A hydraulic pump motor includes: a cylinder block; a plurality of cylinder bores; a port block and a valve plate, the valve plate being provided with a high pressure port and a low pressure port, the port block being provided with a discharge oil passage and a suction oil passage, a piston disposed in each cylinder bore, and oil flowing through the discharge oil passage and the suction oil passage. Further, the valve plate is provided with a reproduction port at a bottom dead center side position, the port block is internally provided with a reproduction oil passage, and the reproduction oil passage passes through a first region on a side of the high pressure port of the virtual plane and passes through a second region on a side of the low pressure port of the virtual plane in the port block.

A swashplate-type axial piston machine includes a housing and at least one working channel extending through a distributor plate. The at least one working channel opens out at an outside on the housing at an associated working port. The at least one working channel includes a first section and a second section. The first section extends over the entire distributor plate. The second section is arranged entirely in the housing. The second section directly adjoins the first section. A first rotary bearing has an outer circumferential surface that defines a circular cylindrical reference cylinder about the axis of rotation.

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 member (28) transfers to an open state when a pressure in the leakage inlet (16) with respect to a pressure in the low-pressure chamber (18) is higher than a predefined control pressure threshold. The device (10) reduces cavitation in hydraulic machine arrangements (40).

There is disclosed a hydrostatic axial piston machine having a pulse reduction device. This device has a connection location or tap in the transition region in front of the high-pressure-side kidney-like elongate hole of a distributor plate. The connection location or tap is connected by means of one or two hydraulically passively controlled switching valves to a high-pressure store. It is used for precompression and consequently for the pulse reduction. In a development, the distributor plate also has a connection location or tap in the transition region behind the high-pressure-side kidney-like elongate hole. The connection location or tap is connected via one or two hydraulically passively controlled switching valves to a low-pressure store. This is used for the decompression and consequently also for the pulse reduction.

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).

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).

A bent-axis axial-piston hydraulic machine may have a cylinder block being movable circumferentially about a first rotation axis. The machine may also have a transmission shaft which is functionally associated with the cylinder block and which can rotate about a transmission axis incident on the rotation axis. The machine may also have a distributor, and a device for angular offsetting which is associated with the distributor to rotate the distributor to cause a variation of effective cubic capacity while a geometric cubic capacity of the machine remains constant. The corresponding method for adjusting the capacity of a bent-axis axial piston hydraulic machine is also disclosed.

A hydraulic motor apparatus includes a motor housing engaged to an end cap having a first porting system and an adapter connected to an external surface of the end cap and having a second porting system. A filter may be attached to the adapter and connected to the second porting system and a pressure reducing valve in the adapter is connected to the second porting system. The assembly may also include a controller operatively connected to the pressure reducing valve and system sensors measuring parameters affected by the output of the hydraulic motor apparatus, whereby the pressure reducing valve is operatively controlled by the controller in response to input from the system sensors.

A port plate for use in an integrated drive generator has a body defining a semi-cylindrical charge port communicating with two circumferentially smaller charge port portions. A diametrically opposed working pressure port has three smaller working pressure ports. A center plane is defined extending through a center axis of a bore within the body and equidistance between circumferential ends of the charge port and the working fluid port. A first angle is defined between the plane and a circumferential end of the smaller charge port. The first angle is between 15 and 25 degrees. An integrated drive generator and a method are also disclosed.

A hydrostatic piston engine comprises a housing with a cylinder drum with cylinder bores mounted rotatably therein. Each of the cylinder bores receives a working piston in a longitudinally displaceable manner, via which a hydrostatic working chamber is delimited by the cylinder bore. The hydrostatic working chamber has an opening on an outer surface of the cylinder drum by which, when the cylinder drum rotates, outlets of a high-pressure chamber and of a low-pressure chamber of the piston engine and a reversing surface arranged between the two outlets in the rotational direction can be passed over in alternating fashion. At least one pressurizing medium channel is provided which, on one hand, opens out in the reversing surface and, on the other, into a pressurizing medium trough of the piston engine.