Abstract: An electrical machine has a rotatably supported rotor, at least one bearing for supporting the rotor in a hub, a spring element having an axially-acting spring force which acts on the bearing and also bearing against the hub with the spring force, the spring element being configured as a disc spring functionable back and forth across a flat position of the spring element, the spring element, in an outer region, bearing against an outer ring of the bearing and, in an inner region, bearing against a hub projection, the hub projection being substantially annular in shape and having a conical spring-support surface that declines outwardly in a radial direction.

Abstract: The invention relates to a securing device for a bearing ring in a housing. At least one spring element engages in an annular groove of the housing and at least one angled collar supports the bearing ring in an axial manner. The spring element is hook-shaped and forms an angle that extends in a radial manner towards the outside and at least partially back in the axial direction. At least one push element is formed on the securing device, which is actively connected to the spring element in such a manner that the spring element is prestressed in an axial manner, by actuating the push element.

Abstract: A rotation support device for a compressor pulley, wherein a three-point contact radial ball bearing (14b) is used as a rolling bearing for supporting a driven pulley, the cross sectional shape of an inner ring raceway track (19b) coming into contact, at one point, with the rolling contact surface of each ball (17a) is formed in a composite arc by smoothly and continuously connecting arcs with different radii of curvature R1 and R2 to each other, and the radius of curvature R1 on a center side in the width direction is made smaller and the radii of curvature R2 on the both end sides in the width direction are made larger (R1<R2) whereby the durability of the rolling bearing for supporting the driven pulley can be assured while reducing the size of the rolling bearing.

Abstract: An axial bearing having a radially inner 4 and a radially outer rolling-contact bearing 2, with the radially inner rolling-contact bearing 4 including an inner bearing ring 5 and a center bearing ring 3 and the radially outer rolling-contact bearing 2 including the center bearing ring 3 and an outer bearing ring 1 as well as a positive-drive element 6-10 for the center bearing ring 3.

Abstract: An improved bearing system is provided for use in high speed rotating machinery such as a turbocharger, wherein a turbocharger shaft is rotatably supported at opposite ends by a pair of angular contact bearings subjected to a predetermined and substantially constant thrust pre-load. The angular contact bearings are carried respectively within a pair of generally cylindrical bearing sleeves which cooperatively define an axially split bearing carrier mounted within a turbocharger housing. A spring reacts between these bearing sleeves for applying a substantially constant axial thrust pre-load transmitted by the bearing sleeves to the angular contact bearings. The mechanical spring thrust pre-load may be supplemented by an hydraulic axial thrust load attributable to oil circulated through the split bearing carrier.

Abstract: Instrumented rolling bearing device of the type including a non-rotating race, a rotating race, at least one row of rolling elements arranged between two raceways of the rotating and non-rotating races, and an assembly for detecting rotation parameters including a non-rotating sensor assembly and a rotating encoder, and an elastic member intended for axially prestressing the rolling bearing, retained axially on the sensor, the elastic member being of annular shape and having a diameter smaller than or equal to that of the outer race of the bearing, the elastic member including a supporting surface designed to be in contact with an element outside the bearing device in order to exert, directly or indirectly, by reaction, an axial force on the non-rotating race in a direction opposite to the detection assembly.

Abstract: To supply a pivot assembly for hard disk drive use that can reliably fix a seal member and solve the problem of out gas, thus reducing the expense and time incidental to the pre-load of a ball bearing. Ball bearings have been joined to both ends of a shaft, and on the outer circumference of these ball bearings, the spacer part is joined to a sleeve disposed between both ball bearings, and a seal member that covers the outer end of the ball bearing has been fixed to the outer circumference of the shaft by laser welding. Because the seal member is fixed by laser welding, the seal member can be reliably fixed and the problem of out gas from the seal member can be solved.

Abstract: In a wheel supporting rolling bearing unit, an inner end opening out of both end openings of a space in which balls 14, 14 are provided is sealed with a cap 17a. An outer end opening is sealed with a seal ring 16c having three seal lips. A rolling resistance that changes based on a preload is regulated in a range of 0.15 to 0.45 N·m, and a running resistance of the seal ring 16c based on a friction between the seal ring and a counter surface is regulated in a range of 0.03 to 0.2 N·m.

Abstract: The present invention relates to a bearing device for supporting a pinion shaft so as to freely rotate with respect to a case. The bearing device comprises a first tilt-contact rolling bearing provided on the connecting-flange-side outer peripheral surface of the pinion shaft and a second tilt-contact rolling bearing formed from an angular ball bearing provided on the pinion-gear-side outer peripheral surface of the pinion shaft, wherein lines of action of the first and second tilt-contact rolling bearings intersect with one another on an outer diameter side, the connecting-flange-side end portion of the first tilt-contact rolling bearing and the pinion-gear-side end portion of the second tilt-contact rolling bearing are respectively sealed with seal members, a sealed space between the seal members is infilled with grease, and the connecting flange is fastened in the pinion-gear direction to thereby preload the first and second tilt-contact rolling bearings.

Abstract: The invention relates to a roller bearing with preloading that comprises a first bearing ring, a second bearing ring and roller members disposed between these two parts, and at least one elastic element that is disposed on the first bearing ring or on a component connected to the first bearing ring and that exercises a preload force on the second bearing ring. According to the invention the preload force generated by the elastic element is transferred to the second bearing ring by means of at least one first bearing. The bearings are preferably fluid dynamic bearings. However, additional roller bearings may be used.

Abstract: The invention relates to a gasket unit (1) for a journal bearing (2), sealing an annular gap (6) between the bearing bushing (3) and the journal (4). The gasket unit (1) comprises a main seal (8) provided with a front seal (9) arranged in front if it, and a spring washer (10) is inserted between the rollers (5) and the primary seal (8).

Abstract: Clutch release bearing device that includes: an operating element; a rolling-contact bearing fitted with a non-rotating ring and a rotating ring and connected axially to the operating element; and an annular fixing ring provided with an axial portion mounted inside the operating element and also with an axially elastic portion whose axially opposite side from the operating element is pressed axially against the non-rotating ring, the fixing ring being able to keep the non-rotating ring axially connected to the operating element and yet allow radial movement.

Abstract: A motor-driven type power steering apparatus includes: a drive gear connected to an output shaft of a motor; a driven gear in mesh with the drive gear, which is connected to a steering unit; a bearing for supporting one end of the drive gear; a support portion in which the bearing is disposed; and a curved leaf spring which has a length larger than a peripheral length of the bearing and fitted between the bearing and the support portion in a resiliently deformed state. The curved leaf spring urges the bearing so that a distance between an axis of the driven gear and an axis of the drive gear decreases.

Abstract: A bearing system which inhibits fretting to extend the life of a bearing. The system is usable in a machine, such as an electric motor, and includes an elastomeric spring positioned between the bearing and a bottom surface of a bore in which the bearing is received. The spring member applies force to the bearing in both an axial direction and a circumferential direction to oppose rotation of the bearing in the bore. The spring member has an annular shape with a plurality of circumferentially spaced teeth.

Abstract: A rotor shaft is supported in a housing of a rotor assembly for a laser level. Bearings support the rotor shaft for rotation relative to the housing. An adhesive fixes an outer race of at least one of the bearings in position between the rotor shaft and the housing. The adhesive is a low viscosity, quick setting anaerobic adhesive, which when cured prevents angular drift of the shaft relative to the housing by eliminating the clearance that would have existed between the outer race and the housing.

Abstract: A conic bearing positioning member for a spindle motor includes a small diameter portion abutting against an inner race of a ball bearing of the spindle motor, a large diameter portion abutting against a rotor of the spindle motor, and at least one resilient connecting portion extending between the small diameter portion and the large diameter portion for biasing the ball bearing and the rotor away from each other, assuring a gap between the ball bearing and the rotor. The conic bearing positioning member may be a helical spring.

Abstract: The bearing device contains two rolling bearings installed on a shaft 9 and a preload is applied to the inner ring of the rolling bearings. The respective dimension for the two rolling bearing inner rings is shortened on both sides in the orientation of the width dimensions of the inner ring, centered on the grooves for the inner ring, with each being set smaller than the dimension of the outer rings. The difference in dimensions is double the difference in the dimensions capable of eliminating rattling of the rolling bearings, when a preload is applied to the outer edge of the inner ring. The outer rings and races are respectively formed to be in a position at half the width dimension of the inner ring from the outer edges of the two outer rings for the two rolling bearings.

Abstract: A pair of pre-loaded ball bearings 1, 2 are fixed to a shaft 3 having a flange 3a to be a reference surface Q formed on one end, and where a clearance C is secured between the surface 1c on the flange side of the inner race 1b of the bearing 1 on the side of the flange 3a and the flange surface 3b.

Abstract: A zero clearance bearing assembly comprising a housing defining a generally cylindrical bearing chamber with a pair of ball bearing units disposed therein. One unit is adjacent an axial thrust reaction surface of frusto-conical configuration and a shoulder on an associated shaft urges the unit into engagement with the surface. The other unit is press fit on the shaft and also has a shaft shoulder urging it toward the thrust surface. An air impeller on the shaft urges the same toward the other bearing unit and the thrust unit reacts to both the impeller load and an axial preload spring engaging the other bearing unit. One or both of the bearing units is provided with an improved radial preload device comprising a spring and a pair of circumaxially spaced reaction surfaces opposing the same.

Abstract: A bearing preload cage assembly for rotatably supporting an axially loaded shaft includes a bearing housing including stationary axially opposed supporting members, first and second axially spaced bearings, each including inner and outer races and rolling elements, first and second cylindrical cage segments coaxial with the shaft, each including a sleeve and circumferentially spaced axially protruding castellations, the outer races engageably received on an internal surface of their associated sleeve, the castellations of each cage segment proximate to and engageable with the outer race of the adjacent bearing, the supporting members proximate to and engageable with an adjacent cage segment, a resilient member biasing at least one of the outer races into full engagement with its rolling elements and, in turn, its rolling elements into full engagement with their inner race whereby the rolling elements of both bearings are maintained in full engagement with their inner and outer races continuously during shaft

Abstract: In a bearing apparatus which is composed of two bearings each including a crown-shaped retainer and in which a lubricant is filled into its raceways, a preload is applied from the retainer pocket-opening side end face of an inner ring, and also a preload is applied from the retainer counter-pocket-opening side end face of an outer ring.

Abstract: A bearing configuration in which a shaft is supported by a first and second bearings, the second bearing being spaced from the first bearing. The first bearing and said second bearing are supported by a corresponding first bore and second bore in a shaft housing, a first axis being coincident with an axis of the first bore and a second axis being coincident with an axis of the second bore. The first axis and the second axis are purposefully offset from one another a sufficient distance to substantially eliminate internal clearance within the first bearing.

Abstract: Bearings (5, 7) fixed to the two ends of a rotation shaft (2) of a motor/generator are pressurized by plate springs 15, 17. The plate springs (15, 17) absorb the deflection off the rotation shaft (2) due to external vibration by the extension and contraction. An effective gaps L is set to value at which the bearings (5, 7) do not collide with the housing (9) in the most compressed state of the plate springs (15, 17). By this setting, the effective gap L is set to a value larger than the maximum amplitude in the direction of the rotation shaft (2) due to the external vibration.

Abstract: A drive device includes an electric drive motor, a housing, at least one shaft driven by the drive motor, compensation elements enabling the end play of the shaft to be adjusted or compensated while the shaft is being mounted, and fixing elements which are used to fix the shaft after the end play has been adjusted or compensated. The compensation elements include a spring element which is arranged inside the housing and which axially actuates the shaft. The fixing elements are not accessible from the outer side of the housing.

Abstract: A play-free radial ball bearing, includes an inner bearing ring and two outer bearing rings which are disposed in spaced-apart relationship and define a common raceway. A spring element applies an axial force on one of the outer bearing rings to thereby press the outer bearing rings resiliently against one another. The outer bearing rings and the spring element are surrounded by a tolerance ring which is made of plastic material to provide a structural unit, whereby the tolerance ring has a shoulder on one end for radially surrounding the spring element and at least one retaining lug on another end for radially surrounding the other one of the outer bearing rings.

Abstract: A spindle motor for a hard disc drive including a motor base having a shaft, a rotor hub rotationally mounted on the shaft and loaded with an information recording disc, a ball bearing attached to an inner center side of the rotor hub for rotationally fixing the rotor hub on the shaft, and a conductive elastic member inserted between the rotor hub and the motor base to electrically contact each other.

Abstract: A conic bearing positioning member for a spindle motor includes a small diameter portion abutting against an inner race of a ball bearing of the spindle motor, a large diameter portion abutting against a rotor of the spindle motor, and at least one resilient connecting portion extending between the small diameter portion and the large diameter portion for biasing the ball bearing and the rotor away from each other, assuring a gap between the ball bearing and the rotor. The conic bearing positioning member may be a helical spring.

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 double-row ball bearing with a preload application structure including an axle and a sleeve surrounding the axle. At least two rows of bearing balls are disposed between the axle and the sleeve. An inner bearing ring is slidably mounted on the axle such that at least one of the two rows of bearing balls is set between the inner bearing ring and the sleeve. The second row of bearing balls is then set directly between the axle and the sleeve. A resilient member is connected to an external side surface of the inner bearing ring, and a preload applying member is connected to the resilient member. The preload applying member applies a preload to the inner bearing ring by increasing pressure on the resilient member. When an appropriate preload is achieved, the preload applying member is fixed to the axle.

Abstract: A ceramic ball bearing assembly has raceway components generally held in residual compression by accompanying metal attachments. In a ceramic ball bearing assembly, an outer raceway is formed that is held in compression by a circumscribing steel ring. The components may be fitted together with the ceramic raceway subject to thermal contraction while the steel ring is subject to thermal expansion. Upon mating, the ceramic raceway slightly expands while the steel ring slightly contracts to impose residual compression upon the ceramic raceway. The residual compression preserves the ceramic raceway despite thermal or other stresses of operating environment. An inner ceramic raceway is constructed by employing one of several of the herein described methods, and the ceramic ball bearing assembly of the present invention may use balls, needles, cylinders, or other rolling elements in order to achieve smooth angular translation between the inner and outer ceramic raceways.

Abstract: A low-profile pivot assembly is disclosed. The assembly includes two generally coaxial bearings having differing diameters so as to define inner and outer bearings. This arrangement permits the pivot assembly to be constructed with a lower profile than conventional pivot bearings. These and other and benefits will become apparent upon a review of the attached figures and the accompanying description.

Abstract: An assembly method of a preload-adjustable rolling bearing unit comprising the steps of providing a shaft having a first inner raceway, an inner ring being press fitted onto the shaft and having a second inner raceway, such that a pitch of both raceways is set greater than a pitch required to give a predetermined preload, providing an outer ring having outer raceways, providing a plurality of balls to be fitted between the outer raceways of the outer ring, and the first and second inner raceways, positioning the balls equidistant apart in the circumferential direction, and vibrating the rolling bearing unit by means of piezo electric elements while moving the inner ring in the axial direction, measuring the resonant frequency of the rolling bearing unit with a vibration sensor to control the preload whereby the inner ring is pressed onto a shaft while vibrating with only a small amount of energy without scratching the raceway and rolling surfaces.

Abstract: A head set assembly for bicycles includes a bearing set with balls received between an upper race and a lower race which is connected to an end of a head tube of a bicycle. The upper race has an annular inclined surface and an annular vertical inside. A pressing ring has an inclined outer surface for being engaged with the annular inclined surface of the upper race, and a flange extending from the inclined outer surface. The flange of the pressing ring is matched with the annular vertical inside of the upper race. The flange is mounted to a steerer tube extending through the head tube. A dust cap is connected onto a top of the pressing ring and a skirt of the dust cap encloses the lower race of the bearing set.

Abstract: A precision spindle unit for low friction performance includes a tubular housing surrounding a shaft, and first and second rolling bearings mounted on the shaft within the housing. The first bearing is axially arrested between the flange of a locking washer fixed to the shaft and a shoulder on the shaft. A second locking washer is fitted to the shaft, and a resilient member is provided between the second locking washer and a side of the inner race ring of the second bearing. The axially inwardly facing side of the outer race ring of the second bearing engages an inwardly projecting shoulder in the housing, with the second bearing being biased between the resilient member and the inwardly projecting shoulder. The locking washers define a slot seal at each axial end of the housing to provide a seal at the outwardly facing sides of the first and second bearings.

Abstract: In a construction in which a double row rolling bearing and a constant velocity joint are mounted to a hub wheel, a fixing ring fixedly mounted to a vehicle-outer side opening of the hub wheel is sandwiched between a vehicle-outer side end face of an outer ring shaft of the constant velocity joint and a bolt integrally mounted to the shaft in the axial direction, thereby coupling the outer ring of the constant velocity joint to the hub wheel. In this case, a simple coupling operation only for mounting the bolt to the shaft suffices, and a pre-load that has been applied to the rolling bearing is maintained invariably.

Abstract: A double row bearing includes a shaft and an inner ring mounted on the shaft. A preloading collar is fixedly mounted on the shaft and an elastic member is disposed between the inner ring and the preloading collar so that the preloading collar applies a predetermined preload to the inner ring through the elastic member. This structure compensates the reduction of the preload due to the temperature rise of the bearing and axial displacement of the inner ring of the bearing.

Abstract: The arrangement is such that the ratio of the diameter of balls 3 in the ultrathin-walled ball bearing to the pitch circle diameter PCD is not more than 0.03, and that the balls 3 are arranged in a single row and in two-point contact with the raceway surfaces 1a and 2a of the outer and inner members 1 and 2. The inner member 2 is composed of first and second raceway rim members 21 and 22 opposed to each other with an axial clearance S defined therebetween, and the internal clearances of the bearing are made negative by adjusting the width of the axial clearance S.

Abstract: A spindle motor of the present invention is capable of keeping its ball (5a, 5b)'s pre-load constant, because a sleeve (6) is capable of being resiliently deformed due to its resiliency, and therefore capable of constantly keeping a pre-load applied to the balls (5a, 5b) from inner and inner ring raceways of inner and outer rings (3a, 4a, 3b, 4b) of ball bearings (3, 4). In this motor, a rotor hub (7) has an axial center bore (8). This bore (8) is provided with: a large-diameter bore portions in its opposite axial ends; and, a small-diameter bore portion (8a) axially interposed between the large-diameter bore portions. An inner diameter of the small-diameter bore portion (8a) is smaller than an outer diameter of the sleeve (6).

Abstract: A device for measuring and adjusting pre-loading on bearings, measuring and adjusting both the mounting and operating loads, wherein elements for applying a preloading and return elements are positioned to constitute a single actuator organ, comprising two ring elements for distributing the preloading, whereof at least one is destined to act against the outer race of a bearing and containing interposed between them a kinematic chain imparting thereon a thrust determined by the action of two or more piezoelectric or magnetostrictive element for applying the preloading and return elements; to the actuator organ being associated an annular loading cell connected in an external feedback control system for measuring and adjusting the preloading.

Abstract: A play-free radial ball bearing, includes an inner bearing ring and two outer bearing rings which are disposed in spaced-apart relationship and define a common raceway. A spring element applies an axial force on one of the outer bearing rings to thereby press the outer bearing rings resiliently against one another. The outer bearing rings and the spring element are surrounded by a tolerance ring which is made of plastic material to provide a structural unit, whereby the tolerance ring has a shoulder on one end for radially surrounding the spring element and at least one retaining lug on another end for radially surrounding the other one of the outer bearing rings.

Abstract: A spindle rotates within a housing on at least two antifriction bearings which have raceways that are inclined to the axis of the bearing and are otherwise configured to transfer thrust loading as well as radial loading. The bearings are mounted in opposition. One of the bearings has a race which fits into an actuator sleeve with an interference fit, and the actuator sleeve, in turn, is fitted into the housing, it having end regions that are located beyond the ends of the bearing. Here the sleeve is fitted to the housing with an interference fit and is further sealed to the housing. The actuator sleeve also has an intervening region between its two end regions, and here the actuator sleeve is located around the race. On its opposite face the actuator sleeve forms a chamber with the housing. When the chamber is pressurized, the intervening region of the sleeve flexes inwardly and contracts the race, thus altering the setting of the two bearings.

Abstract: A virtual ball joint, comprising a pair of bearings disposed about a center of curvature; each of the bearing comprising an inner race and an outer race supporting a plurality of balls therebetween. The inner and outer races have angled surfaces in contact with the balls, such that the outer angled surfaces coincide with an imaginary sphere centered about the center of curvature. A shaft mounted in the bearings may thus be rotated about the center of curvature as if mounted with a ball joint.

Abstract: A ball nut drive assembly includes a ball nut having a bore extending axially therethrough, a ball screw extending through the bore of the ball nut and being cooperatively engaged with the ball nut, and a spring compliant member received on the ball screw and positioned adjacent the ball nut. The spring compliant member is tensioned to bias the ball nut in the axial direction along the ball screw. The ball nut is positioned within a housing, which is preferably fabricated of aluminum, and is generally rotatably supported therein by first and second sets of ball bearings. The spring compliant member is in intimate contact with a first inner surface of the housing and biases the ball nut against a second inner surface of the housing. Races encapsulating the first and second sets of bearings may be positioned adjacent the ball nut and in intimate contact with the first and second inner surfaces of the housing.

Abstract: It is an object of the present invention to provide a motor having a structure so as to prevent the peeling off of adhesive for fixing the bearing. The outer ring of the second ball bearing is fitted into the second ball bearing fitting space of the bearing holder portion of the second end bracket. The annular leaf spring which gives a pressure in the direction toward the first end bracket to the outer ring of the second ball bearing is disposed in the pressure giving structure receiving space which is formed continuously to the second ball bearing fitting space. The annular leaf spring is shaped such that trough and crest portions appear alternately in the circumferential direction. The screw members are inserted into the screw holes formed in the second end bracket. The tip end portions of the screw members are arranged to abut the trough portions of the annular leaf spring.

Abstract: An annular casing partially encloses the outer race of a pair of the angular contact bearings. The casing is split along a radial plane into two casing halves, each casing half being molded of a polymer. The two casing halves are retained axially such that relative axial movement of the angular contact bearings is limited.

Abstract: Bearings (5, 7) fixed to the two ends of a rotation shaft (2) of a motor/generator are pressurized by plate springs 15, 17. The plate springs (15, 17) absorb the deflection off the rotation shaft (2) due to external vibration by the extension and contraction. An effective gaps L is set to value at which the bearings (5, 7) do not collide with the housing (9) in the most compressed state of the plate springs (15, 17). By this setting, the effective gap L is set to a value larger than the maximum amplitude in the direction of the rotation shaft (2) due to the external vibration.

Abstract: A machine tool includes a tool spindle rotatably mounted in a housing. A tool member is disposed in a front spindle segment of the spindle and is releasably clamped by a clamping member. An actuating member is mounted in and is axially movable relative to the spindle to actuate the clamping member. First and second anti-friction bearings are interposed between the housing and the spindle and have different outer diameters. A preload actuating member is disposed to force the second anti-friction bearing in the axial direction to take up the slack in a non-actuated state of the second anti-friction bearing when the spindle is running in a higher speed, thereby resuming the anti-friction function of the second anti-friction bearing when running the tool spindle at a lower speed is intended.

Abstract: A bearing mechanism including two substantially identical ball bearings, each having a longitudinal axis and an inner and an outer race with grooved surfaces facing each other in the races, said bearings being placed in a substantially parallel configuration once assembled in the resultant bearing mechanism, an inner tubular sleeve extending between and against the two substantially parallel ball bearings, said inner sleeve having a thickness and an outer diameter that substantially matches the dimensions of the inner and outer races of the ball bearings, and two bearing caps to be inserted through the two ball bearings, said bearing caps having a substantially tubular shape, each with a flange extending outwardly from one end of the tubular shaped bearing cap, the thickness of the flange matching the dimensions of the inner and/or outer race of the bearings such that, once assembled, the flanges contact the outside surfaces of the races of the substantially parallel ball bearings, thereby exerting a force on

Abstract: An assembly method of a preload-adjustable rolling bearing unit comprising the steps of providing a shaft having a first inner raceway, an inner ring being press fitted onto the shaft and having a second inner raceway, such that a pitch of both raceways is set greater than a pitch required to give a predetermined preload, providing an outer ring having outer raceways, providing a plurality of balls to be fitted between the outer raceways of the outer ring, and the first and second inner raceways, positioning the balls equidistant apart in the circumferential direction, and vibrating the rolling bearing unit by means of piezo electric elements while moving the inner ring in the axial direction, measuring the resonant frequency of the rolling bearing unit with a vibration sensor to control the preload whereby the inner ring is pressed onto a shaft while vibrating with only a small amount of energy without scratching the raceway and rolling surfaces.

Abstract: A precision spindle unit for low friction performance includes a tubular housing surrounding a shaft, and first and second rolling bearings mounted on the shaft within the housing. The first bearing is axially arrested between the flange of a locking washer fixed to the shaft and a shoulder on the shaft. A second locking washer is fitted to the shaft, and a resilient member is provided between the second locking washer and a side of the inner race ring of the second bearing. The axially inwardly facing side of the outer race ring of the second bearing engages an inwardly projecting shoulder in the housing, with the second bearing being biased between the resilient member and the inwardly projecting shoulder. The locking washers define a slot seal at each axial end of the housing to provide a seal at the outwardly facing sides of the first and second bearings.