A self-contained pressure compensation system and a control method thereof are provided, wherein the self-contained pressure compensation system comprises an oil supply device, a pressure compensation device, a power unit associated with the pressure compensation device, and a switch control device, the pressure compensation device supplies oil to the power unit and detects a change in a chamber pressure of itself in real time, the switch control device triggers the oil supply device to supply oil to the pressure compensation device if the chamber pressure is less than a predetermined first threshold and triggers the oil supply device to stop supplying oil to the pressure compensation device if the chamber pressure is greater than a predetermined second threshold. The invention can detect a chamber pressure of the pressure compensation device in real-time and can achieve automatic oil refilling, and can provide pressure compensation for the power unit effectively.

A positioning apparatus for positioning a tubular fluid container in an elongate carrier which is configured as a hollow profile. In order to simplify the positioning of the tubular fluid container, the positioning apparatus includes spring elements, by way of which the tubular fluid container is positioned in the elongate carrier.

A drop-in signal accumulator piston assembly replaces an original equipment (OE) signal accumulator piston in a vehicle transmission hydraulic circuit. The OE signal accumulator piston is positioned in a bore in a valve body that has an open end and a fluid port. The drop-in signal accumulator piston assembly includes a cylindrical sleeve having open first and second ends and a piston positioned in the sleeve. A spring is positioned in part in the piston and in part extending beyond and end of the piston. A plug is positioned in the bore adjacent the sleeve. The sleeve is positioned in the valve body bore, with the piston, and the spring, and the plug is positioned in the valve body bore to enclose the sleeve, the piston and the spring in the valve body bore. A method for replacing an original equipment (OE) signal accumulator piston in a transmission hydraulic circuit is disclosed.

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 vibration damper comprising a working cylinder, which is subdivided by an axially movable piston on a piston rod into a first and a second working chamber filled with a damping medium is disclosed. The vibration damper has at least one compensating reservoir for receiving the damping medium displaced by the piston rod. There is a flow connection between the two working chambers, in which connection there is incorporated a pump assembly. The pump assembly has a fluctuation in the delivery volume with a constant power supply. At least one pulsation accumulator is arranged within the flow connection, wherein the volume and spring rate of the pulsation accumulator are matched to a frequency of a fluctuation of the delivery volume of the pump assembly.

A liquid feeder includes a pump which is prevented from idling, and a replenisher including a cylinder that is a bottomed tube including an opening on a side adjacent to a communication flow path, the opening being connected to the communication flow path, and that is capable of accommodating a liquid in at least a portion of the cylinder, a seal that is housed in the cylinder in a movable manner along the cylinder, and seals the liquid in the cylinder, and a pressurizer to pressurize the seal toward a pump chamber.

A hydraulic block of a slip control system of a hydraulic vehicle brake system includes a hydraulic accumulator, a hollow storage cover, and an accumulator cylinder defined partly by a blind hole in the hydraulic block and partly by the hollow storage cover. The blind hole is closed by the hollow storage cover. An accumulator piston of the hydraulic accumulator is sealed and guided to or close to the ends in the blind hole in the hydraulic block and in the storage cover.

A hydraulic control unit that delivers hydraulic fluid to a limited slip differential includes a hydraulic control unit housing, a sump and a motor. The hydraulic control unit housing has an accumulator housing portion that houses a biasing assembly and a piston. The sump is defined in the hydraulic control unit housing and at least partially occupies a common space with the accumulator housing portion. The motor is configured to pump fluid into an accumulator chamber of the accumulator housing portion. The fluid pumped into the accumulator housing portion at least partially collapses the biasing assembly and introduces a pre-charge into the hydraulic control unit. The biasing assembly is configured to expand and urge the piston in a first direction resulting in fluid being communicated from the hydraulic control unit and into the limited slip differential.

A hydraulic accumulator includes a limiting portion that is fitted into a ring end gap of a snap ring to limit a decrease in a diameter of the snap ring. The snap ring is stamped from a metal sheet by a press machine. Therefore, one of two opposed surfaces of a portion of the snap ring, which is fitted into a groove, forms a sloped surface as a result of shear droop. The limiting portion is fitted into the ring end gap of the snap ring to limit the decrease in the diameter of the snap ring. Thus, it is possible to limit riding of the sloped surface of the snap ring on a corner of the groove, and thereby it is possible to limit removal of the snap ring from the groove.

A hydraulic propulsion system converts heat or thermal energy into hydraulic energy, and such hydraulic energy into mechanical work. The hydraulic propulsion system includes a thermal unit, a hydraulic cylinder with pistons and springs mounted therein, one or more hydraulic motors, one or more hydraulic accumulators, and one or more electrical energy generators, as well as a plurality of flow control valves to control the flow of hydraulic fluid between the various components. The hydraulic propulsion system may be enhanced by a sonic transmission unit including a sonic wave generator.