Abstract: The invention relates to a rotation-slide bearing (25c) which comprises an inner first bearing element (31) with an outer peripheral surface (31a) and an outer second bearing element (32) with an inner peripheral surface (32a). The outer bearing element (32) encloses the inner bearing element (31). At least one first oil groove (38) that extends in an approximately axial relation is provided in the outer peripheral surface (31a) of the inner first bearing element (31) and/or in the inner peripheral surface (32a) of the outer second bearing element (32). In order to improve a rotation-slide bearing of the aforementioned kind in such a way that it can absorb radial and axial forces and has good slide properties, a support shoulder (42a, 42b) with a slide surface (42c) is associated with one of the two bearing elements (31) on one or both sides and axially supports the bearing element (32) with its lateral surface (32c) facing it.

Abstract: The invention relates to an axial piston engine (1) comprising a housing (2) wherein a cylinder drum (17) is arranged. Several axially extending piston bores (21) are embodied in the cylinder drum and arranged in such a way that they are distributed around the longitudinal center axis (7a) of the cylinder drum (17). Pistons (23) are moveably guided in said bores and are supported by sliding shoes (29) on a pivoting mounted on a transversely extending pivoting axis (27). A stop (44b) or a stop (44a, 44b) on both sides of the pivoting axis (27) is/are provided in order to limit the pivoting movements of the pivoting plate (26). In order to stabilize the axial piston engine and provide it with a simple design, the stop (44b) or both stops (44a, 44b) are arranged on a sleeve-like supporting element (45) which is supported by the inner covering surface (3c) of the inside of the housing (4).

Abstract: The invention relates to a hydrostatic machine (1) comprising at least one first hydrostatic unit (E1) and one second hydrostatic unit (E2), each hydrostatic unit (E1, E2) comprising respective pistons (14a, 14b) guided in respective cylinder drums (13a, 13b) and supported by respective swiveling bodies (17a, 17b) that can be adjusted by respective adjustment devices (6a, 6b), and further comprising respective control bodies (25a, 25b). A one-piece main housing body (2) radially surrounds the cylinder drums (13a, 13b), the control bodies (25a, 25b), and the adjustment devices (6a, 6b) of both hydrostatic units (E1, E2), and assigns pressure channels for supplying a pressure medium to and discharging it from the control bodies (25a, 25b) of both hydrostatic units (E1, E2). A first add-on housing body (3a) is disposed on a first side of the main housing body (2), and bears a swiveling body (17a) of the first hydrostatic unit (E1).

Abstract: A method of producing a ball-and-socket joint (1) between a slipper (3) and a piston (2) of a piston engine, which includes configuring the slipper (3) with a joint ball (4) at an end opposite a bottom surface (21); configuring the piston (2) with an overmeasure (x) on a lateral surface (2c), providing a hemispherical joint recess (5) with a recess edge (7) that protrudes beyond the maximum diameter (6) of the joint recess (5) for receiving the joint ball (4) and bringing together the joint recess (5) and the joint ball (4), and hot-beading the recess edge (7) into a form in which it grips the joint ball (4). Also provided is a joint formed by the foregoing method.

Abstract: An axial piston engine (1), including a housing (2) in whose inner compartment (4) a cylinder drum (17) and a swash plate (26) located axially adjacent thereto are situated. Several piston bores (21), which extend approximately parallel to the central axis of the cylinder drum (17) are located in the same, pistons (23) being displaceably guided in the piston bores. The ends of the pistons facing towards the swash plate (26) are supported on the swash plate (26). A driving shaft (7) is rotatably mounted in the housing (2) and is connected to the cylinder drum in a fixed manner secured against rotation therebetween by a multitooth coupling (19) comprising teeth (43a, 44a) and tooth spaces (43b, 44b) which alternate regularly in a peripheral direction and which engage with each other.

Abstract: The invention relates to an axial piston engine (1) with a housing (2), inside the housing interior (4) of which a drive shaft (7) and a cylinder drum (16), arranged axially adjacent to said shaft, are rotatably mounted. The longitudinal mid-axes (9a, 9b) of the driveshaft (7) and the cylinder drum (17) run inclined to each other at an angle (W). Several piston bores (18) are arranged in he cylinder drum (16), running roughly parallel to the mid-axis thereof and in which pistons (21) may run axially up and down. The ends of said pistons, facing the driveshaft (7), are universally pivoted.

Abstract: The invention relates to a filtering device (1) comprising a tubular filter (6). One end of said filter is supported on a base part (2) and the other end is supported on a cupped filter housing (3). The filter housing overlaps the filter (6) with a radial clearance (7) and is detachably connected via the edge (4) thereof to the base part (2). The base part (2) comprises a first flow-through channel (33) which is connected to the clearance (7) and comprises a second flow-through channel (34) which is connected to a cavity (35) of the filter (6). The aim of the invention is to make it possible to attach or detach the filter housing (3) even when tight spatial relationships are present in the vicinity of the filter housing (3) or in order to hold the filter (6) in position against the filter housing (3).

Abstract: An adjusting device (1) for adjusting the swash plate (12) of an axial piston engine (1) with a swash-plate construction has an actuating piston (18) which acts on the swash plate (12) of the axial piston engine (1); and a control value (19). The control valve (19) is used to regulate the actuating pressure which is present in an actuating volume (45) and which is acting on the actuating piston (18), in accordance with a control force acting on a valve piston (20) of the control valve (19). The actuating piston (18) is structurally separate from the control valve (19) and the actuating piston (18) is connected to the valve piston (20) of the control valve (19) by a readjusting spring (34) that opposes the control force.

Abstract: A hollow piston (1) piston engine including a closed annular cavity (9). Said hollow piston constituted of a first piston part (1a) with a base section (3) from which a joint part (4) extends in one axial direction, and from which a peripheral wall (6) that delimits the annular cavity (9) on the outside, and a mandrel (7) that delimits the annular cavity (9) on the inside extend, each as one piece, in the other axial direction. The hollow piston is also constituted of a second piston part (1b) having a cover (8) which is connected to the ends of the peripheral wall (6) and of the mandrel (7), said ends facing away from the base section (3). In order to achieve an economical and simple production while ensuring the provision of a stabile construction, the peripheral wall (6) and the mandrel (7) are formed on the base section (3) without machining.

Abstract: The invention relates to an axial piston engine (1) comprising a housing (2) and a cylinder drum (5) that is pivotably arranged in one interior space (3) of the housing. Several cylinder bores (6) are embodied in said cylinder drum (5). Pistons (7) are moveably guided in said cylinder bores (6) and rest on a swash plate (11) by means of guide shoes (8). The axial piston engine (1) also comprises a retracting device (15). The guide shoes (8) rest on the retracting device (15) when the pistons (7) are retracted. A restraint system (16) is accommodated in the housing (2), can be moved against a spring (40) and is used for supporting the retracting device (15) at the housing (2). The aim of the invention is to improve and stabilise the support of the retracting device (15). To this end, the retracting device (15) is supported by a support device (16a) which is situated behind the retracting device (15) at the side facing away from the swash plate (11). The support device is connected to the swash plate (11).

Abstract: A pressure-control valve (1) comprises a first control piston (1), which is disposed between a first pressure chamber (6), which adjoins the first control piston (1) and is connected to at least one working line (A, B), and a second pressure chamber (7), which adjoins the first control piston (1) and is pushed against a stop (3) by a first preloading spring (4). A throttle (8) connects the first pressure chamber (6) and the second pressure chamber (7). The second pressure chamber (7) is connected to a second control piston (11), which is preloaded by a second preloading spring (17) and which, when a predetermined pressure in the second pressure chamber (7) is exceeded, is displaced to an extent such that a control edge (12) of the second control piston (11) clears a connection of the second pressure chamber (7) to a hydraulic fluid discharge point (23).

Abstract: A dual pump unit comprising two hydraulic pumps (2,3) with coaxially mounted drive shafts (4,5) that are coupled to each other in a non-positive fit by means of a coupling member (28). The coupling member (28) surrounds a connecting member (15), wherein high pressure lines (29,30) and low pressure lines (31,32) are formed. The connecting member (15) extends between two control bodies (33) that are respectively associated with one hydraulic pump (2,3) and which are used to create a cyclic connection between the cylinders (18,19) of the hydraulic pumps (2,3) and the high pressure lines (29,30) and low pressure lines (31,32). The connecting member (15) consists of two connector plates (13,14) defining one of the hydraulic pumps (2,3) respectively on the control bodies (33,43) and an individually formed interchangeable intermediate element (38) arranged between the connector plates (13,14).

Abstract: The inventive hydrostatic gear unit (1) comprises a hydraulic pump (2) and an adjustable hydraulic motor (6) which is connected to the hydraulic pump (2) via operating lines (4, 5). A drive control valve (3) is arranged in the operating lines (4, 5) for adjusting the delivery volume of the hydraulic medium flowing from the hydraulic pump (2) to the hydraulic motor (6). An adjusting device (7) is used to adjust the displacement volume of the hydraulic motor (6). The adjusting pressure of the adjusting device (7) is controlled via a control valve (24). A pilot control (12) is also provided which produces a control pressure in accordance with a transmitter (11). Said control pressure acts on the drive control valve (3) for adjusting the delivery volume flowing from the hydraulic pump (2) to the hydraulic motor (6). Said control pressure also acts on the control valve (24) for adjusting the displacement volume of the hydraulic motor (6).

Abstract: The invention relates to a method for the production of a ball jointed connection between a guide shoe (10) and a cylinder piston (1) of a piston machine. A spherical cap-shaped recess (2) is first of all formed on the cylinder piston (1) and/or the guide shoe (10), whereby the recess (2) is undercut in such a way that the spherical cap-shaped recess (2) comprises a solid angle area (&agr;) of over 180°, and the diameter (D) in the region of the equator plane (5) is greater than the diameter (d) of the recess (2). Furthermore, a spherical head (11) is formed on the corresponding counterpart, that is the guide shoe (10) and/or the cylinder piston (1). In accordance with a first version of the invention, the spherical head (11) is pushed into the spherical cap-shaped recess (2) in such a way that the edge area (6) surrounding the spherical cap-shaped recess (2) is elastically deformed when the spherical head (11) is pushed in, and the surrounding edge area (6) grips behind the spherical head (11).

Abstract: A pressure-control valve (1) comprises a first control piston (1), which is disposed between a first pressure chamber (6), which adjoins the first control piston (1) and is connected to at least one working line (A, B), and a second pressure chamber (7), which adjoins the first control piston (1) and is pushed against a stop (3) by a first preloading spring (4). A throttle (8) connects the first pressure chamber (6) and the second pressure chamber (7). The second pressure chamber (7) is connected to a second control piston (11), which is preloaded by a second preloading spring (17) and which, when a predetermined pressure in the second pressure chamber (7) is exceeded, is displaced to an extent such that a control edge (12) of the second control piston (11) clears a connection of the second pressure chamber (7) to a hydraulic fluid discharge point (23).

Abstract: A control circuit, in particular for a slewing gear of a digger, has a hydraulic fluid tank (21), connected to two adjusting pressure chambers (10, 11). Each of the connections contains a separate brake valve (19, 20). The first of the valves (19) is operated by the differential between the working pressure in the first working conduit (2), and the control pressure in the control conduit (33, 34) charged with the higher pressure. The second valve (20) is operated by the differential between the working pressure in the second working circuit (3) and the control pressure in the control circuit charged with the higher pressure. Slow braking by the brake valves is interrupted when the slewing gear swings out against a resistance such as a heap of debris.

Abstract: A power- and moment-regulating system for at least two adjustable hydraulic pumps (10, 11). A hydraulic servo control apparatus (22, 23) continuously adjusts delivery as a function of pressure in a delivery pressure line (16, 17) and pressures in control lines (20, 21). Each servo control apparatus (22, 23) is provided with a moment valve (42, 43) having a valve piston (62) which moves in a valve sleeve (61) forming a valve seat and whose closure force is determined by a measuring spring (46, 47) which is connected to pump actuator (37, 38) and is preloaded depending upon the set delivery rate. The pressure in control line (20, 21) or pressure in control lines of the other hydraulic pump(s) (11, 10) act both on the valve piston (62) and on valve screen (61) of moment valve (42, 43) associated with the given hydraulic pump (10, 11).

Abstract: A control device for an adjustable hydraulic pump (1), wherein the hydraulic pump is connected to a plurality of users, by delivery lines (5a-d). A first control line (18a-d), is connected to each of the delivery lines downstream of a respective proportioning throttle (6a-d). A first pressure change device (17) selects a highest pressure prevailing in the first control lines and supplies it to a delivery flow control valve (15), which controls an adjusting pressure for an adjusting device (7) for the hydraulic pump, based on a pressure difference between the highest pressure from the first pressure change device and a pressure from a second control line (19) connected to the output of the pump.