A method is provided for controlling a hydraulic cylinder in a work machine, which hydraulic cylinder is arranged to move an implement that is subjected to a load, with the hydraulic cylinder being controlled by a hydraulic machine. The method includes detecting that a lifting movement of the implement is to be initiated, and attaining a basic speed of the hydraulic machine before lifting takes place.

A motor for driving a liquid end of a pump system. The motor having an inner housing having an outer surface, a mechanical actuator disposed in the inner housing, and a water jacket surrounding at least a portion of the outer surface of the inner housing to define a volume between the inner housing and the water jacket. The volume being sized to circulate water within the water jacket so as to transfer heat from the inner housing to the water.

A hydrostatic power unit (2) comprises a variable displacement machine with a continuously variable displacement volume and is operated as a pump and motor and is in a drive connection with an internal combustion engine (3). When operated as a pump, the power unit sucks hydraulic fluid out of a tank (9) and delivers into a delivery side (P), and, when operated as a motor, functions as a hydraulic starter to start the internal combustion engine (3). When operated as a motor, the power unit is supplied with hydraulic fluid from a hydraulic accumulator (30). The displacement volume of the power unit (2) is set by a displacement volume control device (60) actuated by a positioning piston device (61) supplied with hydraulic fluid from a charging pressure circuit (23). The power unit (2) includes a supplemental positioning piston device (80) in an operative connection with the displacement volume control device (60) and which is actuated directly by the pressure present in the hydraulic accumulator (30). By means of a connection of the supplemental positioning piston device (80) with the hydraulic accumulator, the power unit (2) can be adjusted to increase the displacement volume to start the internal combustion engine (3).

A hydraulic actuation unit for controlling the starting and stopping of hydraulic motors includes a first main circuit and a second main circuit, a first recirculation circuit and a second recirculation circuit, a counterbalancing valve, which includes a shuttle, and a first discharge channel and a second discharge channel. The shuttle includes a first check valve and a second check valve. The first check valve includes at least one first flow control element that can move from an open position to a closure position. The second check valve includes at least one second flow control element that can move from an open position to a closure position. The first and second check valves respectively are provided with first damping means and second damping means in order to slow down the passage movement respectively of the first flow control element and of the second flow control element.

A hydraulic motor includes a motor mechanism that rotates by hydraulic liquid pressure led from a hydraulic liquid pressure source. The hydraulic motor includes a casing that defines a casing chamber which accommodates the motor mechanism, a brake mechanism that brakes the rotation of the motor mechanism, a brake release actuator that releases the braking of the brake mechanism by a brake release pressure led from the hydraulic liquid pressure source, and a throttle passage that is in communication with the casing chamber and extracts a portion of hydraulic liquid that is led into the brake release actuator and leads it to the casing chamber.

The invention relates to a valve assembly (50) of a radial piston hydraulic apparatus (1). Said apparatus includes a cylinder block (4) insertable onto a shaft (2) by translation. Said assembly (50) includes: a valve (51) in contact with said cylinder block (4); a valve train cover (52); and a first (541) and second (542) chamber that are defined, respectively, by a first (511, 521) and second (512, 522) space that are located at the interface between said valve (51) and said valve train cover (52), and are intended for the pressurized fluids that enable the conversion of pressure and/or mechanical stress. Said assembly (50) includes an additional section (54) defined by a third space (541, 542) located at the interface between said valve (51) and said valve train cover (52). Said section (54) is intended for receiving a pressurized fluid such as to enable the cylinder block (4) to be inserted onto the shaft (2).

A fluid working machine of the type comprising working chambers of cyclically varying volume and low and high pressure valves to regulate the flow of working fluid into and out of the working chamber, from low and high pressure manifolds, in which the valves are electronically controlled on each cycle of working chamber volume, by way of valve actuation signals, to determine the net displacement of working chambers. Additional valve actuator signals are generated in response to determination that a valve or working chamber has been inactive to adapt the valve to operate more reliably when subsequently actuated, but without significantly altering the net displacement of working chambers.

A device for generating electrical energy from mechanical motion includes a surface float and at least one force modifier disposed at least partially within the interior of the surface float, the force modifier to receive an input force at a pumping cylinder and apply a modified force to a generator through a driving cylinder. The pumping cylinder or the driving cylinder is a tandem cylinder.

A thermal energy storage system comprising a working fluid to store and transfer thermal energy between a heat source and a thermal load and a vessel to store the working fluid. The vessel has an interior region and a floating separator piston in the interior region to separate a hot portion from a cold portion of the working fluid. There is a first manifold thermally coupled to an output of the heat source and to an input of the thermal load and fluidly coupled to the interior region of the vessel and a second manifold thermally coupled to an input of the heat source and an output of the thermal load and fluidly coupled to the interior region of the vessel. There is a controller configured to maintain the working fluid in a liquid state.

An axial piston machine has a displacement volume that is adjustable by a double-acting control cylinder, which is connected to an auxiliary pump via a fluid flow path that includes a first, a second, and a third control assembly. The transfer point is the point of the fluid flow path at which the plate-like housing part contacts the pot-like housing part. The receiving bore of the first, second, and third control assemblies are each arranged directly in the pot-like housing part. The part of the fluid flow path which is arranged downstream of the transfer point extends over its entire length directly in the pot-like housing part.