Abstract: An self-lubrication alignment bearing includes a sleeve having therein a top recess defined in a top portion thereof, a bottom recess defined in a bottom portion thereof to communicate with the top recess via a longitudinally defined channel in which the shaft is rotatably received, a bottom cap received in the bottom recess and a returning passage defined inside the sleeve to communicate the bottom recess with the top recess.

Abstract: An image forming apparatus includes a chassis, a motor, a drive transmission gear that receives rotational force from the motor, a feed roller rotatably supported by the chassis, an intermediate gear that has a circular bearing, receives rotational force from the drive transmission gear, and transmits rotational force to the feed roller gear, and a gear support axle that is inserted through the bearing of the intermediate gear for rotatably supporting the intermediate gear. The gear support axle is provided with a bearing engagement part. The bearing engagement part has at least one flat section, at least one circular section, and at least two support portions formed between the flat section and the circular section, such that the gear support axle is supported by the bearing at at least one of the two support portions.

Abstract: A bearing stave for use in a water-lubricated bearing having a discontinuous surface with a plurality of discrete, separated contact locations for contacting the shaft, the discontinuous surface being made of slippery polymer alloy.

Abstract: A plain bearing comprising a housing and two plain bearing halves forming a cylindrical shape in combination and fixed in the housing. Each of the plain bearing halves has crush reliefs formed at both ends of an inner circumferential surface thereof in a circumferential direction, an oil groove formed on the inner circumferential surface thereof and extending in the circumferential direction, a central crown portion at substantially central position in the circumferential direction and in communication with the oil groove, and inflow preventing portions formed between the crush reliefs and the oil groove.

Abstract: A bush is provided at its sliding surface with oil-supply groove portions. An area ratio of the oil-supply groove portions to the sliding surface of the journal shaft is set to 30 to 90%. A length L1 between the oil-supply groove portions in a circumferential direction and an inner diameter D of the bearing satisfy L1<?D/36. Even in a bearing device in which the journal shaft and the bush mutually rotate in a predetermined angle range or in which the journal shaft and the bush relatively and continuously rotate, the present invention can effectively be used while maintaining the existing sizes of the journal shaft and the bush, and it is possible to prevent partial break of oil film or shortage of oil film.

Abstract: A bearing shell for a crankshaft thrust bearing has a circumferential oil passage (4) formed on the inside of shell (6) of bearing shell (1). An oil passage (4) is connected via a hole (2) to the outside of and to a groove (7) running to one of flanges (5) and a hole (9) at the end of shell (1). In this way, the flange (8) is supplied oil to achieve improved lubrication in the axial loading direction.

Abstract: A plain bearing is described, the bearing being fitted, in use, in an associated bearing housing, the bearing back in contact with said housing is substantially coextensive with the housing in the axial direction wherein the running surface of the bearing is relieved in both the axial and radial directions so as to reduce the contact bearing surface area with an associated shaft journal, in use.

Abstract: Roller vane pump, in particular suited for pumping fluid in a continuously variable automatic transmission of a motor vehicle, provided with a pump housing accommodating a substantially cylindrical carrier, which is rotatable about a central axis, and a cam ring encompassing the carrier in the radial direction, whereby a radial clearance between the carrier and the cam ring varies along a circumference of the carrier, and with a pump shaft extending co-axial with said central axis through the carrier, characterised in that there is provided in the pump housing a bearing bush having an essentially cylindrical central bore through which the pump shaft extends.

Abstract: In order to improve conformability of a sliding surface of a sliding member in an early state of sliding, there is provided a sliding member in which a plurality of holes are formed on a sliding surface, and the diameters (or the opening area) of the holes on the sliding surface are arranged so as to become gradually large as it gets closer to both ends in an axial direction from the center side in the axial direction. This feature decreases the pressurized area as it gets closer to the ends of the sliding surface so that it wears at an early stage, whereby a conformed surface following the deflection of a mating member is provided.

Abstract: The present invention relates to a bearing device including a body formed with an inner groove that does not communicate with the shaft hole of the body. Thus, when the rotation shaft is rotated, the lubricating oil may lubricate the rotation shaft, and may flow back to be stored in the inner groove after the rotation shaft stops rotating, thereby achieving the effect of recycling use. At the same time, the inner groove does not communicate with the inner shaft hole, such that when the rotation shaft is rotated, the lubricating oil contained in the inner groove will not be directly carried out of the body and will not sputter out of the body. Thus, the amount of loss of the lubricating oil may be reduced, thereby increasing the lifetime of the bearing device.

Abstract: A hybrid bearing system that has a self-lubricating portion and a grease lubricated portion each being disposed on the same surface, the system is adapted to accommodate at least two distinct wearing forces generated by different types of motions. The bearing system includes: a first member; a second member, the second member being configured to be rotatably received within the first member; a self lubricating machineable liner system disposed between the first member and the second member; a receiving area disposed on the self lubricating liner system and a portion of either the first or the second member; and a lubrication opening in fluid communication with the receiving area, the lubrication opening providing structure for disbursing a lubrication grease within the receiving area.

Abstract: A bush is provided at its sliding surface with oil-supply groove portions. An area ratio of the oil-supply groove portions to the sliding surface of the journal shaft is set to 30 to 90%. A length L1 between the oil-supply groove portions in a circumferential direction and an inner diameter D of the bearing satisfy L1<&pgr;D/36. Even in a bearing device in which the journal shaft and the bush mutually rotate in a predetermined angle range or in which the journal shaft and the bush relatively and continuously rotate, the present invention can effectively be used while maintaining the existing sizes of the journal shaft and the bush, and it is possible to prevent partial break of oil film or shortage of oil film.

Abstract: A half bearing constituting a cylindrical plain bearing for supporting a shaft for rotation when two of the half bearings are combined together. The half bearing has two circumferential ends each of which has a plurality of circumferential grooves without formation of any crush relief surface. The grooves extend substantially over an overall circumferential dimension of the half bearing and include portions located at both circumferential ends of the half bearing respectively. Each portion has a larger axially sectional area than the grooves formed in a portion of the half bearing mainly subjected to load during rotation of the shaft.

Abstract: A dry bearing (102, FIG. 2(f)) for a hinge pin or the like comprises a bush 402 mounted in a radially supportive housing (16), the bush being formed by a circumferentially discontinuous tubular form made by rolling a strip of steel-backed, bearing material having a filled polymer infiltrated sintered bronze (ISB) lining about a mandrel (FIG. 32, 2(c)). The tubular form is, after mounting and to provide a more uniform inside diameter, burnished by pushing therethrough a burnishing tool (50), having a cylindrical portion (51), of larger diameter than the mounted form. The bearing (and method of manufacture) differ from the art in that a minor part of the lining surface is, prior to passage of the burnishing tool and conveniently when still in strip form, compressed in part as depressions (troughs 442) arrayed over the surface.

Abstract: The lubricant line structure for the radially inner surface of the bearing in accordance with the present invention mainly comprises a plurality of zigzag lubricant lines. The zigzag lubricant lines are symmetrically extended along an axis of the bearing and connected two end surfaces. When a shaft in the bearing is rotated in clockwise or counterclockwise, outer lubricant is sucked into an interior of the bearing so as to form plurality of convergent lubricant points.

Abstract: A shaft bearing member includes an inner circumferential face serving as a sliding surface, an oil groove formed in the inner circumferential face so as to circumferentially extend, and a recess formed in the inner circumferential face so as to extend from at least one of both widthwise sides of the oil groove toward axial end side of the inner circumferential face with respect to the shaft so that the recess is rendered shallower and shallower.

Abstract: An oil-lubricated sliding bearing is provided. The bearing comprises a first member having a sliding surface having at least one groove, and a second member having a sliding surface having at least one groove. The sliding surface of the first member and the sliding surface of the second member slide on each other. The first member is fixed and the second member is movable. The grooves of the first member are inclined from the sliding direction. The bearing includes a linear bearing, a radial bearing, a taper bearing, and a thrust bearing.

Abstract: A shaft bearing member for supporting a shaft so that the shaft is rotatable has an inner circumferential face serving as a sliding surface. The shaft bearing member includes an oil groove formed in the inner circumferential face so as to circumferentially extend, and a plurality of narrow grooves formed on the inner circumferential face so as to extend at a predetermined angle relative to a rotation direction of the shaft from at least one of both widthwise sides of the oil groove toward an axial end side of the inner circumferential face with respect to the shaft. The narrow grooves guide a lubrication oil from the oil groove toward the axial end side with rotation of the shaft. The narrow grooves are shallower and narrower than the oil groove.

Abstract: A sintered plain bearing for motors and gear drives, having a running surface formed by a bearing bore and capable of having lubricant applied to it from lubricant reservoirs in the bearing, in which the bearing bore has, alternatingly distributed over the circumference, high-compaction small-pore running surfaces and axially extending low-compaction open-pore lubricant reservoirs. Lubrication is improved, especially in the initial phases of operation, by the fact that the lubricant reservoirs are constituted by channel structures having at least two longitudinal channels, and that at least in some of the channel structures, some of the channel crests remaining between adjacent longitudinal channels are in contact with the shaft received by the bearing bore in order to transfer lubricant.

Abstract: A Bearing and Bushing assembly where the operational mating surfaces of the bearing and bushing components are each formed with grooves, longitudinally extending the length of each component. The grooves formed in the bushing to be attached to a shaft are spiral, at least two in number, one being a reverse spiral to the other. The bearing assembly has a number of longitudinal, parallel grooves again extending the length of the bearing members. The bearing member is of composite construction. The inner component carrying the grooves being of hard rubber.

Abstract: In order to enhance the fatigue resistance and the anti-seizure property while maintaining the. embeddability, there is provided a plain bearing comprising a bearing alloy layer, an intermediate layer and an overlay layer which are formed on the inner surface of a back metal in this order. The inner surface of the bearing alloy layer is provided with a recess groove “a” extending in the circumferential direction, so that the inner surface is made into a textured uneven condition. The recess groove “a” has a bent portion which is bent relative to the circumferential direction, so that a foreign substance X entering between a mating shaft and the plain bearing is moved in the circumferential direction owing to the rotation of the shaft, the foreign substance X runs against a side edge of the recess groove “a” and moves along the side edge, thereby the embedding of the foreign substance into the overlay layer is promoted.

Abstract: It is an object of the invention to improve wear resistance and an anti-seizure property of a portion , on which a radial load operates owing to tension of a cogged belt or a V-belt, of a plain bearing for an engine. A main shaft portion of a crankshaft is in uneven contact with an upper half bearing owning to tension of the cogged belt and/or the V-belt. A branch groove is formed in a portion forwarder than an oil groove formed on the bearing surface of a upper half bearing of a plain bearing, the branch groove branching off from the oil groove. When an engine stops, lubricant is stored within the branch grooves, and when the engine restarts, the lubricant within the branch grooves is immediately supplied to the uneven contact portion of the main shaft portion though the rotation thereof.

Abstract: A method and apparatus for replenishing oil in a fluid dynamic bearing using a sleeve groove. The replenishing groove is formed in the sleeve surrounding the shaft so that centrifugal force drives the oil to move toward the radial bearings.

Abstract: The bearing mainly includes an inner groove and at least a passage. The groove is arranged on an inner surface of the bearing and connected with a reservoir on one end of the bearing by the passage to induce the outflow lubricant backflow to the groove.

Abstract: A rolled product for a chain and a method for producing the rolled product are disclosed. Plural dimples are formed in a zigzag pattern in at least one of inner and outer peripheral surfaces of the rolled product, the dimples absorbing plastic deformation of a rolled workpiece when the rolled product is forced through a circular orifice of a die, and plural recessed portions are defined by the dimples on any imaginary straight line on the dimpled surface in the axial direction of the rolled product. The absorption of plastic flow by the dimples prevents a waving phenomenon from occurring at the end faces of the rolled product. When the rolled product is used as a chain component such as bushing or roller, it is possible to prevent leakage of a lubricant in the axial direction of the rolled product, and hence possible to improve the lubricant retaining performance in a rotating and sliding portion.

Abstract: A shaft bearing member for supporting a shaft so that the shaft is rotatable has an inner circumferential face serving as a sliding surface. The, shaft bearing member includes an oil groove formed in the inner circumferential face so as to circumiferentially extend, and a plurality of narrow grooves formed on the inner circumferential face so as to extend at a predetermined angle relative to a rotation direction of the shaft from at least one of both widthwise sides of the oil groove toward an axial end side of the inner circumferential face with respect to the shaft. The narrow grooves guide a lubrication oil from the oil groove toward the axial end side with rotation of the shaft. The narrow grooves are shallower and narrower than the oil groove.

Abstract: A shaft bearing member includes an inner circumferential face serving as a sliding surface, an oil groove formed in the inner circumferential face so as to circumferentially extend, and a recess formed in the inner circumferential face so as to extend from at least one of both widthwise sides of the oil groove toward axial end side of the inner circumferential face with respect to the shaft so that the recess is rendered shallower and shallower.

Abstract: Disclosed is a plain bearing having a back metal, a bearing alloy layer and an overlay layer, in which the bearing alloy layer and the overlay layer are formed on the inner surface of the metal in this order. The inner surface of the bearing alloy is provided with circumferential broad width recesses and narrow recesses in which the overlay material is filled. The fatigue resistance and were resistance are ensured by the zone of the narrow width recesses. The plain bearing exhibits high embeddability for a foreign substance by presence of the zone of the broad width recesses.

Abstract: A link assembly for a suspension system of a motor vehicle. The link assembly includes a link having a barrel portion at each end. The barrel portion is narrower than that of previously developed links and is fitted with tapered cone bushings. The narrower links and tapered cone bushings enable a greater degree of articulation of the link without the edges of the barrel portions hitting the surfaces of the mounting brackets to which the link is attached. Each barrel portion also includes an integral ring which limits the lateral movement of each link assembly without limiting torsional movement. Each barrel portion also includes integrally formed grease passageways for enabling lubricant to be held within the barrel portions when the tapered cone bushings are assembled thereto.

Abstract: The invention related to a Bearing and Bushing assembly where the operational mating surfaces of the bearing and bushing components are each formed with grooves, longitudinally extending the length of each component. The grooves formed in the bushing to be attached to a shaft are spiral, at least two in number, one being a reverse spiral to the other. The bearing assembly has a number of longitudinal, parallel grooves again extending the length of the bearing members. In the preferred embodiment the bearing member is of composite construction. The inner component carrying the grooves being of hard rubber.

Abstract: A journal bearing including a generally cylindrical outer surface, and a generally cylindrical inner surface including an inner edge, an outer edge, a midline defined as a circumferential line midway between the inner edge and the outer edge, a least-loaded region and a highest-loaded region, and a first groove pattern symmetric about the midline, the pattern extending from the least-loaded region to the highest-loaded region, the pattern including a lubricant entry point on the midline in the least-loaded region, a lubricant reservoir on the midline on the opposite side of the highest-loaded region from the lubricant entry point, and substantially more grooving in the least-loaded region than in the highest-loaded region.

Abstract: A self-lubricating bearing for use in submersible oil-filled motors is disclosed. The bearing comprises a bearing housing and is fixed against rotation. A bearing sleeve is disposed in the bearing housing. The bearing sleeve is fixed in the bearing housing, and has a slot disposed therethrough. The bearing housing has an inlet and an outlet defined therethrough that intersect the slot in the bearing sleeve. The bearing is disposed about a rotatable shaft in the motor. Rotation of the shaft will cause oil to be drawn in through the inlet so that the shaft and the bearing surface of the bearing sleeve are lubricated. Rotation will also cause oil drawn in through the inlet to be expelled through the outlet back into the motor so that there is a constant circulation of oil through the bearing to provide lubrication.

Abstract: A journal bearing comprises a body having a central longitudinal axis, a cylindrical inner surface coaxially disposed around the longitudinal axis and defining an axial bore, and an outer surface including a peripheral planar section. A lateral face is disposed on an end of the body, and extends between the outer and inner surfaces of the body. A feed channel is formed in the lateral face at an acute angle with respect to the planar section and in an inward direction with respect to the axial bore. A first end of the feed channel communicates with the outer surface of the bearing at a location proximate to the planar section, and a second end of the feed channel communicates with the axial bore. A pocket is formed in the inner surface of the bearing in communication with the second end of the feed channel and extends along a substantially helical path from the lateral face of the bearing. At least a portion of the pocket has a width of greater magnitude than a corresponding depth of the portion.

Abstract: In a rack guide disposed in a casing of a rack and pinion type steering system for slidably supporting a rack bar having rack teeth which engage with a pinion rotatably supported in the casing, the area for bearing the load of the rack bar can be fixed. A slide bearing member 21 has a three-layered structure consisting of a backing metal 22 made of bronze, a sintered alloy layer 23 and a synthetic resin layer 24, the surface of the synthetic resin layer 24 comprising sliding-contact surface portions 25, 26 formed intermittently with the center thereof at the center of curvature “O” of a circular outer peripheral surface of a rack bar 16 and with a radius of curvature equal to the radius of curvature R0 of the same, and the remaining surface portions 27 to 29 formed in other positions than the sliding-contact surface portions 25, 26 so as to be more dented than the sliding-contact surface portions 25, 26.

Abstract: A rotary slide bearing part of a rotary slide slit bearing for supporting a rotary shaft thereon in a rotatable manner, has a first bearing surface portion adapted to be arranged adjacent to a second bearing surface portion of another rotary slide bearing part of the rotary slide slit bearing, a load from the shaft to be borne by the first bearing surface portion is larger than a load from the shaft to be borne by the second bearing surface portion, the first bearing surface portion includes a fluidal pressure generating surface facing close to the shaft to generate a fluidal pressure between the fluidal pressure generating surface and the shaft, a main groove arranged at an circumferential end of the first bearing surface portion adjacent to the second bearing surface portion, and a sub-groove extending from the main groove in a circumferential direction of the first bearing surface portion, and an axial width of the sub-groove is smaller than that of the main groove.

Abstract: Aerostatic airbearing, comprising a counter body (2) having a counter surface (21) and a bearing body (1), having a bearing surface (11) arranged opposing the counter surface (21). In the bearing body (1) are formed a nozzle channel (12) ending at the bearing surface (11) and being connected to a pressure source supplying a feed pressure, and a micro channel structure (13) which extends along the bearing surface (11), is open towards the bearing surface (11) and runs into the nozzle channel (12). The airbearing has a static characteristic curve of the carrying force as a function of the gap width between the bearing surface (11) and the counter surface (21), which curve is defined by the structures of the bearing body (1) and of the counter body (2) and by the feed pressure. The micro channel structure (13) extends, in at least one direction of the bearing surface (11), over the most part of the bearing surface (11).

Abstract: A brushless DC motor including a rotor, a field magnet, and fixed poles having salient poles opposed to the field magnet. A bearing structure includes a rotating portion adapted to rotate with the rotor, a part of which rotating portion contacts the shaft, and a groove formed in the rotating contact portion at a predetermined angle between an angle parallel to the axial direction of the rotating portion and an angle perpendicular thereto. A lubricating oil fills both the rotating contact portion and the groove. A plastic plate is disposed under the rotating portion to bear a thrust force of the rotating portion.

Abstract: An improved lubricant cooling system for a sealed bearing section used in drilling with downhole motors comprises a radial bearing or bearings which preferably contain internal and external spiral grooves such that rotation of the central hollow shaft which supports the drillbit forces lubricant up the external grooves toward the upper seal and then back down in the internal grooves along the cooled hollow shaft which has drilling mud flowing through it. Similarly, the rotation of the hollow shaft forces lubricant through an internal spiral in a lower radial bearing or bearings until it reaches the lower seal at which time it is forced into the external spirals past the thrust bearings in the bearing section. This axial circulation effect allows the removal of heat efficiently from the lubricant by virtue of circulating drilling mud in the hollow shaft and in the outer annulus returning to the surface.

Abstract: There are provided a plain bearing which is excellent in oil retaining property and wear-resistant property. The plain bearing has a number of fine grooves which are parallely formed with one another and extending in the circumferential direction on the inner surface of the bearing, the fine grooves comprising deep grooves and shallow grooves. When this bearing is used as a plain bearing, a large amount of lubricating oil can be retained in the deep grooves and the shallow grooves so that a plain bearing which is excellent in anti-seizure property and wear-resistant property can be obtained. Further, even if the shallow grooves will have been worn out by wear and tear during use of extended period of time, the anti-seizure property and the wear-resistant property can be stably maintained by the lubricating oil retained in the deep grooves.

Abstract: A sliding bearing of a cylindrical shape which bearing is adapted to support a rotation shaft through a lubricant film, comprising a plurality of fine grooves juxtaposed on an inner peripheral face of said sliding bearing in a circumferential direction of the bearing, each of said grooves extending from a backward position of a minimum lubricant film thickness portion at which the lubricant film becomes minimum in thickness on the rotation of said shaft, to a forward position of said minimum lubricant film thickness portion.

Abstract: A slide bearing for a gear pump or the like has a lubrication groove provided in the surface of the cylinder forming the slide bearing. The lubrication groove is constructed to be ending flatly in the area of that edge which, with respect to the shaft rotating direction acts as an inlet edge into the slot between the slide bearing and the shaft. Thus, it is achieved that the slide bearing is sufficiently lubricated also by fluid which flows at a higher viscosity and has an unknown elastic performance.

Abstract: An improved porous bearing and a motor which is provided with the porous bearing in which the friction losses and reflection of shaft are reduced, noises caused by the vibrations are avoided with low cogging or low jitter, and in addition, the manufacturing process is simplified to obtain long-life products at low cost. The number (C) of grooves of the porous bearing meets at least one of the following equations:nA+mB-C.noteq.0, nA-C.noteq.0 and mB-C.noteq.0wherein A is the number of magnetic poles of the motor magnet, B is the number of the slots of the armature, and n and m are integers, respectively.

Abstract: A plastic bearing and plastic conveyor guide track include a lubricating site formed by an oil saturated polymer. In a plastic bearing, a lubricating strip resides in contact with a shaft rotatably supported by the shaft. In the guide track, oil saturated polymer elements are inserted prior to machining and are exposed at selected guide features during machining. Enhanced lubrication results without sacrificing the load bearing capabilities of the plastic material forming the bearing or guide track body.

Abstract: A guide sleeve structure for guiding and supporting the cylinder in the spindle guide tube comprising vertical guide webs(110) formed toward the spindle between the radial line of the ribs(130), and the vertical guide grooves toward the spindle in response to the ribs(130) to structurally withhold the expanding and the shrinking of the slide gap caused by the change of temperature.

Abstract: A transmitting chain is provided which can lower surface pressure between a bushing and a pin, which can well maintain a lubricating state, and which is high in durability so as to be capable of withstanding high load. A groove or a depression, into which lubricating oil, supplied from outside of the chain, is moved, is formed in at least one of a group including an inner peripheral surface of a bushing and an outer peripheral surface of a pin. A difference, space, or clearance, located between an inside diameter of the bushing and an outside diameter of the pin, of portions of the chain not including the groove or depression, is set in a range of from about 0.05 to 0.6% of the outside diameter of the pin.

Abstract: A roll-formed sliding surface bearing bushing is circular in an installed state and has a butt joint which extends throughout the width of the bushing and is closed in an installed state. To ensure a backlash-free bearing arrangement, the bushing has on its outside peripheral surface a trapezoidal profile, which includes an angle of 1.degree. to 30.degree. with the plane which contains the longitudinal axis of the bushing.

Abstract: An improved porous bearing and a motor which is provided with the porous bearing in which the friction losses and reflection of shaft are reduced, noises caused by the vibrations are avoided with low cogging or low jitter, and in addition, the manufacturing process is simplified to obtain long-life products at low cost. The number (C) of grooves of the porous bearing meets at least one of the following equations:nA+mB-C.noteq.0, nA-C.noteq.0 and mB-C.noteq.0wherein A is the number of magnetic poles of the motor magnet, B is the number of the slots of the armature, and n and m are integers, respectively.

Abstract: A porous-plastic bearing comprises a porous-plastic sliding bearing member which is formed by gathering a cluster of plastic particles each having a volume in the range of from about 0.004 mm.sup.3 to about 4 mm.sup.3 and sintering the cluster of plastic particles while setting its porosity at a selected value in the range of from about 10% to about 30%. Furthermore, the sliding bearing member comprises a plurality of plastic particles in any longitudinal or cross section. Pores formed within the sliding bearing member are impregnated with or filled with a lubricating agent.

Abstract: The invention provides a bearing including an inner bearing surface that is formed by a layer of self-lubricating material and that contains axially extending and circumferentially spaced apart lubrication grooves. The inner bearing surface and the grooves therein are formed by conforming the self-lubricating material to the outer surface of a mandrel that has elongated members supported thereon so that the elongated members form the lubrication grooves. An overlayment is then applied on the layer of self-lubricating material, the overlayment including a plurality of filaments wound around the layer of self-lubricating material, and a hardenable liquid to bond the layer of self-lubricating material to the overlayment.

Abstract: A half bearing constituting a cylindrical plain bearing for supporting a shaft for rotation when two of the half bearings are combined together. The half bearing has two circumferential ends each of which has a plurality of circumferential grooves without formation of any crush relief surface. The grooves extend substantially over an overall circumferential dimension of the half bearing and include portions located at both circumferential ends of the half bearing respectively. Each portion has a larger axially sectional area than the grooves formed in a portion of the half bearing mainly subjected to load during rotation of the shaft.