A bent-axis hydraulic pump motor includes: a cylinder block, a retainer plate; and a constant velocity joint, which includes an inner joint element; an outer joint element; and a plurality of balls interposed between block-side ball grooves and shaft-side ball grooves to transmit torque between the cylinder block and the retainer plate, so that all block-side groove planes, which include respective extending axial lines of the block-side ball grooves and the inclined rotation center, are inclined with respect to an axial center of a center shaft and all drive shaft-side groove planes, which include respective extending axial lines of the shaft-side ball grooves and the inclined rotation center, are inclined with respect to an axial center of a drive shaft such that loads applied to a cage in an axial direction from the balls are balanced.

A bent-axis hydraulic pump motor includes: a cylinder block, a retainer plate; and a constant velocity joint, which includes an inner joint element; an outer joint element; and a plurality of balls interposed between block-side ball grooves and shaft-side ball grooves to transmit torque between the cylinder block and the retainer plate, so that all block-side groove planes, which include respective extending axial lines of the block-side ball grooves and the inclined rotation center, are inclined with respect to an axial center of a center shaft and all drive shaft-side groove planes, which include respective extending axial lines of the shaft-side ball grooves and the inclined rotation center, are inclined with respect to an axial center of a drive shaft such that loads applied to a cage in an axial direction from the balls are balanced.

A joint for the angularly adjustable drive-connection of a cylinder block and a driveshaft of a hydrostatic bent axis piston unit. The joint has a shank which is rotatable about its longitudinal axis defining a joint axis, on both ends of the shank roller carriers project radially and basically perpendicular to the joint axis. On each roller carrier a roller is provided rotatable around a roller axis. The rollers are secured in axial direction against slipping-off of the roller carriers by means of an embossed area located axially outside of the roller on the respective distal end portion of the roller carrier.

A multi-stage electric gas pump includes a driving mechanism and an eccentric shaft including a main body having a longitudinal axis, a first eccentric portion, and a second eccentric portion, wherein the first eccentric portion and the second eccentric portion are fixed on the main body. The eccentric shaft is driven by the driving mechanism to produce a first circular movement of the first eccentric portion around the longitudinal axis and a second circular movement of the second eccentric portion around the longitudinal axis, wherein the second circular movement is synchronized with the first circular movement. The multi-stage electric gas pump further includes a first cylinder, a second cylinder, and a third cylinder. The cylinders in three stages are driven by the eccentric shaft so as to achieve three-stage pressurization of gas.

The invention relations to a hydraulic machine of the Dry-Case construction type comprising a hydraulic machine housing for receiving a hydrostatic driving mechanism for conveying hydraulic fluid with a driving shaft operational connected with the driving mechanism. The driving shaft is mounted rotatable about its longitudinal axis in the hydraulic machine housing. Neither the driving mechanism, nor the driving shaft nor its bearings splash or move in a sump of the hydraulic fluid. Lubricant can be pumped to bearings of the driving shaft and to the driving mechanism by a lubrication pump arranged on the driving shaft and being driven by driving shaft. The lubrication pump do not splash in a sump of the hydraulic fluid either and comprise a suction port which leads to a hydraulic fluid reservoir.

The invention relations to a hydraulic machine of the Dry-Case construction type comprising a hydraulic machine housing for receiving a hydrostatic driving mechanism for conveying hydraulic fluid with a driving shaft operational connected with the driving mechanism. The driving shaft is mounted rotatable about its longitudinal axis in the hydraulic machine housing. Neither the driving mechanism, nor the driving shaft nor its bearings splash or move in a sump of the hydraulic fluid. Lubricant can be pumped to bearings of the driving shaft and to the driving mechanism by a lubrication pump arranged on the driving shaft and being driven by driving shaft. The lubrication pump do not splash in a sump of the hydraulic fluid either and comprise a suction port which leads to a hydraulic fluid reservoir.

A hydraulic device includes a shaft mounted in a housing rotatable about a first axis of rotation. The shaft has a flange extending perpendicularly to the first axis. A plurality of pistons is fixed to the flange. A plurality of cylindrical sleeves cooperates with the pistons to form respective compression chambers of variable volume. The cylindrical sleeves are rotatable about a second axis of rotation which intersects the first axis of rotation by an acute angle such that upon rotating the shaft the volumes of the compression chambers change. Each piston has a piston head including a circumferential wall of which the outer side is ball-shaped and the inner side surrounds a cavity. Each of the pistons is fixed to the flange by a piston pin having a piston pin head including a circumferential outer side facing the inner side of the circumferential wall of the piston head.

A hydraulic device includes a shaft mounted in a housing rotatable about a first axis of rotation. The shaft has a flange extending perpendicularly to the first axis. A plurality of pistons is fixed to the flange. A plurality of cylindrical sleeves cooperates with the pistons to form respective compression chambers of variable volume. The cylindrical sleeves are rotatable about a second axis of rotation which intersects the first axis of rotation by an acute angle such that upon rotating the shaft the volumes of the compression chambers change. Each piston has a piston head including a circumferential wall of which the outer side is ball-shaped and the inner side surrounds a cavity. Each of the pistons is fixed to the flange by a piston pin having a piston pin head including a circumferential outer side facing the inner side of the circumferential wall of the piston head.

It includes a plurality of cylinders formed on the cylinder block; a piston slidably inserted into the cylinder; a case accommodating the cylinder block; and a valve plate formed by a core member and a resin layer coating the core member, the valve plate being interposed between the cylinder block and an end cover of the case. The valve plate has a first land portion formed by the resin layer, the first land portion being in sliding contact with the cylinder block; and an outer-side non-contact portion provided closer to an outer side in a radial direction than the first land portion, the outer-side non-contact portion being separated away from the cylinder block. At least a part of the outer-side non-contact portion is an exposed portion where the core member is exposed.

It includes a plurality of cylinders formed on the cylinder block; a piston slidably inserted into the cylinder; a case accommodating the cylinder block; and a valve plate formed by a core member and a resin layer coating the core member, the valve plate being interposed between the cylinder block and an end cover of the case. The valve plate has a first land portion formed by the resin layer, the first land portion being in sliding contact with the cylinder block; and an outer-side non-contact portion provided closer to an outer side in a radial direction than the first land portion, the outer-side non-contact portion being separated away from the cylinder block. At least a part of the outer-side non-contact portion is an exposed portion where the core member is exposed.