Abstract: An internal combustion engine for enhancing a heat radiation property of combustion gas, can sufficiently secure strength thereof relative to combustion gas, and a weight reduction thereof can be realized. A piston for an internal combustion engine is constituted of a head part, a cylindrical skirt part extending from a lower part of the head part. A pair of pin boss parts are formed on both opposing side walls to each other of the skirt part. A plurality of recessed parts, the cross sections thereof being presented as smooth circular arcs, are formed on a surface on an opposing side to a surface facing to a combustion chamber of the head part, that is, to a reverse face.

Abstract: A sliding surface of at least one of sliding members sliding with respect to each other in a sliding direction comprises a protrusion extending along a direction intersecting the sliding direction and fine dimples provided on a surface of the protrusion. In the sliding members, lubricating oil is accumulated in the dimples, and is easily extracted through a drain portion formed by dimple in a running-in operation.

Abstract: The invention relates to a radial piston pump for generating high fuel pressure in fuel injection systems of internal combustion engines, in particular in a common rail injection system, having a driveshaft, supported in a housing, that has an eccentrically embodied shaft portion which cooperates with preferably a plurality of pistons capable of reciprocating radially, relative to the driveshaft, in a respective element bore, in order to aspirate fuel and subject it to high pressure in a high-pressure region. In order to increase the efficiency and lengthen the service life, in the outer jacket face (3) of the pistons and/or the inner jacket face of the element bore, a structure in the &mgr;m range is formed.

Abstract: The present invention relates to a piston for use in a swashplate type compressor. The piston includes a void in the exterior surface of the head region that is positioned at a distance from a region that receives a side load during operation of the compressor. In preferred embodiments, the void comprises a helical groove that extends along a path parallel to the region receiving the side load, and a recess or depression positioned adjacent the region receiving the side load.

Abstract: This engine is substantially free from any vibration and noise, small in friction loss, improved in mechanical efficiency to a considerable extent, compact and lightweight, and applicable to a reciprocating piston engine. The engine comprises: curved cylinders each assuming a circular shape in cross section; curved pistons (1, 1a) each fitting and reciprocating within the cylinder; a rotor (2) carrying the pistons (1, 1a) to keep them in balance and to have them be rockable about the center of the rotor (2), wherein the rotor (2) is provided with connecting rods (6, 6a) to impart half a rocking power of the rotor (2) to each of crank shafts (10, 10a) each of which converts the half of the rocking power to a piece of torque on its axis of rotation; a gear mechanism for receiving the pieces of torque to combine them into an output power; and, an output shaft connected with the gear mechanism for receiving and out-putting the output power.

Abstract: The invention can prevent a heat generation and a seizure due to a sliding friction between a piston and a cylinder in inclined shaft type and swash plate type hydraulic pumps even when they are made high speed.

Abstract: A filled hydraulic piston assembly includes a piston body having first and second ends and a compartment in the piston body extending inwardly from the second end toward the first end. The piston is filled with an insert element which is inserted into the compartment of the piston and then held therein by pushing an annular lip on the second end of the body inwardly and against the adjacent end of the insert element. The insert element is comprised of a material that is less dense than the material of the body but has a higher bulk modulus than hydraulic oil. Oil channels can be formed in a variety of shapes on or around the insert so that oil may flow through the filled piston. The piston insert element can be formed from a variety of materials, such as plastic, magnesium, aluminum or other nonferrous metals. The body is generally comprised of steel.

Abstract: A reciprocating pump is provided for pumping subterranean fluids containing fine solids to surface. The pump comprises a pump barrel, piston and piston rod. The piston rod is suspended form reciprocating production tubing. The barrel is anchored in the casing of a well. A standing valve is located at the bottom of the barrel. The piston and travelling valve are located at the bottom of the piston rod for minimizing the dead-space between standing and travelling valves. Upper and lower stacks of hydraulic piston seal rings are positioned on the piston above and below the travelling valve for minimizing piston height. Each seal has radially flared lips at its leading edge. The piston spaced grooves formed therein, corresponding to the seal ring flared lips.

Abstract: The invention relates to a high pressure reciprocating pump, for a fuel injection system of an internal combustion engine, having at least one piston, which is displaceably supported in a piston guide provided in a housing and therein defines a work chamber. Supported in the housing is a drive shaft, on which a crank element is provided on which a stroke ring, is not rotatable in the housing. The crank element is rotatably supported, the stroke ring has a slide bearing face, associated with the piston on which face the piston is supported with a slide face, so that the piston can be acted upon by the drive shaft. To reduce the danger of so-called seizing of the bearing faces moving back and forth on one another when poorly lubricating media such as fuel and in particular gasoline are being pumped, it is provided that a relief chamber, formed by a recess in the slide face disposed on the piston and open toward the slide bearing face on the stroke ring, communicates with the work chamber.

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: A wobble plate compressor piston has a central aperture formed through its front surface, directly into the ball and socket joint that connects it to the drive plate. High pressure refrigerant and entrained lubricant mist are forced into the gap between ball and socket, collecting in a converging section thereof to form a liquid seal that prevents blow by of refrigerant gas and compression loss. The joint is better lubricated as a consequence, reducing stress on the connecting rod.

Abstract: A sliding bearing, particularly for slippers of hydrostatic piston machines, with a support having a supporting surface on which slides a sliding piece having a sliding and sealing surface. Between the supporting surface and the sealing part of the sliding and sealing surface is a bearing gap height (h.sub.2) and in the sliding and sealing surface at least one shallow recess with a depth (h) bordered by the sealing part of the sliding and sealing surface. At least one connecting channel is connected to a pressure source of the lubricating fluid so that a lubrication gap with a height (h.sub.2 +h) is formed. The lubrication gap is in accordance with the invention designed in such a way that a self-adjusting load bearing capacity dependent on the gap height (h.sub.2) is achieved, whereby in the gap such a flow is created, under the influence of which the velocity of the lubricating fluid is positive (greater than zero) in all directions and the pressure gradient is declining in the flow direction.

Abstract: A piston for use in a compressor that compresses gas containing lubricating oil is disclosed. The compressor includes a housing having a crank chamber and cylinder bores for accommodating the pistons. A swash plate is located in the crank chamber and is supported on a drive shaft. The swash plate is operably connected to the pistons by shoes to convert the rotation of the drive shaft to reciprocation of each piston. Each piston has a head for compressing the gas supplied to the cylinder bore and a skirt projecting from the head toward the crank chamber and connected to the swash plate. A restrictor provided on the skirt slidably contacts an inner surface of the housing to prevent the piston from rotating in the cylinder bore. A sloped surface extends along the edge of an end face of the restrictor. The sloped surface guides the oil in the crank chamber toward the shoes when the piston moves from a top dead center position to a bottom dead center position.

Abstract: A compressor has a piston (11) that reciprocates between a top dead center and a bottom dead center in a cylinder bore (2a) by means of a driving body (9) mounted on a rotary shaft (6) in a crank chamber (5) during the rotation of the rotary shaft (6). The piston (11) has an outer circumferential surface that slides against an inner circumferential surface of the cylinder bore (2a). The outer circumferential surface of the piston (11) is provided with a groove (17; 44; 46) extending in the direction of an axis (S) of the piston (11). During reciprocation of the piston (11), lubricating oil adhered to the inner circumferential surface of the cylinder bore (2a) is collected in the groove (17; 44; 46). When the groove (17; 44; 46) is exposed to the inside of the crank chamber (5) from the cylinder bore (2a) during the reciprocation of the piston (11), the lubricating oil in the groove (17; 44; 46) is supplied to the inside of the crank chamber (5).

Abstract: A number of embodiments of direct piston pin lubrication systems for reciprocating machines such as internal combustion engines. In all of the embodiments, the hollow interior of the piston pin is employed as a distribution passage with radial drillings extending through the piston pin for lubricating the various journals thereof. In some embodiments, the lubricant is sprayed through the wall of the cylinder bore directly into the piston pin and in others it is delivered through a passage formed in the piston.

Abstract: In a piston/liner arrangement for a reciprocating-piston internal combustion engine, wherein a piston with a skirt is axially movable in the liner, at least one of the piston skirt and the liner includes sections with an open-pore surface structure in which a lubricant with a high affinity to the material having the open-pore surfaces structure is disposed so as to form a lifetime lubrication arrangement.

Abstract: A plurality of passageways were provided between the inter-ring cylindrical surface of a piston and a cavity formed behind an oil control ring mounted on the piston. The passageway provides for the passage of blowby gas during downward movement of the piston, thereby permitting the oil control ring to seat against the upper surface of its groove. The present invention effectively controls the flow of oil toward the compression ring of the ring assembly without the requirement for a passageway communicating the inter-ring cavity with a saturated, turbulent flow, oil environment.

Abstract: A piston, which reciprocates in a cylinder bore of an engine, is supplied with lubricating oil. The piston includes pin bosses provided under a piston head, a symmetrical pair of skirts, and side walls connecting the pin bosses and the skirts. The side walls have openings, which communicate the outer side of the walls with the inner side of the walls under the middle section of the head. A recess is defined in the lower surface of the head to receive a spray of lubricating oil. The width of the recess is wider than the width of each skirt at its basal portion. This causes the oil supplied to the lower surface of the head during movement of the piston to be injected against the recess and thus be diffused. As a result, oil passes by the basal section of the skirts and permeates into the space defined by the cylinder bore and the skirts.

Abstract: An articulated piston apparatus including an improved skirt member wherein the skirt member includes a cooling gallery channel with means for providing a directed flow of lubricant from the cooling gallery channel to the elements of the piston apparatus disposed within the skirt bore, wherein during the upward stroke of the piston apparatus a downwardly directed flow of lubricant flows from the cooling gallery channel through a bore from the cooling gallery channel to the skirt bore and therein impinges those elements of the piston apparatus to assure complete lubrication thereof.

Abstract: Spherical joint connecting rod holder rings. The holder ring is formed in two halves which define a socket in which a spherical small end of the connecting rod is retained. The ring further includes a vertical wall which acts as an oil dam to retain oil in a piston cooling gallery. One or more drain holes are formed in the ring to drain oil from the cooling gallery back to the engine crankcase. Futhermore, one or more grooves are formed in the socket surface in order to channel oil into the socket for lubrication of the spherical small end.

Abstract: An improved lubrication system for a two-stroke engine having a lubrication path from an oil sump directly to an induction valve assembly for noise reduction. The oil sump is divided into two chambers with a restricted passage therebetween to ensure lubrication of transmission gears upon startup while reducing drag during operation. A cross-drilled lubrication passage through each crankshaft throw terminates in a second passage proximate a dead-end plug, the second passage being in communication with the piston rod bearing. Each piston skirt includes at least one axial groove in registration with an oil supply passage. Circumferential grooves distribute the oil around the piston skirt from the axial grooves. The pistons may include ceramic top layers for heat insulation to increase the compression ratio possible by raising the ring positions. The engine incorporates an air/oil mixture separator within a balancer shaft chamber and air from the chamber is directed to the intake system.

Abstract: Disclosed is an actuating plunger of an electromagnetic pump, the actuating plunger having a good magnetic characteristic so as to improve the operational efficiency of the electromagnetic pump and reduce the vibration and the operational noise due to the actuating plunger. The actuating plunger has a plunger head made by a high-temperature sintering. The plunger head has a cylindrical side wall, and a plurality of shoulders protruding inwards from a lower end of the cylindrical side wall. A piston is fixedly fitted in the middle of the shoulders. The piston extends downwards so as to be slidably fitted in a second cylinder.

Abstract: The design and construction of past articulated pistons include an open space between a head portion and an independent skirt portion. The open space allows excess cooling fluid, such as oil, to exit the piston and flow toward the cylinder, increasing oil consumption and carbon deposits within the engine. The present invention overcomes these problems by positioning a sealing means within an open space between a head portion and a skirt portion of an articulated piston. The sealing means completely blocks the oil from exiting the piston while being adequately conformable to allow the necessary articulation between the head and skirt portions.

Abstract: A lubricant sealed bearing, which is provided between a piston pin and a small end part of a connecting rod, comprises at least one rolling element and at least one grease standing ring. The grease standing ring is adjacent to an end portion in an axial direction of the small end part. A capacity of a grease pool defined by grease standing ring and an end side in the axial direction of the outer ring, is 40-60% of a theoretical amount of the grease extruded by the rolling element, the movement of the rolling element being caused by the movement of the piston from a top dead point to a bottom dead point and vice versa.

Abstract: A piston for an internal combustion engine has a crown and peripheral wall to carry a piston ring. A support extends between the wall and a bearing housing to receive the connecting rod. A cylindrical support member also extends from the wall around the support to a skirt. The support member is radially inset from the wall and a cylindrical bearing member is located on its radially outer surface.

Abstract: An air-powered actuator having a body with first and second ends, an axially transverse annular bulkhead positioned therebetween, and an output shaft with a splined exterior portion. The body includes first and second end walls with each end wall having a sleeve mounted coaxially within the body about the shaft and projecting axially inward within the body. A piston sleeve is disposed for axial reciprocating movement within the body. The piston sleeve has a pair of piston heads, an outer sleeve, and an inner sleeve. The outer sleeve is mounted coaxially within the body inward of the bulkhead and about the first and second sleeves to define therewith a fluid-tight outer chamber containing the piston heads, each positioned to an opposite side of the bulkhead to define four fluid-tight chambers and to which pressurized air is applied. Also defined is a fluid-tight inner chamber containing lubricating oil. The outer sleeve is attached to the piston heads for reciprocating travel therewith.

Abstract: A pair of orifices of different orifice sizes is provided between each pressure chamber and an accumulator chamber. A larger one serves as a variable orifice and a smaller one as a fixed orifice. The variable orifice becomes effective when a control circuit is functioning properly for variably controlling an axial position of a valve spool. The fixed orifice becomes effective when the control circuit malfunctions and allows the valve spool to be moved into a predetermined position. In another embodiment, a single orifice cooperates with the valve spool to serve as both a variable orifice and a fixed orifice.

Abstract: An apparatus for transferring electrically conductive coating materials such as water-based paint from a source to an electrostatically charged dispenser includes first and second shuttle devices and two large reservoir, piston pumps each having structure for preventing contamination of the coating material and pressure build-up at their piston heads. The first shuttle device is movable between a neutral position wherein it is electrically isolated from a filling station connected to the coating material source, and a transfer position wherein coating material is transmitted to one of the piston pumps through a coupling device which connects the filling station and first shuttle.

Abstract: For carrying out lubrication between a piston (17) and a piston ring (21) installed in an annular groove (23) of the piston, the piston ring comprises a recessed portion (15a, 15b) which is partially recessed from an upper axial end (27) of the piston ring. Lubricating oil is mixed with blow-by gas and flows into the annular groove through the recessed portion. As a result, the lubricating oil is effectively supplied to the annular groove. Therefore, the lubrication is favorably carried out between the piston ring and the piston. The piston ring may be formed from a piston ring member (10) of a ring-shaped plate which has the recessed portion on an outer peripheral surface (13) thereof.

Abstract: A single horizontal cylinder, small refrigeration compressor has a lubrication arrangement which includes a recess on the cylinder block above the cylinder bore which collects oil that drains from the lower end of the motor. A supply passage extends downward from said recess and opens into the cylinder bore near its midpoint. The piston has an elongated shallow groove on the interior between head and skirt lands which is connected to the passage during a major portion of the piston stroke to receive oil from the recess. Drain passage means are provided on the piston to allow oil to flow out of the groove at a lesser rate than it is supplied by the supply passage from the recess.

Abstract: An arrangement wherein a concave portion on a support end of a connecting rod is slidably engaged with a convex portion formed in a lower part of a piston, and a retainer ring member supported on a skirt portion of the piston is placed in contact with the lower part of the concave rod end.

Abstract: A piston for an internal combustion engine with a separate head and skirt which are joined by a piston pin. The ring belt extends downward from the head and terminates above the pin. The space between the lower edge of the ring belt and a section of the head defines a cooling oil ring space. The head is provided with bores which extend from the cooling oil ring space upward toward the top of the head.

Abstract: In order to ensure an adequate supply of oil onto the thrust surfaces of a reciprocating type internal combustion engine piston, recesses are formed in the skirt proximate each thrust surface. The boundary defined between the surface of the skirt and the recess is defined by a rounded surface which smoothly merges the recess with the surface of the skirt, eliminates sharp edges, and permits oil to flow uninhibited out of the recess onto the thrust surfaces.

Abstract: A piston for axial piston machines in the form of a hollow body with an axial cavity therein into which an insert is inserted and is secured axially by means of a collar in the wall of the hollow body surrounding the insert overlapping its outer end face is designed so that while ensuring simple and economical manufacture, stable support of the filler piece and a stability of the shaft of the piston is obtained. This is achieved by providing the collar by pressing the wall of the hollow body, which is longer than its final length, into a plurality of oppositely disposed recesses or into an annular recess in the insert and by cutting the piston formed in this way to length in the general region of the recesses or the annular recess.

Abstract: A piston for an axial piston machine, comprising a hollow body having an axial cavity into which a filler piece of a material of lower specific gravity than the material of the piston is inserted which at least partially fills said cavity, said filler piece being secured axially in the cavity by a shoulder projecting radially inwards from the hollow body, is to be designed so that with simple construction a stable axial securing of the filler piece is ensured. This is achieved in that the filler piece has a recess arranged between its ends on its outer surface into which the section of the hollow body overlapping the recess is pressed in a form fitting and force locking manner.

Abstract: A fluid cylinder has improved wear rings in a combination that includes a tube having a tubular wall and first and second end caps. The tubular wall defines a cylinder bore that has a central axis. Each end cap also has a bore extending along the central axis. A piston assembly is mounted in the cylinder bore with a piston rod mounted in the bore of one of the end caps, so that the piston assembly is slidable along the central axis. The piston assembly includes a piston head that has a reservoir defined by an annular recess opening toward the tubular wall. The reservoir houses a prepacked lubricant. One wear ring closes off the annular recess from the tubular wall. The wear ring seal has a plurality of radial apertures extending therethrough, through which lubricant is capable of flowing to lubricate the piston assembly. Another wear ring closes off a reservoir in the bore of an end cap and functions as the first mentioned wear ring also to lubricate the piston assembly.

Abstract: The invention relates to the dry run-high pressure stage of a multistage piston compressor with a piston designed as a tappet (2) guided in the high pressure cylinder (1) and sealed against the compression space of the cylinder (1) by means of self-lubricating sealing elements (3) forming an annular gap together with the working surface, whereby the latter is formed by a material suitable for dry run. According to the invention, the sealing elements having a height conforming at least to their diameter are embodied in the form of at least two cylindrical sealing elements (3), which are loosely placed one on top of the other in the cylinder (1) on the free end of the tappet (2), provided with working surface guides at least in part areas, and have chamfers (6) on the face side.

Abstract: The very high pressure piston pump can compress a conveying agent (20) to a pressure of approximately 22 kbar. The high pressure sealing comprises a pressure-compensated ice sealing, which operates free of leakage and with reduced friction. To reduce the generally very high frictional forces in the ice sealings, a rotation is superimposed on the translation of the piston (10). The entire machine may be regulated by means of a microprocessor, depending upon the operational parameters and the feed efficiency. Its very high pressure seal has a long service life, even under continued operation in very high pressure ranges.

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: The cylinders of the compressor each have a guide piston connected with a work piston with each being reciprocally mounted within a guide cylinder and work cylinder. In addition, seals are provided between the guide piston and the guide cylinder within a half-portion of the guide piston proximate to the work piston while a scraper ring is provided in a second half-portion of the guide piston remote from the work piston in order to meter lubricant between the guide piston and guide cylinder. Excess lubricant which is splashed from the crank case into the guide cylinder is returned via the scraper ring to the crank case.

Abstract: A hydraulically-operated piston machine includes at least one cylinder and a piston axially movably guided in the cylinder. The piston is connected to a crankshaft or the like by means of a connecting rod. The connecting rod and the piston each have spherically-shaped bearing surfaces serving for connecting the connecting rod and the piston with each other in an articulated manner. The connecting rod defines at its end connected to the piston a radially outwardly facing spherical surface portion which is arranged concentrically with the spherical bearing surface of the connecting rod. The spherical surface portion rests against the surface of a recess defined in the piston, so that a hollow space is defined between the surface of the recess and the spherical surface portion. The piston defines a bore for effecting communication of fluids between the interior of the cylinder and the hollow space.

Abstract: An improvement of pistons for alternative, endothermic four-cycle engines, in which notches or grooves are cut on opposite sides of the oval surface of the piston skirt and arranged in a parallel fashion with respect to the piston pin. The grooves create concavities which are closed off frontally by the cylinder wall and laterally by the piston skirt. The purpose of the grooves is to create a series of pockets for the lubricating oil, which is under pressure during engine operation, and to improve lubrication in the areas of maximum piston stress.

Abstract: A method of manufacturing a piston of an internal combustion engine includes holding a soluble core to a plurality of first projection portions and a plurality of second projection portions and a plurality of third projection portions formed in a pair of straight portions of a strut member for preventing thermal expansion of the piston. The first projections have a bent portion bent outwardly so as to be along an inner face of the soluble core and the second projection portions have a curved holding portion bent inwardly so as to be along a lower surface and inner surface of the soluble core. By holding the strut member and the soluble core in the piston, the soluble core is melted away and an oil-cooling gallery is formed by pouring water into the mold.

Abstract: The present invention relates to a cryopump having a gas bearing formed in a clearance seal between a piston and a cylinder. The gas bearing is formed by forcing pressurized gas from a gas plenum through orifices to the clearance seal.

Abstract: The crosshead has a body formed of solid, metal plate, and of substantially U-shape. It comprises a pair of spaced-apart parallel limbs which are bridged between by an integral transverse member, and the latter is bored through to receive a piston rod therein. Shoe plates are joined to the limbs to guide the body in reciprocation. In the combination with a connecting rod assembly and a piston rod, an end of the piston rod is directly fastened to the connecting rod assembly, and the crosshead is coupled to an intermediate portion of the piston rod.

Abstract: In a reciprocating piston engine, the piston has a top ring and a second ring received in respective ring grooves. The top ring has two end surfaces defining therebetween a gap the open area of which on the side of the combustion chamber, when the top ring abuts against the upper surface of the ring groove, is smaller than an open area of the gap facing a second land clearance when the top ring seats on the lower surface of the ring groove. As the top ring seats on the lower surface of the ring groove during the power stroke when the engine is operated at a high-speed, high-loaded condition, the greater open area of the gap rapidly introduces the combustion pressure into the second land clearance to thereby reduce oil consumption. When the engine works at a low-speed, low-loaded condition, the top ring abuts against the upper surface of the ring groove during the intake and compression strokes, where the smaller open area of the gap reduces the flow of oil from the crankcase to the combustion chamber.

Abstract: A yarn false twisting apparatus is disclosed which comprises a pair of rotating circular discs having cooperating friction surfaces for engaging a running yarn at a twisting zone. A pressure applying member is positioned to apply a biasing force to the rear surface of one of the discs locally at the twisting zone, and the pressure applying member comprises a receptacle slideably mounting a piston which extends from the end of the receptacle to engage the disc. The receptacle is eccentrically mounted to permit selective positioning of the biasing force with respect to the yarn path of travel. The discs are mounted on pivotal rocking arms whereby the ratio of yarn twist to yarn speed may be adjusted, and an eccentrically mounted pin provides closely controlled adjustability for the arms and thus the twist ratio.

Abstract: Piston for internal combustion engines, with an oil scraper ring disposed in an annular groove at the circumference of its head portion. The outer edge of the annular groove adjacent to the piston skirt which adjoins the head portion is bevelled to form a chamfer. In order to ensure the maintenance of an oil film sufficient to prevent dry running of the piston, on the cylinder wall, the width of the chamfer is greater on the thrust side of the piston. The width of the chamfer may decrease essentially continuously from the counter-thrust side to the pressure side.

Abstract: The device of the invention comprises a ball and socket and shoe assembly ich is pressure balanced with hydraulic fluid. This combination provides for low friction and relatively large travels when used as a linear to rotary motion actuator. In accordance with the contributions of the structural elements of the device, hydraulic pressure is applied to the rear of a piston by modulating the fluid pressure through a servo valve. Four pistons are typically used with two pistons driving the support spider clockwise and the other two driving the support spider counter clockwise. The control pressure produces a force through both the piston and pressure balanced shoes. The force is transmitted to the spider which is pivoted about flexures to produce a torque which results in a rotary motion of the spider (support).

Abstract: An improvement of pistons for alternative, endothermic four-cycle engines, in which notches or grooves are cut on opposite sides of the oval surface of the piston skirt and arranged in a parallel fashion with respect to the piston pin. The grooves create concavities which are closed off frontally by the cylinder wall and laterally by the piston skirt. The purpose of the grooves is to create a series of pockets for the lubricating oil which is under pressure during engine operation, and to improve lubrication in the areas of maximum piston stress.