An automatic oil return structure is provided. The automatic oil return structure has an oil storage bag, a piston, and a main body assembly. The piston has an oil storage chamber. The main body assembly has a main channel, a piston oil channel, a pressure regulating channel, a control channel, an operation channel, a minor channel, and an oil return channel. When the pressure of the main channel achieves a limit pressure, the pressure pushes the control blocking assembly away such that the pressure regulating channel communicates with the communication channel, and the pressure also pushes the operating assembly away such that the minor channel communicates with the return channel. At the same time, the pressure of the oil storage chamber pushes the oil blocking assembly, so as to isolate the oil storage chamber from the main channel, and the oil storage chamber communicates with the oil return channel.

A differential pressure motor comprising two working pistons and a rod that move in a hollow space. Walls defining the hollow space have five openings. A valve piston moves between and against the working pistons and can be driven by the working pistons. The valve piston with the five openings forms a valve with which an alternate impact of a first pressure and a second pressure on the working pistons is controllable when the pressures are applied to three of the five openings such that the working pistons periodically move which drives a periodic movement of the valve piston. Also disclosed are a surgical drive system with, a medical lavage system for the debridement of soft tissue and/or bone tissue having, and a medical device for brushing, rasping or sawing soft tissue and/or bone tissue with such a differential pressure motor, and a method for operating a differential pressure motor.

A linear actuator system has a rotary spool valve configuration having a spool, a piston, and a cylinder. The spool and piston have return apertures so positioned, configured and angled to direct return flow towards the center of a spool central return port and spool pressure ports to direct pressurized flow into upper or lower chambers. Rotation of the spool synchronizes and aligns ports and apertures to reverse flows and effect upward and downward translation of the cylinder to vibrationally drive an implement to perform work. The positioned and angled apertures direct the fluid to a region demarcated by a total length of 1.5 times the interior diameter of the spool central return port centered about a piston shoulder. A base plug member having a bull-nose tip, baffles and cavities is disposed within the spool central return port to reduce or eliminate cavitation.

In a fluid circuit for an air cylinder connected to a switching valve provided with exhaust ports, a head-side pressure chamber is connected to the switching valve by a first pipe, and a rod-side pressure chamber is connected to the switching valve by a second pipe. A first restrictor is disposed at a connection point between the first pipe and the switching valve or in the vicinity of a first output port of the switching valve, and a second restrictor is disposed at a connection point between the second pipe and the switching valve or in the vicinity of a second output port of the switching valve.

In general, techniques are described regarding a rotary servo for actuators. A servo assembly includes a cylindrical outer sleeve including ports, a cylindrical outer spool annularly disposed within the cylindrical outer sleeve, a stepper motor mechanically coupled to the cylindrical outer spool, and an actuator mechanically coupled to compressor variable geometry that controls compression provided by a compressor. The cylindrical outer spool includes channels configured to provide fluidic interconnection between the ports and a cylindrical inner spool, where the cylindrical inner spool is annularly disposed within the cylindrical outer spool, and the cylindrical inner spool includes grooves configured to provide fluidic interconnection through the channels of the cylindrical outer sleeve. The stepper motor is configured to rotate the cylindrical outer spool within the cylindrical outer sleeve to deliver a fluid to and thereby actuate the actuator to control the compressor variable geometry.

A fluid actuated linear drive includes a drive housing and a drive member which is movable between two stroke end positions. The drive member has a drive unit with a drive piston which divides off two drive chambers from one another, the drive chambers via two housing channels being connected to axial housing coupling openings which are arranged on a housing rear side. A multi-function module is built onto the housing rear side in a position of use and includes components of an external end position setting device for the drive member and is furthermore provided with module block channel systems which communicate with the housing channels and can be used for the feed and discharge of a drive fluid when the multifunction module is built onto the drive housing in the position of use.

A method for selectively coupling or uncoupling a coupling with a release, arranged between the supply conduit and a cylinder, on the basis of pressure in a supply conduit. The method includes providing an operating pressure prevailing in the supply conduit in order to provide hydraulic liquid to the cylinder on the basis thereof and providing an uncoupling pressure prevailing in the supply conduit for the purpose of activating shut-off valves in the supply conduit and on the cylinder and activating a release which uncouples the coupling. A coupling for respectively coupling and uncoupling a supply conduit which is connected to the coupling to/from a cylinder, as well as to an assembly including a pump, a cylinder, a supply conduit between the pump and the cylinder, and such a coupling.

A connection device between at least one hydraulic pressure supply device, such as the pressure supply device of a mobile work machine, and at least one hydraulic consumer, such as a hydraulically actuatable work tool of at least one attachment device, having hydraulic connectors (2) at the side of the supply device and correspondingly couplable hydraulic connectors (6) at the side of the respective consumer, characterized in that by means of consumer-side data storage devices (8) data relating to the respective consumer is transmitted to the respectively assignable supply device so that, in the coupled state of the mutually assigned hydraulic connectors (2, 6), the respective consumer is individually supplied by its supply device with hydraulic medium of predeterminable pressure and volume flow.

Disclosed is a piston-cylinder assembly of a hydraulic press, which includes a basic cylinder and a first and second piston. A ring cylinder is formed above the basic cylinder as a continuation of the cylinder structure. The first piston is located inside the basic cylinder in the bottom part of the basic cylinder and the second piston is located above the first piston in the top part of the cylinder structure. The piston-cylinder assembly has a first hydraulic fluid space below the first piston and a second hydraulic fluid space below the second piston and the piston-cylinder assembly includes a unified hydraulic fluid channel in flow connection to the first hydraulic fluid space in order to provide a pressure effect in the first piston and to the second hydraulic fluid space in order to provide a pressure effect in the second piston.

A valve mounting mechanism, for mounting a mount valve on a cylinder tube of a hydraulic cylinder, includes: an attachment structure that attaches the mount valve to the hydraulic cylinder; a connection structure that connects a second end part of a hydraulic pipe, whose first end part is connected to the hydraulic cylinder, to a cylinder port of the mount valve; and an adjustment mechanism that adjusts relative positions of a pipe fastening portion, where the hydraulic pipe is fastened to the connection structure, and the mount valve.