Abstract: There is provided a rotary seal capable of delaying a progress of corrosion of a steel-made member without increasing manufacturing cost even when a solution containing an electrolyte is present around a contact portion between a stainless steel-made member and the steel-made member. At least one of (i) a metal fitting portion A between a sleeve 2A of a stainless steel-made slinger 2 of a rotary seal 1A and an inner ring 12 that is a steel-made radially inner member, and (ii) an outside-air side surface of the slinger 2, which includes an outside-air side end portion of the fitting portion A, is provided with at least one of a silane-based adhesive layer containing powder of metal having a higher ionization tendency than iron, a thermosetting resin adhesive layer containing powder of metal having a higher ionization tendency than iron, and a coating film containing powder of metal having a higher ionization tendency than iron.

Abstract: A compressor includes a shell, a compression mechanism, a motor assembly, a driveshaft, and a bearing assembly. The driveshaft is drivingly engaged with the motor assembly and the compression mechanism for rotation about an axis and extends from a first end to a second end. The bearing assembly is disposed within the shell and supports the driveshaft for rotation. The bearing assembly includes a bracket, a hub, and a bushing. The bracket is coupled to the shell and includes an aperture. The hub is disposed within the aperture and defines a bore having a radially inwardly extending lip. The bushing includes a first portion and a second portion. The second portion of the bushing includes a plurality of radially extending engagement features. The second portion of the bushing is disposed within the bore of the hub such that the engagement features engage the lip of the hub.

Abstract: The invention relates to an assembly (1) comprising a first component (2) with an internal toothing (4) and a second component (3) with an external toothing (6), wherein the two components (2, 3) can be connected to one another by a press fit, which is formed between the internal and the external toothing (4, 6), and wherein the internal and the external toothing (4, 6) each comprise a plurality of teeth (5, 7). The teeth (5) of the internal toothing (4) of the first component (2) and/or the teeth (7) of the external toothing (6) of the second component (3) comprise recesses (13, 15) along the tooth flanks (12, 14).

Abstract: Embodiments disclosed herein relate to a steering apparatus for a vehicle. The embodiments provide a vehicular steering apparatus including: a shaft member having several outer axial grooves provided on an outer circumferential surface of a sliding section; a first outer member having a hollow shape, wherein the first outer member has first serration portions axially formed on an outer circumferential surface of thereof and several inner axial grooves formed on an inner circumferential surface thereof to correspond to the outer axial grooves of the shaft member; and a second outer member having a hollow shape, wherein the second outer member has second serration portions axially provided on an inner circumferential surface thereof to correspond to the first serration portions of the first outer member.

Abstract: In a fixed type constant velocity universal joint according to the present invention, six torque transmitting ball tracks (20) are defined as a first track, a second track, a third track, a fourth track, a fifth track, and a sixth track along a circumferential direction. Further, in the fixed type constant velocity universal joint according to the present invention, an axial offset amount of a curvature center of each of track grooves (12) of an outer joint member (13) and an axial offset amount of a curvature center of each of track grooves (15) of an inner joint member (16) are set to 0. Further, in the fixed type constant velocity universal joint according to the present invention, the track grooves (12) of the outer joint member (13) and the track grooves (15) of the inner joint member (16) are each inclined with respect to an axis line.

Abstract: A pinion flange having built-in dampening is disclosed. The pinion flange includes at least one opening through which a ring-shaped damper extends. A ring-shaped support member fits within the opening such that the damper is between the edge surface of the opening in the flange and the support member. A mechanical fastener extends through the opening to connect the pinion flange to other components of the vehicle driveline.

Abstract: An air venting system for a constant velocity joint (20) having an inner race (24), an outer race (22), a cage (26), a plurality of torque transferring elements (28), a drive sleeve, a drive nut and a boot assembly. The outer race has a wall portion (90) having a vent hole (88, 242) with a first and a second axially extending channel (224, 264). A radially extending wall integrally connects the second axially extending channel to the first axially extending channel. A valve (256) having a stopper portion (264), a disk portion (258) and a breather portion (260) is at least partially located within the vent hole. The breather portion (260) further includes an axially extending ring (292) that terminates in a radially extending wall. At least a portion (300) of an edge portion of the radially extending wall of the breather portion of the valve is in direct contact with at least a portion (250) of an outer surface of the wall portion of the outer race.

Abstract: A frictional engagement element includes: a first piston, a second piston, a first urging member for urging the first piston in a direction of releasing a friction plate, and a second urging member for urging the second piston in the direction of releasing the friction plate with an urging force larger than the urging force of the first urging member. One of the first and second pistons has a communicating hole for connecting an engaging hydraulic chamber with an opposite hydraulic chamber and the other of the first and second pistons has a valve part for closing the communicating hole. The difference in travel distance between the first and second pistons in motion due to the different urging forces of the first and second urging members causes the valve part to open the communicating hole.

Abstract: A rear axle drive (2) for an AWD vehicle is presented. The rear axle drive (2) is connected to an hydraulic AWD coupling (3), wherein the rear axle drive (2) comprises a lubrication valve (4) for controlling the level of lubricant in at least one lubricant reservoir (6, 7) of the rear axle drive (2) for providing lubricant to gears and/or bearings of the rear axle drive (2). The lubrication valve (4) is functionally connected to a shut-off valve (5) of the AWD coupling (3) and the lubrication valve (4) of the rear axle drive (3) is controlled by movement of an actuating member (51, 54) of the AWD coupling (3).

Abstract: An axially actuatable positive engagement clutch which includes an input shaft with an input toothing and an output shaft with an output toothing. An axially displaceable connection element can occupy a meshing position which is located in an actuation path (s) between the open position and the closed position and in which the driving toothing engages with the input toothing or the output toothing for the first time during the transition from the open position into the closed position. An actuation device is configured to displace the connection element from the closed position to the open position, and an elastic return element which applies a restoring force to the connection element in direction of the closed position. The return element has a force/deflection characteristic with a local force maximum (F1) which coincides in the actuation path (s) at least approximately with the meshing position of the connection element.

Abstract: A switchable linear actuator device and an overrunning, non-friction, radial coupling and control assembly using the device are provided. The device has magnetic sources which produce corresponding magnetic fields to create net translational forces. The device includes a first and locking members and a stator structure including a first and second electromagnetic sources configured to create first and second electronically-switched magnetic fields, respectively. A translator structure includes first and second cams having contour surfaces and a magnetically-latching, permanent magnetic source magnetically coupled to the stator structure across a radial air gap.

Abstract: A locking-type reverse input blocking clutch includes an unlocking piece having unlocking portions for unlocking an output-side member. The portion of the unlocking piece other than the unlocking portions (i.e., its longitudinally central portion and intermediate portions) is inserted in a recess formed in an inner ring of the output-side member so as to open to the end surface of the inner ring to which torque is applied, and open to the outer periphery of the inner ring so that the entire unlocking piece is located axially within the output-side member. This clutch is thus small in axial dimension, and compact in entire size.

Abstract: The present invention relates to a freewheel (20) comprising a first race (22), a second race (24) rotatable relative to the first race (22) in a first direction of rotation (70), and clamping elements (32) between the first and second race (22, 24) which are in rotary driving connection with the first race (22), wherein, in a second direction of rotation (72) opposite the first direction of rotation (70), the second race (24) is coupled in a rotary entrainment way to the first race (22) in a relative rotation position via at least one of the clamping elements (32). The at least one clamping element (32) is displaceable in axial direction (6) from an initial position into a disengagement position by changing the relative rotational position between the first and second race (22, 24).

Abstract: A clutch device transmits a torque between a rotatable drive-input element and a rotatable drive-output element. Upon demand, the elements are coupled in non-positively locking fashion by a clutch element. Each of the drive-input element and the drive-output element form one clutch surface. A clutch gap decreases in a radial direction relative to at least one axis of rotation of the elements. The clutch element can be placed into a first position and into a second position which differ with regard to the radial position within the clutch gap and thus with regard to the contact pressure between the clutch element and the clutch surfaces. The clutch device permits an axial arrangement of its components, namely, the drive-input element, the clutch elements and the drive-output element, that keeps the size of a clutch device small in a radial direction relative to the axes of rotation.

Abstract: A control device and method are configured to actuate a clutch between a drive unit and at least one driven wheel of a motor vehicle, particularly a passenger car. The control device at least partially engages the clutch differently in dependence on a distance of the motor vehicle from an environment and/or a change of this distance.

Abstract: A method for learning a touch point of a transmission is disclosed. The method may include: moving a sleeve of a synchronizing device in a shift stage gear direction and calculating a predicted rotation speed based on an initial rotation speed and a rotation speed change rate of a transmission clutch; positioning a first point when a difference between an actual rotation speed and the predicted rotation speed occurs and positioning a second point when a difference value between the actual rotation speed and the predicted rotation speed reaches a set speed; calculating a determination time by subtracting a second time to move the sleeve from the first point to the second point from a first time to move the sleeve from the first point to a pre-stored touch point; and performing a correction and control on the touch point based on the determination time.

Abstract: A brake pad for a heavy vehicle disc brake. The brake pad may include a layer of friction material and first and second resilient arms. The first and second resilient arms may be arranged to contact first and second corresponding pad abutment structures to urge the brake pad away from a rotor when the brake pad is urged towards the rotor during application of the brake.

Abstract: A brake pad, a disc brake, and a method of fitting a brake pad. At least one of a first brake pad and a second brake pad and corresponding support structures may have complementary profiles on circumferential faces thereof arranged so as to permit the brake pad to be inserted into a corresponding support structure in a transverse direction of the brake pad and at an angle to a circumferential direction of the support structure.

Abstract: A brake pad for a heavy vehicle disc brake and a disc brake. The brake pad defines a first and second circumferential surfaces. A first spring forms at least part of the first circumferential surface and is arranged to contact the first circumferential pad abutment surface and urge the brake pad, in use, towards the second circumferential pad abutment surface.

Abstract: The invention relates to a disk brake for a utility vehicle, comprising a brake caliper, which extends over a brake disk and which is slidably held on at least one guide bar, which is connected to a stationary brake bracket by means of a screw, wherein the screw is fed through the guide bar, is designed in such a way that the guide bar has impressing elements, which are formed on the end face of the guide bar that lies against the brake bracket, at least in a circumferential and/or radial partial region, which impressing elements engage into the brake bracket in an impressed manner in such a way that an interlocking connection and/or a frictional connection is formed.

Abstract: A brake component positioning assembly that is removably connectable to a component of a heavy-duty vehicle. The brake component positioning assembly enables a brake system component to be positioned away from a wheel end of the heavy-duty vehicle to allow removal or servicing of at least one component of a wheel end assembly or the vehicle brake system. In one embodiment, the brake component positioning assembly includes a base block disposed in a cutout of a torque plate. A positioning block slidably engages one or more guide pins received by or disposed through the base block. A positioning bolt threadably engages the positioning block, whereby upon rotation of the positioning bolt, the positioning block and brake system component are positioned away from the bottom block and wheel end. Components of the brake component positioning assembly can be removably connected to each other.

Abstract: A backplate for a brake pad of a disc brake, a brake pad that includes the backplate, and the method of manufacturing the backplate. The backplate may have a rear wall that may have an outer surface and a stiffening rib formed on the outer surface of the rear wall.

Abstract: A railway brake lining includes one or more primary friction members, one or more secondary friction members, and a base plate. Each of the primary friction members is elastically fastened to the base plate. Each of the secondary friction members is fixed on the base plate. A minimum distance between the friction members and a center of an axle is denoted by r1, and a maximum distance between the friction members and the center of the axle is denoted by r2. The centers of one or more of the primary friction members are located in an area that is at a distance of {r1+(r2?r1)/3} to {r1+2×(r2?r1)/3} from the center of the axle. The total slide contact area T1 of the primary friction members and the total slide contact area T2 of the secondary friction members satisfy 2/25?T2/(T1+T2).

Abstract: A brake lining arrangement, in particular for a disk brake of a motor vehicle, has a rear plate and a friction lining that is connected to the rear plate. The rear plate has a bearing face on which the friction lining is placed. The rear plate also has a member configured for fastening the friction lining on the bearing face. The friction lining has at least one cutout that is configured as a blind bore. At least one connecting pin is arranged fixedly on the rear plate so as to project from the bearing face. The connecting pin is configured to engage at least substantially without play into the cutout.

Abstract: Vibration isolator systems have continuous frameworks wherein the frameworks are formed for specific applications. The continuous frameworks have linkages and voids formed and located such that frequency, direction and magnitude of vibrations are accounted for. The linkages and voids configuration provides elasticity and compliance such that a wide selection of materials is available for effective use. The continuous framework can be configured to include active elements such as a control circuit. The active elements may further include electric and magnetic field generators. Further, elastic and insulating materials can be easily added to the framework.

Abstract: A strut assembly including a first cylinder, a second cylinder configured to reciprocally move within the first cylinder, and a damper assembly positioned within the first cylinder. The damper assembly includes a housing having opposing first and second ends, a floating piston in the housing and a damper piston positioned between the floating piston and the first end of the housing. The damper piston divides the housing into first and second chambers, where the first and second chambers include a hydraulic fluid that provides resistance to the movement of the damper piston in the housing. The strut assembly also includes a gas spring in the first and second cylinders, where the gas spring includes a pressurized gas contained within the first and second cylinders.

Abstract: Methods, systems, and devices are described for isolating a crystal oscillator assembly from shock and/or vibration inputs. A system may include one or more vibration isolators coupled between the crystal oscillator assembly and the base structure, and each of the vibration isolators may include a spring material layer and a damping material layer. The spring material layer may provide a spring force between the crystal oscillator assembly and the base structure. The damping material layer may be adhered to at least one side of the spring material layer, and may provide a damping force between the crystal oscillator assembly and the base structure. Some vibration isolators may further include a constraint layer adhered to the damping material layer, such that the damping material layer is coupled between the constraint layer and the spring material layer.

Abstract: Housing has first and second parallel tubular chambers. The first chamber contains a gas spring whose output shaft connects to a first piston of area A1. The second chamber contains a second piston of area A2<A1. Piston A2 connects to the device's output shaft. The housing has a valve block at one end with an internal port in fluid communication with the volumes of the two chambers that are between the first and second pistons and the valve block containing an incompressible fluid. A spring-biased poppet valve is contained in the internal port. The poppet includes a flow restricting bore therethrough. A force on the output shaft causes the fluid to force open the poppet and displace the piston, A1, to store energy in the gas spring. Upon removal of the force on the device's output shaft, the gas spring pushes the fluid to close the poppet. Hence, only a low volume flow through the bore in the poppet is permitted to dampen output shaft movement.

Abstract: A torque rod, in which a front rubber and a rear rubber are respectively disposed at front and rear sides of a partition of a case fixed to a sub-frame and in which a pipe portion of a rod connected at a front end portion thereof to a power train passes through the front rubber, the partition, and the rear rubber and is coupled to an end plate, may include an attenuation device configured to cause flow of a liquid therein according to a load or vibration transferred from the rod, wherein the attenuation device is separably mounted between the rod and the end plate.

Abstract: A coupling assembly arranged between an input shaft and a rotor shaft of a supercharger includes a first hub, a second hub, a first side coupling assembly, a second side coupling assembly, a central hub and a plurality of coupler pins. The first hub is mounted for concurrent rotation with the input shaft. The second hub is mounted for concurrent rotation with the rotor shaft. The first side coupling assembly has a first side coupling body and a first side elastomeric insert. The first side coupling body includes an inboard body portion having a first series of pockets and an outboard body portion having a second series of pockets. The first side elastomeric insert has a first and second plurality of lobes. The pockets of the first and second series of pockets are tangentially offset relative to each other and each receive respective first and second plurality of lobes therein.

Abstract: A pendulum torsional-vibration reducing device includes: a rotor having a plurality of through-holes formed in the rotor with predetermined intervals in a circumferential direction of the rotor; a rolling element disposed in the through-holes so as to carry out pendular movement; and a casing fixed to the rotor so as to cover the rolling element, wherein the casing includes fixing pieces in tight contact with both side surfaces of the rotor so as to hold the rotor therebetween, and a thickness of the rotor at a position where the fixing pieces are in tight contact is thinner than a thickness of the rotor at a position where a rolling surface to which the rolling element is pushed by centrifugal force is formed.

Abstract: A rotary vibration reduction device for a motor vehicle for transmitting drive power from a drive machine to a drivetrain is provided. The vibration reduction device includes a primary and secondary connectors between the drive machine and drivetrain, and a coupling device between the primary connector and the secondary connector. The coupling device has a vibration reduction actuator with a piston chamber and has a piston element movable to generate a vibration reduction force in response to changes in working pressure in the piston chamber controlled by a pressure-generating device.

Abstract: A magnetorheological dampener for a transmission of a vehicle propulsion system of a vehicle includes a rotor connected to a rotatable shaft of the transmission, a housing defining a cavity in which a portion of the rotor is positioned, a magnetorheological fluid within the cavity of the housing and in contact with a surface of the rotor and a surface of the housing opposing the surface of the rotor, an electromagnetic coil adapted to generate a magnetic field within the magnetorheological fluid, and a controller that controls activation of the electromagnetic coil.

Abstract: The present invention extends to a carabiner intended for use as an adjustable anchor. In general, embodiments of the invention include a carabiner that includes a pinching mechanism. More specifically, some embodiments of the invention include a carabiner having a pinching mechanism that includes one of a slidable pin, a rotatable cam, or a pivotable block. Additionally, some embodiments of the invention include a rope, whereas other embodiments can be used with a rope supplied by a climber.

Abstract: In a wheel train mechanism, a first speed reduction gear, a second speed reduction gear, a third speed reduction gear, a fourth speed reduction gear and an output gear are all made of a resin material. The third speed reduction gear and the fourth speed reduction gear are disposed at a rear stage of the second speed reduction gear and made of a material having rigidity higher than that of the first speed reduction gear and the second speed reduction gear. The output gear is disposed at a rear stage of the fourth speed reduction gear and is made of a material having rigidity higher than that of the fourth speed reduction gear.

Abstract: A drive transmitter includes an internally toothed gear, a first support shaft to rotatably support the internally toothed gear without using a bearing, a drive source to apply a driving force to the internally toothed gear, a rotary body to which the driving force is transmitted via the internally toothed gear, and a grease retainer disposed on the first support shaft and to retain grease on at least one of a portion of the first support shaft facing the internally toothed gear and a portion of the internally toothed gear facing the first support shaft. An image forming apparatus includes the drive transmitter.

Abstract: A helical gear device includes: first and second helical gear respectively and rotatably disposed about first and third mutually parallel axes; a second helical gear meshing with the first and third helical gears so that a rotary motion is transmitted from the first to the third helical gear through the second, the second helical gear having a center bore; a support shaft disposed coaxially with a second axis parallel to the first, and extending through the center bore with a predetermined amount of radial play between the support shaft and the second helical gear, rotatably supporting the second helical gear. The second and third helical gears have a predetermined radial clearance in their reference meshing state in which their pitch circles contact. The radial clearance is smaller than a radial gap of a backlash between the second and third helical gears in the reference meshing state.

Abstract: An apparatus for an air turbine starter for an engine. The air turbine starter includes a housing defining an inlet, an outlet, and a flow path extending between the inlet and the outlet for communicating a flow of gas there through. A turbine member is journaled within the housing and disposed within the flow path for rotatably extracting mechanical power from the flow of gas and having a turbine output shaft. The air turbine starter further includes a planetary gear system drivingly coupled with the turbine output shaft and including a sun gear, a ring gear mounted to the housing, and a set of planetary gears operably coupling the sun gear and the ring gear with the sun gear is coupled to the turbine output shaft.

Abstract: Provided is a dual-clutch transmission, including a dual-clutch device 20; a first primary gear train 41 for transmitting power from a first input shaft 31 to a subsidiary shaft 34; a second primary gear train 42 for transmitting power from a second input shaft 32 to the subsidiary shaft 34; a plurality of output gear trains 51 to 53 rotatably provided on an output shaft 33; and a synchronization mechanism 60 for synchronously joining the output gear trains 51 to 53. Step ratios upon gear shifts performed by only clutch change are set to be smaller than step ratios upon gear shifts performed by both clutch change and gear change.

Abstract: A multi-speed transmission including a plurality of planetary gearsets and a plurality of selective couplers to achieve at least nine forward speed ratios is disclosed. The plurality of planetary gearsets may include a first planetary gearset, a second planetary gearset, a third planetary gearset, and a fourth planetary gearset. The plurality of selective couplers may include a number of clutches and a number of brakes. The multi-speed transmission may have four planetary gearsets and six selective couplers. The six selective couplers may include three clutches and three brakes or four clutches and two brakes.

Abstract: An object of the present invention is to provide a chain guide, which allows easy assembling of a guide shoe to a base member, and reliably prevents detachment of the guide shoe from the base member resulting from vibration or the like during the running of a chain. Provided is a chain guide wherein a base member includes an attachment extension extending upward from a base body part beyond a support surface, and a base-side engaged part formed in the attachment extension, a guide shoe includes a flexible extension extending from a shoe body part, and a shoe-side engaging part formed in the flexible extension, and the shoe-side engaging part is hooked to the base-side engaged part from below, or diagonally from below, or from front or back, to be positioned on the far side of the base-side engaged part during engagement therebetween.

Abstract: A continuously-variable transmission (CVT) assembly is employed for transmitting a torque from an external power-source. The CVT includes a variable-diameter input pulley and a variable-diameter output pulley, each having a respective range of adjustment. The CVT also includes a continuous torque-transmitting element extending between the variable-diameter input pulley and the variable-diameter output pulley, and thereby operatively connecting the input pulley to the output pulley. The CVT additionally includes a first elastic element having a first zero stiffness over the range of adjustment of the variable-diameter input pulley and configured to apply a first constant spring clamping force via the input pulley to the continuous torque-transmitting element.

Abstract: A plate link chain for a continuously variable transmission in a motor vehicle comprising chain links. The chain links have link plates coupled to one another by pairs of rocker pins and at least two different sprocket pitches. At least one absorption mass is arranged between two pairs of rocker pins in an absorption space within a link plate inner contour.

Abstract: A friction roller-type reduction gear includes a sun roller arranged concentrically with an input shaft, a ring roller having a stationary ring roller element and a moveable ring roller element, a plurality of intermediate rollers configured to be in rolling contact with an outer peripheral surface of the sun roller and an inner peripheral surface of the ring roller, a coupling part configured to couple the ring roller and the output shaft, and a loading cam mechanism having a cam ring and configured to change a contact surface pressure of each rolling contact surface. The outer peripheral surface of the sun roller is a concave curved surface of which a shape of an outer edge in an axial cross-section is a single circular arc-shaped concave curve, and an outer peripheral surface of the intermediate roller is a convex curved surface of which a shape of an outer edge in an axial cross-section is a single circular arc-shaped convex curve.

Abstract: A torque transfer mechanism includes an input member to receive an input torque from a propulsion source and an output member coupled to the input member to transfer the input torque to a driveline component. The torque transfer mechanism also includes a damping mechanism having at least one spring element to restrict relative rotation between the input member and the output member. wherein the at least one spring element defines a first spring rate corresponding to an initial range of travel that is less than a second spring rate corresponding to a subsequent range of travel.

Abstract: A curable adhesive applied between teeth of a gear rack forms a gear rack travel stop. The curable adhesive is applied between teeth of the gear rack in fluid form and cured to a solid form.

Abstract: A differential transmission having an epicyclic housing, a first sun gear in the epicyclic housing, a second sun gear also in the epicyclic housing and arranged on the same axis of revolution as the first sun gear, a planetary assembly revolves around the axis of revolution together with the epicyclic housing and couples the two sun gears such that they can rotate in opposite directions, and a coupling device in a receiving space defined between the sun gears for generating a bridging torque which couples the two sun gears in a frictional manner. The coupling device has a first coupling ring element supported via a conical surface against a first conical inner wall of the receiving space, and a second coupling ring element supported via a conical surface against a second conical inner wall of the receiving space, and a spring arrangement axially loads the two coupling ring elements such that they are pressed against the respective conical inner wall of the receiving space.

Abstract: In a strain wave gearing, the addendum tooth profile of an internal gear is defined by the formula a and that of an external gear is by the formula b at a principal cross-section located at a tooth-trace-direction center of the external gear, on the basis of a movement locus (Mc) of ?=1 by the teeth of the external gear with respect to those of the internal gear. It is possible to avoid superimposition of flexion-induced bending stresses and tensile stresses caused by load torque at the major-axis locations of the external gear, and the transmission torque capacity of a strain wave gearing can be improved.

Abstract: A bicycle sprocket is basically provided with a sprocket body and a plurality of chain-driving teeth. The sprocket body includes a central portion, an annular portion and an intermediate portion. The central portion has a first end surface disposed around a central opening on a side surface of the intermediate portion. The annular portion is disposed radially outward from the central portion. The intermediate portion extends between the central portion and the annular portion in a radial direction. The chain-driving teeth extend radially outward from the annular portion of the sprocket body to engage with a bicycle chain. The sprocket body includes a rib protruding from the side surface of the intermediate portion. The rib has a second end surface being axially outermost in the intermediate portion. The second end surface is farther away from the center plane than the first end surface in the axial direction.

Abstract: A gear box includes a casing, a gear that is accommodated in the casing and transmits the power of a motor, an output gear that is connected to the gear in the casing, and a collar that is externally inserted to the output shaft of the output gear and is rotatable relative to both the output shaft and the casing.