Abstract: An endless belt (11) to be provided on a driven pulley (4b) and a pulley rotation support apparatus for supporting the driven pulley (4b). In the pulley rotation support apparatus, there is used a three-point-contact-type or four-point-contact-type radial ball bearing (14b). An offset quantity ?, which is an axial-direction distance between the center ? of a radial load applied from the endless belt (11) to the driven pulley (4b) and the center position ? of the radial ball bearing (14b), is set 40% or less of the pitch circle diameter of the radial ball bearing (14b). The radial clearance of this radial ball bearing (14b) is set 0.2% or less of the above pitch circle diameter.

Abstract: A screw engagement portion between a pulley and a shaft is provided with a thread in a direction to increase the tightening torque when the pulley is driven. A breakable part broken by the axial tension produced when the tightening torque acting on the screw engagement portion is above a predetermined value, is also provided. The stress to break the breakable part is mainly a tensile stress. The tensile stress is substantially uniformly distributed in a cross section and, hence, the stress distribution of the breakable part can be relatively precisely predicted and analyzed. Consequently, the necessity of determining aspects of the breakable part, such as dimension, material, and the like, by trial and error is reduced. The breakable part can be broken without being subject to fatigue fracture.

Abstract: A power transmission system including an integrally molded hub and elastic member, where stress is inhibited from concentrating at the gate marks remaining after integral molding. In a pulley driven by a belt, a plastic pulley side relief section 1a provided at a pocket section of the pulley and a plastic hub side relief section provided on an iron outer ring of the hub engaged at the pocket section whereby power is transmitted from the pulley to the shaft. The hub side relief section and outer ring forming parts of the hub, the iron inner hub to be fastened to the shaft, and the plastic cylindrical part are integrally molded so that the gate mark for plastic injection is formed near to or further to the outer circumference of the outer ring.

Abstract: An idler pulley with an integral bearing carrier insert comprising: a pulley body having a peripheral surface for accepting and retaining an endless belt; and a tubular bearing carrier insert forming a central hub along a perpendicular axis of the idler pulley body, the hub having an inner circumferential surface and an outer circumferential surface.

Abstract: A power transmission device includes a first one-way clutch that transmits a rotational power of a pulley to a rotating shaft, and a second one-way clutch that transmits a rotational power of a rotor of a motor to the rotating shaft. The first one-way clutch is of inner cam type in which an engagement cam-surface is formed in an outer periphery of a first inner ring, while the second one-way clutch is of outer cam type in which an engagement cam-surface is formed in an inner periphery of a second outer ring. This arrangement improves engagement performance of the first one-way clutch as well as reducing heat generation of the second one-way clutch, so that the lifetime of grease is prolonged.

Abstract: A bearing device equipped with a resin-made pulley has, at one axial end portion of an outer ring, cutout portions which are formed so as to be opened on their outward side of the axial direction and spaced from one another at a specified interval in a circumferential direction of the outer ring. Each cutout portion has a rectangular-shaped sloped surface which is sloped radially outward of the outer ring along an axial direction from an opening-side end to the center of the outer ring so as to adjoin the cylindrical surface portion on the axially opposite side to the opening. Each cutout portion further has side faces which are generally parallel to a vertical bisector plane of the sloped surface containing a center axis of the outer ring on circumferential both sides of the sloped surface in a cross section perpendicular to the center axis of the outer ring.

Abstract: A fan idler pulley having a threaded hub for attaching a fan shaft. The pulley also comprises a receiving portion for engaging a bearing. The bearing is further engaged with a cup. The entire assembly is mounted by a pin press fit though the cup into a mounting surface such as an engine block or front cover. The pulley may be engaged to either the inner race or the outer race of the bearing.

Abstract: A pulley unit includes a pulley and a rotor concentrically disposed for relative rotation, a one-way clutch interposed in an annular space therebetween, rolling bearings provided on opposite sides of the one-way clutch, and a seal ring for sealing the annular space. An inner diametrical surface of the pulley forms an outer ring raceway of the one-way clutch and the rolling bearing, and an outer diametrical surface of the shaft body forms an inner ring raceway of the one-way clutch and the rolling bearing. An outer diameter side of an annular portion of a retainer of the rolling bearing on the side of the seal ring is reduced so as to increase a storage volume of lubricating oil between the rolling bearing and the seal ring.

Abstract: In an automotive compressor, a pulley (6) is rotatably supported on a compressor housing (1) through a bearing (5) to have an axial gap (10) left between the compressor housing and the pulley. A waterproof cover (13) covers the axial gap and serves to suppress water from the outside from reaching the bearing. The waterproof cover is fixed to the compressor housing by a ring-shaped fastener (14). Instead of use of the waterproof cover, the axial gap may be controlled in size thereof.

Abstract: A tensioning or deflection pulley for a belt drive includes a carrier and a track roller comprised of an inner ring, an outer ring, and a connecting assembly, including a wheel disk extending between the inner and outer rings, and a rib assembly disposed in both sides of the disk in circumferential spaced-apart relationship, for interconnecting the inner and outer rings. The track roller is supported on the carrier by a sealed rolling-contact bearing via a fastening screw. A first sealing element is connected to the track roller on a carrier-distal side, and a second cap-shaped sealing element is disposed between the carrier and the track roller and detachably secured to the inner ring of the track roller to thereby seal the track roller on both sides.

Abstract: A pulley includes a radial rolling bearing and a pulley main body which are integrated to each other by an insert molding method. Therefore, a metal insert member is not required between the resin pulley main body and the radial rolling bearing, thereby reducing production cost of the pulley. Further, an axial dimension of an outer ring of the radial rolling bearing is set larger than an axial dimension of an inner ring thereof, so that a contact area between the radial rolling bearing and the pulley main body is increased. Therefore, a connection strength between the radial rolling bearing and the pulley main body is increased, and a surface area of the radial rolling bearing is increased, thereby improving heat radiation performance of the radial rolling bearing.

Abstract: A ball screw mechanism that can drive a movable pulley disk in an axial direction includes a screw cylinder and a nut member. A stopper pin is inserted through the screw cylinder from one end surface of the circumferential wall of the screw cylinder to the other end surface. As an end portion of the stopper pin is engaged with a notch portion of a transmission case, the rotation of the screw cylinder is inhibited. A stopper projection is provided on the nut member. As the other end portion of the stopper pin abuts against the stopper projection, the rotation range of the nut member is regulated. The stopper projection and the stopper pin function as excessive fastening preventing means for preventing the excessive fastening of the ball screw mechanism.

Abstract: A load spreader for use in pulley assemblies, where the load spreader engages the bearing and not the axle bolt, thereby allowing a single sized load spreader to be utilized with various sized axle bolts. The load spreader comprises a planar surface having a bore, and at least two arms disposed about the bore, with the arms extending substantially perpendicular from the planar surface which engage a bearing inner surface.

Abstract: The specification discloses a pulley assembly including a spun-formed pulley and a bearing secured within the pulley. The bearing is secured using any combination of press-fitting, adhering, coining, or peening. A manufacturing method also is disclosed.

Abstract: A drive mechanism for mounting on one side of a support wall to receive a drive shaft from a drive motor on the other side of the support wall, the drive shaft extending through an opening in the wall. The drive mechanism has a mounting member, the mounting member including a sleeve with a through bore, the sleeve having an inner end and outer end. The sleeve is detachably connectable at its inner end to the one side of the support wall and receives the drive shaft in its through bore when connected to the support wall. The drive mechanism also has a driven unit, the driven unit having a driven shaft, a pulley encircling the driven shaft but radially spaced therefrom, and a connector joining one side of the pulley to one end the driven shaft. The driven unit is mounted on the sleeve of the mounting member with the driven shaft inserted snugly within the bore of the sleeve from the outer end of the sleeve and the pulley concentric about the sleeve and spaced outwardly therefrom to provide an annular chamber.

Abstract: An engine accessory belt drive includes a self-aligning pulley assembly including a relatively stationary outer assembly and a universally pivotable inner assembly supported by the outer assembly and able to be locked in position by tightening of a fastener. During alignment of the self-aligning pulley with the belt, the fastener is maintained in the loose position, allowing limited universal pivoting of the rotational axis of the pulley as a result of belt tension forces which act to align the pulley. After the pulley is aligned, the fastener is tightened to fix the rotational axis of the pulley and the inner assembly in the aligned position of the pulley. Features of the inner and outer assemblies of the pulley assembly are also described.

Abstract: A power transmission device includes a first one-way clutch that transmits a rotational power of a pulley to a rotating shaft, and a second one-way clutch that transmits a rotational power of a rotor of a motor to the rotating shaft. The first one-way clutch is of inner cam type in which an engagement cam-surface is formed in an outer periphery of a first inner ring, while the second one-way clutch is of outer cam type in which an engagement cam-surface is formed in an inner periphery of a second outer ring. This arrangement improves engagement performance of the first one-way clutch as well as reducing heat generation of the second one-way clutch, so that the lifetime of grease is prolonged.

Abstract: A plate 13e, the outer diameter side of which is fixed to be integral with a plate section 13c, and which is provided with an engagement part 13g to be engaged with a shoulder 13f formed on the inner diameter side of a boss section 13a, is integral with a center hub 13. Thereby, even if a bridge section 13d is broken and the plate section 13c moves in the detachment direction of the center hub 13, the engagement part 13g of the plate 13e is engaged with the shoulder 13f of the boss section 13a, whereby the plate section 13c and the boss section 13a are engaged and coupled with each other while interrupting the torque transmission. Accordingly, even if the bridge section 13d is broken, the boss section 13a as well as the plate section 13c side are prevented from being detached from a pulley 10.

Abstract: The invention relates to a deflection pulley (1), intended for a traction drive, which includes a rolling-contact bearing as well as a ring body (4). A securing screw (8) as well as a spacer sleeve (9) serve as retaining elements.

Abstract: An engine accessory belt drive includes a self-aligning pulley assembly including a relatively stationary outer assembly and a universally pivotable inner assembly supported by the outer assembly and able to be locked in position by tightening of a fastener. During alignment of the self-aligning pulley with the belt, the fastener is maintained in the loose position, allowing limited universal pivoting of the rotational axis of the pulley as a result of belt tension forces which act to align the pulley. After the pulley is aligned, the fastener is tightened to fix the rotational axis of the pulley and the inner assembly in the aligned position of the pulley. Features of the inner and outer assemblies of the pulley assembly are also described.

Abstract: Plural auxiliary devices such as a water pump and a generator coupled to a serpentine belt-drive system are driven by an internal combustion engine mounted on an automobile vehicle. The generator is divided into a first generator having a pulley in which a one-way clutch is installed and a second generator having a usual solid pulley. Fluctuations in the belt tension caused by changes in instantaneous rotational speed of the internal combustion engine are suppressed or reduced by the one-way clutch installed in the pulley of the first generator. An inertia torque of a rotor of the first generator may be made higher than that of the second generator because effects of the inertia torque on the belt tension fluctuations are alleviated by the one-way clutch.

Abstract: A radial ball bearing 14 of the three point contact type or four point contact type is used for the rolling bearing for a compressor pulley. The offset amount &dgr;, that is the axial distance between the center &agr; of the radial load applied to the follower pulley 4 from the endless belt 11, and the center &bgr; of the radial ball bearing 14 is 40% or less of the diameter of the pitch circle. In addition, the radial clearance of the radial ball bearing 14 is 0.2% or less of the diameter of the pitch circle. With this construction, the durability of the rolling bearing to support the follower pulley 4 is secured while made compact.

Abstract: A ball bearing for a pulley that is a component of a wrapping connector transmission device installed to an engine for an automobile. In the bearing, the depths of ball grooves formed in the inner ring and the outer ring of the ball bearing are set so that the risk rate of the ball being stranded on the shoulder becomes approximately the same for the inner ring and the outer ring under pure thrust load. Furthermore, the depth of the ball groove of the outer ring is set shallower than the depth of the ball groove of the inner ring. The depth of the ball groove of the outer ring is set in a range of 12-19% of the diameter of the ball.

Abstract: The rotation transmitting device comprises a pulley connected to a shaft so as not to rotate relatively, and a supporter for supporting the pulley rotatably through a bearing. The bearing 26 is incorporated into the pulley such that the fitting position of the bearing becomes inside both end edges of the outer periphery of the pulley in the direction of the rotation axis of the pulley.

Abstract: A decoupler for an alternator pulley in a serpentine drive system has a resilient, helical spring member that couples the alternator pulley with a hub structure through a spring retaining member. A bushing is disposed between the spring retaining member and the hub structure to facilitate sliding engagement therebetween. An annular sleeve member is disposed between the spring member and the alternator pulley to facilitate sliding engagement therebetween. The spring member is connected at one end thereof to the hub structure and connected at an opposite end thereof to the spring retaining member. The resilient spring member transmits the driven rotational movements of the alternator pulley by the serpentine belt to the hub structure such that the alternator shaft is rotated in the same direction as the alternator pulley while being capable of instantaneous relative resilient movements in opposite directions with respect to the alternator pulley during the driven rotational movement.

Abstract: Chain guides for the front sprockets of bicycles are disclosed. More particularly, the chain guides are adapted or configured for bicycles that have multiple (usually 2 or 3) sprockets/chain rings mounted to the crank assembly. The setup is provided to freely allow shifting between the gears. All of the chain guide variations presented are provided with an outer flange attached to a roller section so that these portions roll together with the chain they restrain. Additional optional features include aspects to do with roller positioning, bracket mounting, roller configuration and supplemental chain restrain means (including a stop/post member and inner roller flange.

Abstract: The invention is an improved locked-center idler of the type having a pulley supported by a bearing. The bearing is mounted upon a tension adjusting member. It is improved by the tension adjusting member being in communication with a dual function fastener.

Abstract: In a fixing structure of a pulley unit in which the pulley unit is attached to a part from which a rotary shaft that is inserted into and is rotatably supported by a central hole of a housing protrudes in a state where the rotary shaft is protruded from an end face of the housing, a housing side end portion of the pulley unit is inserted into an opening side area in the central hole of the housing so that an outer peripheral face of the housing side end portion of the pulley unit overlays an inner peripheral face of the opening side area in the central hole of the housing in a shaft center direction.

Abstract: A power transmitting mechanism transmits power from an engine to a drive shaft of a compressor. A pulley is supported by the compressor and is coupled to the engine. A hub is attached to the drive shaft. Rollers are located on the pulley. Elastic transmission arms are located between the pulley and the hub. The distal end of each arm is curved, and the proximal end is coupled to the hub. When the rollers are engaged with the arms, power is transmitted between the pulley and the hub. When, due to excessive torque, the rollers escape from the corresponding arm, power transmission between the pulley and the hub is disconnected. The distal ends of the arms are movable in the radial direction. When the rollers disengage from the corresponding arms, the distal ends of the arms move radially such that the pulley and the hub relatively rotate without interference by the arms.

Abstract: A radial ball bearing 14 of the three point contact type or four point contact type is used for the rolling bearing for a compressor pulley. The offset amount &dgr;, that is the axial distance between the center &agr; of the radial load applied to the follower pulley 4 from the endless belt 11, and the center &bgr; of the radial ball bearing 14 is 40% or less of the diameter of the pitch circle. In addition, the radial clearance of the radial ball bearing 14 is 0.2% or less of the diameter of the pitch circle. With this construction, the durability of the rolling bearing to support the follower pulley 4 is secured while made compact.

Abstract: The over-running clutch pulley of the preferred embodiments of the invention includes a sheave member defining a sheave input surface adapted to engage an input device, a hub member defining a hub output surface adapted to engage an output device, and a clutch cartridge. The clutch cartridge includes a sheave engagement sleeve coupled to a sheave cartridge surface of the sheave member, a hub attachment sleeve coupled to a hub cartridge surface of the hub member, and a coil spring having the first end attached to the hub attachment sleeve. The coil spring is adapted to engage the sheave engagement sleeve upon the acceleration of the sheave member in a first rotational direction relative to the hub member, and to disengage the sheave engagement sleeve upon the deceleration of the sheave member in the first rotational direction relative to the hub member.

Abstract: A torsionally flexible coupling has a hub ring (1) and a vibrationally isolated pulley (2) surrounding the hub ring (1) at a radial distance, a spring body (4) made of a rubber-elastic material being situated in the gap (3) formed by the distance, and comprises a sliding-contact bearing (5) for mutual support of the hub ring (1) and the pulley (2), the sliding-contact bearing (5) having a sliding-contact surface (6) on the side facing the hub ring (1) or the pulley (2), the sliding-contact surface having at least one elastically flexible projection (7) in the radial direction which comes in contact with the surface (8, 9) of the hub ring (1) or the pulley (2) under elastic prestress.

Abstract: A sprocket includes a bore for receiving a bearing, and a pair of protecting casings engaged onto the sides of the sprocket for shielding and protecting the bearing, and for preventing dirty particles or the other particles from engaging into the bearing to damage the bearing, and for increasing the working life of the bearing and the sprocket. The bearing includes an inner sleeve having an orifice, the casings each includes a hub secured in the orifice of the inner sleeve. The casings each includes a peripheral fence having a chamber for receiving grease.

Abstract: A pulley unit improved in the axial positioning of the cage of the one-way clutch is disclosed. The outer radius of the orbital portion of the inner rings of two rolling bearings disposed at both axial sides of the cage are designed to be larger than the inner radius of the cage, so that the axial movement of the cage is constrained. Due to this structure, the projecting and recessing portions disposed on the cage of the one-way clutch and on the inner ring become inutile, and these can be eliminated.

Abstract: A compressor includes a power transmission mechanism. The power transmission mechanism includes a shaft, and a first rotation member fixed to the shaft. The first rotation member includes a plurality of accommodation portions. The power transmission mechanism also includes a second rotation member rotatably arranged around the periphery of the first rotation member. The second rotation member has an inner surface facing the first rotation member, and the second rotation member includes a plurality of recessed hollows formed in the inner surface. The compressor further includes a plurality of balls. During operation, a first portion of each of the balls is positioned within a corresponding one of the accommodation portions, and a second portion of each of the balls is positioned within a corresponding one of the hollows, such that a rotational motion of the second rotation member is transmitted to the first rotation member via the balls.

Abstract: An insulative resin coating film 9 of the range of 10 to 40 &mgr;m thick is formed, by electrodeposition coating, on the outer surface of a pulley 2 inclusive of an outer surface 2E of the iron pulley 2 which is in sliding contact with a belt 3 and an inner surface 2I fit to a rotary shaft 4. With formation of the insulative resin coating film, an electrical resistance after 10 hours of the unit running is 1 M&OHgr; or larger. A static electricity caused by a friction between the pulley 2 and the belt 3 is −1 kV or lower. As a result, a potential difference between the rolling element and the race ring (outer ring or inner ring) is 1 V or lower.

Abstract: In this driving force transmission apparatus, with a simple constitution employing a one-way clutch 20 instead of an electromagnetic clutch, the driving force derived from the motor 33 can be transmitted to the rotating shaft 1 during engine stops, and the driving force of the engine can be transmitted to the rotating shaft 1 during engine operations. Also, the pulley 3 is held against the connecting portion 11 and the fixed-side member 26 by means of first and second two ball bearings 21, 30 disposed axially adjacent to first and second inner cylinder portions 6, 7, respectively, between which the opening portion 5 of the pulley 2 is interposed. This simple driving force transmission apparatus can switch between transmission and non-transmission of driving force from pulley to rotating shaft, and transmits the driving force of a motor directly to the rotating shaft in the non-transmission state.

Abstract: A fan idler pulley having a threaded hub for attaching a fan shaft. The pulley also comprises a receiving portion for engaging a bearing. The bearing is further engaged with a cup. The entire assembly is mounted by a pin press fit though the cup into a mounting surface such as an engine block or front cover. The pulley may be engaged to either the inner race or the outer race of the bearing.

Abstract: A device includes a power-transmission pulley rotatably mounted on an automotive accessory housing, a drive plate fixedly connected to a rotating shaft of the accessory, and shear pins which connect the pulley and the drive plate. The shear pins each have a notched portion and a flanged portion which is offset from the notched portion and which is sandwiched between the pulley and the drive plate. The diameter of shear-pin insertion holes formed in the drive plate is larger than the shear pins which are fixedly connected to the pulley. The shear pins are fixedly connected to the drive plate.

Abstract: A radial ball bearing 14 of the three point contact type or four point contact type is used for the rolling bearing for a compressor pulley. The offset amount &dgr;, that is the axial distance between the center &agr; of the radial load applied to the follower pulley 4 from the endless belt 11, and the center &bgr; of the radial ball bearing 14 is 40% or less of the diameter of the pitch circle. In addition, the radial clearance of the radial ball bearing 14 is 0.2% or less of the diameter of the pitch circle. With this construction, the durability of the rolling bearing to support the follower pulley 4 is secured while made compact.

Abstract: A power transmission device includes a driving rotary member, a driven rotary member fixed to one end of a rotary shaft of a driven device, a first intermediate friction member disposed between the driving rotary member and the driven rotary member, and a spring for pressing the driving rotary member against the first intermediate friction member, thereby pressing the first intermediate friction member against the driven rotary member. The driving rotary member is provided with at least one first concave segment, the driven rotary member is provided with at least one convex segment and at least one second concave segment, and the first intermediate friction member is provided with at least one lug. The at least one lug is adapted to engage the at least one first concave segment and to simultaneously abut the at least one convex segment.

Abstract: A pulley unit improved in axial positioning of a cage of a one-way clutch is provided. An outer radius of an orbital portion of inner rings of two rolling bearings disposed at both axial sides of the cage are designed to be larger than an inner radius of the cage, so that axial movement of the cage is constrained. Due to this structure, projecting and recessing portions disposed on the cage of the one-way clutch and on an inner ring become unnecessary and can be eliminated.

Abstract: In a motorized conveyor pulley of the type comprising a cylindrical pulley drum with axially opposite end plates enclosing an electric motor and drive transmission, the pair of end plates of the pulley are constructed with an increased axial thickness compared to prior art end plates and are supported on a pair of shaft ends by pairs of bearings and are sealed by a pair of lubricant seals between each pair of bearings. The enlarged end plates and the pairs of bearings resist bending loads exerted on the conveyor pulley by the conveyor belt and thereby reduce loading stresses on the motor and drive transmission contained in the pulley permitting more economical manufacture of the motor and drive transmission.

Abstract: A ball bearing for a pulley that is a component of a wrapping connector transmission device installed to an engine for an automobile. In the bearing, the depths of ball grooves formed in the inner ring and the outer ring of the ball bearing are set so that the risk rate of the ball being stranded on the shoulder becomes approximately the same for the inner ring and the outer ring under pure thrust load. Furthermore, the depth of the ball groove of the outer ring is set shallower than the depth of the ball groove of the inner ring. The depth of the ball groove of the outer ring is set in a range of 12-19% of the diameter of the ball.

Abstract: In a fixing structure of a pulley unit in which the pulley unit is attached to a part from which a rotary shaft that is inserted into and is rotatably supported by a central hole of a housing protrudes in a state where the rotary shaft is protruded from an end face of the housing, a housing side end portion of the pulley unit is inserted into an opening side area in the central hole of the housing so that an outer peripheral face of the housing side end portion of the pulley unit overlays an inner peripheral face of the opening side area in the central hole of the housing in a shaft center direction.

Abstract: A drive sprocket for an endless chain on a track-type undercarriage includes a toothed wheel having a plurality of circumferential teeth extending from a root circle. A pair of mounting rings fixed to opposite axial sides of the wheel support a respective pair of rotating rings by means of bearings, each rotating ring forming a tread having a diameter which is small than the diameter of the root circle. The endless chain has a plurality of links connected end-to-end, each link having a pair of spaced apart guide webs extending in the direction of travel and connected by a cog which engages between two adjacent teeth on the toothed wheel, each guide web being profiled to ride on one of the treads.

Abstract: An idler having a flexible member. The flexible member comprises a rubber or elastomeric material. The flexible member also defines a gas chamber. The spring rate of the flexible member is a function of the flexible material and the size of and pressure in the gas chamber. A belt or chain bearing surface of the flexible member bears upon a belt or chain trained between two pulleys. The flexible member is compressible in response to a preload caused as the idler is pressed against the chain or belt. The flexible member damps vibrations in the belt or chain during operation. This results in quieter operation of the idler/pulley system as well as increases the operating life of the belt.

Abstract: The invention comprises an idler pulley, having a web and a belt bearing surface connected to the web. The web is aligned with and affixed to an inner race outer surface of a bearing by a fastener. The pulley is stamped, formed or spun out of sheet metal and may have a central hole described by a lip for alignment with a central axis of the bearing. The outer race of the bearing may be affixed to a mounting surface.

Abstract: The combination comprising, a bearing housed in a belt pulley, a sealing disk covering the bearing clamped between the head of a screw and the inner ring of the roller bearing, means attaching said sealing disk 4 directly to the inner ring axially and radially and including projections 13, 14 extending into the bore of the inner ring to secure the screw 3 for transport.

Abstract: An object of the present invention, in an idler pulley having a pulley main body formed of steel sheet, is to prevent the pulley main body and the outer ring of a bearing from creeping and the pulley main body from slipping off. An idler pulley according to the invention comprises a pulley main body adapted to have a belt entrained therearound, a ball bearing fitted in the pulley main body, and a shaft member fitted in the inner ring of the ball bearing, wherein a layer of a soft metal whose Young's modulus is lower than those of the pulley main body and the outer ring of the bearing is interposed between the inner surface of the pulley main body of steel sheet and the outer surface of the outer ring of the bearing.