Abstract: A sleeve has a thrust dynamic pressure generating groove arrangement for generating a dynamic pressure in a thrust direction between another member and the sleeve. The sleeve is formed in the following manner. First, a mold is prepared which is provided with a portion corresponding to the thrust dynamic pressure generating groove arrangement. Injection molding is carried out by using this mold and material containing binders and metal particulates, thereby forming a work-in-process piece having the thrust dynamic pressure groove arrangement in a cavity of the mold. Then, binders in the work-in-process piece are removed by heating, and thereafter metal particulates in the work-in-process piece are sintered.

Abstract: The present invention is directed to a constant velocity joint (“CV joint”) and, more particularly, to a Rzeppa CV joint and method of forming the same. The method generally includes the steps of forming a bell shaped outer bearing race and separating the bell shaped outer bearing race into a disc shaped outer bearing race and a stub shaft. The method may further include the step of machining the bell shaped outer bearing race to create the stub shaft integrally connected to the disc shaped outer bearing race, before separating the bell shaped outer bearing race into the disc shaped outer bearing race and the stub shaft.

Abstract: A journal bearing has a lining of bearing metal applied to a steel backing. The surface of the lining is laser peen hardened to locally increase the hardness and the seizure resistance of the lining. The underlying core of the lining is unaffected and maintains good conformability of the lining. The overall lining thus possesses both good seizure resistance and conformability.

Abstract: A plain bearing and method for making the plain bearing are described, the plain bearing having an overlay alloy layer at a sliding surface of the plain bearing, the plain bearing comprising a layer of a strong backing material, a layer of a first bearing alloy bonded to the strong backing material and a layer of a second bearing material comprising said overlay material bonded to said first bearing alloy layer wherein said second bearing material comprises tin having included in the matrix thereof an organic levelling agent.

Abstract: The invention relates to a method of forming the inside wall of a support bearing of given height H and suitable for receiving a cylindrical portion of a cylindrical element for co-operating with the inside wall, said method comprising the steps of estimating a deflection f taken up by the cylindrical element between the center and one of the ends of the support bearing, estimating a nominal radius R using the relationship R=H2/8f, determining an inside wall for the support bearing that occupies a toroidal surface having a throat diameter equal to a diameter of the cylindrical element, ignoring predetermined clearance, and having a meridian radius lying in a range of ±15% about the nominal radius R, and machining the support bearing in such a manner that its inside wall occupies the toroidal surface as determined in this way.

Abstract: A motor and method of assembly of a motor having a stator core and at least a first end shield. The method includes selecting a bearing cap from one of a plurality of bearing caps. Each of the plurality of bearing caps has a different bearing cap length and is dimensioned for attachment to the first end shield. The bearing cap is selected from the plurality of bearing caps as a function of a width of the stator core. The invention is also a motor system that includes a stator core selected from a plurality of stator cores and a bearing cap selected from a plurality of bearing caps. Each of the plurality of stator cores has a different stator core width and each of the plurality of bearing caps has a different bearing cap length. The bearing cap is selected as a function of a width of the selected stator core.

Abstract: To make a peripheral lip region to be formed with chamfered portions by the use of a plastic working technique, to enable the use of a cup forming punch of a simplified shape so that a mold used therewith can be easily assembled and the punch when worn down can easily be repaired, a method of making an outer race of a constant velocity universal joint of a tripod type includes an upsetting step during which not only are outer peripheral shapes of a small diameter portion (W3a) and a large diameter portion (W3b) defined, but a recess (Wb) having a tapered peripheral wall face (Wba), which eventually defines general shapes of the chamfered portions (10) of the outer race (1), is formed in an end face of the large diameter portion (W3b). During a cup forming step, the tapered peripheral wall face (Wba) defined during the upsetting step is rearwardly pushed while its shape is maintained.

Abstract: A method for reducing seizure when a cageless ball bearing is placed in a hostile environment where foreign particles can enter the bearing, comprises removing at least one ball from a full complement of balls. In so doing, a larger circumferential gap between balls is created, thereby making it more difficult for foreign particles to become lodged between balls and seize the ball bearing.

Abstract: A bearing having bearing elements made of Type 60 Nitinol made by an investment casting process for producing near net shape parts of Nitinol includes making a ceramic mold having a series of spherical cavities, pouring molten Nitinol into the mold cavities, cooling the mold and the Nitinol in the cavities to produce solidified Nitinol balls, and breaking the mold away from the Nitinol balls. Nitinol rods for roller bearings can be made by conventional casting directly from the crucible in a draw-down oven. The bars are hot machined or hot rotary swaged and then centerless ground and laser cut to length, or are first cut to length and then centerless ground individually for crowned roller elements. The balls are broken or cut from the risers, leaving the gates attached, and are consolidated by healing under pressure in a hot isostatic press, then ground to the desired size. The balls or rollers are polished, then treated to create an integral ceramic finish.

Abstract: The material of the wall inside a hole in a housing is squeezed toward the center of the using a staking tool with a diameter larger than that of the hole. The material necessary for forming a locking section can be obtained from only a small part of the entire area of the wall of the hole. The amount of material necessary for the entire process is secured and the material is pressed so as to contact with an end face of the outer race using the staking tool, forming the locking section. Accordingly, the locking section provides sufficient strength. Also, since only the small part of the entire area of the wall is necessary as described above, there is no decrease in strength or deformation as to the thin housing.

Abstract: Bearing reinforcement for a shaft (3) mounted in bearings in a cast light-metal housing (1, 2) such as an engine block or a gearbox housing, in which an insert (5) that forms a bearing seat for the shaft (3) is made of an MMC material, i.e. a metal matrix composite, and in which the base material of the MMC material consists of the same metal as the metal that comprises the principal component in the light-metal housing, wherein the MMC material of the insert (5) is reinforced with 10-70% ceramic material by volume in the form of particles or fibers. The invention also describes a method for fabricating inserts (5) in which they are formed into a bar having the same cross-section as the radial cross-section of the insert, whereupon separate inserts are cross-cut from the bar by means of high-speed machining or water cutting.

Abstract: One or more force application members (e.g., a force transmission member and/or a hydraulic force application member) may be employed to provide a desired adjustment (e.g., a preload and/or a compression) to an adjustable spacer of a bearing assembly. The hydraulic force application member may provide a first stage of the adjustment to the spacer, and the force transmission member may be threadingly rotated to apply a second stage of the adjustment to the spacer. An additional force application member may (e.g., contemporaneously) oppose at least one of the force application members in the providing of the adjustment to the spacer. This opposing force may cause a gap between certain surfaces (e.g., in a press) until the adjustment to the spacer is completed. The closure of the gap may serve to indicate the completion of the desired adjustment to the spacer. A housing rotatable on a portion of the bearing assembly may be prevented from rotating at the closure of the gap.

Abstract: A sliding member (12) is disclosed that has superior slidability and durability at a low cost. A top sliding surface (12a) of the sliding member (12) is formed by a nitriding process that creates a compound layer (14) and a diffusion layer (15) on a base metal (16) of the sliding member (12). The buff polishing process is thinly performed on an outermost layer portion (14a) of the compound layer (14), such that a portion of the compound layer (14b and/or 14c) remains.

Abstract: A method and apparatus for packing wheel bearings with grease. A frame is provided for supporting an axle assembly comprising an axle shaft with a wheel mounted on a wheel bearing at each end. A horizontally mounted ram and cylinder is mounted adjacent each wheel. Each ram has a greasing head at its distal end and each head has a nose portion adapted to pivot relative to a body portion. Each nose portion has an open-mouthed greasing chamber. Each ram is advanced toward each wheel so that each open-mouthed greasing chamber is in communication with a wheel bearing. Pressurized grease is delivered to a greasing chamber and, therefor, to a bearing.

Abstract: Prior to forming a thermal spray coating layer (28) on an end face (23B′) of a structural base material (23′) to be shaped into a boss, firstly an inner masking member (32) is fitted in an original hole (23A′) of the structural base material (23′) and then an outer masking member (33) is fitted on outer peripheral side of the structural base material (23′). In the next place, by the use of a hard material, a thermal spray coating layer (28) is formed on an annular coating area (23B1′) which is exposed between the inner and outer masking members (32) and (33). Surface areas on the end face (23B′) of the structural base material (23′), corresponding to an allowance range of a machining operation by which the original hole (23A′) is ultimately shaped into a joint pin hole of a specified diameter, are left as a non-coating area (23B2′) free of the thermal spray coating layer (28).

Abstract: A bearing device comprising a shaft body having an axially cylindrical portion in a free end side thereof and a rolling bearing fitted around an outer peripheral surface of the shaft body, wherein the cylindrical portion is bent and deformed radially outward by a rolling caulking to be caulked thereby on an outer end face of an inner ring of the rolling bearing. An inner peripheral surface of the cylindrical portion is formed by a turning work, and a residual stress left in a surface layer of the inner peripheral surface of the cylindrical portion by the turning work is set to a value capable of restraining a crack generation ratio in the inner peripheral surface to less than a predetermined rate, desirably to not more than 5 kgf/mm2.

Abstract: A method of forming an annular collar (11) that is essentially radial on the hollow annular end portion (12) of a part (7), said method comprising the following steps:—radially deforming the end portion (12) by means of a first tool (16), the axis (18) of the tool (16) and the axis (5) of the end portion (12) forming a non-zero angle &agr; between them, so as to obtain a collar preform (17) that is essentially radial; and—deploying said preform (17) by means of a second tool (23), so as to obtain final shaping of the collar (11) by pressing. The invention also relates to a method of retaining a bearing (1) on a shaft (7), and to an assembly comprising a shaft (7) and a bearing (1).

Abstract: An apparatus and method for setting a gap in a hydrodynamic bearing of a disc drive spindle motor. The invention comprises placing an end of the shaft into shaft support apertures in the hub, fitting a thrust bearing counterplate into a recess defined by an annular retaining flange that is proximate the end of the shaft, and deforming the counterplate to form a gap between the end of the shaft and a surface of the counterplate.

Abstract: An intermediate molding (41) is formed so that a cylindrical arm-to-be portion (42) projects from the cylindrical outer surface of a body portion (13) of the arm-to-be portion (42). The arm-to-be portion (42) has a given thickness and a hole (42a) with a diameter greater than the inner diameter of a projecting connector portion (20) of an arm portion (15). A pair of flat face portions (42b) extending parallel to the axis of the body portion (13) are formed on the cylindrical outer surface of the arm-to-be portion (42). A tap (44) that has an external thread (43) formed along its cylindrical outer surface is inserted into the hole (42a) of the arm-to-be portion (42). Concave faces (49),(49) are concaves respectively formed on the opposing surfaces of an upper die (47) and a lower die (48) so as to have a shape like a half cylinder with a curvature corresponding to that of the cylindrical outer surface of the projecting connector portion (20).

Abstract: To provide a method of manufacturing a friction member with high painting performance in which undesirable matters, which stick to the friction member before painting, are removed, and degreasing and recovery of damaged portions are carried out. In the method of manufacturing a friction member in which a friction material is attached to a metal back plate and they are painted, after the friction material is attached to the back plate, the back plate is treated before painting. The treating prior to painting process may be shot-blasting or coating with phosphate. With this treatment before painting, parting compounds that are adhered when the friction material is attached to the back plate is to be removed; dirty things and attached matters are removed; and flaws due to blasting are recovered, resulting in improved painting performance in adhesiveness.

Abstract: A structure of at least a stationary-side race of a bearing is transformed into a lower bainite structure through an isothermal transformation treatment. Furthermore, the adjustment is made for hardness to HRC=54 to 64, an amount of residual austenite to not more than 5% and an area percentage of 0.8 &mgr;m or longer carbide to not more than 20% based on the total area of secondary carbide. Thus is prevented the occurrence of a white layer in the rolling bearing.

Abstract: A bearing arrangement for a gear pump comprises first and second separate bearing blocks each having a respective block housing. The first and second bearing blocks together defining an axially directed bearing surface including a bridge region formed from an erosion resistant material which acts to separate inlet and outlet ports of the pump and a second region formed from a reduced friction material. The bridge region is defined by first and second insert members cast within respective ones of the block housings. The first and second bearing blocks are arranged such that respective surfaces of the first and second insert members mate with one another, and the first and second insert members are arranged such that the bridge region of the bearing surface is flush with the second region.

Abstract: A method of improving the performance and service life of a new bearing component, the component having at least one dynamic frictional surface the method includes subjecting the at least one dynamic frictional surface to a surface finishing operation thereby providing the surface with a surface roughness value RA of approximately 18-80 &mgr;in, preferably greater than 24 &mgr;in, and most preferably 30-36 &mgr;in. The method is particularly advantageous when applied to bearing components utilized in high-load, low rpm applications.

Abstract: The method of and apparatus for producing fluid dynamic bearing parts is provided. Sets of grooves are formed by an electrochemical machining apparatus based on a design specification. The electrochemical machining process includes a process for extracting one bearing part in every predetermined number of machining cycles during the bearing parts production, a process for measuring shapes of the grooves on the extracted bearing part, a process for comparing the shapes of the grooves on the extracted bearing part with the design specification data, and a process for changing settings of the electrochemical machining apparatus depending on the result of the comparison. With these processes a stable and precise production of grooves on the fluid dynamic bearing parts are possible during mass production.

Abstract: Method for making diamond bearings and diamond bearing components. Some methods include sintering diamond feedstock and a substrate under high pressure and high temperature to create a sintered polycrystalline diamond compact with a non-planar bearing and articulation surface. Various machining, grinding and polishing methods for finishing the compact are provided.

Abstract: A flange includes a housing having a body with a reinforcing member encased within the housing. The flange can be configured to house a bearing. The flange can alternatively be configured to act as a leveler for machinery. The flange is formed by a) preparing a mold for the housing, b) preparing a metallic band for insertion into a space in the mold, c) suspending the band within the mold, d) introducing a thermosetting material into the mold to encase the band, and e) cooling the thermosetting material.

Abstract: A problem of the invention resides in that in a hydrodynamic bearing apparatus for rotatably supporting a rotor by a hydrodynamic bearing, wear of the apparatus caused by sliding contact of dynamic pressure bearing faces in starting and stopping thereof is prevented to thereby promote durability, working of a dynamic pressure generating groove is facilitated and the bearing faces are prevented from being adsorbed to each other.

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 method of manufacturing sliding bearings of the type in which a sliding guide surface is formed by using a resin liner, including fixing a thermosetting resin, which constitutes the resin liner, on the whole or a part of a sliding guide surface of a first member by an injection molding operation using the first member as a core, thereafter molding a second member, which covers a sliding guide surface of the first member, by a metal molding operation with the resin liner-fixed first member placed firmly as a core in a metal mold, and thermally curing the resin liner with the heat working on the sliding surface of the first member during the molding of this second member.

Abstract: For a machine housing with a split bearing arrangement, particularly journal bearing in piston machines, with a bearing cover clampably arranged via corresponding profiles on a bearing block, it is proposed that a bearing cover having a profile in its clamping face and acting as the tool electrode be used to produce by an electrical discharge machining process a corresponding profile in the clamping face of the bearing block of the machine housing serving as the workpiece electrode in order to achieve an advantageous formation of the profile. After the electrical discharge machining process, the bearing cover is mounted to the bearing block.

Abstract: A method for setting one or more hydrodynamic bearing gaps in a disc drive spindle motor is provided. In one embodiment, a method setting one or more hydrodynamic bearing gaps in a disc drive spindle motor includes disposing a rotary member against one or more working surfaces such that substantially no gap exists therebetween and inducing creep between the rotary member and the working surfaces. The creep creates a bearing gap therebetween the rotary member and at least one of the working surfaces. The creep may be induced by thermally cycling the motor components or applying a force to a tool coupled to a member having at least one of the working surfaces disposed thereon.

Abstract: A split bearing arrangement in a machine housing, particularly a crankshaft journal bearing for piston machines. The split bearing arrangement including a bearing block and a bearing cover that are made of materials of different hardnesses. In order to provide a material anchoring between the bearing cover and the bearing block that can be subjected to high loads and is cost-effective to produce, the bearing arrangement provides the bearing cover, which is made of an iron material, with cutting-edge like projections protruding above its clamping faces and, furthermore, provides grooves in the corresponding clamping faces of the bearing cover and the bearing block. These grooves in an initial mounting of the bearing cover with the required force serve to receive the material of the bearing block that is displaced in the pressing-in process when the projections are pressed into the opposite clamping faces of the bearing block, which is made of a light metal.

Abstract: A bearing manufacturing method for a compressor is disclosed. Since an oxide-coated layer is formed at the surface of the bearing and electrolized in a tiomolybedenic acid ammonium aqueous solution so that the molybedene emulsion can be infiltrated in the fine pores of the oxide-coated layer. Accordingly, the abrasion resistance of the bearing can be increased while the friction coefficient is remarkably reduced, and thus, a reliability of the compressor and an energy efficiency can be increased.

Abstract: A method of assembling a bearing house for a rotary shaft, such as a camshaft, comprising a bearing cap secured to a relatively massive component, such as a cylinder head. The bearing cap and the massive component afford respective semi-circular recesses which cooperate to define a circular hole in which the rotary shaft may be received. The method comprises connecting the bearing cap to the massive component, deforming at least spaced portions of the bearing cap into intimate contact with the massive component so as to produce a unique relocation position, boring the circular hole in the bearing cap and the massive component, removing the bearing cap, inserting the shaft into the semi-circular recess afforded by the massive component and reconnecting the bearing cap to the massive component.

Abstract: An armature for a selectively engageable and disengageable coupling and a method of making the armature are provided. The armature includes a substantially annular body that is disposed about a first axis. The body may be formed by stamping or fine-blanking. One side of the body is hardened through a nitriding process. A grinding wheel is then applied at an angle to the same side of the body along a diametrical line of the body extending perpendicular to the first axis. As a result, the body is configured so that the thickness of the body increases as the distance from the diametrical line increases. In particular, the thickness of the body varies along each cross-section taken along the line from a minimum thickness at the innermost portion of the cross-section to a maximum thickness at the outermost portion of the cross-section. The inventive armature reduces galling, and the resulting noise, that occur during burnishing of couplings incorporating the armature.

Abstract: A method of forming a stator assembly which adapts the stator assembly to receive a roller assembly in a rotary machine is disclosed. Various details of the method are developed which may be used for the manufacture, the modification, and the repair of the stator assembly. The method includes forming a liner for the stator assembly independently of the stator assembly; and, disposing the liner in the stator assembly to adapt the stator assembly to receive the roller assembly.

Abstract: A machining tool for manufacturing a radial bearing, and a manufacturing apparatus and a manufacturing method using the machining tool are provided. The machining tool includes an inner surface finishing tool to finish an inner circumference surface of a bearing hole provided on a radial bearing. The inner surface finishing tool includes a tool shaft main body member that defines a hollow storage section provided within the tool shaft main body member, a rotatable core piece member mounted inside the hollow storage section in a manner to be rotatable within the tool shaft main body member, and a plurality of roll machining members each with a circular cross-sectional roll machining surface. The plurality of roll machining members rollably abut against the outer circumference surface of the rotatable core piece member. The plurality of roll machining members are in contact under pressure with the inner circumference surface of the bearing hole.

Abstract: A method of forming a bearing comprising adding an aqueous colloidal dispersion of at least one particulate material to an aqueous dispersion of polytetrafluoroethylene. The method also comprises mixing the dispersions for a period sufficient to allow the polytetrafluoroethylene to coagulate to form a mush, spreading the mush onto a support, and curing the mush to form a bearing lining layer on the support.

Abstract: A bearing comprising a metal base body corresponding to a whole or a part of elements of the bearing with a polycrystallized glass layer located on the metal base body, and a method comprising forming a whole or a part of elements of a bearing with molten glass or of a base metal with a laminated glass layer and carrying out a heat treatment for polycrystallizing the glass.

Abstract: One or more force application members (e.g., a force transmission member and/or a hydraulic force application member) may be employed to provide a desired adjustment (e.g., a preload and/or a compression) to an adjustable spacer of a bearing assembly. The hydraulic force application member may provide a first stage of the adjustment to the spacer, and the force transmission member may be threadingly rotated to apply a second stage of the adjustment to the spacer. An additional force application member may (e.g., contemporaneously) oppose at least one of the force application members in the providing of the adjustment to the spacer. This opposing force may cause a gap between certain surfaces (e.g., in a press) until the adjustment to the spacer is completed. The closure of the gap may serve to indicate the completion of the desired adjustment to the spacer. A housing rotatable on a portion of the bearing assembly may be prevented from rotating at the closure of the gap.

Abstract: A crush sleeve has a plurality of protrusions distributed about its inner or outer circumference, usually along its axial midpoint. A two-piece bearing ring is positioned over the crush sleeve with the protrusions between the two portions of the two-piece bearing ring. The two portions of the two-piece bearing ring are forced against the protrusions in opposite axial directions, thereby deforming the protrusions, until a desired clearance results within the bearing. The two-piece bearing ring may be either an inner or outer bearing ring.

Abstract: To provide a method for mounting an outer sleeve onto a housing in low cost and with high precision in a linear sliding apparatus, the linear sliding apparatus has a shaft, and the outer sleeve is fitted around the shaft and slidable in a linear manner relative to the shaft. The method includes the steps of: engaging any desired position of an outer circumference of the outer sleeve with a stationary member in a convex and concave engagement; and fixing the stationary member to the housing by a fastening member, thereby mounting the outer sleeve on the housing.

Abstract: When inserting a finishing tool 41 into a bearing hole 13A3, firstly, by inserting an insertion guide portion 41c formed on the leading end side of the finishing tool 41 into the bearing hole 13A3, the finishing tool 41 is inserted into the bearing hole 13A3 in such a manner that the angle and parallelism of the axis of a pressure contact working portion 41b, which is situated on the rear side of the finishing tool 41 and continues with the insertion guide portion 41c, can be gradually aligned with the axis of the bearing hole through a floating holder mechanism 42. In a state where the axis of the pressure contact working portion 41b is automatically aligned with the axis of the bearing hole with high precision, the working of the bearing hole using the pressure contact working portion 41b is started.

Abstract: A ball-nut transmission in which each of the balls used for transferring drive between a shaft member and a nut member are encapsulated between a hemispherical cavity formed in one of the members and a helical groove provided in the other of the members.

Abstract: A method for fabricating a self-lubricating foil-type material having a low frictional coefficient from a stack of an expanded-metal sheet and at least one polytetrafluoroethylene (PTFE) strip by compression and heating. The stack is first calendered and then the calendered stack is heated to sinter the PTFE.

Abstract: The invention relates to an eccentric orbiting type planetary gear device which requires no pre-load adjustment for the bearing, and is small in the number of components when compared with the conventional device, and is improved in performance and in assembling efficiency, and a method of manufacturing the device.

Abstract: A simplified method of manufacturing and assembling a unitized seal uses only three basic components, and no steps involving direct molding of elastomer to casings, or gluing or otherwise securing elastomer to the casings. Two simple, inner and outer casings have axially opposed, radially overlapping annular webs, and radially opposed, oppositely axially extending seal walls. An integral seal unit has coplanar, inner and outer disks joined at a frangible central seam. Each disk has a pair of converging seal lips disposed symmetrically to either sid of a respective seal wall. When the unit is squeezed axially between the casings during assembly, the seal walls enter between the seal lips, bottom out on the disks, break the seam, and embed the disks automatically into the casings, with no other assembly steps needed.

Abstract: A method for forming a precision groove in a cylindrical surface of an article such as a sleeve-shaft hydrodynamic journal bearing system includes the steps of: aligning a groove-forming machine to an axial datum plane of the article defined in a spaced-apart relation with the cylindrical surface by a predetermined nominal first dimension, translating the groove-forming machine in an axial direction toward and upon a first edge of the cylindrical surface by an amount equal to the predetermined nominal first dimension and thereupon forming a first groove axial step segment in the cylindrical surface until a second predetermined axial datum plane is reached, simultaneously axially translating and rotating the groove-forming machine from the second axial datum plane until a third predetermined axial datum plane is reached and thereupon forming the precision groove pattern in the cylindrical surface between the second axial datum plane and the third axial datum plane, and axially translating the groove-forming ma

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 then 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 preload-adjustable bearing is constructed of a first rotary unit and second rotary unit. The first rotary unit has a first race and second race arranged immobile in a direction approaching toward each other. The second rotary unit has a third race and fourth race. The third race is located opposite the first race while the fourth race is located opposite the second race. The third race is fixed relative to the second rotary unit in a direction away from the fourth race. The fourth race is fitted with the second rotary unit with an interference formed therebetween movably relative to the second rotary unit. The fourth race is movable toward the third race under axial pressure applied between the fourth race and the second rotary unit.