A radial piston device includes a housing and a pintle fixed thereto that includes an inlet and an outlet, each aligned with a pintle axis. A rotor is rotatably disposed around the pintle and includes radially oriented cylinders. A piston is axially displaceable in each cylinder and includes a head defining a spherical contact surface. A thrust ring is rotatably disposed within the housing about the rotor and is in contact with each piston, such that a rotation of the rotor rotates the thrust ring. An inner surface of the thrust ring defines a toroidal contact surface. A contact location between the spherical contact surface and the toroidal contact surface varies as the rotor rotates about the pintle. A drive shaft is engaged with the rotor, such that a rotation of the rotor rotates the drive shaft.

A radial piston device includes a housing and a pintle fixed thereto that includes an inlet and an outlet, each aligned with a pintle axis. A rotor is rotatably disposed around the pintle and includes radially oriented cylinders. A piston is axially displaceable in each cylinder and includes a head defining a spherical contact surface. A thrust ring is rotatably disposed within the housing about the rotor and is in contact with each piston, such that a rotation of the rotor rotates the thrust ring. An inner surface of the thrust ring defines a toroidal contact surface. A contact location between the spherical contact surface and the toroidal contact surface varies as the rotor rotates about the pintle. A drive shaft is engaged with the rotor, such that a rotation of the rotor rotates the drive shaft.

A hydraulic radial piston device includes a housing, a pintle having a pintle shaft, a rotor mounted on the pintle shaft and defining a plurality of cylinders, and a plurality of pistons displaceable in the cylinders. The radial piston device further includes a piston ring that provides an interface for the pistons. The radial piston device includes various configurations for improving the performance and efficiency of the device.

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 pump can have a support having a guide extending around an axis, a radial position of the guide relative the axis varying around the axis, and a first oil passage formed in the support; a rotary assembly mounted to the support via support bearings, and rotatable around the axis, the rotary assembly having a second oil passage and a cylinder, the cylinder extending radially relative the axis, an inlet port fluidly connecting the first oil passage to the cylinder, and an outlet port fluidly connecting the cylinder to the second oil passage, and a piston slidingly mounted in the cylinder, a radially-outer end of the piston further slidingly engaged with the guide.

The rotating hydraulic machine (102) comprises: a housing (10), a shaft (20) movably mounted relative to the housing about an axis, an apron (24) rigidly connected to the shaft and extending around at least a portion of the housing, a cam (12) rigidly connected to either the housing or the shaft, a cylinder block (42) rotationally connected to the other of either the housing or the shaft, the cylinder block comprising pistons capable of engaging with the cam to produce a relative rotation between the shaft and the housing, first and second guide bearings (28) each bearing directly on the housing and the apron, and at least a third guide bearing (37) bearing directly on the housing and the cylinder block.

The rotating hydraulic machine (102) comprises: a housing (10), a shaft (20) movably mounted relative to the housing about an axis, an apron (24) rigidly connected to the shaft and extending around at least a portion of the housing, a cam (12) rigidly connected to either the housing or the shaft, a cylinder block (42) rotationally connected to the other of either the housing or the shaft, the cylinder block comprising pistons capable of engaging with the cam to produce a relative rotation between the shaft and the housing, first and second guide bearings (28) each bearing directly on the housing and the apron, and at least a third guide bearing (37) bearing directly on the housing and the cylinder block.