A brake system damping device includes a first chamber on which hydraulic pressure is to be applied, a second chamber with a compressible medium located therein, and a first separating element configured to separate the first and second chambers. The damping device further includes a third chamber with a compressible medium located therein and a second separating element configured to separate the second and third chambers. The second and third chambers are connected in a medium-conducting manner via a passage in the second separating element. The first separating element is configured to move a closure element to close the passage when the hydraulic pressure in the first chamber has reached a predefined pressure value. The first and second separating elements form an assembly in which the first and second separating elements extend along an axis and the first separating element is covered radially on the outside by an envelope surface.

A pulse damper constructed in accordance to one example of the present disclosure includes a first housing member, a second housing member, a diaphragm and a valve. The first housing member defines a fuel chamber at an internal space thereof. The first housing member can further have a fuel inlet and a fuel outlet. The second housing member can define a pressurized chamber. The diaphragm can be disposed between the first and second housing. The diaphragm separates the fuel chamber and the pressurized chamber. The valve can be disposed on the second housing and be configured to selectively pass air into and out of the pressurized chamber corresponding to a desired predetermined pressure within the pressurized chamber. Increased pressure within the pressurized chamber will resist movement of the diaphragm into the pressurized chamber.

A ride control valve includes a valve housing (30) having a main spool (32) longitudinally displaceably arranged in the valve housing, a balance spool (34), and fluid passage points for a pressure supply (P), a tank return line (T), an accumulator (14) and a boom cylinder unit (10). The balance spool (34) continuously balances the pressure between the fluid ports of the accumulator (14) and the boom cylinder unit (10). The main spool (32) is controlled by the operator and initially interconnects these fluid ports of the accumulator (14) and the boom cylinder unit (10), starting from a closed fluid connection, via a restricted fluid connection, to a fully opened fluid connection, or disconnects them from each other in reverse sequence.

A hydraulic control system HCS for controlling a variable ratio transmission of a power generating system. A hydraulic motor/pump unit 140 is operably connected to a superposition gear, and is connected to a hydraulic circuit that comprises an orifice 28 and/or a relief valve 29 that opens at a predetermined hydraulic pressure. The hydraulic circuit switches between a variable low-speed operating mode and a torque limiting high-speed operating mode. In the torque limiting high-speed operating mode the hydraulic motor/pump unit 140 is driven by the superposition gear and drives hydraulic fluid through the orifice 28 and/or relief valve 29 to provide a passive torque limiting function. In the variable low-speed operating mode the hydraulic motor/pump unit 140 drives the superposition gear and the hydraulic control system provides a desired rotor 101 speed by controlling hydraulic fluid flow rate through the hydraulic motor/pump unit 140.

The present invention provides an improved high-low hydraulic system for compacting machinery, such as balers, horizontal balers, compactors, transfer station compactors, and the like. The high-low hydraulic system comprises at least one double rotary pump, a plurality of directional control valves, a pilot-operated back pressure reducing valve, a flow control valve, a plurality of one-way valves, and a plurality of pressure switches. The high-low hydraulic system may be regenerative or non-regenerative and provides many advantages over conventional hydraulic systems. Such advantages include greater system efficiency due to a reduced back pressure during the time of the retraction stroke and clever flow sequencing, mitigation of hydraulic shocks at the beginning and end of compaction and retraction strokes, and reduced cycle time of the cylinder during operation due to the concurrent filling of the rod end side during decompression of the blind end side after the compaction stroke. Moreover, the present high-low hydraulic system allows for the cylinder to operate at three or more independent speeds. Additionally, the present high-low hydraulic system may also comprise an accumulator and pressure transducer that further assist with substantially maintaining a predetermined hydraulic pressure on the blind end side after the completion of the compaction stroke.

A hydraulic actuator includes an energy recuperation device which harvests the energy generated from the stroking of a shock absorber. The energy recuperation device can function in a passive energy recovery mode for the shock absorber to store recovered energy as fluid pressure or it can be converted to another form of energy such as electrical energy.

The present disclosure relates to a hydraulic circuit for a forklift, and more particularly, to a hydraulic circuit for a forklift which is capable of preventing an engine from being stopped due to surge pressure that instantaneously occurs when a lift cylinder reaches an end stroke and thus cannot be operated any further when the lift cylinder is extended. According to the hydraulic circuit for a forklift according to the exemplary embodiment of the present disclosure, which is configured as described above, the accumulator is provided on the hydraulic line through which the working fluid is provided to the lift cylinder, and as a result, the accumulator may quickly absorb surge pressure when the surge pressure is produced in the lift cylinder or the hydraulic line.

A hydraulic drive system associable with a multi-press punching apparatus for operating a plurality of punching tools includes a plurality of hydraulic cylinders provided with respective pistons defining thrust chambers and return chambers inside the hydraulic cylinders and associated with corresponding punching tools, a reversible first pump connected to the thrust chambers and arranged to send oil to, or suck oil from, at least one of the thrust chambers so as to move the respective piston, a plurality of selector valves interposed between the first pump and the thrust chambers of the hydraulic cylinders and activable to connect the first pump to the thrust chambers, and a hydraulic accumulator connected to the return chambers and arranged for maintaining in said return chambers oil at a defined preload pressure.

The present disclosure relates to variable recruitment actuator systems and related methods. In one embodiment, a variable recruitment actuator system may include a high-pressure fluid connection and a plurality of actuators. A variable recruitment actuator mechanism may selectively recruit a subset of the plurality of actuators based on a position of the variable recruitment actuator mechanism by selectively placing the subset of the plurality of actuators in fluid communication with the high-pressure fluid connection. A control system to control the position of the variable recruitment actuator mechanism may operate based on an input from a user.

A hydraulic actuator arrangement (1) is described comprising a hydraulic actuator having a pressure chamber (2), a cylinder (3) in a cylinder housing (4), and a piston (5) connected to a piston rod, a hydraulic pump (7) connected to the pressure chamber (2) and an electric motor (8) driving the hydraulic pump (7), wherein the pump (7) and the motor (8) are arranged within the actuator. Such an actuator arrangement should have many application possibilities. To this end, a hydraulic pressure amplifier (10) is arranged between the hydraulic pump (7) and the pressure chamber (2).