A double-headed piston type swash plate compressor includes a rotation shaft, a housing, a swash plate, two cylinder bores, a double-headed piston, and two shoes. The double-headed piston includes two shoe holders, a neck, two heads, and two coupling portions. Each of the coupling portions includes an outer portion and an inner portion. A direction orthogonal to both of an opposing direction of the inner portion and the outer portion and the axial direction of the double-headed piston is referred to as a widthwise direction. The inner portion includes a narrow portion and a wide portion. The wide portion projects out of the narrow portion in the widthwise direction and has a larger width than the narrow portion. An outer surface of the wide portion is slidable on a wall surface of the corresponding cylinder bore when the double-headed piston reciprocates in the cylinder bores.

A double-headed piston type swash plate compressor includes a rotation shaft, a housing, a swash plate, two cylinder bores, a double-headed piston, and two shoes. The double-headed piston includes two shoe holders, a neck, two heads, and two coupling portions. At least one of the two coupling portions includes a load receiving portion. The load receiving portion is configured to receive bending load that is applied from the swash plate to the double-headed piston and acts toward an inner side in the radial direction. The load receiving portion is separated from the wall surface of the cylinder bore when load applied to the double-headed piston is less than a specific threshold value. The load receiving portion abuts against the inner wall of the cylinder bore and receives the bending load when the load applied to the double-headed piston is greater than the specific threshold value.

A variable displacement swash plate type compressor includes a rotary shaft, a swash plate, and an actuator. The actuator includes a partition body, a movable body, and a coupling member located radially outward of the rotary shaft of the swash plate. The movable body has a guide surface for changing the inclination angle of the swash plate and a sliding portion that slides on the rotary shaft or the partition body. When viewed in a direction that is perpendicular to a direction in which the rotational axis of the rotary shaft extends and perpendicular to a first direction, the guide surface has a curved shape that is configured such that a normal of the guide surface and the rotational axis of the rotary shaft intersect in a zone surrounded by the sliding portion in the entire range of change in the inclination angle.

A variable displacement type swash plate compressor includes a housing having therein a swash plate chamber and a plurality of cylinder bores, a drive shaft, a swash plate, a link mechanism, and a plurality of the pistons. The compressor further includes a partition member, a movable member, and a control pressure chamber, and a control mechanism. First and second seal members are disposed between the partition member and the movable member and between the drive shaft and the movable member, respectively, and are elastically deformed to provide sealing between the control pressure chamber and the swash plate chamber. At least one of a clearance formed between the partition member and the movable member and a clearance formed between the drive shaft and the movable member when the swash plate is at its minimum inclination angle is greater than when the swash plate at a maximum inclination angle position.

Disclosed are hollow pistons made from a single piece of starting material and methods of manufacturing hollow pistons from the single piece of starting material.

A linear compressor and a method for manufacturing a linear compressor are provided. A piston of a linear compressor may include a surface treatment body made of aluminum or an aluminum alloy; a first surface treatment provided on an outer surface of the surface treatment body by a first vacuum deposition process; and a second surface treatment provided on an outer surface of the first surface treatment by a second vacuum deposition process.

An axial piston pump having several pistons has a magnetic encoder (5), which is arranged on a swash plate, and a magnetic field sensor, which is arranged in such a way that it faces towards the magnetic encoder (5). The magnetic encoder (5) has at least two permanent magnets (2, 3) and a plate (4) which consists of a ferromagnetic material. The permanent magnets (2, 3) are arranged on the plate (4) in such a way that they each faces a magnetic pole towards the plate (4), and this pole is at least partially covered by the plate (4) in each case.

A method of producing a piston blank, comprising producing an intermediate blank of a piston for an axial piston machine by extrusion wherein the intermediate blank includes a shaft portion, a ball head portion, and a sealing portion, wherein the shaft portion connects the ball head portion to the sealing portion. The method also includes producing a piston blank of the piston from the intermediate blank and machining a through-opening in the intermediate blank, wherein the through-opening extends within the piston blank in the longitudinal direction.

A swash plate compressor has bosses on the inner faces of the bridges of its pistons that contact the outer face of the swash plate only between the edges to eliminate wear at the edges and to thereby increase the life of the compressor.

A piston ring is used for a reciprocating compressor. In the piston ring, polytetrafluoroethylene and polyetheretherketone or polyimide account for 50% or more by mass in total. The piston ring does not contain polyphenylene sulfide. The piston ring has a tensile strength within a range of more than 15 MPa and less than 100 MPa.