Abstract: A method is provided for forming wear-resistant layer on the surface of cylinder bores a cylinder drum of a hydrostatic axial piston machine within which a respective piston is moved in a manner subject to intensive wear. The cylinder bores are gas nitrocarburized in two stages to minimize the wear and include a thin uniform connecting layer that has a thickness of 4 to 16 ?m and a comparatively thick underlying diffusion layer.

Abstract: A hydraulic cylinder has a cylinder housing in which is formed a pressure chamber variably bounded on one side by a piston of a piston subassembly that is longitudinally displaceable. A piston rod is rigidly connected with the piston, wherein the piston has an outer contour, which permits tilting of the piston subassembly in the cylinder housing, and a projection, which is at the pressure chamber side and on which a sealing element is centered and retained by a retaining ring. The sealing element has an encircling sealing lip that slidably and sealably bears against a sliding surface of the cylinder housing. The retaining ring is provided on the side thereof opposite from the sealing element with a stiffened prolongation.

Abstract: A radial piston machine includes at least one piston unit with a piston and at least one rolling element rotatably mounted in a rolling element receptable of the piston. The piston of the piston unit is polished.

Abstract: A piston unit for a radial piston machine includes a piston and a roller or a roller element. The roller or roller element has a circular cylindrical jacket apart from a chamfer. A hydrostatic pressure- or force-relief element is provided in a contact area between the piston and the roller. The hydrostatic pressure- or force-relief element forms a pressure field in the contact area. The roller or roller element also has one or two end-face holes. Due to the hole(s), the roller is slightly weakened at the associated end section such that Hertzian stress is reduced at the same associated end section.

Abstract: The present invention utilizes rolling elements, such as balls or rollers acting as bearings carried in openings in the skirt or equivalent portion of a piston, to engage the cylinder walls and replace the sliding bearings of the skirt with the roller elements in the skirt. The rolling elements then absorb all or some of the thrust loads conventionally absorbed by the skirt walls sliding along surfaces of an associated cylinder and thereby reduce the friction forces developed by the reciprocating action of the piston skirt.

Abstract: The present invention utilizes rolling elements, such as balls or rollers acting as bearings carried in openings in the skirt or equivalent portion of a piston, to engage the cylinder walls and replace the sliding bearings of the skirt with the roller elements in the skirt. The rolling elements then absorb all or some of the thrust loads conventionally absorbed by the skirt walls sliding along surfaces of an associated cylinder and thereby reduce the friction forces developed by the reciprocating action of the piston skirt.

Abstract: A piston including a body having a guiding and sealing surface, a base, and a top, which top is provided with a cradle-shaped recess in which a journal-bearing lining is retained by stop surfaces formed on the edges of the recess. The stop surfaces are formed by deforming the edges of the recess towards the inside thereof.

Abstract: An improved piston ring suitable for use in an internal combustion engine is disclosed comprising a plurality of races sized to receive elongate rollers disposed around the circumference thereof. The elongate rollers may be shaped as a prolate ellipsoid or other rounded shape. The piston ring may seat within a groove in fluid communication with an oil channel extending through a piston rod and opening into a rod bearing connecting the piston rod to a crankshaft. A crankshaft has a corresponding oil channel therewith and has an opening positioned to periodically align with the opening in the rod bearing when rotated. Oil is pumped into the oil channel in the crankshaft to force oil over the piston rings. Drain apertures may be formed in another groove formed in the piston to conduct oil away from the piston.

Abstract: A device for supporting and for at least contributing to the activation of an actuating element. An outer thin-walled bearing ring defines a pressure space to which pressure is applied. The outer thin-walled bearing ring at least partially bounds a circumference of the pressure space. A piston supports the actuating element and moves longitudinally within the pressure space with respect to the outer thin-walled bearing ring. Roller bodies configured to roll on the outer thin-walled bearing ring for supporting the actuating element.

Abstract: A centering support for a piston in a piston-type pump having a diaphragm extending between the piston and the cylinder to define a product end of the pump and a driven end of the pump includes at least three equally radially spaced, centering elements extending radially outwardly from the piston for contacting the cylinder wall. The centering elements define a gap between the piston and the cylinder wall. The centering elements are disposed on the piston spaced from the diaphragm at the product end of the pump.

Abstract: A drive and guide means for a load to be moved which comprises a rodless drive piston adapted to be driven by a pressure medium in a pressure medium cylinder, such piston having at least one force transmission part extending outward through a longitudinal slot in a wall of such cylinder. A flexible sealing tape for seals off the longitudinal slot on either side of the force transmission part. An anti-friction bearing arrangement serves to take up a load and/or to guide the piston, such anti-friction bearing arrangement being arranged in the housing of the pressure medium cylinder. An anti-friction bearing arrangement is arranged within the cylinder space of the pressure medium cylinder in or on the drive piston. This means that pressure medium cylinders with an extremely small cross section and an extremely simple structure may be produced economically.

Abstract: This invention relates to a piston with skirt being formed by four sets of bearing grooves as the main structure, and a cylinder liner with four ball bearing rolling tracks. The bearing groove is in doughnut shape and has a circular cross-section to hold the ball bearing in circulation during the reciprocating motion of the piston. Two lines of ball bearings on each side of a piston pin are in line contact to the bearing tracks of the cylinder liner and share the piston thrust load. Lubrication of the ball bearings is ensured by oil slots through the piston head under the oil ring groove to the exposed ball bearings in rolling contact and to the top of the bearing groove.

Abstract: In order to reduce the weight and manufacturing cost of a piston for a hydraulic actuating cylinder, the piston, the piston rod and the external reinforcement cap are combined to form a unitary integral part. The unitary part is advantageously a single extrusion product. The piston is shaped so as to be able both to slide along the length of the inner cylinder wall, and to tilt upon deflection or lateral displacement of the piston rod in the bore of the cylinder, while still maintaining its hydraulic seal.

Abstract: This invention relates to a piston with its skirt being cut to locate four sets of bearing pads and circulating roller bearings. Each pad has been milled to have a doughnut shaped groove with half of a roller cross-section to hold the roller bearing in circulation during the piston reciprocating motion. Two lines of roller bearings on each side of a piston pin are in contact with the cylinder liner and share the piston thrust load. Lubrication of the roller bearings is ensured by oil slots through the piston skirt under the oil ring groove to the top of the grooves of the bearing pads and to the exposed roller bearings in rolling contact.

Abstract: A hydraulic power unit combining a number of cylinders using ball bearings to displace hydraulic fluid sequentially with controlled flow to a number of hydraulic actuators. A power unit could combine a minimum of two cylinders through ten or twelve cylinders in a practical hydraulic power unit. The inherent bi-directional nature of this combination of fluid displacing ball bearings, cylinder and porting arrangement offers a unique opportunity to change fluid flow by reversing input drive. The torsional reaction component of the opposed reciprocator drives is utilized to rotate the core cylinder assembly to realign outlet and return fluid flow. This realignment can be used to reverse the fluid circuits or redirect the fluid to other work.

Abstract: This invention relates to a piston with its skirt being cut to locate four sets of bearing pads and circulating bearing balls. Each pad has been milled to have a doughnut shaped groove with half of a circle cross-section to hold the ball bearing in circulation during the piston reciprocating motion. Two lines of bearing balls on each side of a piston pin are in contact with the cylinder liner and share the piston thrust load. Lubrication of the ball bearings is ensured by oil slots through the piston skirt under the oil ring groove to the top of the grooves of the bearing pads and to the exposed bearing balls in rolling contact.

Abstract: Apparatus for harnessing and utilizing, inter alia, gravitational and centrifugal forces generated at a location eccentric from the axis of rotation of a rolling wheel. The apparatus includes pumps that can be attached in a tangential relationship to a path of wheel rotation of an automobile wheel in order to pressurize under-inflated tires and maintain tire pressure at a preset value. A double acting unitary piston assembly is supported for antifrictional reciprocation in a pump housing along a line tangential with respect to a path of wheel rotation so that gravitational force will principally displace the piston assembly to effect working strokes for inflating a pneumatic tire. Compression ratio parameters of the pump are preselected to cause the pump to be effective at wheel rotation velocities above which gravitational forces are no longer effective to operate the pump. A device is also provided to adjust the compression ratio of the pump to thereby adjust the air pressure to be maintained in the tire.

Abstract: A piston of an internal combustion engine, arranged to suppress engine noise and vibration while improving the frictional resistance and seizure resistance of a piston skirt. The piston skirt of the piston is formed at its outer peripheral surface with a pair of depressions. A projection having a spherical surface is formed at the bottom surface of each depression and protrudes radially and outwardly relative to the piston skirt. A heat-resistant pad is loosely fitted in each depression and has a cylindrical inner surface which is in slidable contact with the spherical surface of the projection, so that the pad makes its swinging movement in accordance with the oscillating rotational movement of the piston body around the axis of a piston pin during the reciprocating action of the piston.

Abstract: A peristrophic internal combustion engine with increased power output has greater torque and reduced friction. The distance of rotation between the inertia weights and the crankpins is increased to increase torque. These transposed inertia weights are embodied in top and bottom journals of the connecting rods and in the pistons assemblies. Each piston assembly includes a top piston-ring-holder piston and a lower, bearing piston joined to reciprocate in the cylinder. The lower bearing piston may have a circumferential ring, cylindrical barrel rollers, or spherical ball bearing arrangement contacting the cylinder wall while the upper piston carries the piston rings. The spherical ball bearing arrangement allows lower piston rotation about the piston axis. Inner and outer cylinder liners increase the cylinder operating life and reduce combustion heat loss through the cylinder wall.

Abstract: This application relates to a piston having two sets of three roller bearings mounted by means of milled grooves in a lightweight skirt of less diameter than the piston head. Each triangularly arranged set of roller bearings is symmetrically arranged to give a rolling three point stability and rolling anti-friction support to the piston as it reciprocates in the cylinder. Lubrication of the roller bearings is enhanced by openings through the piston skirt in the area of the oil rings above the roller bearings. The roller bearing axles are mounted in milled grooves.

Abstract: A stone guide for guiding the honing stone of a superfinishing machine. The stone guide receives a honing stone unit which comprises a honing stone and a honing stone holder. The honing stone holder defines a shoulder and a contact surface. The stone guide includes a piston and a piston rod, at one end of which there is disposed a contact surface, and a rapid-clamping device displaceable in the piston rod. The rapid-clamping device includes a further piston, a further piston rod connected to the further piston and a clamping element which defines a shoulder. Both pistons are displaceable by means of a pressure medium such that displacement of the piston effects lowering of the honing stone unit unto a workpiece and the upward movement of the further piston effects engagement of the contact surfaces.

Abstract: A rotary actuator is operable under the influence of fluid pressure to rotate a driven member. The rotary actuator includes a drive member which extends into a chamber in a housing. Helical splines interconnect a piston and the drive member to rotate the drive member upon axial movement of the piston in the chamber. The piston is held against rotary movement relative to the housing in one embodiment by a pair of rollers that engage tracks disposed on opposite sides of the piston and in another embodiment by a corresponding oval-shaped configuration of a portion of the piston and an internal portion of the chamber in the housing. In one embodiment of the invention, a rack gear on the piston rotates a pinion to actuate a valve and restrict fluid flow to the chamber when the piston is approaching an end-of-stroke position. A one-way clutch may be connected with the drive member so that the driven member is only rotated in one direction rather than being oscillated upon back and forth movement of the piston.

Abstract: A reciprocating engine comprising a cylinder, a piston performing reciprocating movement within the cylinder, a crank shaft performing rotational movement, a connecting rod connected rotatably at its one end to the crank shaft and at its the other end to the piston, and rollers each mounted on the side portion of the piston, in which the piston is in rolling contact with the cylinder through the rollers.

Abstract: In a machine of the kind in which an operative member under the actuation of driving means is reciprocatable relative to a guide member in order to exert forces in a predetermined direction on a workpiece, toothed and elongate roller bodies having their axes of rotation extending perpendicularly to said direction are interposed between the guide member and the operative member in order to prevent the latter from tilting. The teeth of each roller body mesh with the teeth of racks extending in said direction of movement of the operative member and being provided on both the guide member and the operative member in a manner to cause each roller body to transmit under torsional strain balancing forces in its axial direction. The roller bodies also have cylindrical surface portions being coaxial with and having the same diameter as the pitch circles of their teeth, said cylindrical portions being in rolling contact with rollways provided on both the operative member and the guide member.

Abstract: A reciprocating engine comprising a cylinder, a piston performing reciprocating movement within the cylinder, a crank shaft performing rotational movement, a connecting rod connected rotatably at its one end to the crank shaft and at its the other end to the piston, and rollers each mounted on the side portion of the piston, in which the piston is in rolling contact with the cylinder through the rollers.

Abstract: An improvement for a variable volume device in the form of a rectilinear case having disposed therein a rectilinear outer piston structure and a rectilinear inner piston structure within the outer piston structure, the inner piston being carried for rotation on a crank shaft and in turn inducing a reciprocal movement of the outer piston structure in the case, the improvement comprising rollers positioned between the outer piston structure and the case, and the inner piston structure and outer piston structure to facilatate thrust and force accomodation therebetween, and sealing strip means positioned in sealing relationship between the outer piston structure and rectilinear case, and inner piston structure and outer piston structure, and particularly an embodiment in which the sealing strips means of the inner piston structure bear against the side portion of the outer piston structure sealing ring means and a bearing plate positioned to support the rollers, whereby the rectilinear innerrunning pistons may be

Abstract: The piston and cylinder of a hydraulic power booster are provided with opposed longitudinal grooves effecting a pocket for a series of rollers axially aligned and on an axis parallel to that of the piston-cylinder axis. A leaf spring in the piston groove maintains a radial bias on the rollers towards the cylinder groove. The rollers effect a sliding guide or key between the piston and cylinder to prevent rotation or twisting of the piston in the cylinder.

Abstract: Means and method are provided for utilizing a piston and cylinder combination eliminating the usual sealing and oil rings and their accompanying friction and replacing them with ball bearings which in the principal embodiment are captured in splitring cages which are snapped into the existing grooves of the piston. Having thus lost the sealing ability of the piston, an accordion-type diaphram is utilized in the top of the cylinder to define the compression or combustion chamber.