An electro-hydraulic linear actuator module comprising a stator having a cylindrical bore therethrough, a linear electric machine translator movable axially within the stator bore, a positive displacement chamber adjacent each end of the translator for holding, in use, an incompressible fluid, first and second fluid pathways, one to each chamber, for the flow of an incompressible fluid, wherein movement of the translator along the stator bore alters the volumes of the chambers.

An electrohydraulic system for use under water includes an electrohydraulic actuator and a container. A hydraulic cylinder or a hydraulic motor and a hydraulic machine are arranged in an internal space of the container. The hydraulic machine is mechanically coupled to a rotary drive unit for a common rotary movement, and the hydraulic machine adjusts the hydraulic cylinder or the hydraulic motor. The rotary drive unit is arranged outside the container and is configured to couple to and decouple from the hydraulic machine. A device in one embodiment includes the electrohydraulic system.

Actuators having electroactive valves are described herein. The actuators can move from a first position to a second position and lock in the second position using an electroactive valve. The device can include an actuator having a fluid-impermeable membrane. The fluid-impermeable membrane can define a compartment, the compartment having a central region, an edge region extending from and fluidly connected with the central region, an electroactive valve between the central region and the edge region, and a dielectric fluid. When actuated, the actuators can force fluid through the electroactive valves and into the edge region. Once in the edge region, the electroactive valves can prevent return flow until receiving an actuation signal.

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 movement processing unit generates a work equipment operation signal for moving a bucket to a loading point and a swing operation signal related to a target swing speed, based on a command for starting an automatic movement of the bucket. A target speed changing unit changes the target swing speed so that the work equipment does not interfere with the loading target during a swing of a swing body.

A servohydraulic drive includes a hydrostatic displacement machine, an electric machine that is mechanically speed-coupled with the displacement machine, a hydraulic cylinder that is fluidically connected to the displacement machine via first and second working lines, a hydraulic accumulator, and a supply unit. The displacement machine has a stroke that is adjustable via a hydraulic adjustment device. The cylinder is configured to be activated by reversal of the fluid flow through the displacement machine in opposite directions. The accumulator is preset to a low pressure and is fluidically connected via a valve assembly in each case to the lower pressure working line. The supply unit is configured to supply the adjustment device with pressurized fluid under the necessary pressure for the adjustment regardless of the present pressure in the working lines such that the displacement machine is configured for an active and load pressure-independent adjustment of its stroke volume.

The present application is directed to a system for converting linear motion to rotary motion. The system includes at least first and second cylinders. The first and second cylinders are in fluid communication with each other. The system also includes a first piston. The first piston is slidably disposed in the first cylinder. The system further includes a second piston. The second piston is slidably disposed in the second cylinder. The first and second cylinders contain an incompressible fluid. The first piston is in operative connection with the second piston such that movement of the first piston in a first direction causes movement of the second piston in a second direction, wherein the second direction is opposite the first direction.

A marker band locator system locates a marker band, from a plurality of marker bands in a hopper, into a band receiver for further processing. A hopper is configured to loosely hold a plurality of marker bands and a band receiver, configured in an indexer, is configured under the hopper such that marker bands gravity feed down to the band receiver. A vacuum source produces a vacuum on the band receiver and if a marker band is properly located therein, the marker band forms a seal with the band receiver and the vacuum pressure exceeds a threshold vacuum pressure level. The indexer then actuates to a secondary position for further processing and removal of the marker band. If the vacuum pressure does not exceed the threshold, a burst of air jostles the marker bands in the hopper until a marker band is seated properly.

A marker band locator system locates a marker band, from a plurality of marker bands in a hopper, into a band receiver for further processing. A hopper is configured to loosely hold a plurality of marker bands and a band receiver, configured in an indexer, is configured under the hopper such that marker bands gravity feed down to the band receiver. A vacuum source produces a vacuum on the band receiver and if a marker band is properly located therein, the marker band forms a seal with the band receiver and the vacuum pressure exceeds a threshold vacuum pressure level. The indexer then actuates to a secondary position for further processing and removal of the marker band. If the vacuum pressure does not exceed the threshold, a burst of air jostles the marker bands in the hopper until a marker band is seated properly.

Pump-controlled hydraulic circuits are more efficient than valve-controlled circuits, as they eliminate the energy losses due to flow throttling in valves and require less cooling effort. Presently existing pump-controlled solutions for single rod cylinders encounter an undesirable performance during certain operating conditions. Novel circuit designs employ use of different charge pressures on a pair of pilot-operated charging-control valves or different piston areas and/or spring constants on a shuttle-type charging control valve to shift a critical loading region in a load-force/actuator-velocity plane to a lower load force range, thereby reducing the undesired oscillations experienced in the response of the typical critical loading region. One or more specialized valves are controlled by fluid pressures to provide throttling in the circuit only within the critical loading region, thereby reducing the oscillatory amplitude while avoiding throttling-based energy losses outside the critical region over the majority of the circuit's operational overall operating area.