pressure accumulator device (20) can be connected with the respective high-pressure side hydraulic connection (6a, 6b) and, simultaneously, the respective low-pressure side hydraulic connection (6b, 6a) can be connected with a hydraulic balancing device (30). A valve device (50) is provided for this simultaneous connection. The valve device (50) is a hydraulically controlled shuttle valve device (51) connected to the two hydraulic connections (6a, 6b), the high pressure accumulator device (20) and the hydraulic balancing device (30).

Abstract: A master cylinder includes a piston seal installed in a circumferential groove. The piston seal includes an annular base section, an inner circumferential lip section protruding from an inner circumferential side of the base section to come in sliding contact with an outer circumferential surface of a piston, an outer circumferential lip section protruding from an outer circumferential side of the base section to abut the circumferential groove, and an intermediate protrusion section protruding from between the inner circumferential lip section and the outer circumferential lip section of the base section to a forward side of the outer circumferential lip section. A step difference section is formed at the outer circumferential side. The circumferential groove has a step section that always abuts an outer circumferential surface of the step difference section.

Abstract: A compressor swash plate includes a base member having a flat plate shape, and a coating layer formed on a surface of the base member and having projections formed in a linear shape, in which the following inequalities are satisfied when a plane part formed on a prism is pressed against the coating layer with a pressure of 30 MPa: 0.01?B?0.06 and 10?S?40, where B indicates widths (mm) of surfaces of the projections in contact with the plane part, and S indicates a percentage (%) of a total sum of an area Si of the contact surfaces (a gross area of the surfaces of the projections in contact with the plane part) relative to a reference area (an area of a part of the coating layer against which the plane part is pressed).