Hydraulic radial piston device

A hydraulic radial piston device comprising:

• a housing;
• a pintle attached to the housing and having a pintle shaft, the pintle having a first end and a second end separated by a length of the pintle, the pintle defining a first fluid channel adjacent the first end and a second channel adjacent the second end;
• a rotor mounted on the pintle shaft and configured to rotate relative to the pintle shaft about a rotor axis of rotation, the rotor having a plurality of cylinders;
• a plurality of pistons, each being displaceable in each of the plurality of cylinders;
• a piston ring disposed around the rotor and having a piston ring axis of rotation, the piston ring configured to rotate about the piston ring axis of rotation as the rotor rotates relative to the pintle shaft about the rotor axis of rotation;
• and
• a drive shaft rotatably supported within the housing and rotatable with the rotor;
• wherein an exterior of pintle shaft includes a bearing surface for supporting rotation of the rotor either directly or by an intermediate fluid, wherein the pintle defines a first rotor communication port in fluid communication with the first fluid channel and a second rotor communication port in fluid communication with the second channel, the exterior of the pintle shaft defining a first recess in fluid communication with the first rotor communication port and a second recess in fluid communication with the second rotor communication port, the bearing surface at least partially surrounding the first and second recesses, the pintle shaft including first and second timing recesses formed as notches in the exterior of the pintle shaft at opposite sides of the first recess, the first rotor communication port configured to be selectively in fluid communication with the plurality of cylinders as the rotor rotates, the second rotor communication port configured to be selectively in fluid communication with the plurality of cylinders as the rotor rotates, and the first and second timing recesses being configured to adjust timing of fluid communication between the first rotor communication port and the plurality of cylinders as the rotor rotates about the pintle shaft.

A hydraulic radial piston device comprising:

• a housing;
• a pintle attached to the housing and having a pintle shaft, the pintle having a first end and a second end separated by a length of the pintle, the pintle defining a first fluid channel adjacent the first end and a second channel adjacent the second end;
• a rotor mounted on the pintle shaft and configured to rotate relative to the pintle shaft about a rotor axis of rotation, the rotor having a plurality of cylinders;
• a plurality of pistons, each being displaceable in each of the plurality of cylinders;
• a piston ring disposed around the rotor and having a piston ring axis of rotation, the piston ring configured to rotate about the piston ring axis of rotation as the rotor rotates relative to the pintle shaft about the rotor axis of rotation;
• the pintle shaft having an axial dimension that extends along the rotor axis of rotation and a circumferential direction that extends around the rotor axis of rotation;
• and
• a drive shaft rotatably supported within the housing and rotatable with the rotor;
• wherein an exterior of the pintle shaft includes a bearing surface for supporting rotation of the rotor either directly or by an intermediate fluid, wherein the pintle defines a first rotor communication port in fluid communication with the first fluid channel and a second rotor communication port in fluid communication with the second channel, the exterior of the pintle shaft defining a first recess in fluid communication with the first rotor communication port and a second recess in fluid communication with the second rotor communication port, the bearing surface surrounding the first recess such that first and second opposite axial sides and first and second opposite circumferential sides of the first recess are bound by the bearing surface, the first rotor communication port configured to be selectively in fluid communication with the plurality of cylinders as the rotor rotates, and the second rotor communication port configured to be selectively in fluid communication with the plurality of cylinders as the rotor rotates;
• wherein the pintle shaft includes first and second timing recesses formed as notches in the exterior of the pintle shaft at the opposite first and second circumferential sides of the first recess, the first and second timing recesses being configured to adjust timing of fluid communication between the first rotor communication port and the plurality of cylinders as the rotor rotates about the pintle shaft.

A hydraulic radial piston device comprising:

• a housing;
• a pintle attached to the housing and having a pintle shaft, the pintle having a fluid inlet end and an opposite fluid outlet end;
• a rotor mounted on the pintle shaft and configured to rotate relative to the pintle shaft about a rotor axis of rotation, the rotor having a plurality of cylinders;
• a plurality of pistons, each being displaceable in each of the plurality of cylinders;
• a piston ring disposed around the rotor and having a piston ring axis of rotation, the piston ring configured to rotate about the piston ring axis of rotation as the rotor rotates relative to the pintle shaft about the rotor axis of rotation;
• and
• a drive shaft rotatably supported within the housing and rotatable with the rotor;
• wherein the pintle includes an integrated bearing surface for supporting rotation of the rotor either directly or by an intermediate fluid, wherein the pintle includes a lubrication groove defined though the integrated bearing surface and configured to feed hydraulic fluid for lubricating the integrated bearing surface, wherein the lubrication groove includes a first pintle lubrication groove that extends through the integrated bearing surface at an exterior of the pintle between the fluid inlet end of the pintle and one of a rotor inlet communication port and a rotor outlet communication port, wherein the lubrication groove includes a second pintle lubrication groove that extends through the integrated bearing surface at the exterior of the pintle between the fluid outlet end of the pintle and one of the rotor inlet communication port and the rotor outlet communication port, the integrated bearing surface integrally formed to surround the rotor inlet communication port and the rotor outlet communication port except for at the first and second lubrication grooves, the rotor inlet communication port formed on the pintle shaft and configured to be selectively in fluid communication with the plurality of cylinders, and the rotor outlet communication port formed on the pintle shaft and configured to be selectively in fluid communication with the plurality of cylinders;
• wherein the hydraulic radial piston device is a pump, wherein the first pintle lubrication groove extends between the fluid inlet end of the pintle and the rotor inlet communication port, and wherein the second pintle lubrication groove extends between the fluid outlet end of the pintle and the rotor inlet communication port.

A hydraulic radial piston device comprising:

• a housing;
• a pintle attached to the housing and having a pintle shaft, the pintle having a first end and a second end separated by a length of the pintle, the pintle defining a first fluid channel adjacent the first end and a second channel adjacent the second end;
• a rotor mounted on the pintle shaft and configured to rotate relative to the pintle shaft about a rotor axis of rotation, the rotor having a plurality of cylinders;
• a plurality of pistons, each being displaceable in each of the plurality of cylinders;
• a piston ring disposed around the rotor and having a piston ring axis of rotation, the piston ring configured to rotate about the piston ring axis of rotation as the rotor rotates relative to the pintle shaft about the rotor axis of rotation;
• the pintle shaft having an axial dimension that extends along the rotor axis of rotation and a circumferential direction that extends around the rotor axis of rotation;
• and
• a drive shaft rotatably supported within the housing and rotatable with the rotor;
• wherein an exterior of the pintle shaft includes a bearing surface for supporting rotation of the rotor either directly or by an intermediate fluid, wherein the pintle defines a first rotor communication port in fluid communication with the first fluid channel and a second rotor communication port in fluid communication with the second channel, the exterior of the pintle shaft defining a first recess in fluid communication with the first rotor communication port and a second recess in fluid communication with the second rotor communication port, the bearing surface surrounding the first recess such that first and second opposite axial sides and first and second opposite circumferential sides of the first recess are bound by the bearing surface, the first rotor communication port configured to be selectively in fluid communication with the plurality of cylinders as the rotor rotates, and the second rotor communication port configured to be selectively in fluid communication with the plurality of cylinders as the rotor rotates;
• wherein the bearing surface axially and circumferentially bounds the second recess except for a lubrication groove or grooves defined by the exterior of the pintle shaft through the bearing surface, the lubrication groove or grooves providing lubrication of the bearing surface and extending axially along the pintle shaft to an axial side of the second recess.