A hydraulic machine with oscillating axial cylinders includes a plurality of oscillating axial cylinders, put in synchronous rotation between a first rotating element, a rotating disc, which supports one end of the cylinder, bottom or piston, and a second rotating element, a rotating barrel, which supports the opposite end of the cylinder; each cylinder is connected to said rotating elements with a ball joint towards each of them; each ball joint is holed to allow for the passage and the feeding/discharge through it of the hydraulic liquid. At least the bottom or the piston is connected to the respective rotating element with a ball joint having a spherical surface with a diameter equal to or greater than the cylinder bore.

A failure diagnosing device configured to diagnose failure of a swash plate pump includes: a history acquiring portion configured to acquire actual history data, the actual history data indicating a time-lapse change of the suction flow rate or suction pressure in a predetermined period of time; and a failure detecting portion configured to detect generation of an abnormality between a piston and a shoe based on the actual history data acquired by the history acquiring portion.

A failure diagnosing device configured to diagnose failure of a swash plate pump includes: a history acquiring portion configured to acquire actual history data, the actual history data indicating a time-lapse change of the suction flow rate or suction pressure in a predetermined period of time; and a failure detecting portion configured to detect generation of an abnormality between a piston and a shoe based on the actual history data acquired by the history acquiring portion.

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 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 hydrostatic positive displacement machine has an adjustable swept volume, and has a lifting element, a rotor with positive displacement elements supported on the lifting element, and a hydraulic adjusting device that adjusts the swept volume and includes an adjusting piston that is mounted in or on a cylinder, is movable axially rectilinearly in relation to the cylinder, and is adjacent to a pressurizable adjusting chamber. A bearing gap is formed between a circular-cylindrical bearing surface of the adjusting piston and a circular-cylindrical bearing surface of the cylinder. The adjusting piston is mounted hydrostatically, wherein at least three pressure pockets are distributed uniformly in a row over the circumference of a bearing surface. Pressure fluid flows into each pressure pocket via a fixed throttle, which is assigned only to the respective pressure pocket, and flows out of each pressure pocket via the bearing gap.

A hydrostatic positive displacement machine has an adjustable swept volume, and has a lifting element, a rotor with positive displacement elements supported on the lifting element, and a hydraulic adjusting device that adjusts the swept volume and includes an adjusting piston that is mounted in or on a cylinder, is movable axially rectilinearly in relation to the cylinder, and is adjacent to a pressurizable adjusting chamber. A bearing gap is formed between a circular-cylindrical bearing surface of the adjusting piston and a circular-cylindrical bearing surface of the cylinder. The adjusting piston is mounted hydrostatically, wherein at least three pressure pockets are distributed uniformly in a row over the circumference of a bearing surface. Pressure fluid flows into each pressure pocket via a fixed throttle, which is assigned only to the respective pressure pocket, and flows out of each pressure pocket via the bearing gap.

A bent axis plunger-type variable hydraulic motor pump, including a cylinder body, a plunger, a ball connecting rod, a plunger spherical hinge, a multistage ball track spherical hinge shaft, a multistage ball track bearing ring, a retainer plate, an oil distributing plate, an oil distributing plate pin shaft, a suspension circle, a bushing bearing ring, a box bushing shaft, a box, a large variable ball connecting rod assembly, and a small variable ball connecting rod assembly. The large and small variable ball connecting rod assemblies are mounted on the box. The multistage ball track spherical hinge shaft is supported on the multistage ball track bearing ring, and a multistage rolling element holder in which a rolling element is provided is mounted in the multistage ball track spherical hinge shaft. Two ends of the ball connecting rod are hingedly connected to the multistage ball track spherical hinge shaft and the plunger.

A rotatable piston assembly for a reciprocating piston type hydraulic machine includes a rotatable piston configured for a controlled rotation and configured to reciprocate within a cylinder bore of the reciprocating piston type hydraulic machine.

A rotatable piston assembly for a reciprocating piston type hydraulic machine includes a rotatable piston configured for a controlled rotation and configured to reciprocate within a cylinder bore of the reciprocating piston type hydraulic machine.