An arrangement that can be turned by an assigned hydraulic pressure and flow, related to a chain saw supported by a harvesting unit for crosscutting timber, wherein a bearing arrangement is arranged for the chain saw and oriented between a guide bar housing and the chain saw's drive motor unit, wherewith an oscillatory motion can be activated by a hydraulic control valve, through which hydraulic flow is alternatively controlled via feed or connection lines to the bearing arrangement, for a first or second operating mode. The arrangement is activated via hydrostatic pressure and coordinated with the guide bar housing, and with the drive motor unit, via surrounding perforated discs oriented in parallel and aligned around an axis of rotation for a drive shaft. The hydrostatic affects the arrangement's oscillatory motion for a reciprocal motion pattern, while spent hydraulic oil serves as a lubricating film between the opposing bearing surfaces.

A cylinder is installed within a case, and an output shaft and an arm that is integrated thereto and extends in a radial direction are installed within the cylinder. A piston extending in an arc slides and is displaced in a circumferential direction of the cylinder within the cylinder. One end portion of the piston is rotatably connected to the arm. The cylinder is internally provided with a first pressure chamber in which the arm is housed and a second pressure chamber in which the other end portion of the arm is slidably installed. A pressure medium is fed into one of the first and second pressure chambers and discharged from the other, and the output shaft pivots in a rotational direction.

A cylinder is installed within a case, and an output shaft and an arm that is integrated thereto and extends in a radial direction are installed within the cylinder. A piston extending in an arc slides and is displaced in a circumferential direction of the cylinder within the cylinder. One end portion of the piston is rotatably connected to the arm. The cylinder is internally provided with a first pressure chamber in which the arm is housed and a second pressure chamber in which the other end portion of the arm is slidably installed. A pressure medium is fed into one of the first and second pressure chambers and discharged from the other, and the output shaft pivots in a rotational direction.

A rotary oscillating sub-assembly for positive displacement pumping of a fluid, said sub-assembly comprising: a hollow body defining a cavity having a wall with two ducts passing therethrough; a piston co-operating with said cavity to define a working chamber and including a channel that opens out longitudinally into said working chamber, said piston being movable angularly so as to put said working chamber into fluid-flow communication with one, then none, then the other of said ducts, and being movable in longitudinal translation to reciprocate so as to cause the volume of said working chamber to vary and successively suck in and then discharge said fluid, said piston carrying a sealing gasket that is formed of at least a sealing ring, a sealing half-ring, and at least one sealing strip that longitudinally connects said sealing ring to said sealing half-ring.

A rotary positive displacement pump for fluids, in particular for the lubrication oil of a motor vehicle engine (60), has a displacement that can be regulated by means of the rotation of a stator ring (12) having an eccentric cavity (13) in which the rotor (15) of the pump (1) rotates. The stator ring (12) is configured as a multistage rotary piston for displacement regulation and is arranged to be directly driven by a fluid under pressure, in particular oil taken from a delivery side (19) of the pump or from a point of the lubrication circuit located downstream the oil filter (62). The invention also concerns a method of regulating the displacement of the pump (1) and a lubrication system for a motor vehicle engine in which the pump (1) is used.

A rotary compressor or pump has a cam with a plurality of lobes mechanically engaging a plurality of pistons. The lobes urge the pistons from an open to a closed position within a piston void, the closure of the piston into the piston void creating compression or pressure of a material. Each piston is linked to another piston, and as one piston is closed by the cam, the other piston is opened by a linkage.

A thick matter pump with a conveying chamber which extends along a closed path from an inlet opening via an outlet opening back to the inlet opening, with the result that the conveying chamber forms a first connecting path and a second connecting path between the inlet opening and the outlet opening. A first piston performs a conveying movement along the first connecting path of the conveying chamber, with the result that, by way of the conveying movement, thick matter is conveyed out of the conveying chamber through the outlet opening, and thick matter is introduced through the inlet opening into the conveying chamber. A shut-off element is arranged in the conveying chamber, which shut-off element, in a first state, shuts off the second connecting path and, in a second state, opens the second connecting path in order to permit a movement of the first piston along the second connecting path. Moreover, the invention relates to a method for conveying thick matter.

A multi-stage compressor includes a compression module configured to compress a refrigerant therein through reciprocation of a plurality of pistons provided in a front housing, a rear housing coupled to the front housing to define an internal space between the front housing and the rear housing; a separation plate located between the front housing and the rear housing to separate the internal space between the front housing and the rear housing into a front space and a rear space; and a partition wall coupled to the rear housing to partition the rear space into an injection space before a refrigerant injected thereinto is primarily compressed, a primary discharge space from which the refrigerant is discharged in a primary compressed state by some of the pistons, and a secondary discharge space from which the primary compressed refrigerant is discharged.

A radial piston machine includes a rotor within a housing that is rotatable about an axis, a shaft coupled to the rotor, a distributor which surrounds the shaft and cannot rotate with the rotor and that contacts the rotor in an axial direction, a plurality of brake discs including first brake discs and second brake discs arranged side-by-side along the axis, wherein the first brake discs are coupled to the housing for torque transmission, and the second brake discs are coupled to the shaft for torque transmission, and an actuator configured to releasably exert a brake force in the axial direction on the brake discs. The distributor is located axially between the rotor and the actuator, and the brake discs are located axially between the distributor and the actuator. When the brake force is exerted the brake force is supported by the distributor in the axial direction.

The present disclosure provides a two-dimensional motor piston pump, including a two-dimensional motor and a two-dimensional piston pump. The two-dimensional motor and the two-dimensional piston pump are nested with each other and arranged coaxially. The two-dimensional motor includes a stator and an outer rotor, and the outer rotor is coaxial with the stator and is sleeved outside the stator. The two-dimensional piston pump includes: a flow distribution mechanism including a flow distribution rotor and a pump body, a piston mechanism including a left cam and a right cam; a roller assembly including a roller and a roller shaft, and a pump housing, a left end cover, and a right end cover.