Described herein is a fluid circuit device. The device incorporates at least one pressure balancing valve located between at least two fluid volumes that can be in a pressure differential arrangement wherein the at least one pressure balancing valve acts to address a pressure differential by opening a fluid volume or volumes to a third pressure equalising volume. In use, the fluid circuit device may in one embodiment be used in an energy absorption apparatus.

A technique facilitates wellbore operations and utilization of wellbore equipment, e.g. equipment comprising actuation devices for downhole tools. According to an embodiment, the system comprises a pump solution for an electrically control device, e.g. an electrically controlled valve. The system may comprise hydraulic circuitry which utilizes bellows to effectively enclose the hydraulic circuitry. Consequently, the system enables an electrically control downhole system having components hydraulically actuated via a closed loop hydraulic system.

A subcooler is made up of a plate type heat exchanger. The accumulator is located between a compressor and the subcooler in a width direction of an outdoor unit in a planar view. The subcooler overlaps with the accumulator in the width direction in the planar view. As a result, a compact heat pump can be provided when the subcooler is a plate type heat exchanger.

A subcooler is made up of a plate type heat exchanger. The accumulator is located between a compressor and the subcooler in a width direction of an outdoor unit in a planar view. The subcooler overlaps with the accumulator in the width direction in the planar view. As a result, a compact heat pump can be provided when the subcooler is a plate type heat exchanger.

The present disclosure relates to a variable pressure vessel. The vessel includes a liquid chamber and a gas chamber and a moveable barrier therebetween. The vessel has a volume, a first stroke, and a second stroke. The liquid chamber and the gas chamber each have a variable volume that changes responsive to the first stroke and the second stroke. The gas chamber has an outer wall wherein at least a portion of the outer wall is thermally conductive and allows heat to transfer therethrough. Movement of the moveable barrier between the liquid chamber and the gas chamber causes the volume in the liquid chamber and the volume in the gas chamber to displace each other. The volume in the gas chamber plus the volume in the liquid chamber is generally constant and generally equals the volume in the variable pressure vessel.

Provided are a volume change compensation device capable of reducing a manufacturing burden with a simple configuration and a damper device including the volume change compensation device. A damper device 100 includes a rotary damper, and includes a volume change compensation device 140 in a shaft 121 of a rotor 120. The volume change compensation device 140 includes an inner cylinder piston 142 pressed by an inner cylinder piston pressing elastic body 145 in a body tube 141 communicating with a hydraulic fluid housing portion 103 of the damper device 100 through a connection path 141a. The inner cylinder piston 142 is formed in a bottomed cylindrical shape opening on a connection path 141a side. In the inner cylinder piston 142, an inner cylinder inner small piston 143 is pressed against a bottom portion 142b by a small piston pressing elastic body 144. An air hole 142c is formed at the bottom portion 142b of the inner cylinder piston 142. The inner cylinder inner small piston 143 slides in the inner cylinder piston 142 according to the amount of hydraulic fluid 150 in the inner cylinder piston 142.

A hydraulic cooler pressure isolation circuit for a header of an agricultural harvester equipped with a reservoir and a pump. The circuit comprises a hydraulic fluid cooler, a supply line extending from the hydraulic fluid cooler to the pump, a return line extending from the hydraulic fluid cooler to the reservoir, and a drain line operatively in fluid communication with the return line for connecting to the reservoir. A first valve, a second valve, a return valve, and a bypass valve of the circuit operate to direct hydraulic fluid flow through the cooler under normal system operating conditions, and direct hydraulic fluid flow to bypass the cooler when the system experiences high pressure operating conditions at the cooler.

Presented herein are systems and methods that allow for adapting at least one dimension of an accumulator in a hydraulic system when faced with certain dimensional constraints and to vary the compliance or stiffness of an accumulator.

An actuating drive for a control valve contains a working cylinder which has a piston and a piston rod and forms an actuator for the control valve. The piston bounds a first pressure space and a second pressure space to displace the piston counter to the force of a spring by applying pressure to the first pressure space via a working medium. A working medium circuit is connected to the working cylinder at first and second pressure connections to introduce and evacuate the working medium into/from the first and second pressure spaces. The working medium circuit has a working medium pump connected to convey the working fluid, at a pressure side, to the first pressure connection, and at a suction side, to the second pressure connection. The first pressure space is permanently connected, so as to convey working fluid, to the second pressure space via a bypass line.

Universal control circuitry for an electro-hydraulic valve actuator system includes logic gate circuitry to control one or more of a closing solenoid valve, an opening solenoid valve, an emergency shutdown solenoid valve, and a hydraulic fluid pump motor to route hydraulic fluid through a hydraulic circuit to actuate a valve via a hydraulic actuator according to received commands. The universal control circuitry is configured to control operation for multiple different configurations of a hydraulic valve actuator system including double-acting configurations, single-acting spring-to-open configurations, and single-acting spring-to-close configurations, each with or without an emergency shutdown arrangement (which may be configured to trip based on an external shutdown input alone or in combination with a local system power failure), a hydraulic accumulator, and maintained or momentary input commands.