Abstract: A hydraulic piston machine is described comprising a piston (1) having a hollow (2) secured by a wall (3) and an insert (4) arranged in the hollow. Such a machine should have a high efficiency at low costs. To this end the insert (4) comprises a section (29) which extends out of the hollow (2).

Abstract: A piston (1) having a piston shaft (2), a ball head (3) at one end of the piston shaft (2), and a slider shoe (4) mounted to the ball head (3), wherein the ball head (3) has a through channel (5), the slider shoe (4) has a sliding surface (6) and a through hole (7) in communication with an end of the through channel (5), and a plastic material (8) is arranged in a gap between the slider shoe (4) and the ball head (3) and forms an inner coating (9) of the through hole (7). The production of such a piston should be facilitated. To this end a sealing surface (14) is arranged at the end of the through channel (5) wherein the sealing surface (14) surrounds the opening of the through channel (5) into the through bore (7) and an inner diameter of the sealing surface (14) is smaller than an inner diameter of the inner coating (9) of the through bore (7).

Abstract: A piston (1) of a hydraulic piston machine is described, the piston (1) having a hollow (2) surrounded by a wall (3) and an insert (4) arranged in the hollow (2). Such a piston is used to have a piston machine with high efficiency at low costs. To this end at least two pliable rings (12, 13) are arranged between the insert (4) and the wall (3).

Abstract: A piston (1) having a piston shaft (2), a ball head (3) at one end of the piston shaft (2), and a slider shoe (4) mounted to the ball head (3), wherein the ball head (3) has a through channel (5), the slider shoe (4) has a sliding surface (6) and a through hole (7) in communication with an end of the through channel (5), and a plastic material (8) is arranged in a gap between the slider shoe (4) and the ball head (3) and forms an inner coating (9) of the through hole (7). The production of such a piston should be facilitated. To this end a sealing surface (14) is arranged at the end of the through channel (5) wherein the sealing surface (14) surrounds the opening of the through channel (5) into the through bore (7) and an inner diameter of the sealing surface (14) is smaller than an inner diameter of the inner coating (9) of the through bore (7).

Abstract: A valve plate assembly (1) of a hydraulic axial piston machine is described, the valve plate assembly comprising a wear plate (2) made of a ceramic material surrounded by a compression ring (4). Such a valve plate assembly should be produced and maintained in a cost-effective manner. To this end, the wear plate (2) is connected to a support plate (3) by means of the compression ring (4).

Abstract: A check-valve (1) including a housing (2, 3) having an inlet (5), an outlet (6), a fluid flow path between the inlet (5) and the outlet (6) and a valve seat (7) in the fluid path, the valve seat (7) having a valve seat axis (8), a valve element (9), a valve element support (12) arranged in the housing (2, 3) and supporting the valve element (9), is described, wherein the section (19) of the fluid flow path is formed between the housing (2, 3) and the valve element support (12) and the valve element (9) is moveable between a position in which it rests against the valve seat (7) and a position in which contacts against the valve element support (12). Such a check-valve should have a simple construction keeping low noise and wear. To this end, the valve element support (12) includes at least one recess (12) having an open side to the section (19) of the fluid flow path and connecting the section (19) of the fluid flow path to a space between the valve element (9) and the valve element support (12.

Abstract: The invention relates to a device for supplying ports to a machine section (26) of a hydraulic machine arrangement (40), the device (10) comprising a low-pressure inlet port (12), a leakage inlet (16), a low-pressure chamber (18) having a low-pressure opening (22) for establishing fluid communication with the machine section (26), a high-pressure outlet port (14), and a high-pressure chamber (20) that is in fluid communication with the high-pressure outlet port (14), the high-pressure chamber (20) having a high-pressure opening (24) for establishing fluid communication with the machine section (26), wherein the low-pressure inlet port (12) is in fluid communication with the low-pressure chamber (18), wherein a leakage path (36) extends from the high-pressure chamber (20) through the machine section (26) to the leakage inlet (16), characterized in that the device (10) further comprises a control valve member (28) connecting the leakage inlet (16) to the low-pressure chamber (18), wherein the control valve memb

Abstract: A valve plate assembly (1) of a hydraulic axial piston machine is described, the valve plate assembly comprising a wear plate (2) made of a ceramic material surrounded by a compression ring (4). Such a valve plate assembly should be produced and maintained in a cost-effective manner. To this end, the wear plate (2) is connected to a support plate (3) by means of the compression ring (4).

Abstract: A hydraulic axial piston machine (1) is described, the machine comprising a housing, a cylinder block (2) rotatably mounted in the housing about an axis or rotation (7) and having at least one cylinder (3), and a valve arrangement (4) between the cylinder block (2) and the housing, the valve arrangement having a first part (4) rotating with the cylinder block (2) and a second part mounted stationary with respect to the housing. Such a machine should have a high efficiency. To this end the first part (4) comprises an elastically deformable spring section (9).

Abstract: A hydraulic piston machine is described comprising a piston (1) having a hollow (2) secured by a wall (3) and an insert (4) arranged in the hollow. Such a machine should have a high efficiency at low costs. To this end the insert (4) comprises a section (29) which extends out of the hollow (2).

Abstract: A piston (1) of a hydraulic piston machine is described, the piston (1) having a hollow (2) surrounded by a wall (3) and an insert (4) arranged in the hollow (2). Such a piston is used to have a piston machine with high efficiency at low costs. To this end at least two pliable rings (12, 13) are arranged between the insert (4) and the wall (3).

Abstract: A method for producing a water-hydraulic machine having a first member (1) and a second member (2) in sliding contact with a contact surface (3) of the first member (1), wherein the second member (2) comprises a surface made of a friction reducing plastic material and the contact surface (3) is a metallic surface, is disclosed. The machine should have a low risk of damages. To this end, the method includes the steps of using a first member (1) comprising a first part (4) having the contact surface (3) and a second part (5), using a high temperature hardening process at a temperature of at least 1000° C. to give a deep surface hardening of the contact surface (3) of the first part (4), machining of the first part (4) to the desired geometry, assembling the first part (4) and the second part (5) to form the first member.

Abstract: The invention relates to a device for supplying ports to a machine section (26) of a hydraulic machine arrangement (40), the device (10) comprising a low-pressure inlet port (12), a leakage inlet (16), a low-pressure chamber (18) having a low-pressure opening (22) for establishing fluid communication with the machine section (26), a high-pressure outlet port (14), and a high-pressure chamber (20) that is in fluid communication with the high-pressure outlet port (14), the high-pressure chamber (20) having a high-pressure opening (24) for establishing fluid communication with the machine section (26), wherein the low-pressure inlet port (12) is in fluid communication with the low-pressure chamber (18), wherein a leakage path (36) extends from the high-pressure chamber (20) through the machine section (26) to the leakage inlet (16), characterized in that the device (10) further comprises a control valve member (28) connecting the leakage inlet (16) to the low-pressure chamber (18), wherein the control valve memb

Abstract: A pump device (1) is provided comprising: a shaft (2), rotor means (3a, 3b) fixed to said shaft (2) in rotational direction, said rotor means (3a, 3b) having pressure chambers (5a, 5b) the volume of which varying during a rotation of said rotor means (3a, 3b), port plate means (15a, 15b) having a through going opening (16a, 16b) for each of said pressure chambers (5a, 5b) and being connected to said rotor means (3a, 3b) in rotational direction, and valve plate means (17a, 17b) cooperating with said port plate means (15a, 15b). It is intended to pressurize a high volume of fluid, in particular water, within a limited space.

Abstract: An axial piston machine (1) is shown, comprising: a shaft (2) having an axis (3) of rotation, a cylinder drum (4) connected to said shaft (2) and having at least a cylinder (5) parallel to said axis (3) of rotation, a piston (6) movable in said cylinder (5), a swash plate (13), a slide shoe (11) pivotally mounted to said piston (6), and holding means holding said slide shoe (11) against said swash plate (13), said holding means having a pressure plate (14) and a number of coil springs (15) arranged between said cylinder drum (4) and said pressure plate (14). The object is to have a reliable operation of said machine with a simple construction. To this end each coil spring (15) is at least at one end fixed by a protrusion (20) extending into said coil spring (15).

Abstract: A water-hydraulic machine (1) is disclosed with at least two parts which are movable relative to one another, of which one has a surface composed of a plastic (5, 12, 13, 15, 19) with friction-reducing properties. With such a design the wear in case of a water-hydraulic machine should be kept low. To this end, the plastic (5, 12, 13, 15, 19) is formed as a polymer with ceramic filler.

Abstract: A pump device (1) is provided comprising: a shaft (2), rotor means (3a, 3b) fixed to said shaft (2) in rotational direction, said rotor means (3a, 3b) having pressure chambers (5a, 5b) the volume of which varying during a rotation of said rotor means (3a, 3b), port plate means (15a, 15b) having a through going opening (16a, 16b) for each of said pressure chambers (5a, 5b) and being connected to said rotor means (3a, 3b) in rotational direction, and valve plate means (17a, 17b) cooperating with said port plate means (15a, 15b). It is intended to pressurize a high volume of fluid, in particular water, within a limited space.

Abstract: An axial piston machine (1) is shown, comprising: a shaft (2) having an axis (3) of rotation, a cylinder drum (4) connected to said shaft (2) and having at least a cylinder (5) parallel to said axis (3) of rotation, a piston (6) movable in said cylinder (5), a swash plate (13), a slide shoe (11) pivotally mounted to said piston (6), and holding means holding said slide shoe (11) against said swash plate (13), said holding means having a pressure plate (14) and a number of coil springs (15) arranged between said cylinder drum (4) and said pressure plate (14). The object is to have a reliable operation of said machine with a simple construction. To this end each coil spring (15) is at least at one end fixed by a protrusion (20) extending into said coil spring (15).

Abstract: The invention concerns a rotor (1) for an electric drive motor of a refrigerant compressor with a cylinder ring (2), several permanent magnets (14) resting on the radial inside of the cylinder ring (2), each permanent magnet (14) forming a ring section, and fixing elements (15) between the permanent magnets (14), said fixing elements (15) engaging a fixing geometry (4, 16) of the cylinder ring (2). It is endeavoured to simplify the manufacturing of such a rotor. For this purpose, the cylinder ring (2) is located in a carrier (5), which comprises a bottom (6) and a circumferential wall (7), the permanent magnets (14, 14a, 14b) resting on the bottom (6), and each fixing element (15, 15a, 15b) comprising at least one projection (17, 18), which covers a side (24) of the permanent magnet (14, 14a, 14b) facing away from the bottom (6).