The machine comprises distribution ducts connected to respective ones of first, second, and third enclosures (40, 42, 44), and a cylinder-capacity selector (21) suitable for being caused to take up a large cylinder capacity configuration in which the second enclosure (42) is connected to one of the main ducts (2), while the first and third enclosures (40, 44) are connected to the other main duct (1), and a small cylinder capacity configuration in which the second and third enclosures (42, 44) are connected to said one of the main ducts (2), while the first enclosure is connected to the other main duct (1). The machine further comprises a safety valve (150) having at least a first port (56) connected to said one of the main ducts (2), and a second port (58) connected to the third enclosure (44). Said safety valve is suitable, when the cylinder-capacity selector (21) is caused to go into the large cylinder capacity, for being caused to go into a first configuration that isolates the first and second ports (56, 58) from each other, and, when the cylinder-capacity selector is caused to go into its small cylinder capacity, for being caused to go into a second configuration that interconnects the first and second ports (56, 58).

The machine comprises distribution ducts connected to respective ones of first, second, and third enclosures (40, 42, 44), and a cylinder-capacity selector (21) suitable for being caused to take up a large cylinder capacity configuration in which the second enclosure (42) is connected to one of the main ducts (2), while the first and third enclosures (40, 44) are connected to the other main duct (1), and a small cylinder capacity configuration in which the second and third enclosures (42, 44) are connected to said one of the main ducts (2), while the first enclosure is connected to the other main duct (1). The machine further comprises a safety valve (150) having at least a first port (56) connected to said one of the main ducts (2), and a second port (58) connected to the third enclosure (44). Said safety valve is suitable, when the cylinder-capacity selector (21) is caused to go into the large cylinder capacity, for being caused to go into a first configuration that isolates the first and second ports (56, 58) from each other, and, when the cylinder-capacity selector is caused to go into its small cylinder capacity, for being caused to go into a second configuration that interconnects the first and second ports (56, 58).

A radial piston device includes a housing, a pintle attached to the housing and having a pintle shaft, a rotor rotatably mounted on the pintle shaft and having cylinders, pistons displaceably received in the cylinders, and a drive shaft coupled to the rotor and rotatably supported within the housing. The radial piston device includes mechanisms for reducing a pressure loss of hydraulic fluid flowing into the pintle shaft.

An automotive hydraulic actuating system for actuating a movable vehicle part, like a roof part or a wheel suspension. The actuating system comprises a pump unit. The pump unit comprises a piston pump which has a pump rotor and an electric motor which has a motor rotor. The pump rotor and motor rotor are incorporated into a single common rotor. The rotor is a one piece item. The rotor is positioned inside a pump chamber around a pump stator of the piston pump. The pump stator provides a full support to the common rotor. Advantageously, without a separate motor stator, the pump unit has a more compact configuration. Additionally, the pump unit has an improved dynamic performance which contributes to a silent and reliable operation at a high rotational speed.

The present invention relates to a hydraulic device (10) with radial pistons, comprising: a shaft (12) arranged along an axis (1); a cover (13) forming a casing element, the cover and the shaft being free to rotate with respect to one another; a distribution assembly comprising: a multi-lobe cam (14); a cylinder block (15); a distributor (16) configured to exert a thrust force (P) against the cylinder block (15) along the axis (11) of the shaft; an assembly (22) of mechanical bearings comprising at least one mechanical bearing (22a) mounted in radial contact between the cover (13) and shaft (12), said assembly being configured to take up the thrust force (P) exerted by the distributor (16); and a radial contact ball bearing mounted in radial contact between the cover (13) and the shaft (12).

The present invention relates to a hydraulic device (10) with radial pistons, comprising: a shaft (12) arranged along an axis (1); a cover (13) forming a casing element, the cover and the shaft being free to rotate with respect to one another; a distribution assembly comprising: a multi-lobe cam (14); a cylinder block (15); a distributor (16) configured to exert a thrust force (P) against the cylinder block (15) along the axis (11) of the shaft; an assembly (22) of mechanical bearings comprising at least one mechanical bearing (22a) mounted in radial contact between the cover (13) and shaft (12), said assembly being configured to take up the thrust force (P) exerted by the distributor (16); and a radial contact ball bearing mounted in radial contact between the cover (13) and the shaft (12).

The device has an internal distributor to be disposed in a casing portion (10A), and has a body (15) that has an outside axial face (15B) provided with two grooves (17, 19) respectively for feed and for discharge. The distributor has distribution ducts (23A, 23B, 23C) that open out in a distribution radial face and a cylinder capacity selector that has a slide (50) suitable for being moved in an axial bore (53) for connecting the distribution ducts to one or the other of the grooves. The device further has a control chamber (52) provided between a first end wall (15) of the bore and the first end (50A) of the slide, and an opposing spring (55) disposed in a return chamber (52) situated at the second end (53) of the bore and closed, at the end closer to the distribution face (15A), by a second end wall (55) of the distributor.

The device has an internal distributor to be disposed in a casing portion (10A), and has a body (15) that has an outside axial face (15B) provided with two grooves (17, 19) respectively for feed and for discharge. The distributor has distribution ducts (23A, 23B, 23C) that open out in a distribution radial face and a cylinder capacity selector that has a slide (50) suitable for being moved in an axial bore (53) for connecting the distribution ducts to one or the other of the grooves. The device further has a control chamber (52) provided between a first end wall (15) of the bore and the first end (50A) of the slide, and an opposing spring (55) disposed in a return chamber (52) situated at the second end (53) of the bore and closed, at the end closer to the distribution face (15A), by a second end wall (55) of the distributor.

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. Internal distribution conducts configured to hydraulically connect the internal annular flow passages with the cylinder block timing holes are integrally formed within the rear case part, too.

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.