The disclosure relates to a hydraulic control block for controlling a pressure medium supply of a hydraulic cylinder of a hydraulic spindle. The hydraulic control block includes a generic hydraulic switching structure electively configurable in each of a plurality of specific hydraulic switching structures, each of the plurality of specific hydraulic switching structures having a respective hydraulic cylinder with a number of piston areas which differs from a number of piston areas in the respective hydraulic cylinders of each of the other of the plurality of specific hydraulic switching structures.

A fluid system includes a variable-speed and/or a variable-torque pump to pump a fluid, at least one proportional control valve assembly, an actuator that is operated by the fluid to control a load, and a controller that establishes a speed and/or torque of the pump and a position of the at least one proportional control valve assembly. The pump includes at least one fluid driver that provides fluid to the actuator, which can be, e.g., a fluid-actuated cylinder, a fluid-driven motor or another type of fluid-driven actuator that controls a load. Each fluid driver includes a prime mover and a fluid displacement assembly. The fluid displacement assembly can be driven by the prime mover such that fluid is transferred from the inlet port to the outlet port of the pump.

An actuator operable to move a valve stem between an opened position and a closed position includes a cylinder including an open side and a close side, the cylinder coupled to the valve stem, a first pump connected to the cylinder and operable to deliver a first high-pressure fluid to the open side of the cylinder to move the valve stem toward the opened position, and a second pump separate from the first pump, the second pump connected to the cylinder and operable to deliver a second high-pressure fluid to the close side of the cylinder to move the valve stem toward the closed position.

An artificial muscle that includes a housing having an electrode region and an expandable fluid region and an electrode pair positioned in the electrode region, the electrode pair having a first electrode fixed to a first surface of the housing and a second electrode fixed to a second surface of the housing. The first and second electrodes each have two or more tab portions and two or more bridge portions. Each of the two or more bridge portions interconnects adjacent tab portions and at least one of the first and second electrodes includes a central opening positioned between the two or more tab portions and encircling the expandable fluid region. A dielectric fluid is housed within the housing and the electrode pair is actuatable between a non-actuated and an actuated state such that actuation from the non-actuated to actuated state directs the dielectric fluid into the expandable fluid region.

An artificial muscle that includes a housing having an electrode region and an expandable fluid region and an electrode pair positioned in the electrode region, the electrode pair having a first electrode fixed to a first surface of the housing and a second electrode fixed to a second surface of the housing. The first and second electrodes each have two or more tab portions and two or more bridge portions. Each of the two or more bridge portions interconnects adjacent tab portions and at least one of the first and second electrodes includes a central opening positioned between the two or more tab portions and encircling the expandable fluid region. A dielectric fluid is housed within the housing and the electrode pair is actuatable between a non-actuated and an actuated state such that actuation from the non-actuated to actuated state directs the dielectric fluid into the expandable fluid region.

A control system is provided for a power machine that includes a hydraulic charge circuit with a hydraulic charge pump, and a variable displacement drive pump. A signal for control of displacement of the drive pump can be diverted from the hydraulic charge circuit downstream from the pump, including via a flow path that branches from the hydraulic charge circuit from a location upstream of a hydraulic load.

A method for controlling a hydraulic actuator (2) of a system (1) by means of a valve having a valve element is described. A position of the valve element determines a pressure supplied to a hydraulic actuator (2). In such a method a variable dead band should be minimized. To this end a start position of the valve element is preadjusted as a function of at least one parameter outside the hydraulic actuator (2).

The invention provides an actuator device, which has: an output element, which is acted on by a fluid and as a result is movable into a holding position; two solid-state actuators, which are able to be activated alternately; a coupling element common to the solid-state actuators; a discharge duct, via which the fluid is able to be discharged from the output element; and at least one valve element, which is adjustable between a blocking closed state and an open state, in which the valve element allows the fluid to be discharged from the output element via the discharge duct and allows the output element to move from the holding position into at least one yielding position, wherein the valve element is actuable, via the coupling element of the respective solid-state actuator, by the respective activation of the solid-state actuator and is able to be moved into the closed state.

A pump unit for clutch actuation, having a high-pressure port for clutch actuation, a low-pressure port for a lubricant flow, a single drive motor and a dual pump, which is driven by the drive motor and has a high-pressure outlet, which is connected to the high-pressure port with a high-pressure line, and a low-pressure outlet, which is connected to the low-pressure port with a low-pressure line, wherein a prefilling line which leads from the low-pressure line to the high-pressure line is provided.

A fluid-powered linear motor with rotary pistons is disclosed. An application is for a downhole motor but it could be used in other applications. Rotational pistons provide increased torque generation as the torque generated is proportional to motor length. Since downhole drills are long (generally up to a maximum length of 30 ft.), a high-torque motor can be produced using this method. A pressurized fluid is used to drive the piston assemblies to produce bit shaft power. This concept employs rotary pistons and a mechanical rectifier to convert the rotational reciprocation produced by a reciprocating rotational piston into continuous rotary motion. Integration of synthetic diamond bearing assemblies into the motor allows for reduced friction and abrasive drilling fluid compatibility.