Abstract: A hydrostatic radial piston unit of the cam-lobe type of construction having a non-rotary, stationary shaft defining a rotational axis of the hydrostatic radial piston unit. A non-rotary, stationary casing houses the shaft in a torque proof connection. A rotary casing is provided which is rotary around the rotational axis. A pair of roller bearings supports the rotary casing in a rotatable manner against the stationary casing, wherein the pair of roller bearings is arranged in an axial overlapping area in which the stationary casing and the rotary casing overlap.

Abstract: A hydrostatic radial piston unit of the cam-lobe type of construction including a non-rotary, stationary casing. The stationary casing includes a through hole defining a rotational axis of the hydrostatic radial piston unit. A rotary casing is mounted rotary to the non-rotary, stationary casing in an axial overlapping area. A park brake mechanism includes at least two brake discs arranged adjoined in the overlapping area. An end cover closes the non-rotary casing on a rear end side of the hydrostatic radial piston unit facing away from the rotary casing. The end cover pre-tensions a disc spring against a disc-shaped brake piston both located in the rear end portion of the stationary casing to generate an axially oriented spring force.

Abstract: A hydrostatic radial piston unit of the cam-lobe type of construction having a non-rotary, stationary shaft defining a rotational axis of the hydrostatic radial piston unit. A non-rotary, stationary casing houses the shaft in a torque proof connection. A rotary casing is provided which is rotary around the rotational axis. A pair of roller bearings supports the rotary casing in a rotatable manner against the stationary casing, wherein the pair of roller bearings is arranged in an axial overlapping area in which the stationary casing and the rotary casing overlap.

Abstract: A hydraulic control circuit for a hydraulic motor operable at least at two displacements, having a proportional speed control valve with a control valve spool continuously moveable by means of a force generated by a pilot pressure being controlled by a continuously, electrically adjustable pilot valve having an electrical actuator, wherein the control valve spool is moveable between a full-torque end position, a reduced-torque end position, and at least one intermediate position. A time related control current function is provided for controlling the current applied to the electrical actuator for controlling the pilot pressure including a pre-current portion with a constant non-zero current and a current ramp portion during which the current is raised or lowered continuously from a ramp starting current level to an intermediate current level.

Abstract: Hydrostatic radial piston unit comprising a front case part accommodating a drive shaft via shaft bearing means so that the drive shaft can rotate around a central axis relative to the front case part. A rear case part is attached on one side to the front case part and closed on another side in order to define an internal volume. A cylinder block is disposed in the internal volume and attached to the drive shaft in a torque proof manner. Axially disposed timing holes in the cylinder block connect radially oriented working volumes in the cylinder block with a cylinder block front face that is arranged perpendicularly to the central axis and faces away from the front case part. Integrally within the rear case part internal annular flow passages are formed and are connected to an inlet and an outlet of the radial piston unit and running basically in circumferential direction around the central axis.

Abstract: A hydrostatic radial piston unit of the cam-lobe type of construction including a shaft defining a rotational axis of the hydrostatic radial piston unit. The shaft extends with a front end region from a non-rotary, stationary rear casing to a front casing. Within the front casing a cylinder block is housed and fixed in a torque-proof connection to the front end region of the shaft. In the cylinder block radially reciprocating working pistons are disposed in radially oriented cylinder bores to and from which cylinder bores hydraulic fluid can be conducted by means of a distributor. The distributor is arranged rotationally fixed with respect to the front casing and rotationally free relative to the shaft. A circumferential cam-lobe surface with which the working pistons can interact, is formed integrally with the front casing on its radial inner side.

Abstract: A seal between an outer part and a circular cylindrical inner part, which is accommodated within the outer part at least in sections, includes a sealing ring having a groove portion and consisting of high-temperature-resistant thermoplastic plastics material. The outer part and the inner part are movable in a linear manner in relation to each other. A circumferential groove, into which the groove portion of the sealing ring is inserted at least in sections, is realized on an inner circumference of the outer part or on an outer circumference of the inner part. The sealing ring is in one part, and the groove is closed.

Abstract: A seal between an outer part and a circular cylindrical inner part, which is accommodated within the outer part at least in sections, includes a sealing ring having a groove portion and consisting of high-temperature-resistant thermoplastic plastics material. The outer part and the inner part are movable in a linear manner in relation to each other. A circumferential groove, into which the groove portion of the sealing ring is inserted at least in sections, is realized on an inner circumference of the outer part or on an outer circumference of the inner part. The sealing ring is in one part, and the groove is closed.

Abstract: A hydrostatic power train includes a hydraulic pump, which is connected, via a first main pipe and a second main pipe, to a first hydromotor unit driving a front axle and to a second hydromotor unit driving a rear axle. The first and second hydromotor units can be adjusted in terms of their displacement via a first and second variation device. A direction of travel is defined as forward movement (F) or reverse movement (R) by a position of an operating lever. The first and the second variation devices are controlled by a control valve which takes up a first control position upon a forward movement (F) determined by the position of the operating ever and which takes up a second control position upon reverse movement (R) determined by the position of the operating lever and which takes up a second control position upon reverse movement (R) determined by the operating lever.

Abstract: A hydraulic control circuit for a radial piston engine with two speeds. The changeover between the speeds takes place through the alteration of the absorption volume, the delivery side being connected to the discharge side with a bypass connection by a valve arrangement for a selected number of engine pistons. The control circuit provides a space-saving way of ensuring that the changeover between speeds occurs smoothly and in such a manner to preserve the individual components as far as possible. To this end, at least one intermediate switching position, in which the delivery side is throttled to the discharge side, i.e. connected by a diaphragm-type arrangement, is provided in front of valve arrangement between the two end switching positions. The valve arrangement is preferably driven such that a valve body can be moved through the intermediate switching position at a controlled speed.

Abstract: A hydraulic radial piston engine has a lifting ring fixed to the casting, a rotor mounted opposite the lifting ring such that it is rotatable about an axis of rotation, multiple piston seats aligned radially in the rotor relative to the axis of rotation, and multiple pistons each displaceably mounted in a piston seat and which, over at least part of their length, have a non-circular guiding and sealing cross section that is coincident with a non-circular guiding and sealing cross section of the piston seats. Circularly cylindrical rollers are borne by the piston. With a given overall size, a greater swept volume per piston is possible and therefore a greater torque is produceable.

Abstract: The invention concerns a control for a hydrostatic power train (1) comprising a hydraulic pump (2) which is connected, via a first main pipe and a second main pipe (7, 8), to a first hydromotor unit (5, 5?) driving a front axle and to a second hydromotor unit (6, 6?) driving a rear axle. The first and second hydromotor units (5, 5?, 6, 6?) can be adjusted in terms of their displacement via a first and a second variation device (30, 31, 30?, 31?) respectively. A direction of travel is defined as forward movement (F) or reverse movement (R) by a position of an operating lever (37). The first and the second variation devices (30, 31, 30?, 31?) are controlled by a control valve (32, 32?) which takes up a first control position upon a forward movement (F) determined by the position of the operating lever (37) and which takes up a second control position upon reverse movement (R) determined by the operating lever (37).

Abstract: What is disclosed is a radial piston machine having a plurality of radial pistons each guided in a respective cylinder space, wherein the cylinder spaces may be connected with supply and drain passages for pressure medium via control recesses. The opening cross-sections of the control recesses and of the supply and drain passages are provided with curved end face portions.

Abstract: A hydraulic radial piston engine which comprises a lifting ring which is fixed to the casing, a rotor mounted opposite the lifting ring such that it can be rotated about an axis of rotation, a large number of piston seats aligned radially in the rotor with respect to the axis of rotation, a large number of pistons, each of which is displaceably mounted in a piston seat and which, over at least part of their length, have a guiding and sealing cross section that deviates from a circular shape and which is coincident with a guiding and sealing cross section of the piston seats which deviates correspondingly from the circular shape and remains constant as far as the outside of the rotor, and circularly cylindrical rollers which are borne by the pistons in bearing seats and aligned with their axis of rotation in the direction of the axis of rotation of the rotor, to support the pistons on the lifting ring.

Abstract: The invention relates to a hydraulic control circuit for a radial piston engine with two speeds. The changeover between the speeds takes place through the alteration of the absorption volume, the delivery side (22, 122, 222) being connected to the discharge side (24, 124, 224, 324) with a bypass connection by means of a valve arrangement 830, 130, 230, 330, 430) for a selected number of engine pistons. The aim of the invention is to provide a particularly space-saving means of ensuring that the changeover between speeds occurs smoothly and in such a manner as to preserve the individual components as far as possible. To this end, at least one intermediate switching position (230-Z; 330-Z2; 330-Z3), in which the delivery side (22, 122, 222) is throttled to the discharge side (24, 124, 224, 324), i.e. connected via a diaphragm-type arrangement (231; A1; A2; 282; 284-A; 284-B; 286-B; 382-2; 384-2), is provided in front of valve arrangement (30, 130, 230, 330, 430) between the two end switching positions.

Abstract: What is disclosed is a radial piston machine having a plurality of radial pistons each guided in a respective cylinder space, wherein the cylinder spaces may be connected with supply and drain passages for pressure medium via control recesses. The opening cross-sections of the control recesses and of the supply and drain passages are provided with curved end face portions.

Abstract: A hydrostatic vehicle drive (1) comprises a first hydropump (2) and a second hydropump (3) as well as a first hydromotor (7) and a second hydromotor (12). The hydromotors (7, 12) each drive separate drive lines. During straight-ahead travel operation, the hydropumps (2, 3) and the hydromotors (7, 12) are coupled to one another in a single, closed hydraulic circuit without crossed connections in such a manner that an input connection (6) of the first hydromotor (7) is connected to an output connection (5) of the first hydropump (2) and an input connection (9) of the second hydropump (3) is connected to an output connection (8) of the first hydromotor (7). An input connection (11) of the second hydromotor (12) is connected to an output connection (10) of the second hydropump (3), whilst an input connection (14) of the first hydropump (2) is connected to an output connection (13) of the second hydromotor (12).