Abstract: When an inner race (12) rotates at a speed lower than a predetermined speed, a sealing body (27) contacts the sealingface part (21c), but when the inner race (12) rotates at a speed more than the predetermined speed, a contacting pressure to a sealing face part (21c) is reduced or the sealing body (27) is isolated so as to form a non-contacting seal, and therefore, for example, at the low speed, the sealing body (27) forms a contacting seal, thereby to compensate a low speed-low sealing ability of the non-contacting seal such as the labyrinth seal, and on the other hand, at high speed rotation, the sealing body (27) reduces the contacting pressure to the sealing face part (21c), and otherwise separates therefrom to form the non-contacting seal as the labyrinth seal, whereby it is possible to solve the problem of heating or abrasion at the contacting part.

Abstract: A sealing device equipped with a lip made of a rubber material composition wherein the rubber material composition comprises 100 parts by weight of a tetrafluoroethylene-propylene copolymer and 0.02 to 10 parts by weight of an ethylene-propylene-based copolymer is described, by which a long life sealing device that is not deteriorated even when used under an environment where chemicals such as a cutting lubricant containing an additive adversely affecting rubbers contact the sealing device is provided.

Abstract: A bearing and seal assembly for supporting and sealing end portions of a rotatable paddle shaft in the end walls of a mortar mixer or the like. Each bearing and seal assembly includes a bearing and seal housing removably attached to an end wall of the mixer drum by bolts to facilitate replacement of the bearings and seals as becomes necessary during use. The outside wall of the housing includes a peripheral ring or shoulder for engagement with a conventional bearing puller to facilitate removal of the housing, bearings and seals as a single unit. Preassembled housing, bearing and seal units can then be used as replacements. The bearings and seals are also spaced longitudinally to provide a space for abrasive materials that may migrate past the seals to extend the life expectancy of the bearings by decreasing exposure to contamination.

Abstract: A screw actuator comprises a screw (1) and a nut (2) which are each provided with at least a helical groove (3,4), and a series of rollers or balls (5) which are in rolling contact with the grooves (3,4). A sleeve (6) is provided which surrounds the nut (2) at least partly. The sleeve (6) may carry a seal (7) which acts between the nut (2) and screw (1); e.g. a wiper seal. The seal (7) may be fixedly connected to the nut (2), and frictionally engage the screw (1).

Abstract: The present invention relates to an assembly comprising:

Abstract: A double seal bearing includes a labyrinth seal mechanism. The double seal bearing is provided with a pair of annular inner and outer sealing plates having respective central openings with a remaining slight clearance between each respective sealing plate and one of the inner and outer races, respectively, so as to assure the labyrinth seal function.

Abstract: An anti-wrap guard system for shielding an exposed bearing assembly of an agricultural apparatus from any material borne by a rotatable shaft that in the course of operating the apparatus may naturally come in contact with the exposed bearing including a guard being disposable between a working section of the rotatable shaft and the bearing assembly supporting the shaft, the guard substantially blocking the material from the bearing. A windrow merger and a method of guarding are further included.

Abstract: Rolling contact bearing (1) which comprises an outer race (2), and a series of rolling bodies (4) which are arranged between the two races (2, 3), and at least one sealing covering (5) arranged laterally to the rolling bodies (4) and between the two races (2, 3); the rolling contact bearing (1)* being characterised by the fact that it also comprises at least one extra shield (15) which is integral to the inner race (3) and which is arranged laterally to increase the sealing capacity of the covering (5) itself.

Abstract: The damper assembly includes a centering spring about a bearing for a rotating shaft. The centering spring is fixed to and spaced from a fixed component. One or more annular arrays of brush bristles project from the fixed component and have tips in engagement with the non-rotating, radially and orbitally movable centering spring. With the brush bristles engaging the centering spring, the vibrations and dynamic loadings of the shaft on the bearing and centering spring are damped.

Abstract: An inner ring of a bearing for placement over a shaft having a first end with a series of finger extensions and a series of slots between the extensions, the inner ring further including finger extension slot seals positioned within the slots and a finger extension seal positioned on the outer diameter of the extensions.

Abstract: A technique is provided for securing seal to inner and outer rings of a bearing assembly. The rings present interface surfaces which may include annular grooves. The seals and rings are positioned within specialized tooling, and a portion of each seal is plastically deformed to secure the seals to the receiving rings. One or both rings may receive a seal, and the seals may include features, such as elastomeric sealing members, which cooperate to isolate interior regions of the bearing assembly from the surrounding environment.

Abstract: A sealing assembly for a bearing assembly. The sealing system comprising a removable cover and a rotatable member. The bearing assembly also comprising a bearing insert and a bearing housing. The removable cover is securable to the bearing housing. The rotatable member is secured to the removable cover. The rotatable member has an opening for a rotatable shaft to pass into the bearing assembly through the rotatable member. The opening through the rotatable member is adapted to receive the rotatable shaft and to form a seal against the rotatable shaft.

Abstract: An environment-friendly rolling bearing is proposed in which at least one of inner ring, outer ring, rolling elements, seals and retainer is formed of a biodegradable material.

Abstract: Sealing device for a flanged bearing for a wheel hub in which the flanged ends (13) of the outer race (11) have the metallic rings (14) of a sealing device (15) pressed on to their internal surfaces; each metallic ring (14) incorporates a rubber element (16) which is suitable for forming a static seal on the outer race of the bearing; the rubber element (16) extends towards the inner race (10) of the bearing (12) to then bend back towards the outside of the bearing itself with an appendix (17), which forms two seals (18 and 19) on the internal surface of a second metallic ring (20); the latter is pressed on to the external surface of the inner race (10) of the bearing; a rubber element (21) is applied to the ring (20) in correspondence with its free end (22) which is axially turned towards the inside of the device; the rubber element (22) presents at least two lips (24 and 25), one of which creates a dynamic seal between the two races (10 and 11) of the bearing together with the above-mentioned lips (24 and 2

Abstract: A steering knuckle is supported on a road wheel of an automotive vehicle by a hub assembly which includes a housing fitted into a bore in the knuckle and hub having a flange to which the road wheel is attached and also a spindle which projects from the flange into the housing. The bearing has cones which fit over the spindle between a shoulder on the hub flange and an integrally formed abutment on the other end of the spindle. The ends of the bearing contain seals which exclude contaminants from the interior of the bearing. A slinger is fitted to the spindle and may be captured between the cone at the inboard end of the bearing and the abutment. The slinger extends outwardly past the spindle abutment and seal at the inboard end of the bearing and has a circular peripheral edge which lies close to the surface of the bore in the steering knuckle, thus providing an additional barrier to exclude contaminants from the bearing.

Abstract: A bearing assembly has a sleeve, a first ball-receiving chain enclosing the sleeve, a second ball-receiving chain enclosing the sleeve, the first ball-receiving chain engaging with the second ball-receiving chain, a collar, a first gasket, a second gasket, a first rubber washer, and a second rubber washer. The first gasket, the sleeve, and the second gasket are inserted in the collar. The first rubber washer encloses the sleeve. The second rubber washer encloses the sleeve. The first ball-receiving chain and the second ball-receiving chain receive a plurality of balls.

Abstract: The sealing members 14a, 14b comprise a film member produced by forming an aluminum or alumina deposition film on at least one side surface of a film-like core material. One side surface outer circumferential rim part of the sealing members is bonded and fixed on the outer end surface of outer rings 9, 9 constituting the rolling bearings 4, 4.

Abstract: A linear guide apparatus includes a slider, a guide rail opposing the slider with a clearance provided therebetween, a plurality of rolling elements which are rotatably interposed there between, and a contact seal device for sealing an opening of the clearance. A side seal member of the contact seal device is made of a rubber material composition containing fluoro rubber. The rubber basically comprises at least one of copolymers that are vinylidenefluoride-tetrafluoroethylene-polypropylene terpolymer and tetrafluoroethylene-polypropylene copolymer.

Abstract: A bearing assembly (10) comprising relatively rotatable structures (12, 14) and a bearing (16), the bearing (16) is configured to work in operative association with the relatively rotatable structures (12, 14) to enable relative rotation therebetween, the relatively rotatable structures (12, 14) co-operate to define a bearing chamber (34), wherein the bearing chamber (34) is further defined by means to vary the volume (20) of the bearing chamber (34) between a first volume and a second volume, the second volume being greater than the first volume.

Abstract: A steering knuckle is supported on a road wheel of an automotive vehicle by a hub assembly which includes a housing fitted into a bore in the knuckle and a hub having a flange to which the road wheel is attached and also a spindle which projects from the flange into the housing. The hub assembly also includes an antifriction bearing located between the spindle and the housing. The bearing has cones which fit over the spindle between a shoulder on the hub flange and an integrally formed abutment on the other end of the spindle. The ends of the bearing contain seals which exclude contaminants from the interior of the bearing. A slinger fits around the spindle where it is captured between the cone at the inboard end of the bearing and the abutment.

Abstract: A sealed rolling bearing in which a rolling member is disposed in a bearing space formed between an outer race and an inner race to rotate the outer race and the inner race relatively to each other, and rotation seal members are disposed at both ends of the bearing space in the axial direction thereof while a stationary seal member is disposed on the side of the inner race, thereby sealing the bearing space. The bearing is provided with a vent on the side of the inner race for approximating a fluid pressure in the bearing space to an outside fluid pressure by causing the inside of the bearing space to communicate with the outside when the state of fluid in the bearing space and state of the outside fluid have a predetermined relationship.

Abstract: As a grease to be enclosed in the portion in which a rolling bearing is installed, there is used a urea-based grease. An elastic material constituting a sealing plate is made of a vulcanizable fluororubber composition containing a vinylidene fluoride-tetrafluoroethylene-propylene terpolymer or tetrafluoroethylene-propylene bipolymer.

Abstract: A bearing unit comprising a bearing having an inner ring, an outer ring and a plurality of rolling elements arranged so as to be freely rotatable between the inner ring and the outer ring, and a sealing device arranged on axially opposite sides of the bearing, wherein the sealing device has a fixed ring spacer, a rotating ring spacer, and a non-contact seal section attached to the rotating ring spacer and extending towards the fixed ring spacer to be maintained in a non-contact condition with respect to the fixed ring spacer.

Abstract: A double seal bearing includes a labyrinth seal mechanism. The double seal bearing is provided with a pair of annular inner and outer sealing plates having respective central openings with a remaining slight clearance between each respective sealing plate and one of the inner and outer races, respectively, so as to assure the labyrinth seal function.

Abstract: An oil pump that can be reduced in weight and is excellent in wear resistance and easy to manufacture is provided. The oil pump includes an oil pump housing formed of aluminum alloy, and an inner rotor and an outer rotor that slide along the oil pump housing with contact kept therebetween to suck and discharge oil. Composite layers including porous metallic bodies are arranged at parts of the oil pump housing that contact the inner rotor and the outer rotor. Pores of the porous metallic bodies are impregnated with the aluminum alloy constituting the oil pump housing.

Abstract: A sealed rolling bearing comprising inner rings which can be divided in the axial direction and have a wall portion for defining part of a seal space therebetween, outer rings which can be divided in the axial direction to define a bearing space together with the inner rings between the outer rings and the inner rings, rolling elements provided in the bearing space, end face seal members provided at the opposite ends in the axial direction of the bearing space, respectively, and an intermediate seal member provided in the seal space, and the intermediate seal member comprising a seal body which can be eccentric due to centrifugal force during rotation, and a seal which comes into contact with the wall portion for defining the part of the seal space during halt.

Abstract: Rolling contact bearing (1) for an electric motor presenting an inner race (2) which revolves around a rotation axis (A) and which is suitable for being mounted on a drive shaft of the motor itself, an outer race (3) which is fixed coaxial to the inner race (2), a number of revolving elements (4) which are interposed between the two races (2, 3) and at least one sealing element (8), which is mounted onto one side of the rolling contact bearing (1), and which is integral to the fixed race (3) so that it at least partially closes a gap between the two races (2, 3); a protective shield (10) which is mounted on the same side as the sealing element (8) and which is integral to the revolving race (2), and which presents a first annular section (10) which projects towards the inside of the gap (L) and which radially overlaps the sealing element (8) in order to partially shield the sealing element (8) itself.

Abstract: A rotary shaft is inserted to a tank through a hole formed in a wall of the tank. A casing is provided outside the tank, and the rotary shaft is supported by a bearing arranged in the casing. The casing is watertightly connected to the wall including the hole through a flexible joint. Seal members are arranged in the casing to seal the clearance between the rotary shaft and the casing. A sleeve is fitted on the rotary shaft so that the sleeve is watertightly in contact with at least one of the seal members, and the sleeve can be moved along the rotary shaft to change the seal member in contact with the sleeve. The bearing and the seal member are not affected by the deformation of the tank since the flexible joint connects the tank and the casing, and the rotary shaft can rotate smoothly while securing high sealing quality. The alignment of the axes of the bearing and the hole in the tank can be easy since the bearing is provided outside of the tank, and thus assembly and maintenance of the structure are easy.

Abstract: A rolling bearing device comprises an outer ring 105 provided with an internal raceway 106 formed on its bore, an inner ring 101 provided with an external raceway 102 formed on its cylindrical exterior surface, at least one row of rolling bodies 111 arranged between the two raceways 102, 106 and at least one sealing member 121 secured to one of the rings. The sealing member 121 comprises an annular metal reinforcement 123. The device comprises a part 126 for connecting between the reinforcement 123 and the ring which supports it, the connecting part 126 being formed by a filler metal which, after melting and cooling, provides attachment, sealing and molds to the shapes of the said reinforcement and the said ring.

Abstract: A wheel end is provided where the spindle is an integral cast and machined trumpet-shaped arm made from high strength ductile iron, and a seal retainer is provided to locate and protect the inner wheel bearing and wheel end from debris. The trumpet-shaped arm is formed with a long parabolic radius machined with a reasonable surface finish to reduce or significantly eliminate stress concentrations. The mating cast iron seal retainer is employed to provide proper location for the inner wheel bearing and to transfer axial loads of the bearing to the spindle shoulder. In addition, the seal retainer retains the inner half of the seal face and provides a sealing surface to prevent escape of the axle wheel end oil. In this design, the outside diameter of the seal retainer is made to fit inside the wheel hub bore where it is protected from rocks, stumps, other debris, etc.

Abstract: Improved shield designs for ball bearing based spindle motors that exhibit improved containment of grease and the base oil within the bearings at accelerated conditions of temperature and speed is disclosed. Improved shield designs are provided at the shield OD contact area, the use of an impervious shield material, the use of barrier films, shield/bearing designs that use tortuous paths and labyrinth schemes for reducing the oil and grease loss from the shield ID gap of DASD spindle ball bearings, and improved stainless steel shield designs.

Abstract: A sealed rolling bearing in which a rolling member is disposed in a bearing space formed between an outer race and an inner race to rotate the outer race and the inner race relatively to each other, and rotation seal members are disposed at the both ends of the bearing space in the axial direction thereof while a stationary seal member is disposed on the side of the inner race, thereby sealing the bearing space. The bearing is provided with vent means on the side of the inner race for approximating a fluid pressure in the bearing space to an outside fluid pressure by causing the inside of the bearing space to communicate with the outer when the state of the fluid in the bearing space and state of the outside fluid become a predetermined relationship.

Abstract: A sealing device for a roll bearing which includes an outer ring, an inner ring, a rolling element rotatably interposed between the outer and inner rings, and a retainer, comprises a seal holder having a seal holder portion and a seal body attached to the seal holder portion. A portion of the retainer is received in a sealing space defined by the seal holder portion while the portion of the retainer is being disposed outside a range of interference with the seal holder portion. The sealing device further comprises conical surfaces 10 and 19 which are provided as fitting surfaces of a seal holder portion 9a and a seal body 17 fit to the seal holder portion 9a. Accordingly, a space 23 into which one end of a retainer of the bearing is receivable can be formed, and the inside diameter d of the seal holder portion 9a can be reduced.

Abstract: In a guiding device for mechanical members, which consists of two parts intended to engage by sliding friction, one of the two parts, called the smooth part, has a smooth, functional, i.e. friction, surface and the other part, called the pierced part, has at least one functional, i.e. friction, surface, including emergent cavities intended to accommodate a grease of the lubricating-paste type and especially an EP grease (extreme-pressure grease) comprising a soap-type constituent, an oil-type constituent and an extreme-pressure additive. The contact angle &thgr; between the functional surface of the smooth part and the grease is in the range from 20 degrees to 40 degrees and the material of the pierced part is such that the contact angle between the functional surface of the pierced part and the grease is in the range from 45 degrees to 75 degrees. The device may be of the slideway/runner type, shaft/bearing type, ball/socket joint type, etc.

Abstract: A sealable bearing race assembly including a first component and a second component cooperatively mateable with each other to yield a sealed bearing assembly. The first component has a first circular channel for accommodating a bearing structure such as a plurality of ball bearings, and flanked by a first lateral flat border and a first medial flat border. The first lateral flat border has a first biaser there behind for urging that border away from an underlying first support. The second component has a second circular channel alignable with the first channel, and is flanked by a second lateral flat border and a second medial flat border. The second medial flat border has a second biaser there behind for urging that border away from an underlying second support.

Abstract: A hub (4) for supporting a non-driven road wheel has a hole section formed to have an opening in the central portion at either end of the hub. A tone wheel (19) is fitted onto the shoulder portion of an inner ring (5) fixed to the axially inner end of the hub 4, and has a function to work as a seal member, such that the opening at the axially inner end of the hole (8, 63a) is covered. In addition, a cap (27) is fitted into the axially outer end of the hub (4) to cover the opening at the axially outer end of the hole (8, 63b).

Abstract: Apparatus for sealing bearing assemblies includes a first bearing with a first inner race, a second bearing with a second inner race, a shaft, the first and second inner races being juxtaposed on the shaft with their inner surfaces facing the shaft, thus forming a gap between opposing edges of the races, the opposing edges of the first and second inner races are beveled to form a deformation. The apparatus has an annular ring including a positioning member having an inwardly projecting edge for axially positioning the annular ring on the first and second inner races, and a seal for sealing the annular ring against the first and second inner races. The inwardly projecting edge of the positioning member engages the beveled opposing edges of the first and second inner races so that oil supplied between the shaft and the inner surfaces of the races is prevented from flowing through the gap.

Abstract: Shield designs for ball bearing based spindle motors that exhibit containment of grease and the base oil within the bearings at accelerated conditions of temperature and speed are provided at the shield OD contact area, the use of an impervious shield material, the use of barrier films, shield/bearing designs that use tortuous paths and labyrinth schemes for reducing the oil and grease loss from the shield ID gap of DASD spindle ball bearings, and stainless steel shield designs.

Abstract: A rolling contact bearing has a rotating unit to be integrally assembled to a rotating race (11) of the bearing, comprised of a first metallic annular insert (19) which forms a substantially disc-shaped radial wall (22) and a non-rotating unit to be integrally assembled to the non-rotating race (10) of the bearing, comprised of a second metallic annular insert (15) which has a sealing covering (14) with at least one sealing lip (18) suitable for sliding against the axially inner side of the disc-shaped wall (22); the rotating unit forms at least one substantially radial rotating surface (25) of a given minimum diameter (DR) and the non-rotating unit forms at least one substantially radial non-rotating surface (25) with a maximum diameter (DS) lesser than the minimum diameter, where the units are reciprocally positioned in such a way that the rotating surface (25) is facing the non-rotating surface (23a) from an inner axial position to form an axial stop for the non-rotating surface (23a), so as to provisional

Abstract: A bearing assembly that avoids excess grease yet provides additional oil as needed from one or more reservoirs in one or more shields mounted on the assembly.

Abstract: A rolling bearing having an inner ring, an outer ring, and a plurality of rolling elements between the rings. A seal is mounted in the annular space between the rings comprising a flat disk (6), mounted to one of the bearing rings made of a material with good electrical conductivity. An annular member (9), attached to the other bearing ring whereby the seal functions as a current bridge to carry away electrical current according between the two bearing rings.

Abstract: A bearing assembly for mounting on a journal at the end of a shaft employs a seal wear ring disposed between the backing ring and the end face of the axially inwardly directed bearing cone, with the outer cylindrical surface of the seal wear ring cooperating with a resilient sealing element for sealing the bearing. The inner diameter of the seal wear ring is greater than the diameter of the shaft journal to provide a clearance there between along the full length of the wear ring. Counterbores are provided in an outwardly directed surface of the backing ring and in the axially inwardly directed end face of the bearing cone, with the counterbores in the backing ring and bearing cone being dimensioned to provide an interference fit sufficient to provide a substantial radially compressive load in the ends of the seal wear ring upon assembly of the bearing.

Abstract: A bearing seal assembly for an oscillating actuator, comprises an outer bearing raceway, an inner bearing raceway mounted concentric with the outer raceway, and an annular deformable liquid impermeable membrane having an axial length of not more than one tenth the radius thereof, an inner peripheral edge sealingly secured to the inner bearing raceway, and an outer peripheral edge sealingly secured to the outer raceway for enabling limited relative rotation between the inner raceway and the outer raceway with minimum axial distortion of said membrane. In one embodiment, the membrane is stretched to eliminate surface distortion under torsional stress. Another embodiment illustrates waves molded into the membrane for reducing torsional forces.

Abstract: A rolling contact bearing is described with a sealing device suitable to discharge the electrostatic currents which accumulate in a autovehicle; the sealing device (13, 32) has at least one sealing element (17, 37, 43) made of elastic conductive material integral with the stationary race (11) of the bearing and said sealing element engages, by sliding contact, a surface (21, 22, 40, 41, 33) integral with the rotating race (10, 35) of the bearing. The sealing element made of elastic conductive material (17, 37, 43) co-operates with the sealing device (13, 32) to form a hermetically sealed chamber (26, 24, 39, 44); said chamber contains electrically conductive grease and is placed between the outside environment and the bearing inner portions (14) which normally contain lubricant grease.

Abstract: A tension roll includes a rolling bearing protected by a sealing disk and having an outer ring possessing an end face and a bore surface, and an injection molded plastic roller shell arranged on the outer ring of the rolling bearing. The roller shell includes sections that are molded in one piece and cover the end face and the bore surface of the outer ring up to the sealing disk.

Abstract: The invention permits stacking of seals without possibility of the sticking of their synthetic rubber seal members to one another. Moreover, when assembling the seals to produce anti-friction bearings, the invention permits storing the seals as a stack in a stocker of an automatic assembler and, unlike the case of using silicon or like prior art anti-sticking material, substantially eliminates generation of fine particles or the like adversely affecting precision apparatuses and deteriorating the reliability thereof. In an anti-friction bearing comprising an inner ring (1), an outer ring (2), and rolling elements (3) provided between the inner and outer rings, a side gap between the inner and outer rings is closed by seals (4) of the invention, which each include a synthetic rubber seal member (6) and a surface active material (7) coated thereon.

Abstract: A bearing seal includes an annular body in sealing contact with the outer race of a bearing. The annular body includes a sealing resilient annular member fitted on a shield portion and projecting from the shield portion to contact in a sliding and sealing manner a sealing surface spaced apart from the bearing. The annular body is attachable to the outer race ring of the bearing by way of an annular bulge provided on the resilient member. The annular bulge is attachable by snap-action in a circumferential groove in the inner surface of the outer race ring of the bearing.

Abstract: In a structure for lubricating an oil seal interposed between a shaft and an outer circumferential member that surrounds the shaft, a bearing device provides: a shaft rotatable; an outer case surrounding the shaft and including a large-diameter portion, a medium-diameter portion, a small-diameter portion, and a contact portion connecting the medium-diameter portion and the small-diameter portion; a bearing assembly disposed in the large-diameter portion for supporting the shaft; an oil seal assembly interposed between the shaft and the outer case and contacting the medium-diameter portion and the contact portion; and a lubricant-containing member fitted to the oil seal assembly and molded plastically in an annular shape out of a resinous material containing a lubricant. The structure improved by the bearing device ensures satisfactory lubricating effects in a consistent manner.

Abstract: A low friction shielded bearing assembly for supporting a machine shaft, for example a spindle shaft of a food cutting machine, includes a rolling element radial and thrust bearing subassembly containing ball or roller elements supported between inner and outer relatively rotatable bearing races with seal elements for retaining lubricant within the bearing subassembly. A flanged, fretting and corrosion resistant sleeve is fixed within the inner race of the bearing subassembly with the flange of the sleeve shielding an adjacent bearing seal against direct impingement by sprayed cleaning fluids. The sleeve also transmits radial and thrust loads to the inner race. The bearing subassembly is retained within an annular retainer that is adjustably attached to a machine frame to permit adjustment of the location of the rotational axis of a shaft supported by the bearing and to permit adjustment of the bearing location axially along the shaft and relative to the machine frame.

Abstract: A wheel mount for a wheel comprises a spindle, a hub for surrounding the spindle and a bearing assembly interposed between the spindle and the hub. The spindle extends from an end of an axle of a vehicle and has a generally decreasing diameter from its proximal end to its distal end. The spindle is provided with a pair of lands near the ends of the spindle for receiving bearings, and has bearing retainers near the respective ends also, the distal retainer being removably attached. These inboard and outboard bearing retainers define an axial bearing space. The hub has a central aperture with an inboard land and an outboard land provided on an internal surface of the central aperture, also for receiving bearings. The bearing assembly comprises an inboard bearing and an outboard bearing in spaced apart relationship within the axial bearing space. The inboard bearing has an internal diameter larger than the internal diameter of the outboard bearing.