A compressor (100) and a vehicle are disclosed. The compressor (100) includes: a housing (1); a separating component (2) dividing an interior of the housing (1) into a low-pressure chamber (13) and a high-pressure chamber (14); a cylinder component (3); a crankshaft (4); a plurality of oil transmission grooves (5); and at least one oil transition groove (6). During the rotation of the crankshaft (4), each oil transition groove (6) is intermittently in communication with oil transmission grooves (5) adjacent thereto. The oil transition groove (6) is alternately in communication with two oil transmission grooves (5) located at two circumferential sides of the oil transition groove (6). An oil-way passage (31) of the cylinder component (3) is in communication with one of oil transmission grooves (5), and another one of oil transmission grooves (5) or the oil transition groove (6) is in communication with the low-pressure chamber (13).

A hydrostatic axial piston machine includes a cylinder drum that rotates during operation and has a plurality of cylinder bores in which displacement pistons are arranged, each of which opens out in a control opening in one end face of the cylinder drum, and having a control part against which the cylinder drum bears with the end face and on which two kidney-shaped control ports in the form of circular arcs are provided. Between the two kidney-shaped control ports, a first changeover web and a second changeover web are formed, wherein two sets of compensating openings that are able to be overlapped by control openings are located in the changeover webs with one compensating opening of each set located in each changeover web, and the compensating openings in the two sets of compensating openings are connected together via respective compensating fluid paths.

A hydrostatic axial piston machine includes a cylinder drum that rotates during operation and has a plurality of cylinder bores in which displacement pistons are arranged, each of which opens out in a control opening in one end face of the cylinder drum, and having a control part against which the cylinder drum bears with the end face and on which two kidney-shaped control ports in the form of circular arcs are provided. Between the two kidney-shaped control ports, a first changeover web and a second changeover web are formed, wherein two sets of compensating openings that are able to be overlapped by control openings are located in the changeover webs with one compensating opening of each set located in each changeover web, and the compensating openings in the two sets of compensating openings are connected together via respective compensating fluid paths.

A piston pump includes a ported member that is moveably disposed within an internal space of a housing between a rotating group and the housing. The ported member includes a first face facing the rotating group and a second face facing a fluid inlet and outlet. The ported member includes an intake port and a discharge port. Moreover, the ported member includes a balance aperture configured to pass fluid between the biasing member and a pump chamber as the rotating group rotates within the internal space such that the biasing member biases the ported member toward a balanced position within the internal space. The balance aperture has a rim at the first face. The rim is clefted at a relief feature of the first face. The relief feature is recessed into the first face.

A nitriding layer (13) is formed on the front surface side of a base material of a cylinder block (7) including an opening side end surface (7B) and each cylinder hole (12). Then, a piston sliding surface (12A) of each cylinder hole (12) is formed as a compound layer-removed hole (17) by removing a compound layer (16) that is located on the front surface side of the nitriding layer (13) by using polishing means such as, for example, honing and so forth. Further, a compound layer-removed surface (18) is formed on a part (A) where a compound layer-removed hole (17) and a cylinder inlet side tapered surface (12B) of each cylinder hole (12) intersect by using the polishing means such as, for example, the honing and so forth. This compound layer-removed surface (18) is formed as a tapered-state inclined surface of an angle α.

A swash-plate type piston pump motor includes: a rotary shaft; a cylinder block that rotates together with the rotary shaft; a plurality of pistons (5) each of which is inserted so as to be reciprocable in each of a plurality of cylinders formed in the cylinder block; a plurality of piston shoes (6) attached so as to be swingable to an end portion (501) of each piston; a swash plate (7) inclined with respect to an axis of the rotary shaft and having a sliding surface (41) being in contact with a plurality of piston shoes; and a shoe retainer (8) configured to press the piston shoe against the sliding surface. Each piston shoe includes a shoe body (71) being in contact with a sliding surface, and an elastic body (79) provided between the shoe body and the shoe retainer.

A swash-plate type piston pump motor includes: a rotary shaft; a cylinder block that rotates together with the rotary shaft; a plurality of pistons (5) each of which is inserted so as to be reciprocable in each of a plurality of cylinders formed in the cylinder block; a plurality of piston shoes (6) attached so as to be swingable to an end portion (501) of each piston; a swash plate (7) inclined with respect to an axis of the rotary shaft and having a sliding surface (41) being in contact with a plurality of piston shoes; and a shoe retainer (8) configured to press the piston shoe against the sliding surface. Each piston shoe includes a shoe body (71) being in contact with a sliding surface, and an elastic body (79) provided between the shoe body and the shoe retainer.

A hydraulic fracturing pump includes a power end with a plurality of torsion tubes extending between sides of a crankcase housing in which a crankshaft is rotatably mounted. The crankshaft is coupled by piston arms to crossheads disposed to reciprocate along crosshead axes that are perpendicular to the crankshaft. Disposed within the crankcase housing are a plurality of ribs generally perpendicular to the crankshaft and extending from the base of the crankshaft housing to an upper surface of the crankshaft housing. The torsion tubes are generally adjacent the upper surface of the crankcase housing and pass perpendicularly through each of the plurality of ribs and are attached to the ribs to provide rigidity to the power end.

A hydraulic fracturing pump includes a power end with a plurality of torsion tubes extending between sides of a crankcase housing in which a crankshaft is rotatably mounted. The crankshaft is coupled by piston arms to crossheads disposed to reciprocate along crosshead axes that are perpendicular to the crankshaft. Disposed within the crankcase housing are a plurality of ribs generally perpendicular to the crankshaft and extending from the base of the crankshaft housing to an upper surface of the crankshaft housing. The torsion tubes are generally adjacent the upper surface of the crankcase housing and pass perpendicularly through each of the plurality of ribs and are attached to the ribs to provide rigidity to the power end.

A connector plate, for mechanically and hydraulically connecting a hydraulic machine with a hydraulic attachment part, includes a plurality of hydrostatic connector recesses. Each recess has a first side that includes a first orifice opening to the hydraulic attachment part, and a second side with a second orifice opening to the hydraulic machine. The plurality of orifices are arranged so as to open in a substantially axially parallel manner with respect to a drive shaft of the hydraulic machine. A hydraulic machine includes such a connector plate, and a hydrostatic unit includes such a hydraulic machine and a hydraulic attachment part.