Abstract: In a piston and connecting rod assembly for reciprocating piston machines the bending load applied to the piston pin bosses owing to the deformation of the piston pin to an oval shape should be prevented and the weight should be reduced. This is accomplished in that the piston pin is I-shaped in cross-section with wide flanges, the outer surfaces of which are shaped in accordance with an arc of a circle.

Abstract: An aluminum alloy piston for an internal combustion engine has two spaced piston pin bosses. A steel alloy bushing is fitted in each boss. A ceramic piston pin is fitted in said bushings.

Abstract: A piston machine, particularly a hydraulically-actuated piston machine, comprises at least one cylinder having an axis, a piston axially slidable in the cylinder and having a piston bottom with an inner surface, a piston rod turnably connected with the piston and having a piston rod shaft, a turning member mounted on the piston rod and having a side which is opposite to the piston rod shaft and has a convex circular surface, a pressing member having a shell surface which is in sliding contact with the circular surface of the turning member, the pressing member having a side which is opposite to the turning member and is provided with a convex circular surface abutting against the inner surface of the piston bottom, the circular surface of the pressing member and one of the circular surfaces of the turning member and the shell surface of the pressing member having central axes with central axes projections along their common orthogonals forming an angle of approximately 90.degree..

Abstract: A piston for combustion engines has connecting rod mounting apertures or pin bosses for receiving a gudgeon pin for a connecting rod, which bosses have resilient regions in the form of annular resilient sectors (17, 16) by the formation of slots in the axial direction of the piston. These annular spring sectors can however also be provided on the little end. Upon the occurrence of disturbing oscillations coming from the region of the crank shaft, these are transmitted axially of the resilient annular sectors and suppressed.

Abstract: Radial piston pump, particularly for liquids, comprising at least one rad cylinder, at least one radial piston with associated piston head, at least one piston guide shoe, at least one eccentric element, and a device for attachment of the radial piston with the piston guide shoe or shoes. The piston heads contact with their bearing surfaces the bearing surfaces of the associated piston guide shoe or shoes, but the piston heads are not attached with the piston guide shoes at their bearing surfaces. On the side not contacting the piston head the piston guide shoe contacts the eccentric element. The piston head has an outer shoulder, which is grasped by the device for attaching the radial piston with the piston guide shoe or shoes. This device comprises a connecting sleeve associated with each individual radial piston, which embraces with an inner flange the outer shoulder of the associated piston head.

Abstract: In a reciprocating machine, there is provided a hollow piston including a dome portion on one end and a base portion on the opposite end. The base portion includes a central bore into which a rod is hermetically fixed in radial and angular alignment. The extending end of the rod has a reduced diameter portion adapted to fit into the central bore of a second member such as a cross-head assembly, and to be secured thereto in radial and axial alignment with the piston.

Abstract: To reduce deformation of the piston pin for the rotating connection of a ton and a connecting rod in a piston cylinder system, especially in internal combustion engines, where the piston pin is made of fiber-reinforced composite material in which fibers running in different directions are placed, it is proposed that the piston pin is secured against rotation around its longitudinal axis in the piston or in the connecting rod, and has first regions in which the fibers are arranged in planes parallel to the piston pin axis and when secured against rotation in the piston, running parallel to the piston axis, or when secured against rotation in the connecting rod, running parallel to the connecting rod axis, so that they have a component running parallel to the piston axis or to the connecting rod axis.

Abstract: In a radial piston pump, motor, transmission the deep diving or entering piston shoe is utilized and swingably borne in the pivot-bed of the radially reciprocating piston. Since deep diving piston shoes have large piston strokes, the shoes pivot in the pistons in large angles. Thereby a considerable force-portion of the load on the piston is transfered to the wall between the piston and the cylinder, whereby heretofore short pistons occasionally produced welding and sticking between the cylinder wall and the piston wall. The piston therefore receives radially extending portions, which may extend beyond the medial portion of the piston shoe and may even enter into the ring groove of the piston stroke actuator ring. Thereby a very long guidance of the piston on cylinder wall portions is obtained, which makes the application of effective pressure balancing pockets at correct location between piston wall and cylinder wall possible.

Abstract: The piston pin for a piston of an internal combustion engine is provided with a certain number of passages, each opening into the annular groove of the bearing bushing of the connecting-rod small end and into either of the annular grooves of the pin bearings. The passages are provided in a peripheral portion of the piston pin so to avoid a central portion of the pin, in which a concentration of metallic impurities is maximum.

Abstract: A piston arrangement including a hollow piston, a piston pin extending within the piston, an intermediate abutment within the piston supporting the pin between its ends, and a transmission member, e.g., a connecting rod, engaging the pin on each side of the intermediate abutment. The intermediate abutment may be supported by the circumferential wall of the piston, or by the piston head, and may be formed as one piece with the piston. The transmission member may have a forked end for engaging the piston pin, the intermediate abutment being between the arms of the fork. The piston pin may be two separate aligned pins each having an end located within the intermediate abutment. The piston, intermediate abutment, piston pin, and transmission member may all be formed of a ceramic material.

Abstract: In the embodiments of the invention described in the specification, a piston and a connecting rod of an internal combustion engine have opposed approximately semi-cylindrical bearing regions partially enclosing a pin, leaving free gaps between the bearing regions to permit swivel motions of the piston and connecting rod about the axis of the pin. Two symmetrical rings which surround the pin axis retain the bearing regions against the pin. The provision of such opposed bearing regions reduces the oscillating mass of the link joint.

Abstract: In connection with a plunger piston for internal combustion engines, the connecting rod, which is hinged thereto via a gudgeon pin, is laterally guided at its small end by being in abutting contact with the internal faces of the gudgeon pin bosses. For this purpose, there are provided, only in the zone at the level of the gudgeon pin axis, limited contact surfaces between the connecting rod small end and the gudgeon pin bosses. By this means, the influence of deformations of the piston on the guidance of the connecting rod is eliminated to a very large extent.

Abstract: An improved heat insulated piston assembly for an internal combustion engine and a method of assembly. The improved piston assembly includes a piston constructed of a sleeve having an interference fit about a heat insulated core. The core has a first end positioned flush with an end of the sleeve and has a second end located within the sleeve with a concave configured cavity formed therein. Mating in the concave configured cavity of the core is a connecting rod having a spherical ball shaped end. The spherical ball shaped end is securely held in the cavity by a retaining ring which attaches to the piston sleeve. The retaining ring allows for limited movement of the spherical ball shaped end of the connecting rod in the cavity while providing a means for returning the piston to its bottom position during the intake stroke.

Abstract: The invention relates to an engine including a cylinder defining a combustion chamber which receives a mixture for combustion thereof, and a piston slidably mounted therein for reciprocation between a first and a second limit position whereat the chamber defines its minimum and maximum volume, respectively. A pair of rotatably mounted parallel crankshafts are arranged equidistantly relative to the longitudinal axis of the cylinder, each having a crankarm rotatable about its respective crankshaft axis. Coupling means connect the crankshaft together for synchronising rotation thereof with the crankarm of one crankshaft having an angular advance over the crankarm of the other crankshaft. A rocker member pivotally connected to the piston for rocking movement about a pivot axis extends normal to the longitudinal axis of the cylinder, and a pair of connecting rods interconnect the rocker member and the respective crankarms of the crankshafts with each connecting rod being pivotally connected to the member.

Abstract: Improved multi-cylinder pumps wherein a plurality of co-planar positioned connecting rods are radially disposed about a crankshaft and wherein a plurality of generally cylindrical spool-like wrist pins are rotatively coupled to the connecting rods. The improvement comprises an assembly wherein the wrist pins have opposed end regions bordering a smaller diameter central region that contains one or more ring receiving grooves and which wrist pins are mountable in overlapping relation to retainer ring containing grooves formed in the connecting rods. Upon mounting retainer rings in the connecting rod grooves and inserting and rotatively locking the wrist pins in the connecting rods, the connecting rods, wrist pins and retainer rings are integrally locked together in radially extending relation.

Abstract: An improved heat insulated piston assembly for an internal combustion engine and a method of assembly. The improved piston assembly includes a piston constructed of a sleeve having an interference fit about a heat insulated core. The core has a first end positioned flush with an end of the sleeve and has a second end located within the sleeve with a concave configured cavity formed therein. Mating in the concave configured cavity of the core is a connecting rod having a spherical ball shaped end. The spherical ball shaped end is securely held in the cavity by a retaining ring which attaches to the piston sleeve. The retaining ring allows for limited movement of the spherical ball shaped end of the connecting rod in the cavity while providing a means for returning the piston to its bottom position during the intake stroke.

Abstract: A piston assembly and a method for manufacturing piston assemblies. The piston assembly comprises a piston body, a connecting rod, a wrist pin, and a retaining spring holding the wrist pin within the piston body and maintaining the connecting rod spaced from a sidewall of the piston body. The retaining spring includes a central member, first and second side members, and resilient tab means. The central member is located between the wrist pin and a head of the piston body. The first and second side members extend rearward from opposed sides of the central member, between the connecting rod and the sidewall of the piston body, maintaining the connecting rod spaced therefrom, and define aligned spring openings receiving the wrist pin. The resilient tab means extends forward from the central member, engages the head of the piston body, and urges the first and second side members into pressure contact with the wrist pin to maintain the wrist pin within the piston bore.

Abstract: A two-stroke engine includes an intake-and-scavenge valve in the cylinder head together with a fuel injection system, a recirculating type pressure lubricating system, and a blower or turbo charger assisting in charging the cylinder with air and also assisting in scavenging the exhaust gases . The piston head is domed with one side curving downwardly towards the exhaust port formed through the wall of the cylinder above the bottom dead center position of the piston head. The exhaust port slopes outwardly and downwardly following generally the slope of the piston to facilitate the flow of exhaust gases therethrough assisted by the scavenging air entering through the inlet-and-scavenger valve. The valve is operated by a cam mounted on a cam shaft upon the cylinder head which in turn is operatively connected to the crankshaft. The width of the cam lobe is such that the opening, closing and duration of opening of the valve is controlled with the valve being opened approximately 140.degree.

Abstract: An engine employing oval pistons and cylinders with dual connecting rods for each piston. The connecting rods are connected to each piston by a common wrist pin and to a composite crankshaft. The crankshaft includes a main bearing between the connecting rods of each of the pistons. It also includes a middle portion associated with each piston including two crank pins and the shaft therebetween for receipt of the centrally located main bearing.

Abstract: Multi-cylinder in-line and radial pumps having an improved structure for coupling the piston heads to the crankshaft such that the number of parts commonly employed and the size of the resulting pump is greatly reduced when compared to prior art pumps now on the market. Both in-line piston pumps and radial diaphragm pumps are included. The connecting rods comprise plates, each having a bore through the thickness dimension thereof for receiving a cylindrical lobe formed eccentrically on the pump's crankshaft. Formed on one end of each of the connecting rods is a generally cylindrical bore, also extending through the thickness dimension of the connecting rod, the center of this bore being displaced inwardly of the end edge surface of the connecting rod by a distance which is less than the radius of the bore.

Abstract: A reciprocating-piston drive mechanism comprises a reciprocating-piston assembly defining a spherical socket and including a piston body. A connecting rod is arranged for pivoting movement in a plane and has a ball head fitted in the spherical socket. A coupling between the ball head and the piston assembly is arranged to transform the pivoting movement of the connecting rod and ball head into a reciprocating rotation of the piston body about its axis. The coupling includes a first coupling member attached to, and non-rotatable relative to, the piston body, and a second coupling member attached to, and carried by, the ball head, the second coupling member engaging the first coupling member.

Abstract: An improved piston pin assembly which includes a hollow tubular piston pin and one or more supports positioned within the hollow space formed by the piston pin so as to inhibit deflection of the piston pin when the assembly is subjected to load conditions.

Abstract: This piston design serves to increase engine horsepower, and causes less friction, while simultaneously reducing fuel consumption. It consists primarily of a propeller-topped piston, secured, by its wrist pin, in a rotatable swivel member in the top of a connecting rod, that is secured to an engine crankshaft.

Abstract: A piston intended for use in refrigeration compressors and other applications wherein a heat barrier is provided in the piston skirt between the head of the piston and the wrist pin. The heat barrier substantially reduces the conduction of heat from the higher temperature piston head to the wrist pin bearing surfaces, which would otherwise result in rapid wear of the wrist pin bearings and ultimate failure of the compressor. The heat barrier preferably comprises a pair of openings extending through the wrist pin bosses in close proximity to the wrist pin holes thereby partially thermally isolating the wrist pin holes from the head of the piston. The openings are spaced on opposite sides of an axial line extending from the piston head to the wrist pin holes so that there remains a bridge of the piston skirt material to provide the necessary support for hydraulic loads that occur when the compressor slugs.

Abstract: A light-weight, high-strength composite pin for use in pin-jointed reciprocating mechanisms and a method of preparation thereof is provided. Basically, the pin has a tubular metal sleeve and an interior fiber-reinforced resin core. At least 50% of the fibers in the core are continuous fibers which are oriented at a predetermined specific angle of orientation ranging, in general, from 0.degree. to about .+-.25.degree.. Indeed, in a preferred embodiment of the present invention, the fibers are cross-plied at an angle of orientation of from about 5.degree. to about 12.degree..

Abstract: An internal combustion engine piston is fitted with bushes between its piston pin and the cross bore in the piston. The diameters of the piston pin and the piston cross bore are dimensioned independently of each other to meet the requirements imposed upon them, which allows the piston pin to be dimensioned only to such size as is required to withstand the bending stress imposed by the connecting rod, thus permitting the size of the piston pin and the reciprocating mass to be reduced in relation to conventional practice.

Abstract: A device at a brake actuator for permitting thrust force transmission between an axially movable push rod (4) of the actuator and a brake block holder (6) moving out of line with the push rod.In order to ensure force transmission irrespective of the brake block holder movements and to avoid any slippage between the members a transmission part (5) is arranged between the push rod (4) and the brake block holder (6) and has spherical surfaces in engagement therewith, these surfaces having a common center.

Abstract: In a cast light-alloy piston having a skirt which is recessed adjacent to the piston pin bosses, the two sides of the skirt are unsymmetrical with respect to the piston pin bosses.For an improved adaptation to the different conditions of operation of the engine, the skirt is connected to the piston pin bosses on one side by supporting ribs which extend at an angle of 30 to 60 degrees to the piston pin axis, and on the other side by supporting ribs extending at an angle of 90.degree. to the piston pin axis.

Abstract: A connecting rod for reciprocating piston engines, especially axial cylinder-type reciprocating piston engines, with the connecting rod including a tubular shaft having hollow spherical shells mounted at the ends thereof. The tubular shaft and the hollow spherical shells are constructed from a sheet metal-like material and are joined to form a one-piece connecting rod body by way of welding joints. A lubricating tube is arranged within the tubular shaft and extends between the spherical shells so as to equalize the lubricant between surfaces of the hollow spherical shells.

Abstract: In radial piston fluid handling devices, such as for example pumps or motors, piston shoes are pivotable connected to the respective pistons. The invention improves the swing-member portion of the piston shoe in order to increase the efficiency and pressure bearing capability thereby, that the endface of the pivot portion is formed part-cylindrically by a radius which is a little bit shorter than the radius of the associated piston. The fluid pressure balancing pocket in the pivot member becomes formed accordingly, so that the pressure bearing capacity of the piston-piston-shoe pivot-assembly becomes considerably improved.

Abstract: The invention relates to a compressor of the type used in refrigeration systems. In these compressors the piston pin in the transversely extending piston bore is of lesser length than the diameter of the piston such that undesired chambers are formed at opposite ends of the pin. The stroke is normally of a length that the piston pin and these chambers intersect the lower edge of the cylinder. Gas trapped in these chambers expands rapidly with an undesired popping noise when fluid communication is established at the end of the down stroke between the chambers and the interior of the crankcase. Throttling passages are provided between these chambers and the interior of the crankcase to prevent pressure build-up in the chambers and the accompanying popping noise.

Abstract: A shot tip assembly for an injection molding machine of the type having a shot tube for conducting molten material into a die cavity of the machine. The shot tip assembly has a shot tip which is reciprocal within the tube and forms a close sliding fit with the tube for forcing the molten material through the tube and into the die cavity. A shot tip adapter is provided for the shot tip and has one end captively but relatively movably mounted in the shot tip, the adapter being connected at the other end to a reciprocal shot rod. A movable or swivel connection is provided between the adapter and the tip to permit the tip to move or swivel slightly on the adapter to thereby accommodate any misalignment between the shot tube and the shot tip as they are moved relative to one another. The injection machine with which the shot tip assembly is used has power means for example, a hydraulic shot cylinder for driving the shot rod, and consequently, the shot tip in the shot tube.

Abstract: Shock absorber effectively absorbs shock to bumper of automobile by compressive deformation of cushion, regardless of direction from which shock comes. Shock absorber comprises hollow tubular cushion placed within cylinder having one end closed. Plunger fits within open end of cylinder to compress and deform hollow tubular cushion. Shock applied to plunger is mitigated by resistance provided by hollow tubular cushion. Particular structure between cylinder and plunger inhibits sudden return of plunger to original position while providing little resistance on downstroke of plunger.

Abstract: A hygienic device has a pump for propelling liquid in a flow of pulses, a motor for driving the pump, a switch for supplying power to the motor and means for delivering the propelled liquid to a point of use. A control enables adjustment of the pressure of the delivered liquid. The switch is formed as part of the motor winding assembly and therewith is effectively encapsulated. The pump includes a piston in one end of which is a recess defining a resilient spherical seat and which cooperates with a spherical bearing formed on one end of a piston rod. The control has a valved bypass arrangement wherein various stops and abutments cooperate to permit accurate determination of high and low pressure adjustment during assembly. A rotor within the motor has a cylindrical bore with longitudinal lugs that interfit with ribs on a bearing member that is pressed into the bore. Other features, such as a tilt-out nozzle storage shelf, are included.

Abstract: The invention relates to a piston assembly for compressor and the method of making the assembly. A piston body is molded with spaced apart downwardly open grooves formed with concave semicylindrically shaped summits and parallel side walls. The summits and sidewalls are formed with pimples. A connecting rod pin having a connecting rod attached thereto is press fitted into the grooves. The pimples may serve as weld pimples by being softened by a welding current. The pimples on the sidewalls may alternatively be mechanically swaged to press inwardly against the rod to hold it in its installed position.

Abstract: A fluid operated linear motor of the piston and cylinder type. The piston is secured to a rod by a threaded connection and the mating threads are proportioned and dimensioned so that pivotal movement available in the threaded connection is enough to compensate at least in part for manufacturing tolerances and eccentricities and prevent or reduce abnormal distribution of lateral forces by the piston on the outer cylinder.

Abstract: An improved piston and rod assembly that can be readily disassembled at several places so that the entire assembly need not be necessarily removed from an engine during servicing, and which includes dismantleable bearings around a cross pin about which the piston is pivotally supported on the piston rod, and a dismantleable bearing that supports the piston rod on a crankshaft, and shims being placable behind the bearing blocks so to selectively change a length of piston stroke within a cylinder.

Abstract: An improved piston assembly for high-power internal combustion engines such as supercharged diesel engines. The piston includes separate head and skirt portions. An elongated bearing member having an external journal surface is formed across the bottom of the piston head. A wrist pin, which is attached to or integral with a connecting rod, defines a generally tubular shaped bearing member having an internal bearing surface in which the piston head bearing member is journaled to permit rotational movement between the connecting rod and the piston head. The external journal surface on the piston head is supported by the wrist pin along its entire length to prevent any flexing of the wrist pin when high compressive forces are applied to the piston head. The skirt is connected to the wrist pin by thrust bearings which engage an external journal surface on the wrist pin substantially along its entire length to permit rotational movement between the piston head and the piston skirt.

Abstract: A ball and socket joint and method of making in which a piston, especially a compressor piston, and most particularly a piston for a compressor that pumps refrigerant, has a top wall and a depending skirt and is connected to the upper end of a connecting rod by a ball joint which is made by forming a spherical socket in the upper end of the connecting rod and riveting a ball to the underside of the top wall of the piston and forming the upper peripheral region of the socket of the connecting rod around the upwardly facing side of the ball. In practice, the ball is placed in the socket of the connecting rod and the rod is formed about the ball and then the ball is riveted to the piston.

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: Locking means for a piston pin is loosely mounted in the bosses of a piston and which piston is larger in outside diameter than the external distance between the bosses. At least one angled locking pin having one arm secured in the boss and extending approximately parallel to the axis of the boss is provided and the other arm of the locking pin is bent so as to extend before the opening of the boss.

Abstract: Integrally formed brake shoe for use with cylindrical automotive brake drums in hydraulic brake systems are fabricated by bending and shaping sections of extruded lengths of the material having a T-shaped cross-sectional configuration. Connector pins for transmitting brake actuating forces between the hydraulic cylinder pistons and the brake shoes are concavely rounded at their piston abutting ends, and either concavely or convexly rounded at their brake shoe abutting ends, for face-to-face sliding contact with complemental abutting surface portions, respectively, of the hydraulic pistons and brake shoes.

Abstract: An axial piston machine has a cylinder barrel mounted on a shaft and rotatable with respect to a portion of the casing. Between the cylinder block and the casing portion is a disc. The side of the disc adjacent the casing portion is concave and abutting casing portion is correspondingly convex. The disc is restrained against rotation and forms part of the valving means for the cylinder barrel. In one embodiment the casing and shaft are in two articulated sections. The shaft sections lie in a common plane and are pivotable with respect to each other about a point and the casing sections are pivotable about an axis normal to that plane and offset with respect to the shaft pivot point. In another embodiment the casing and shaft are each a single unit.

Abstract: To permit dry operation of a piston within the cylinder, the cylinder is made of metal, and the piston is made of polytetrafluorethylene; the piston, preferably, is formed with an annular ring groove extending downwardly from an end face thereof to leave a circumferential lip, the groove having a spring located therein biasing the lip outwardly against the cylinder wall, to provide for sealing contact of the lip against the cylinder wall, which is additionally reinforced by pressure of the gas being compressed by movement of the piston within the cylinder, tending to expand the lip against the piston surface, at the time when the compression is highest, and sealing is the most desired.

Abstract: An improved piston assembly for high-power internal combustion engines such as supercharged diesel engines. The piston includes separate head and skirt portions. An elongated tubular-shaped bearing member having an internal bearing surface and an external journal surface is formed across the bottom of the piston head. A connecting rod passes through an opening in the lower center of the bearing member and is attached to a wrist pin which rotates against the internal bearing surface of the tubular-shaped bearing member to permit rotational movement between the connecting rod and the piston head. The wrist pin is supported by the bearing surface along its entire length to prevent any flexing of the wrist pin when high compressive forces are applied to the piston head. The skirt is connected to the piston head by thrust bearings which engage the external journal surface of the bearing member substantially along its entire length to permit rotational movement between the piston head and the piston skirt.

Abstract: In a Bourke type engine wherein at least two cylinders are disposed coaxially and oppositely so that the free ends of piston rods extending from pistons reciprocable in said cylinders may be connected by a yoke in coaxial alignment with each other and with the cylinders to reciprocate concurrently as a unit, with the yoke having means rotatably to engage a rotating crank by which the force developed by reciprocation of the pistons is converted to rotating driving motion, the improvements wherein the inner end of the piston rod is placed in abutment with the underside of the piston head and the yoke is modified to house a block slider instead of a rolling bearing to provide better bearing surfaces and lubrication thereof.

Abstract: In a spreading disc brake relative angular movement of the pressure plates to initiate the application of the brake is effected by a fluid pressure actuator acting on a pull-rod through a pivotal thrust coupling so arranged as to confine rocking movement of the pull-rod to a single plane normal to the brake axis.

Abstract: A radial motor powered by pressurized gas is disclosed as used for starting the internal combustion engine of a portable implement such as a powered chain saw or lawn mower. The motor is designed for economical manufacture and assembly, durability, and economy of gas used. It includes pistons formed of stiff resilient material that in assembly are snapped onto the outer ends of connecting rods and held in place during operation of the motor without the use of retaining rings, pivot pins or screws. The inner ends of these connecting rods are held in sockets in connecting rod mounting means either by the shapes of the sockets or by the resilience of either or both of the connecting rod and mounting means. The motor includes a rotatable valve driven by a free end of the crankshaft to feed gas to the cylinders.

Abstract: A piston has a pair of support members extending away from the piston head offset from a piston ring portion, a piston rod being carried on a connecting rod which is clamped between the support members by a bolt. The bolt is loosely received in a bore in the connecting rod, the force between the piston and the piston rod being taken by a frictional force between the connecting rod and the support members to prevent a bending force being applied to the bolt.

Abstract: A rotor is rotatably mounted in a housing and formed with angularly spaced radially oriented cylinder bores in each of which a piston is radially reciprocable. The radially outer end of each piston is formed with an inwardly extending recess having a length greater than the length of the piston stroke. A control ring which is eccentric relative to the rotor surrounds the latter, and its inner circumferential surface is slidingly contacted by respective piston shoes each of which is associated with one of the pistons and each of which has a shaft that is freely received in the recess of the associated piston and whose length is also greater than the length of the piston stroke.