A refrigeration device includes a compressor, a condenser, an expansion valve, an evaporator, intake electromagnetic valves and exhaust electromagnetic valves, two-position three-way electromagnetic valves or two-position five-way electromagnetic valves, a cylinder group, a volume-variable airproof container, two-position two-way electromagnetic valves and a generator. The cylinder group is composed of two or more cylinders, refrigerant flows successively through the compressor, the intake electromagnetic valves, the cylinder group, the exhaust electromagnetic valves, the condenser, the expansion valve and the evaporator and finally enters the compressor from the evaporator, the cylinder group can do work to generate electricity through atmospheric pressure in the volume-variable airproof container and compensates for electric energy consumed by the compressor, and therefore the electric energy can be saved.

A method for manufacturing an at least sectionally spherical-cap-shaped recess on a drive shaft for a hydrostatic axial piston machine includes whirling of the recess and heat treatment of the recess to form a wear layer. A drive shaft for a hydrostatic axial piston machine includes at least one recess manufactured according to the method. A hydrostatic axial piston machine includes a drive shaft with at least one recess manufactured according to the method.

A rotary fluid pump-motor includes first and second rotor assemblies and a bent cylinder sleeve. The first rotor assembly includes a first rotor, a piston cylinder, and a flange ring with an inclined guide surface. The second rotor assembly includes a second rotor and a piston. The first and second rotors are rotatably movable about inclined first and second rotor axes, respectively. The bent cylinder sleeve receives the piston cylinder and the piston therein through respective sleeve openings to define a piston chamber therebetween. The bent cylinder sleeve is in at least intermittent contacting relationship with the flange ring's inclined guide surface and rotatably movable about the first rotor axis with respect to the inclined guide surface such that the bent cylinder sleeve moves along the first rotor axis relative to the piston cylinder based upon its circumferential position along the inclined guide surface to correspondingly vary the piston chamber's volume.

A fluid pressure rotary machine includes a cylinder block that is fixed to a rotary shaft and includes a plurality of cylinder bores, a piston disposed to be free to slide in each cylinder bore such that a volume chamber is defined thereby, a swash plate that causes the piston to reciprocate such that the volume chamber expands and contracts, and a valve plate that slides against the cylinder block and includes an intake port and a discharge port communicating with the volume chamber. The valve plate includes a sliding surface formed to project in a spherical shape against the cylinder block. The cylinder block includes a sliding surface formed as an indentation corresponding to the shape of the sliding surface of the valve plate. A minute gap is formed between the sliding surface of the valve plate and the sliding surface of the cylinder block in an outer edge position.

An internal combustion engine enabling asymmetric port timing has an engine mechanism including a crankshaft having a crankpin to which each piston of an opposed pair of pistons is connected and by which the pistons are reciprocatable in a respective one of axially inline cylinders. The mechanism also includes a crosshead having opposite ends on each of which a respective piston is mounted, and a coupling between the crosshead and the crankpin by which the pistons are caused to oscillate circumferentially as the pistons are driven to reciprocate.

A piston for an axial machine includes a piston body having a cavity that is closed in a pressure-tight way. The cavity is divided into a plurality of chambers, arranged one beside the other in cross-section.

A hydraulic pressure exchanger comprising a drum rotatable about an axis, a front plate arrangement having a front plate and a pressure shoe, said drum including a plurality of working cylinders, each working cylinder having a front opening and, during rotation of this drum, said front opening sliding over said pressure shoe along a path, said pressure shoe having at least two kidney-shaped openings, said kidney-shaped openings being arranged in said path. The hydraulic pressure exchanger should be operated with low noise. To this end said pressure shoe is arranged between said drum and said front plate and comprises at least one pressure cylinder arranged between two neighboring kidney-shaped openings, a piston being arranged in said pressure cylinder and resting against said front plate, said pressure cylinder being connected with a supply opening in a side of the pressure shoe opposite said front plate, said opening at least partly overlapping said path.

A fixed shaft of a hydraulic unit is provided including a body having a first end and a second opposite end. A first flange and a substantially identical second flange are integrally formed with the body of the shaft adjacent the second end. The second end of the body has an outer diameter of 0.9900.005 inches (2.5150127 cm). The first and second flange each have an axial length parallel to a longitudinal axis of the body of about 0.0850.010 inches (0.2160.0254 cm). The first and second flange having an outer diameter of 1.359 inches (3.452 cm). The first flange and the second flange are separated by from one another by a distance of about 0.3162 inches (0.8031 cm). The portion of the body between the first flange and the second flange has an outer diameter of about 1.2013 inches (3.051 cm).

Positive displacement machines and methods therefor capable of increasing a load-carrying capacity of a piston-cylinder lubrication interface of positive displacement machines having a cylinder block, a cylindrical bore defined in the cylinder block, a piston reciprocably disposed within the cylindrical bore, and a working fluid within the piston-cylinder lubrication interface to provide a load-bearing function between the piston and the bore wall of the cylinder bore. The method includes providing at least one circumferential groove on a bore wall of the cylindrical bore within the piston-cylinder lubrication interface having an opening facing the piston and that is in fluidic communication with the piston-cylinder lubrication interface so as to contain a portion of the working fluid, and operating the positive displacement machine such that the working fluid enters the cylindrical groove and promotes hydrostatic balancing of pressure of the working fluid within the piston-cylinder lubrication interface.

To provide an axial piston motor, comprising at least one main burner, which has at least one main combustion space and at least one main nozzle space, and comprising at least one pre-burner, which has at least one pre-combustion space and at least one pre-nozzle space, wherein the pre-combustion space is connected to the main nozzle space by way of at least one hot gas feed, that has improved operating and control characteristics even under non-steady-state operating conditions, the pre-nozzle space of the pre-burner has at least one auxiliary hot gas feed.