Abstract: A method for manufacturing a bushing of a self-lubricating plunger includes: S1. uniformly mixing a base metal powder with a reinforcing metal powder to obtain a mixture, putting the mixture into a mold for pressing by a hydraulic press machine to form a blank, then sintering the blank to form a tubular metal foundation having a plurality of micropores; S2. melting a metal matrix lubricant by heating up, wherein the metal matrix lubricant includes a metal substance of low melting point and a basic lubricating powder dispersed in the metal substance, and the metal substance has a melting point higher than a storage temperature of the bushing and lower than a working temperature of the plunger; and S3. immersing the tubular metal foundation in the molten metal matrix lubricant to fill the micropores of the tubular metal foundation with the metal matrix lubricant, then cooling down the temperature.

Abstract: An engine piston assembly includes a piston with two opposing boss bores, a first interlocking piston button with at least one interlocking protrusion compatible with at least one interlocking recess in the first boss bore, and a second interlocking piston button with at least one interlocking protrusion compatible with at least one interlocking recess in the second boss bore. The interlocking protrusions serve to prevent the buttons from rotating inside the boss bores and deforming an oil control ring inside an oil control ring groove of the piston assembly.

Abstract: A piston rod for piston compressors, wherein the piston rod has a base body with one end facing the piston, one end away from the piston, and at least one cavity. The cavity is filled with a solid, whose specific thermal conductivity is greater than that of the base body. Furthermore, the invention concerns a piston compressor with a piston and a nonlubricated piston rod seal, wherein the piston is connected to the described piston rod.

Abstract: A piston for an internal combustion engine may include a plurality of pin bores for accommodating a piston pin. The pin bores may be transversely oval to a longitudinal axis of the piston. The pin bores may be formed in a circular cylindrical manner at a zenith of ?=0° and at a nadir of ?=180°. The pin bores may be formed in an oval manner with an oil-holding volume at an equator of ?=90° and ?=270°. The pin bores may include a transition between the equator and the zenith and between the equator and the nadir that runs in a continuous and differentiable manner.

Abstract: The arrangement is applied to a compressor which comprises: a crankcase, carrying a cylinder provided with a lateral slot and in which is housed a piston provided with two radial holes and with an eccentric axial hole; a connecting rod connected to a crankshaft driven by an electric motor and having a smaller eye mounted in the piston; and a wrist pin having a first end turned to the bearing hub of the crankcase, a second end turned to the lateral slot of the cylinder and a diametrical hole, adjacent to the second end in which is provided an engaging means, for the axial and rotational coupling of a tool for mounting and indexing the wrist pin, in the interior of the piston, in a position in which the diametrical hole is axially aligned with the eccentric axial hole, so as to allow an elastic pin to be introduced in said diametrical hole and in said eccentric axial hole.

Abstract: A lubricating configuration in a two-stroke cycle, opposed-piston engine for a piston wristpin minimizes losses in oil pressure at the wristpin as the piston approaches bottom center and reduces the required oil supply pressure to the engine. The wristpin is constructed to absorb and store oil pressure energy when oil pressure at the wristpin is high, and to release that stored energy to pressurize the oil at the wristpin when connecting rod oil pressure is low.

Abstract: An embodiment discloses a brake booster input rod, including: a front end portion to which an input piston of a brake booster is connected; a rear end portion to which a yoke connected with to a brake pedal is attached; and an annular boot installing groove to be engaged with, when a boot covers a front portion of the input rod, a rear end bead portion of the boot with a fastening margin. Through rolling, two annular groove portions and an annular ridge portion are formed to each have a triangular section. The ridge portion functions as a rear side wall of the boot installing groove.

Abstract: A coupling system for receiving a push rod includes a housing defining an internal channel having a sloped wall, and a piston received within the internal channel. The piston includes at least one flexible member arranged within the channel to be acted upon by the sloped wall to engage the push rod. The only external force required to couple the push rod is an axial force on the piston in a direction. The only external force required to de-couple the push rod is an axial force on the piston in an opposite direction.

Abstract: The present invention relates to a piston and a piston-connecting rod assembly for internal combustion engines or compressors, featuring a pinless connecting rod assembly having a joint claw, whereas the joint claw is formed to partly encompass an upper joining end of a connecting rod, whereas the joint claw is formed as a part of an inner section of the piston, and whereas the inner section is radially encircled by a cylindrical piston skirt. According to the invention at least one bar element is arranged extending between the inner section and the piston skirt, whereas the bar element divides a first open section from at least one second open section being arranged between the inner section and the piston skirt.

Abstract: A ratchet assembly may include a steer ring, a steer ring side structure, a steer cylinder bracket arm, a steer cylinder, a ratchet lock gear, a steering collar, a ratchet cylinder, a ratchet lock bar, and at least one sensor. When in a particular locked position, operation of the steer cylinder rotates the steer ring, the ratchet lock gear, and the steering collar. When in an unlocked position, operation of the steer cylinder rotates the steer ring around the ratchet lock gear.

Abstract: Provided is a piston push rod assembly which can prevent discomfort from being imparted during the operation of a brake pedal by a driver. A piston push rod assembly, wherein: a second piston is provided with a piston slide section which is housed in a cylinder and which slides relative to the cylinder, and a connection tube section which is connected to a push rod; the piston slide section is covered by metal plating; the connection tube section has a non-plated section; and the second piston and the push rod are connected by the caulking of the connection tube section when the push rod has been inserted inside the connection tube section.

Abstract: Pin bosses of a piston for an internal combustion engine each have a pin bore for supporting a piston pin. In order to reduce the tangential stresses in the zenith area of the pin bores, and thus to extend the service life of the piston, the inner areas of the pin bores as viewed in the direction of the bore axis have areas on both sides of the zenith that have a greater distance from the bore axis than the zenith of the pin bore, and the outer areas of the pin bores, as viewed in the direction of the bore axis, are transversely oval relative to the piston axis.

Abstract: A braking system includes a brake booster with a power piston assembly structure defining a guide bore which possesses an open end, the guide bore defining a bore axis. A pivot structure is positioned in the guide bore and including (i) a body having an interior surface that defines a cavity, and (ii) a plurality of extensions protruding inwardly from the interior surface. A pedal rod includes (i) a ball-shaped distal end portion is retained in the cavity by the plurality of extension members, and (ii) a shaft extending from the ball-shaped distal end portion. A retainer is secured to the power piston assembly structure so as to prevent advancement of the pivot structure through the open end of the power piston assembly structure. The retainer defines a frusto-conical passageway through which the shaft extends enabling the shaft to pivot.

Abstract: A piston system including a body defining a bore and a piston positioned inside the bore and mounted for reciprocation therein. The piston includes a crown and a skirt extending generally away from the crown, the skirt including a pair of opposed panel portions. The piston further includes a transition portion configured to first engage the body during reciprocation of the piston in the bore. The piston is configured such that additional movement of the piston in the bore after the first engagement causes additional contact between the piston and the body, the additional contact increasing or moving in a circumferential direction about the piston. The piston is configured such that maximum side loading forces from the body to the piston are applied to the piston at one of the panel portions.

Abstract: The pneumatic cylinder includes a cylinder body, a non-pressure head, a hollow piston rod, a piston head, and a push rod. The cylinder body has a mounting flange and an inlet port. The non-pressure head has a mounting flange. The hollow piston rod has an open end and a closed end. The piston head is secured to the hollow piston rod and defines the closed end of the hollow piston rod. The push rod has a socket end inserted within the hollow piston rod and a coupler end. The non-pressure head has a hollow rod guide bearing and a hollow rod seal and the piston head has a piston guide bearing and a piston seal. The hollow rod guide bearing and the hollow rod seal each slidably engage the hollow piston rod. The piston guide bearing and the piston seal each slidably engage the cylinder body.

Abstract: A wrist pin and method of reducing wear between members thereof, a piston, a connecting rod, and methods of construction thereof are provided. The wrist pin has a first portion extending between opposite ends configured for receipt in piston pin bores and a second portion extending between opposite ends configured for receipt in the pin bores. The second portion is configured for relative movement with the first portion. The piston includes a piston body having axially aligned pin bores, wherein at least one of the pin bores has a feature to prevent relative rotation of a wrist pin member. The connecting rod includes a connecting rod body having small end bore. The small end bore has a contour to allow relative rotation of a first wrist pin member therein and a feature to prevent relative rotation of a second wrist pin member therein.

Abstract: The piston is provided with a pair of radial holes opened to an external circumferential recess and lodging and retaining one respective end of a pin, to which is coupled a driving mechanism to reciprocate the piston inside a cylinder. The radial holes are completely sealed in order that the axial extension of a bottom radial gap provided by a bottom bearing surface of the piston work together with the axial extension of a top radial gap provided by a top bearing surface to provide the required leakage restriction of the refrigerant gas and also the required bearing of the piston inside the cylinder. The axial extension of each of the top bearing surface and of the bottom bearing surface is insufficient to provide by itself said required leakage restriction of the refrigerant gas.

Abstract: The disclosure relates to a sprayer with a reservoir for a fluid, such as for a pesticide, with a pump device for pressurizing the fluid, whereby the pump device includes a pump drive, which is movably coupled to a pump piston by means of a pump connecting rod, whereby the pump connecting rod features a first connecting rod part and a second connecting rod part, whereby in order to connect the first connecting rod part and the second connecting rod part, at least one connecting device is provided, by means of which the connecting rod parts can be interlocked in at least two different latching levels.

Abstract: A single-piece piston body for an internal combustion engine includes a crown portion having a circumferential ring belt including an oil ring groove configured to accommodate an oil control ring and a skirt portion having a first skirt wall disposed on the major thrust side and a second skirt wall disposed on the minor thrust side of the piston, and two box walls that connect the skirt walls and which are set back with respect to the ring belt. A first plurality and a second plurality of axial drain passages extend from the oil ring groove to the bottom of the crown portion, the first and second pluralities of axial drain passages being substantially centered at opposite box sides of the piston and each plurality of axial drain passages spanning an arcuate portion of about 45-75 degrees.

Abstract: The invention relates to a hybrid pin (14) for connecting a piston for an internal combustion engine to a piston rod, the hybrid pin (14) consisting of a sleeve (3) made of steel and consisting of a core (2) which is pressed into the sleeve (3) and which is made of a lightweight metal alloy that can be cold-formed. The inner surface of the sleeve (3) has a profile, whereby an elastic elongation of the core (3) in the axial direction after the core (3) is pressed into the sleeve (3) is prevented to such an extent that the sleeve (3) is longer than the core (2) at both ends of the hybrid pin (14).

Abstract: A piston apparatus for an engine includes a piston pin that is inserted in a smaller end portion of a connecting rod and having a cross-section changing portion where a cross section changes at a portion of the piston pin, and a fixing member that engages the connecting rod and a piston through the cross-section changing portion so as to restrain longitudinal movement of the piston pin with respect to the connecting rod.

Abstract: A mounting arrangement for the piston of a reciprocating hermetic compressor, comprising: a cylinder (1), inside which is defined a compression chamber (C); and a piston (10) provided with a pair of radial holes (11), each lodging and retaining one end of a pin (20), to which is coupled a driving mechanism of the compressor to reciprocate the piston (10) inside the cylinder (1), said radial holes (11) being completely sealed in relation to the radial gaps (15) of the bearing surfaces (10a, 10b) of the piston (10), so that both radial gaps (15) operate as means for restraining the leakage of refrigerant gas outwardly and inwardly in relation to the compression chamber (C).

Abstract: A piston assembly comprises a piston body, a connecting rod, and a wrist pin. The piston body includes a pair of first cross bores presenting a piston sliding surface. The connecting rod includes a second cross bore presenting a rod sliding surface which is axially aligned with the first cross bores of the piston body. A wrist pin is disposed in the aligned cross bores and couples the piston body to the connecting rod. The wrist pin also presents a pin sliding surface facing the rod sliding surface and the piston sliding surfaces. A coating is applied to at least one of the sliding surfaces, such as by dipping, brushing, atomizing, spraying, printing, or screen printing. The coating includes a polymer matrix, such as polyamide imide (PAI), and hard particles, such as Fe2O3, disposed throughout the polymer matrix. The hard particles have a hardness of at least 600 HV/0.5.

Abstract: A piston assembly including a piston body pivotally connected to a connecting rod by a wrist pin. The wrist pin includes a sealed cavity therein partially filled with a heat transfer medium. The heat transfer medium may be composed of a fusible alloy. The sealed cavity may be comprised of discrete compartments. The wrist pin may be integrated with the connecting rod and share a conjoined sealed cavity therewith so that heat transfer medium can draw heat effectively away from the piston body.

Abstract: A piston with a piston boss in which a piston-pin bore is provided for accommodating a piston-pin. The piston-pin bore widens in the direction of a piston of a piston inner area with the widening above a bore axis with regard to a piston stroke axis, is less than the widening below the bore axis or vice versa.

Abstract: A linking arm conveying generally linear movement from a piston into generally radial movement of a crankshaft is disclosed. The linking arm includes a shaft extending between a piston pin end and a crankshaft pin end. The piston pin end defines a piston pin bore. A piston pin bore surface is defined by the piston pin bore, where the piston pin bore includes a non-circular transverse profile having at least two curved surfaces that each include a distinct radius, where the at least two curved surfaces are positioned in different locations around a periphery of the transverse profile.

Abstract: An input rod for connecting a vacuum brake booster to a pedal linkage member, wherein the input rod includes a connecting portion adapted to be connected to the pedal linkage member. The input rod further including a hollow body portion formed from a stamped flat blank.

Abstract: A wrist pin and method of reducing wear between members thereof, a piston, a connecting rod, and methods of construction thereof are provided. The wrist pin has a first portion extending between opposite ends configured for receipt in piston pin bores and a second portion extending between opposite ends configured for receipt in the pin bores. The second portion is configured for relative movement with the first portion. The piston includes a piston body having axially aligned pin bores, wherein at least one of the pin bores has a feature to prevent relative rotation of a wrist pin member. The connecting rod includes a connecting rod body having small end bore. The small end bore has a contour to allow relative rotation of a first wrist pin member therein and a feature to prevent relative rotation of a second wrist pin member therein.

Abstract: A detachable connecting rod includes a first member (410)a large end portion (411) having a trough hole (H1), and a first connection rod portion (412) extending from the large end portion (411), the first connection rod portion (412) having a pair of spaced apart arms defining a coupling groove (413) extending in the same direction as an axial direction of the through hole (H1); a second member (420) including a small end portion having a through hole (H2), and second connection rod portion (422) extending from the small end portion, the second connection rod (422) portion being inserted into the coupling groove (413) and a coupling unit for coupling the first connection rod portion (412) to the second connection rod portion inserted (412) into the coupling groove (413) of the first member (410). The detachable connecting rod is useable in a compressor.

Abstract: A piston assembly for use in an internal combustion engine is provided by the present disclosure. The piston assembly includes a piston body having an extended piston mantel, a piston face, an internal cavity, and a wrist pin support. Two oil retainer seals are located concentrically about the extended piston mantel near a distal end, each oil retainer seal having an internal groove and being formed of a polymer material. Two compression clips are disposed within the internal grooves of the two oil retainer seals and are adapted to assist the oil retainer seals in establishing contact with an inner wall of a cavity in a cylinder of the internal combustion engine. The piston body is formed of an engineered composite material.

Abstract: A piston extends along a central axis with an upper crown and a boss depending from the crown. The boss has opposite sides extending along opposite sides of the central axis to a free end and an annular pocket extending laterally into at least one of the sides. The boss further includes an opening extending through the free end into the pocket. The opening has a width extending from the side in which the pocket extends toward the other side of the boss. An assembly including the piston further includes a connecting rod terminating at a small end configured for receipt in the pocket with a shank extending from the small end. The small end can be provided with an external bearing material on a convex outer surface, and the small end is unobstructed from lateral movement along the opening over a full stroke of the piston.

Abstract: A piston pump device has a support unit, a pump cylinder, and a pump piston arranged in the pump cylinder. The pump cylinder has a longitudinal center axis, and a cylinder bottom arranged perpendicular to the longitudinal center axis. The pump piston is movable relative to the cylinder bottom, and the pump cylinder is secured on the support unit by a securing unit. The securing unit has a leaf spring, which permits a pivoting movement of the longitudinal center axis of the pump cylinder relative to the support unit. The piston pump device is wear-resistant and runs quietly. When used as a suction pump, the piston pump device additionally permits a controllable air flow until the pump comes to a stop.

Abstract: A piston assembly for an internal combustion engine is provided, including a piston and at least one insert. The piston includes an annular recess, a first surface, a ring belt and a skirt. The annular recess is located between the ring belt and the skirt. The insert may include a longitudinal portion and one or more opposing arms. The insert may be configured to be coupled with the piston. The arm(s) may extend laterally from the longitudinal portion and may be configured to abut the skirt, thereby orienting the insert relative to the piston. The insert may be disposed along the first surface, and aligned with the piston skirt such that the arms of the insert form a circumference about the piston skirt. The arms may at least partially enclose the annular recess at the piston skirt.

Abstract: Piston pin for a connecting rod in a reciprocating internal combustion engine, wherein the piston pin carries at least in the area of the running surface a thermal sprayed slide layer of a metallic bearing material or slide bearing material, as well as reciprocating internal combustion engine with a connecting rod with small and with large connecting rod eye, wherein at least the running surface of one of the piston pins is formed of a thermal sprayed slide layer of a metallic bearing material, which exhibits a lower hardness than the running surface of the corresponding connecting rod eye and process for manufacturing a described piston pin with the steps of a extrusion molding or machining a piston pin preform, introduction of a recess in the area which will later become the running surface, roughening the outer surface in the area of the recess, application of a coating of a bearing material by a thermal spray process.

Abstract: Pin bosses (1) are proposed for the piston (2) of an internal combustion engine, having in each case one pin bore (3) which has a zenith-side ovality in the region (15) of the bore center (7), wherein the zenith-side ovality of the pin bore (3) increases starting from the bore center (7) radially to the outside and radially to the inside, and the nadir-side ovality increases starting from the bore center (7) radially to the inside. As a result, the shape of the pin bore (3) is adapted to every load-dependent deformation of the piston pin. As a result of this, in addition, the lubrication of the piston pin is improved in the region of the bore center (7).

Abstract: A connecting rod and methods for making the same are disclosed. A connecting rod may include a shaft extending between a piston pin end and a crankshaft pin end. The piston pin end generally defines a bore opening extending along an axis. The connecting rod further includes a bore surface formed integrally with the piston pin end and extending about an inner circumference of the bore opening. The bore surface may define a plurality of dimples that extend axially along the bore surface. The bore opening further may further include profiled surfaces adjacent opposing ends of the bore opening.

Abstract: In a pressure booster having a cylinder mechanism, a floating mechanism is disposed between pistons and a piston rod, the floating mechanism being capable of absorbing offset (off centered) loads that are imposed on the pistons from the piston rod. The floating mechanism is constituted from swing bolts connected to both ends of the piston rod, support plates mounted onto end surfaces of the pistons and which swingably support the swing bolts therein, and fixing plates disposed between the ends of the piston rod and the support plates.

Abstract: There is provided a slide part used in an environment where there is a lubricant containing a molybdenum compound including a hard protective layer formed on an outermost surface of a substrate of the slide part; in which: the hard protective layer includes mainly carbon, nitrogen, and a metal element; the hard protective layer is composed of a complex of an amorphous carbon body containing nitrogen and a compound crystal of the metal element; the compound crystal is composed of at least one of a metal carbide, a metal nitride, and a metal carbonitride; and a surface hardness of the hard protective layer is 1800 or larger in Vickers hardness.

Abstract: A multi-axially forged mono-bloc piston includes a lower crown part forged of steel and including a pair of pin bosses and an integral skirt formed as one piece with the pin bosses 20. The lower crown part is friction welded to an upper crown part to form at least one closed oil gallery within the piston head. The lower crown part is forged in the longitudinal direction of the piston as well as laterally to impart longitudinal and laterally forged features of the piston. The laterally forged features may comprise undercut recesses formed in the piston skirt to reduce material in the overall piston structure. The lateral forging may also result in the piston skirt portion being discoupled from the piston head by laterally forged slots formed in the lower crown part 14 between the skirt and head.

Abstract: A piston has a piston body with a pair of pin bosses having pin bores aligned along a central axis. The pin bores have bearing surfaces, wherein at least one recess extends axially across at least one of the bearing surfaces. A groove extends partially about the bearing surface circumference and is arranged in fluid communication with the recess. The recess and groove provide a lubrication feature to the pin bore, while the bearing surface has an uninterrupted portion for enhanced load carrying capacity.

Abstract: A method and apparatus for accommodating mis-alignment of a piston rod in a reciprocating force delivery device is provided. A piston rod is coupled to a piston by a pivot bearing disposed around the piston rod inside the piston. The pivot bearing contacts an internal surface of the piston and provides a biaxial pivot point, which may also be triaxial, for the piston rod inside the piston. The pivot point is located near the centroid of the piston, enabling forces not aligned with the axis of the piston to be decoupled into axial and transverse components. The force decoupling avoids rotational moment on the piston, minimizing the possibility of metal-to-metal contact between components of the piston and the cylinder liner.

Abstract: The invention relates to a reciprocating piston engine, particularly a coolant compressor for motor vehicles, comprising at least one piston movably supported in a cylinder, and comprising a pivot element (1), preferably designed as a pivot ring, supported on a guide body (5) that is attached to a shaft (3) in an axially movable fashion such that said pivot element can execute a pivot motion, causing movement of the at least one piston, wherein spring forces of at least one return spring (15) act on the pivot element (1) in the direction of a start position in which said pivot element is pivoted at a starting pivot angle (alpha start) to a plane (E) on which the rotary axis (D) of the shaft (3) stands upright. At least one further spring element (19) acts on the return spring (15) with an initial tension when the pivot element (1) is in the start position.

Abstract: A reciprocating pump assembly has a pump within a housing. The pump has a crankshaft that rotates and a crosshead that is connected to a plunger via a pony rod. The plunger pumps fluid through cylinders in the pump. A connecting rod connects at one end to the crankshaft and at another end to the crosshead to translate the crankshaft's rotational movement into linear movement of the crosshead and thereby the plunger. The end connected to the crosshead is secured to the crosshead by a bushing located within the crosshead that allows the connecting rod end to pivot during operation. The bushing extends more than 180 degrees, retaining the connecting rod with the crosshead without the need for a wrist pin. The end secured by the bushing can be retained within the bushing by a lock plate, and retainers without the need for a wrist pin.

Abstract: A piston pin includes a cylindrical sleeve and an insert, the insert material having a lower volume weight than that of a material of the sleeve. For instance, the insert can be made of an aluminium alloy, of titanium, of a TiAl alloy or of a composite material. The insert has a length approximately equal to, or less than, that of the sleeve and is firmly secured to the latter by force- or interference-fitting.

Abstract: A piston of an internal combustion engine has a piston crown provided with a ring zone and adjoining a piston skirt encompassing a piston interior, the skirt having two load-bearing skirt wall segments and two pin bosses. Each pin boss encompassing a boss hole is connected to a boss base body by a boss support, the base body having ribs to increase stiffness, which are aligned to the extent possible in the direction of the boss holes continuously connecting the pin bosses. The curved or arched ribs thereby cover a pivoting range of a connecting rod.

Abstract: The disclosure relates to a sprayer with a reservoir for a fluid, such as for a pesticide, with a pump device for pressurizing the fluid, whereby the pump device includes a pump drive, which is movably coupled to a pump piston by means of a pump connecting rod, whereby the pump connecting rod features a first connecting rod part and a second connecting rod part, whereby in order to connect the first connecting rod part and the second connecting rod part, at least one connecting device is provided, by means of which the connecting rod parts can be interlocked in at least two different latching levels.

Abstract: A piston including a crown and a skirt extending generally axially away from the crown. The skirt includes a pair of opposed skirt panel portions and a band spaced away from the crown and extending generally around a perimeter of the piston. The piston further includes a pair of strut assemblies, each strut assembly including a pair of struts which converge in a radially outward direction. Each strut terminates at or adjacent to one of the panel portions.

Abstract: The present invention reduces weight while assuring required rigidity of a piston reduces cost of the piston. A piston includes first and second pin bosses supporting a piston pins, a first side wall coupling the first pin boss and a piston skirt, a second side wall coupling the second pin boss and the piston skirt, and a pair of bridges coupling the first and second side walls and forming upward spaces just above. First and second through holes are formed in the first and second side walls. The first and second through holes and the upper spaces are formed by a single punching process using a punch and, simultaneously, the bridges are formed.

Abstract: The present invention relates to a piston (10) for an internal combustion engine having a piston head (11) and a piston skirt (16) with piston hubs (17) which are each connected to a hub bore (18) for receiving a piston bolt, wherein the piston hubs (17) are in the shape of a trapezoidal or step-shaped support in which the inner faces (19) of the piston hubs (17) include an acute angle (?a) with the central axis (M) of the piston. The invention provides that each hub bore (18) is embodied as a shaped bore which is widened at least in its inner area in such a way that the widened portion increases in size in the direction of the inner end (18?) of the hub bore (18) forming facets (120, 220) on the lateral surface (18) of the hub bore (18), and that the facets (120, 220) include an acute angle (?a, ?) with the central axis (M) of the piston.

Abstract: The invention relates to a piston pin bearing of an internal combustion engine, in which a cylindrical piston pin is mounted. The aim of the invention is to create a hub bore shape that is improved compared to prior art in order to significantly reduce mechanical stress in the piston and thus extend the service life of the piston. Furthermore, the shape is to prevent noise from being generated in the piston pin bearing. The aims are achieved by the fact that the surface line of the highly oval outer surface, which runs in the zenith of the hub, extends at an angle to the hub axis from a radially outward point to a radially inward point on the piston side such that the greatest degree of ovalness defined by the oval diameter thereof is created at the respective inner ends of the hub bores and does not exceed a predefined value of the oval diameter.