The present disclosure relates to a zeroing device comprising a piston movable along an axis, at least one biasing member for biasing the piston along the axis, and an axially displaceable zeroing member limiting axial movement of the at least one biasing member. The present disclosure further relates to a variable displacement hydraulic unit including said zeroing device.

A split-cycle internal combustion engine includes a variable displacement compressor having two or more cylinders, an adjustment mechanism for varying the displacement volume of the compressor and possibly the phase between the compressor and the motor, and a rotary motor having two or more expansion chambers. A passage valve system located between the compressor and the motor transfers working fluid and combustion exhaust products, and, in addition, mechanically and thermally isolates the compressor from the high pressures and temperatures present in the motor.

A hydrostatic piston engine comprises a housing with a cylinder drum with cylinder bores mounted rotatably therein. Each of the cylinder bores receives a working piston in a longitudinally displaceable manner, via which a hydrostatic working chamber is delimited by the cylinder bore. The hydrostatic working chamber has an opening on an outer surface of the cylinder drum by which, when the cylinder drum rotates, outlets of a high-pressure chamber and of a low-pressure chamber of the piston engine and a reversing surface arranged between the two outlets in the rotational direction can be passed over in alternating fashion. At least one pressurizing medium channel is provided which, on one hand, opens out in the reversing surface and, on the other, into a pressurizing medium trough of the piston engine.

The present invention addresses the problem of providing a swash-plate hydraulic motor or a swash-plate hydraulic pump having a structure in which the swash plate can be stably held without mounting a shoe to the swash plate-side end of a tilt control piston. An example of the embodiment of the present invention is a swash-plate hydraulic motor (1). A spherical section (8b) is integrally formed on the swash plate-side end surface of a tilt piston (8), and a groove (10) into which the spherical section (8b) is fitted in a slidable manner is formed in the support surface (7b) (second support surface (7b2)) of the swash plate (7). The groove (10) is a part of the second support surface (7b2) and has a shape having a predetermined width and having a longitudinal direction which is oriented perpendicularly to the direction which connects two pivots (11).

A hydraulic motor includes a motor mechanism that rotates by hydraulic liquid that is supplied/discharged from a hydraulic liquid pressure source through one of a first motor passage and a second motor passage. The hydraulic motor comprises a casing that defines a casing chamber which accommodates the motor mechanism, and a flushing passage that is in communication with the casing chamber and extracts a portion of the hydraulic liquid from a low pressure side among the first motor passage and the second motor passage and leads it to the casing chamber.

A piston in a liquid-pressure rotating device in which pistons are arranged at a cylinder block rotatable together with a rotating shaft, includes: a cylindrical peripheral wall main body portion including a hollow portion, an opening portion formed at one end of the body portion and communicating with the hollow portion; a lid portion welded to an inner peripheral surface of the opening portion sealing the hollow portion and including an outer surface formed as a pressure receiving surface which receives liquid pressure; and a stress reducing portion provided on an inner peripheral surface of the body portion, the inner peripheral surface in contact with or close to an end portion of a welded portion formed between the opening portion and the lid portion, the end portion located at the hollow portion side, the stress reducing portion configured to reduce stress acting on the end portion of the welded portion.

A hydraulic axial-piston machine achieves a control cut-off by an additional control edge of a control valve of an actuating mechanism for swiveling a swash plate.

A system for controlling a coiled tubing injector head includes a hydraulic control line in fluid communication with each drive motor, a valve associated with one or both hydraulic control lines, and a sensor associated with each drive motor. Each sensor is configured to output to a digital computer a signal representative of a motor speed, and at least one valve associated with a hydraulic control line is operable to regulate pressure in the hydraulic control line and thereby increase or decrease the speed of the corresponding motor until both speed sensors report substantially matching motor speeds.

An apparatus and a method for converting linear motion to rotary motion are provided. In some embodiments, the apparatus may include a plate having a plurality of connection points and a channel. The apparatus may also include a wobbler having an end that extends along the first axis and a cylindrical body having a second axis that is offset from the first axis by a first angle. The plate may be rotatably connected to the cylindrical body and configured to rotate about the second axis. The apparatus may further include a plurality of flexure assemblies connected to the plurality of connection points of the plate.

A device and method for treating a wound of a patient with negative pressure is provided. The device comprises a heat-assisted pump system. The pump system can be powered in part by heat derived from the patient. The pump system may be configured to be highly planar, light weight, and portable. The pump system may comprise a Stirling engine or a thermal acoustic engine.