Abstract: A piston pin structure for an engine is provided, which suppresses integral resonance of a piston, a piston pin, and a smaller end part of a connecting rod with respect to a larger end part of the connecting rod on the combustion stroke, as well as suppresses an increase of noise on other strokes, and restricts the fixed dynamic absorber inside the piston pin from coming off and ensures a coming-off function. The piston pin structure may include a dynamic absorber including a fixed part fixed to a piston pin, a movable part extending in the axial direction of the piston pin, and a supporting part for swingably supporting the movable part with respect to the fixed part. A restriction mechanism for mechanically restricting the movement of the dynamic absorber in the axial direction may also be included.

Abstract: A flow restrictor (1) for use in bearing formation between a piston (2) and a cylinder (3) of a gas compressor (4). The gas compressor (4) includes a protective pad (5) that externally surrounds the cylinder (3), and an inner cavity (6) is disposed between the protective pad (5) and the cylinder (3), fluidly fed by a discharge flow from a compression movement exerted by the piston (2). The gas compressor (4) further includes a bearing formation gap (7) that separates an outer wall of the piston (2) and an inner wall of the cylinder (3). A flow restrictor (1) is provided with a housing (12) that fluidly associates the inner cavity (6) to the bearing formation gap (7). The flow restrictor (1) includes a limiting tube (8) associated with the housing (12), provided with at least one restraining portion provided with a cross section sized to limit the gas flow from the inner cavity (6) to the bearing formation gap (7).

Abstract: A compressor includes a cylinder and a piston moveable in an oscillating manner in the cylinder and having transverse play in relation to a movement direction. An end face of the piston delimits a compression chamber in the cylinder. A diameter of the piston reduces toward the end face.

Abstract: Known compressors are equipped with gas bearings, in which the bearing nozzles are continuously supplied with a stream of gas. According to the invention, the gas bearing is a self-sufficient bearing, in which the supply pressure is independent of the delivery pressure. To achieve this, the compressor is equipped with a gas reservoir with a bearing supply pressure.

Abstract: A piston compressor comprises a piston (12) which oscillates in a cylinder (14). A compressed-gas supply arrangement is provided which comprises a compressed-gas accumulator (34), a compressed-gas supply line (18) between a compressed-gas source (20) and the compressed-gas accumulator (34). Further, the compressed-gas supply line (18) comprises an inlet valve (42) which is open when the piston (12) is in a filling position. The inlet valve (42) is defined by a cylinder wall opening (22) and a piston wall opening (38) which are located opposite each other when the piston (12) is in the filling position, thus defining an open valve, and which are closed by the piston wall (40) and the cylinder wall (24), respectively, when the piston (12) is in the non-filling position, thus defining a closed valve. Thereby, a valve is provided which does not comprise any moving parts and is thus easy to manufacture, is highly reliable and has a long service life.

Abstract: Hybrid gas bearing, planar spring clearance seal compressors and methods that provide a hybrid planar spring supported/gas bearing supported piston. In accordance with the method, a gas bearing is energized to center the piston in the cylinder prior to rigidly attaching the planar spring or springs between the piston and the compressor frame. This automatically and very accurately centers the piston in the cylinder to provide the added stiffness of a planar spring and gas bearing in an easily manufactured configuration. Various exemplary embodiments are disclosed, including embodiments having the piston cantilevered from one end using a single or multiple springs, an embodiment having a spring on each end of the piston, a double piston embodiment and embodiments using and not using the gas bearing during operation of the compressors.

Abstract: A high pressure fuel pump having a variable fuel injection rate, including a pump body, a pump cylinder formed in the pump body and a piston reciprocable within the pump cylinder, which defines a pressurization chamber. The pump piston has a reduced diameter portion which provides a primary piston. A piston annulus is slidably mounted thereon and provides a secondary piston. An annular actuation chamber adjoins the secondary piston opposite the pressurization chamber. An actuation passage is provided between a return fuel drain and the actuation chamber, which is selectively open or closed passively by pump piston movement and/or dynamically by operation of an actuation solenoid valve. If the actuation chamber passage is open, then during the pressurization stroke the secondary piston will remain stationary relative to the pump body, but if it is closed then the secondary piston must stroke in unison with the primary piston.

Abstract: In a linear compressor having a compression mechanism for compressing and discharging a refrigerant, an inflammable refrigerant or a natural refrigerant such as propane, isobutane, carbon dioxide or the like is used as the refrigerant while no lubricating oil is filled up, thereby improving the system efficiency and reducing the amount of refrigerant.

Abstract: Piston compressor for compressing gas, comprising a frame with at least one cylinder which has an essentially horizontal axis, a piston which is reciprocable in the cylinder, a piston rod which at one end thereof is fixed to the piston, while the other end thereof is coupled to a crosshead which is guided in the frame and is reciprocable by a drive mechanism, and bearing means which support the piston/piston rod unit, formed by the piston and the piston rod connected thereto, relative to the frame.

Abstract: There is described a piston for an axial piston machine with which the skirt surface (12) of the piston shaft (15) has, at its forward end region (Y) which transforms into the piston end face (11) and/or at its rear end region (X) lying towards the piston head, a bevel (16; 18; 19; 21) with continuously varied radiuses of curvature.

Abstract: An advance mechanism for a pump comprises a fluid operable piston arranged to have pressurized fluid applied to a first end thereof to adjust the axial position of the piston. The arrangement further comprises means for applying fluid under pressure to a part of the piston remote from the first end thereof in order to apply a torque to the piston. In one embodiment, the means for applying comprises a passage extending within the piston, the passage communicating with the first end of the piston such that high pressure fluid is received by the passage.

Abstract: Gas cushions are maintained between a piston and a cylinder of a gas lubricated reciprocating engine which are effective in retarding the approach of the piston to the cylinder wall under the thrust of side forces from the connecting rod. The cushion are maintained by viscous flow forces for sufficient time exceed a half cycle of crankcase rotation.

Abstract: A member oscillates on a face and another member pivots on a bed of the first member. Passages are provided through the members to lead a lubrication fluid under pressure into a fluid pocket between the mentioned face and one of the members. The fluid pressure in the pocket carries a major portion of the load of one of the members on the face. The oscillation of the members has one stroke under higher load and one under less load. The pivotal movement of the other member controls the flow of fluid through the passages to provide high pressure in the fluid pocket at the stroke under higher load and lower pressure in the pocket at the stroke under less load. The arrangement is especially suitable to be provided on pistons and piston shoes of radial piston machines. But it can also serve to carry load on other members of machines or vehicles, wherein at least two movements are taking place and a source of supply of fluid under pressure is available.

Abstract: An apparatus for providing a gas phase film lubrication between a reciprocal piston and a cylinder of an uncooled oilless internal combustion engine; the piston is effective to drive a rotary crankshaft in response to an expanding gas charge. The apparatus comprises: (a) means connecting the crankshaft to said piston for transferring reciprocal thrust into rotary thrust, such means aligning the piston concentrically within the cylinder wall to limit the imposition of side loads on said piston (i.e., less than 80 psi); (b) interfacing walls on the piston and cylinder (i) sized to provide a predetermined annular gap therebetween at ambient conditions that has a radial dimension in the range of 0.001.+-.0.

Abstract: A pair of circumferential sliders are positioned symmetrically on opposite sides of a piston, an inner surface of each circumferential slider being connected to a respective bevel rack gear. The rack gears are driven by bevel pinion gears that are attached to opposite ends of a wrist pin connecting the piston to a connecting rod. A pair of passages extend from the top of the piston to a pair of opposite, symmetrically positioned windows that are enlarged and reduced as a crankshaft connected to the lower portion of the connecting rod rotates in order to apply combustion or compression gas pressure in a cylinder to opposed varying areas of the cylinder wall so as to offset the varying lateral component of force applied by the connecting rod to the piston.

Abstract: A gas bearing system for a piston 24 of a linear compressor 20 in which gas from the piston head space 26 is injected into a high pressure reservoir 106 within the piston when the working fluid in the piston head space is at high pressure. In one embodiment, gas from a low pressure reservoir 104 is exhausted into it when the piston working space fluid is at low pressure. Gas flow is directed between high pressure and areas of low pressure during operation of the piston. This gas flow is directed between the piston and its surrounding sleeve 30 in a manner which holds the piston 24 in suspension away from the sleeve 30 to thereby reduce the friction and wear experienced by the piston and sleeve.

Abstract: A reciprocating piston internal combustion engine comprises a piston movably disposed within an engine cylinder, the top surface of the piston defining thereon a combustion chamber; a space formed in the cylinder; a movable member disposed within the space and movable in the direction of a minor thrust side cylinder wall upon receiving a gas pressure within the combustion chamber; and a device for providing the gas pressure into the space of the piston during compression stroke of the engine so that the movable member receives the gas pressure, thereby effectively reducing piston slap noise.

Abstract: A gas bearing system for a piston 24 of a linear compressor 20 in which gas from the piston head space 26 is injected into a high pressure reservoir 106 within the piston when the working fluid in the piston head space is at high pressure. In one embodiment, gas from a low pressure reservoir 104 is exhausted into it when the piston working space fluid is at low pressure. Gas flow is directed between high pressure and areas of low pressure during operation of the piston. This gas flow is directed between the piston and its surrounding sleeve 30 in a manner which holds the piston 24 in suspension away from the sleeve 30 to thereby reduce the friction and wear experienced by the piston and sleeve.

Abstract: An integral power steering gear assembly includes a piston and cylinder combination having greater output efficiency through improved fluid balancing and cushioning of the piston at its ends. The improved cushioning utilizes oil capillary slots in lieu of previously proposed epoxy resin strips. The slots may be fed with high pressure fluid filled by feed grooves along the sides of the piston adjacent the output rack. The slots are designed to have a shallow depth, preferably 0.001 inch-0.0025 inch, which is sufficient to provide for high capillary attraction of the oil molecules to the slot. The trapped oil molecules prevent slip stick action, that is molecular interaction between the piston and cylinder wall, but at the same time, the oil molecules remain trapped or isolated within the walls of the slot thereby minimizing leakage from the slot. The operating oil is delivered with higher efficiency in the power steering unit by a bifurcated oil delivery passage communicating with the inlet slot of the piston.

Abstract: Plastic wear strips are provided on a power steering piston or cylinder to improve the efficiency of translation movement of the piston in the cylinder during operation. The plastic surface of the strip, which is preferably on the piston, minimizes wear by providing a differential molecular structure at the interface between the cylinder wall and the surface of the piston since the cylinder wall is machined metal. The strips are positioned adjacent the ends of the rack where wear, caused by the load from the pressurized hydraulic fluid on the opposite side of the piston adjacent the inlet slot, is potentially the greatest. Plastic filling is provided in preferred arcuate grooves around the piston to form the wear strips. A single strip, or alternatively a group of independent strips, can be used and both serve to interrupt the surface of the piston so that molecular interaction of the two surfaces, or "slip-stick" effect, is effectively prevented. The wear strips extend through a 60.degree.

Abstract: A sealing device for a high pressure hydraulic piston mechanism in which the gap between the cylinder in which the piston is slideable to pressurize delivery fluid therein is sealed by sealing fluid drawn from a separate supply to that of the delivery fluid, delivery means being associated with the sealing fluid supply and being operable in response to pressurization of the delivery fluid to deliver sealing fluid to said gap at a pressure sufficient to form a seal therein, the sealing fluid of said seal being in direct contact with the pressurized delivery fluid and the piston being movable in at least one hydrostatic bearing supplied with sealing fluid in parallel to the supply thereof to said gap between the piston and the cylinder.

Abstract: A rolling stand with hydraulic adjustment of the mill rolls comprises a hydraulic cylinder whose piston is acted upon by the adjustment spindle and whose cylinder body, in turn, bears upon the block in which the back-up or pressure roll is journaled. The sliding seal of the piston rides in a cylinder lining which is disposed in the cylinder and is sealed relative to the latter with stationary O-rings so that pressure equalization on both sides of the liner is possible, thereby preventing expansion of the line upon subjection of the cylinder to high pressures.

Abstract: A compressed air engine having specially designed cylinder heads and piston configurations in order to reduce friction and maximize the application of air from a pressurized air source. The disclosure includes a lubrication system whereby the mechanical parts receive oil via a lubrication arrangement including a conveyor chain continually bathed in oil.

Abstract: Engine piston arrangements including at least one friction reducing gas bearing recess in a thrust loaded portion of the piston skirt and connected to the space between the top two piston rings to provide blowby gas to pressurize the bearing recess and support at least part of the thrust forces on the piston skirt.

Abstract: An integral power steering gear with a valve in the piston is provided having a short piston and cylinder to conserve space and weight. The input shaft is mounted on a bearing carried by an inwardly projecting annular portion on the bearing cap. The projecting portion mates with a recess in the end of the piston when the piston is moved to the full extreme in that direction. The valve guide pin has been relocated at the input shaft end of the valve where maximum support of the valve is realized and improved reversibility of the valve under all conditions is gained. In the bearing cap, both a high pressure seal and a low pressure weather seal are provided. An insert ring between the two seals serves as backup to the high pressure seal. In an alternative embodiment, the insert ring may be tapered toward the inside of the gear to allow use of a thin wiper-type seal.

Abstract: An improved oil damped piston for use in internal combustion engines, pumps, compressors, or the like. The piston includes a generally cylindrical piston body having a crown and a depending skirt. A pair of spaced bands of polytetrafluoroethylene are carried by the skirt and each has a surface radially outwardly of the skirt. Each of the band surfaces includes a configuration defining a pumping surface for directing lubricant on a cylinder wall into the space between the band. The oil in the space damps side to side movement of the piston within its cylinder.

Abstract: A piston for a compressor having at both ends a step-down portion which defines an annular cavity when the piston is mounted in the cylinder, the said cavity being very thin while its length is dependent on the weight and the length of the piston. A rider ring is located at the center of the piston and piston rings are inserted between the rider ring and the step-down portion.

Abstract: An apparatus for providing a gas phase film lubrication between a reciprocal piston and a cylinder of an uncooled oilless internal combustion engine; the piston is effective to drive a rotary crankshaft in response to an expanding gas charge. The apparatus comprises: (a) means connecting the crankshaft to said piston for transferring reciprocal thrust into rotary thrust, such means aligning the piston concentrically within the cylinder wall to limit the imposition of side loads on said piston (i.e., less than 80 psi); (b) interfacing walls on the piston and cylinder (i) sized to provide a predetermined annular gap therebetween at ambient conditions that has a radial dimension in the range of 0.001.+-.0.