The invention relates to an actuator device comprising at least one output element, which can be applied with a fluid and can thereby be moved into at least one retaining position. An actuator is provided which can be operated in a pumping operation by controlling the actuator, in which at least one part of the actuator can be alternatingly moved in a first direction and in a second direction opposite the first direction via the controlling of the actuator, whereby the fluid can be conveyed to the output element in order to apply the output element with the fluid. A discharge channel is also provided, via which the fluid can be discharged from the output element.

A hydraulic system includes a first and a second rotating hydraulic machine, the first and second hydraulic machine being arranged to provide a torque via a common output shaft; a first valve arrangement for providing a differential hydraulic pressure level over the first hydraulic machine by using two sources of hydraulic fluid having different hydraulic pressure levels, a second valve arrangement for providing a differential hydraulic pressure level over the second hydraulic machine by using two sources of hydraulic fluid having different hydraulic pressure levels; and a control unit configured to control the first valve arrangement and the second valve arrangement such that different discrete levels of torque are provided via the output shaft of the hydraulic system. A hydraulic system for providing different discrete levels of torque using one hydraulic machine and a plurality of differential pressure levels, and a method for controlling a hydraulic system, are also provided.

In a hydraulic drive system performing the load sensing control by using a pump device having two delivery ports whose delivery flow rates are controlled by a single pump controller, surplus flow is prevented and energy loss at an unload valve and a pressure compensating valve is reduced in combined operations in which two actuators are driven at the same time while producing a relatively large supply flow rate difference therebetween. A boom cylinder 3a is connected so that the hydraulic fluids delivered from delivery ports P1 and P2 of a pump device 1a are merged and supplied to the boom cylinder 3a. An arm cylinder 3h is connected so that the hydraulic fluids delivered from delivery ports P3 and P4 of a pump device 1b are merged and supplied to the arm cylinder 3h. A travel motor 3d is connected so that the hydraulic fluid delivered from one (delivery port P2) of the delivery ports of the pump device 1a and the hydraulic fluid delivered from one (delivery port P4) of the delivery ports of the pump device 1b are merged and supplied to the travel motor 3d. A travel motor 3e is connected so that the hydraulic fluid delivered from the other (delivery port P1) of the delivery ports of the pump device 1a and the hydraulic fluid delivered from the other (delivery port P3) of the delivery ports of the pump device 1b are merged and supplied to the travel motor 3e.

A coolant pump assembly having a combined hydraulic drive pump and a coolant circulating pump is disclosed herein, for use in connection with a utility vehicle, such as a ride-on or stand-on mower. Such a vehicle includes at least one combination pump assembly that utilizes a first fluid circuit to hydraulically drive a wheel of the vehicle and a second fluid circuit to cool one or more vehicle components.

An actuator arrangement for applying a torque to a shaft of a machine, in particular a reciprocating piston engine, includes: a) at least one actuator device for applying the torque; and b) at least one rotatable seismic mass coupled to the shaft. The at least one actuator device is designed to apply the torque to the shaft between the seismic mass and the shaft. A corresponding method is provided for active damping of torsional vibrations of the shaft having the actuator arrangement.

There is provided a control module for a hydraulic system. The module comprises a tank and a plurality of valves. The tank is configured to store hydraulic fluid and is substantially cylindrical. The plurality of valves fluidly connect with the tank and are configured to control distribution of hydraulic fluid from the tank to one or more components of the system. The plurality of valves are spaced around a circumference of the tank. One or more passages fluidly connect the tank with at least one of the plurality of valves and/or a first of the plurality of valves with a second of the plurality of valves.

In one aspect, a system (110) for performing an action is disclosed. In one arrangement and embodiment, the system (110) comprises: a tool (118) operable to perform at least the action; a controller (122); storage (124) storing electronic program instructions for controlling the controller (122); and an input/output means (126). In one form, the controller (122) is operable, under control of the electronic program instructions, to: receive input via the input means; process the input, and on the basis of the processing, control the tool to perform the action. In one embodiment, the action comprises a hydraulic tuning action in respect of a system, such as a hydraulic pump (114), comprising a hydraulic circuit.

A pressurized fluid supply system for a vehicle transmission is provided. The fluid supply system has a pump with at least high and low pressure outputs that supplies high and low pressure components via a directional valve. The pressurized fluid supply system minimizes the parasitic loss upon a vehicle engine.

Wave energy conversion systems are provided utilizing a mass of water entrained in a collapsible water mass enclosure that is suspended beneath a float (e.g., a vehicle, buoy, platform, etc.) to provide an inertial force in opposition to the rising heave-induced acceleration of the float. The water mass enclosure is communication with a generator, such as by tethering one end of a tethering means to the generator and the other to the enclosure. The enclosure may be placed in communication with an intermediary hydraulic system, which is also in communication with the generator. In certain embodiments, the system will include a reel system for deploying and retrieving the water masse enclosure.

An adaptor is used to couple a prime mover to an actuator. The adaptor includes a first portion that attaches to the prime mover and a second portion that attaches to the actuator. The outer surface of the first portion is defined by at least one flat portion connected by at least one arcuate portion. The second portion has a bore configured to accept the first portion, with an inner surface shaped to complement the outer surface of the first portion. A bore through the first portion accepts a drive shaft of the prime mover therethrough where the drive shaft is configured to engage the actuator.