CN1293320C

CN1293320C - Bearing device

Info

Publication number: CN1293320C
Application number: CNB028185358A
Authority: CN
Inventors: 宫崎晴三
Original assignee: Seiko Corp
Current assignee: Seiko Corp
Priority date: 2001-09-21
Filing date: 2002-09-19
Publication date: 2007-01-03
Anticipated expiration: 2022-09-19
Also published as: CN1556902A; WO2003027523A1

Abstract

A bearing device in which the inner surface of a housing 112 coaxially supporting a pair of ball bearings 111 supporting a spindle shaft S is formed with a step portion 113 abutting against the end surfaces of the outer rings of the ball bearings 111, wherein the opposite ends of the housing 112 are formed with fitting portions 112a for the ball bearings 111, and the inner surface of the housing between the fitting portions 112a and the step portion 113 is larger than the outer diameter of the ball bearings 111. Further, the press fitting length of the press fitting portion between the shaft and the inner ring is not more than 1/3 of the shaft diameter.

Description

Bearing means

Technical field

The present invention relates to be used for the drum spindle motor, LBP of for example VCR (video cassette recorder), tape stream usefulness bearing means with the supporting of the running shaft of the magnetic disk memory spindle motor of motor, HDD (hard disk drive) motor etc., HDD reel cage, other motors.

Background technique

For example in the drum spindle motor of VCR, tape stream usefulness, as the bearing of its main shaft of supporting, the existing bearing means as shown in figure 30 of packing into.This bearing means is by a pair of rolling bearing 11,11 of the main shaft S of supporting spindle motor and keep the shell cylindraceous 12 of those rolling bearings 11,11 to constitute on same axis.

Shell 12 has the inner face with the outer diametric plane close fit of rolling bearing 11, forms end difference 13 as shown in figure 31 on the inner face of this shell 12.Rolling bearing 11 is made of outer ring 11a, inner ring 11b, solid of rotation 11c, retainer 11d etc.

Such bearing means has following advantage: because if be embedded in the outer ring 11a of rolling bearing 11 at shell 12, the end face apical grafting of outer ring 11a is formed on the end difference 13 of the inner face of shell 12, the end face of outer ring 11a is positioned in the shell 12, so can easily carry out the assembling of rolling bearing 11 and shell 12.

But, under the situation of above-mentioned existing bearing device, during the end face apical grafting end difference 13 of outer ring 11a, if to radially inclination, bearing also all tilts outer ring 11a a little, its result is because with respect to the axle core, shell has the problem that the running accuracy of making reduces at radially core shift and whirling.In addition, for outer ring 11a not to radially tilting, be necessary that the reduction of therefore seeking cost is difficult with end difference 13 abrasive machining accurately.

The present invention makes in view of the above-mentioned problems, as its first purpose, provides the bearing means of the reduction of the raising that can seek running accuracy and cost.

In addition, as the bearing means that is used for such use, in axle, be pressed into the assembling rolling bearing.In the bearing means of this form, have according to purposes, the different various sizes of machine.The diameter of axle of axle and the size of rolling bearing (footpath direction and axle direction size) are according to its purposes and machine and different.

In axle, be pressed under the occasion of assembling rolling bearing, have axle and one side of inner ring or the situation that crook on both sides.

Therefore, the spy opens in the bearing means of flat 9-53644 communique, and in order to reduce crooking of bending shaft etc., the length that is pressed into assembling is as 1/2～3/4 of the axle direction size of bearing.

Open in the disclosed technology of flat 9-53644 communique the spy, for example as the axle direction size (width) of rolling bearing when greatly selecting, the length that is pressed into assembling also becomes greatly more than necessity, considers because the influence that bending shaft is subjected to according to occasion.

The present invention is because of making in view of above-mentioned thing, its second purpose is for the axle of various sizes and the assembling of rolling bearing, can suitably set the length that is pressed into assembling, the bearing means that makes the stress that applies on inner ring and the axle reduce and make the running accuracy raising can be provided.

In addition, the 3rd purpose of the present invention is, can be because of the influence of the expansion that is subjected to the department of assembly, outer ring that is pressed into by rolling bearing, and make sleeve to the assembly manipulation of the shell difficulty that becomes, therefore, can seek the raising of installation exercise, and the build-up tolerance between sleeve and the shell is set suitable interference assembling, can access sufficient adhesive strength by assembling, provide because the raising of installation precision can be sought the bearing means of the raising of bearing performance.

In addition, in the drum spindle motor of above-mentioned VCR, tape stream usefulness,, pack into and open the bearing means shown in clear No. 6222223 communiques " rotating head device " as the spy as the bearing of its main shaft of supporting.

In this bearing means, have along the 1st bearing portion and the 2nd bearing portion of main shaft (hereinafter referred to as " the axle ") arranged coaxial of spindle motor (figure does not show) as an example.

When inner track formed on the periphery of above-mentioned axle in the 1st bearing portion, inner track formed on the inner ring that is assemblied on the above-mentioned axle in the 2nd bearing portion.

Then, the helical spring of packing between the 1st bearing portion and the 2nd bearing portion is by this helical spring additional preload in the 1st bearing portion and the 2nd bearing portion.

Because form the inner track of the 1st bearing portion in the periphery of axle, and if the 2nd bearing portion that on axle, embeds inner ring relatively, can remove the gap between axle and the inner ring.Therefore, can suppress the axle runout of the 1st bearing portion, improve precision.

But the 2nd bearing portion as noted above is because form inner track by the inner ring that is embedded on the axle, by spring extruding inner ring and additional preload, so be necessary assembled shaft and inner ring more loosely.

If it is more loosening that the assembling of axle and inner ring becomes, there is danger with respect to the runout of axle generation inner ring.Its result is because with respect to the axle core, and shell has the problem that the running accuracy of making reduces at radially core shift and whirling.In addition, for the outer ring not to radially tilting, be necessary Jiang Gebu abrasive machining accurately, the reduction of therefore seeking cost is difficult.

The present invention makes in view of the above-mentioned problems, as its 4th purpose, provides the bearing means of the reduction of the raising that can seek running accuracy and cost.

Summary of the invention

For reaching above-mentioned first purpose, the invention discloses a kind of bearing means, have, the a pair of rolling bearing of supporting spindle, with the shell that on same axle, keeps the tubular of those rolling bearings, inner face assembling at above-mentioned shell keeps above-mentioned rolling bearing, wherein, at the central axis by bearing and the intersection point of wrapping angle elongation line, and be the department of assembly that above-mentioned shell is set on the crossing position of the outer diametric plane in outer ring of the plane, footpath at right angle and above-mentioned rolling bearing with respect to the axle direction of above-mentioned rolling bearing.

In addition, in the end difference that the cycle surface of the inner face setting of above-mentioned shell and above-mentioned rolling bearing contacts, in the both end sides setting of above-mentioned shell and the department of assembly of bearing outside diameter, the shell inner face of above-mentioned department of assembly and the above-mentioned end difference ground, the big footpath of external diameter than above-mentioned rolling bearing is formed.

In addition, a kind of bearing means, wherein, the a pair of rolling bearing of assembling retainer shaft and supporting axle on same axle, at the central axis by bearing and the intersection point of wrapping angle elongation line, and be the department of assembly that is provided with on the inner ring aperture surface of the plane, footpath at right angle and the above-mentioned rolling bearing position of intersecting with above-mentioned axle with respect to the axle direction of above-mentioned rolling bearing.

In addition, at the central axis that passes through bearing and the intersection point of wrapping angle elongation line, and with respect to the axle direction of above-mentioned rolling bearing is the department of assembly that is provided with on the inner ring aperture surface of the plane, footpath at right angle and the above-mentioned rolling bearing position of intersecting with above-mentioned axle, from the shaft outside diameter of above-mentioned department of assembly, be provided with than the less diameter reducing part in footpath of the inner ring inside diameter of above-mentioned rolling bearing to the ball side.

In addition, above-mentioned rolling bearing is a deep groove ball bearing.

In addition, above-mentioned rolling bearing is an angular contact bearing.

If as such formation, even because the outer ring tilts with respect to the axle center, in the department of assembly of shell and outer ring outside core shift become minimum, so, do not have the situation of shell core shift and whirling with respect to the axle center.In addition, the situation that does not also exist the axle center to tilt with respect to shell.

Because like this, can not tilt with respect to the axle center for the outer ring, and carry out abrasive machining end difference accurately, so can seek the reduction of cost.

In the bearing means that the present invention relates to, a pair of rolling bearing as supporting spindle can use ball bearing.In addition, in the bearing means that the present invention relates to, because at the central axis that passes through ball bearing and the intersection point of wrapping angle elongation line, and with respect to the axle direction of ball bearing is the department of assembly that shell and outer ring external diameter are set on the outer diametric plane of the plane, footpath at right angle and the ball bearing position of intersecting, so situation that even existence is tilted with respect to the axle center on the outer ring, shell is also hardly to core shift radially, at stationary axle and make under the occasion of shell rotation, the rotation runout of shell can be suppressed be inferior limit.

In addition, because at the central axis that passes through ball bearing and the intersection point of wrapping angle elongation line, and with respect to the axle direction of above-mentioned ball bearing is the department of assembly that is provided with on the inner ring aperture surface of the plane, footpath at right angle and the above-mentioned ball bearing position of intersecting with axle, from the shaft outside diameter of above-mentioned department of assembly to the ball side, setting is than the less diameter reducing part in footpath of the inner ring inside diameter of above-mentioned rolling bearing, so even inner ring tilts with respect to the axle center and is fixing, with the department of assembly of inner ring aperture surface on form with respect to the core shift of rotating center minimumly, axle does not rotate runout in fixing outer ring and when making the axle rotation.

Above-mentioned second purpose of the present invention, by reaching as lower bearing equipment: a kind of bearing means has axle and be pressed into the inner ring that is assemblied on this, wherein, make the assembling length that is pressed into that is pressed into the department of assembly between above-mentioned axle and above-mentioned inner ring become below 1/3 of the diameter of axle.

In addition, above-mentioned second purpose of the present invention, by reaching: a kind of bearing means as lower bearing equipment, have, axle is pressed into the rolling bearing that is assemblied in the inner ring on this with possessing, wherein, make the assembling length that is pressed into that is pressed into the department of assembly between above-mentioned axle and above-mentioned inner ring become below 1/3 of the diameter of axle.

The assembling length that is pressed into that preferably will be pressed into the department of assembly is taken as below 1/3 and more than 1/10.The assembling length that is pressed into that is pressed into the department of assembly is taken as more than 1/10, is because if littler than 1/10, guarantees that the breakaway force that is pressed into the department of assembly just becomes difficult.

The present inventor finds, is that the benchmark setting is pressed into assembling length by the diameter of axle with axle, can access the suitable state that is pressed into for the axle of various sizes and the assembling of rolling bearing.

If by the bearing means of above-mentioned formation, irrelevant with the width of the rolling bearing of assembling, the stress that applies on inner ring and the axle is diminished, can prevent crooking of those, the runout in the time of can suppressing to rotate and seek the raising of running accuracy.

Here, be pressed into the department of assembly and represent that axle and inner ring are pressed into the part of assembling, be pressed into the axle direction length that assembling length represents to be pressed into the department of assembly.

In addition, in above-mentioned bearing means, if constitute: be pressed into the department of assembly and be arranged on, contain the wrapping angle elongation line of rolling bearing and the intersection point of the central axis of axle, and at axle direction is the plane, footpath at right angle and the crossing position of aperture surface of inner ring, be pressed into the department of assembly because be positioned near the point of action (intersection point of the central axis of wrapping angle elongation line and axle), so can reduce because the runout of the generation of the inclination of rolling bearing.If constitute by this, the precision of bearing top-joining part etc. need not become highi degree of accuracy, can access cheap and high-precision bearing means.

Here, the wrapping angle elongation line represents to connect the line that the straight line of two point of contact of the solid of rotation of rolling bearing and rail wheel prolongs in axle side (inner ring aperture surface side).

In above-mentioned bearing means, if form following formation: be pressed into the department of assembly and be arranged on, the axial position that deviates from respect to the intersection point of the central axis of the wrapping angle elongation line of rolling bearing and axle, because being pressed into the department of assembly deviates from from point of action, on inner ring and axle, be difficult to produce and crook, so can reduce NRRO.In addition, be difficult to be subjected to the influence of the out of roughness accuracy to shape of the outer diametric plane of axle, inner ring aperture surface.

Further, in the above-described configuration, the withdrawing portion that is pressed into assembling length that adjusts is set preferably on the aperture surface of the outer diametric plane of axle and/or inner ring.Like this, between axle and inner ring, form radial clearance,, also can adjust the length that is pressed into the department of assembly in the above range easily and correctly even the axial relative position of axle and inner ring changes by withdrawing portion.

For reaching above-mentioned the 3rd purpose, the invention discloses a kind of bearing means, possess outer ring with rolling bearing at the sleeve cylindraceous that is pressed into installation interior week, above-mentioned sleeve is installed and supportive device by assembling in the cylindrical portion of device, wherein,

With the department of assembly, outer ring and the device department of assembly that is assemblied in the above-mentioned sleeve periphery of above-mentioned cylindrical portion in week in the above-mentioned sleeve of the above-mentioned outer ring of assembling, in the axial direction dislocation and formation of above-mentioned sleeve,

On the periphery of device department of assembly of removing above-mentioned sleeve and the peripheral part relative, form the diameter reducing part of comparing path with the reference dimension of said apparatus department of assembly with department of assembly, above-mentioned outer ring.

In the bearing means that constitutes like this, if in sleeve, be pressed into the outer ring of rolling bearing, because the influence of the expansion by this department of assembly, outer ring that is pressed into, on the periphery of the sleeve periphery relative, occur and the initial size bulge of specific diameter size increase mutually with the department of assembly, outer ring.

But, department of assembly, outer ring and device department of assembly are in axle direction dislocation and setting, and the scope that the bulge of sleeve periphery occurs is compared the formation of path ground with the reference dimension of device department of assembly in advance, by suitably selecting the degree of path, surpass the reference dimension of device department of assembly so can prevent the external diameter of bulge.

In addition, the build-up tolerance between sleeve and the device is set suitable interference fit, can obtain sufficient adhesive strength by cooperation.

For reaching above-mentioned the 4th purpose, the invention discloses a kind of bearing means, have, the 1st bearing portion and the 2nd bearing portion along the axle arranged coaxial, when the inner track of above-mentioned the 1st bearing portion forms on above-mentioned axle, the inner track of above-mentioned the 2nd bearing portion forms on the inner ring that is assemblied in above-mentioned axle, and the middle helical spring that additional preload between above-mentioned the 1st bearing portion and above-mentioned the 2nd bearing portion is housed, wherein, the rigging position of above-mentioned axle and above-mentioned inner ring is with axis by above-mentioned with in the corresponding position, plane of the footpath direction of the intersection point of the elongation line of the wrapping angle of above-mentioned the 2nd bearing portion.

In the bearing means that constitutes like this, will with axis by axle and in the corresponding position, plane of the footpath direction of the intersection point of the elongation line of the wrapping angle of the 2nd bearing portion as the rigging position of axle and inner ring assembling.

Like this, when in axle, embedding the inner ring of the 2nd bearing portion, can suppress because the runout that produces with respect to the inclination of the inner ring of axle.

In addition, among the present invention, the outside dimension of outer ring is compared less with the outside dimension of outer ring in above-mentioned the 2nd bearing portion in above-mentioned the 1st bearing portion.

Compare with the outside dimension of outer ring in the 2nd bearing portion by the outside dimension that makes outer ring in the 1st bearing portion less, so in the pilot hole of the flange that the 1st, the 2nd bearing portion embeds, can be with the position of corresponding the 2nd bearing portion as wide diameter portion.

Thereby, can end difference be set in pilot hole, when on wide diameter portion, embedding the 2nd bearing portion, by the 2nd bearing portion of apical grafting on the end difference of wide diameter portion, so can in the position of standard the 2nd bearing portion be located simply.

In addition, among the present invention, solid of rotation in above-mentioned the 1st bearing portion and the solid of rotation in above-mentioned the 2nd bearing portion are same sizes.

Because the solid of rotation of the solid of rotation of the 1st bearing portion and the 2nd bearing portion becomes same size, so the solid of rotation separately of the 1st, the 2nd bearing portion can constitute by same parts.Thereby solid of rotation separately that can shared the 1st, the 2nd bearing portion reduces the accessory number.

Description of drawings

Fig. 1 is the axle direction sectional drawing of the bearing means that relates to of the 1st example of the present invention;

Fig. 2 is that the part of bearing means shown in Figure 1 enlarges sectional drawing;

Fig. 3 is the axle direction sectional drawing of the bearing means that relates to of the 2nd example of the present invention;

Fig. 4 is that the part of bearing means shown in Figure 3 enlarges sectional drawing;

Fig. 5 is the axle direction sectional drawing of the bearing means that relates to of the 3rd example of the present invention;

Fig. 6 is that the part of bearing means shown in Figure 5 enlarges sectional drawing;

Fig. 7 is the axle direction sectional drawing of the bearing means that relates to of the 4th example of the present invention;

Fig. 8 is that the part of bearing means shown in Figure 7 enlarges sectional drawing;

Fig. 9 is the axle direction sectional drawing of the bearing means that relates to of the 5th example of the present invention;

Figure 10 is that the part of bearing means shown in Figure 9 enlarges sectional drawing;

Figure 11 is the axle direction sectional drawing of the bearing means that relates to of the 6th example of the present invention;

Figure 12 is the axle direction sectional drawing of the bearing means that relates to of the 7th example of the present invention;

Figure 13 is the sectional arrangement drawing of the bearing means that relates to of expression the 8th example of the present invention;

Figure 14 is the sectional arrangement drawing of the bearing means that relates to of expression the 9th example of the present invention;

Figure 15 is the sectional arrangement drawing of the bearing means that relates to of expression the 10th example of the present invention;

Figure 16 is the sectional arrangement drawing of the bearing means that relates to of expression the 11st example of the present invention;

Figure 17 is the sectional arrangement drawing of the bearing means that relates to of expression the 12nd example of the present invention;

Figure 18 is the sectional arrangement drawing of the bearing means that relates to of expression the 13rd example of the present invention;

Figure 19 is the sectional arrangement drawing of the bearing means that relates to of expression the 14th example of the present invention;

Figure 20 is the explanatory drawing of the method for the expression axle runout of measuring rolling bearing;

Figure 21 is that the axle that is illustrated in rolling bearing is gone up bowing under load load, the explanatory drawing of the method whether evaluation axle runout changes;

Figure 22 is the chart of expression test result;

Figure 23 is the sectional arrangement drawing of the 16th example of the bearing means that the present invention relates to;

Figure 24 is the sectional arrangement drawing of the state before the installation of shell of bearing means shown in Figure 23;

Figure 25 is the B part expanded view of Figure 24;

Figure 26 is the sectional arrangement drawing of the 17th example of the bearing means that the present invention relates to;

Figure 27 is the sectional drawing of the 18th example of the bearing means that expression will the present invention relates to state of packing on shell;

Figure 28 is the sectional arrangement drawing of the 18th example of the bearing means that the present invention relates to;

Figure 29 is the sectional arrangement drawing of the 19th example of the bearing means that the present invention relates to;

Figure 30 is the axle direction sectional drawing of existing bearing device;

Figure 31 is that the part of bearing means shown in Figure 30 enlarges sectional drawing;

Figure 32 is the sectional arrangement drawing of expression the 15th example of the present invention;

Figure 33 is the sectional arrangement drawing of the state before the installation of shell of bearing means shown in Figure 32;

Figure 34 is the expanded view of the A part of Figure 33.

Embodiment

Below, based on the form of description of drawings enforcement of the present invention.

Fig. 1 is the axle direction sectional drawing of the bearing means that relates to of the 1st example of the present invention, and Fig. 2 is the sectional drawing of wanting portion that expression relates to the bearing means of identical example.Among Fig. 1, bearing means 110 is by a pair of deep groove ball bearing 111,111 of main shaft (axle) S of supporting spindle motor and support the shell cylindraceous 112 of those ball bearings 111,111 to constitute on same axis.

Shell 112 has the inner face with the outer diametric plane close fit of rolling bearing 111, at the inner face of this shell 112, forms end difference 113 as shown in Figure 2.Ball bearing 111 is made of outer ring 111a, inner ring 111b, solid of rotation 111c, retainer 111d etc.

The 112a of department of assembly of shell 112,112a assembles respectively at the outer diametric plane of outer ring 111a, the 112a of these departments of assembly, the shell inner face 112c between 112a and the end difference 113, as shown in Figure 2, with the external diameter of ball bearing 111 be the external diameter formation of outer ring 111a with comparing big footpath.

In addition, it is on the position that diametric plane 111e intersects outside the outer ring of plane, the footpath R at right angle and ball bearing 111 that the 112a of department of assembly of shell 112,112a are arranged on by the intersection point P of the elongation line L of the central axis A of ball bearing 111 and wrapping angle and with respect to the axle direction of ball bearing 111.In this example for the diameter of axle: the bearing 111 of 2mm, bearing width: 3mm, will from end difference 113 position of intersecting, the position about the cycle surface 2.1mm of top side mutually as diametric plane 111e outside the outer ring of plane, footpath R and ball bearing 111, with the axle direction length of the 112a of department of assembly of shell 112 as 0.6mm about.

Assemble under the occasion of the bearing means 110 that this example relates to, the fixing bearing 111 in left side among the figure on axle S moves shell 112 right side from figure to left, cycle surface is pushed up mutually with end difference 113.Then, from the bearing 111 on the right-hand embedding right side of shell 112, on the end difference 113 with after outer ring 111a pushes up mutually, by signature pressure amount control preload and the assembling of inner ring 111b.

In such formation,, as shown in Figure 2, form annular gap 114 between the outer diametric plane of outer ring 111a and the inner face 112c of shell 112 if be embedded in the outer ring 111a of ball bearing 111 at shell 112.Like this,, in the department of assembly, become minimumly,, can seek the raising of running accuracy so, do not exist shell at radially core shift and whirling with respect to the axle center with respect to the axis of rotation core shift even because outer ring 111a has to a certain degree with respect to the axle center.In addition, there is no need to carry out for outer ring 111a is not tilted with respect to the axle center abrasive machining end difference accurately, so can seek the reduction of cost.

Further, in this example, because at the central axis A of passing through ball bearing 111 and the intersection point of wrapping angle elongation line L, and with respect to the axle direction of ball bearing 111 112a of department of assembly that shell 112 is set on the position that diametric plane 111e intersects outside the outer ring of plane, the footpath R at right angle and ball bearing 111,112a, even outer ring 111a tilts, shell 112 tilts also minimum, so can be with at fixed main shaft S and the rotation runout inferior limit ground of the shell 112 under the occasion of shell 112 rotations is suppressed.

The present invention is not limited to above-mentioned example.For example, as the 2nd example of representing among Fig. 3 and Fig. 4, also be provided with on main shaft S than the little diameter reducing part 116 in the internal diameter footpath of inner ring 111b on the two ends of the axial region 115 that the inner ring 111b with ball bearing 111 can be assembled.If by such formation, because the annular gap 117 (with reference to Fig. 4) by forming between the aperture surface of inner ring 111b and diameter reducing part 116, the inclination of allowing inner ring 111b is so can reduce the influence that the inclination by inner ring 111b produces.

In addition, as the 3rd example of representing among Fig. 5 and Fig. 6,111,111 on a pair of ball bearing of supporting spindle S is provided with helical spring 18, has added axial preload by this helical spring 118 on the 111a of the outer ring of ball bearing 111.

Further, as the 4th example of representing among Fig. 7 and Fig. 8, at the two end part of shell 112 tackiness agent hand-hole 119 is set, make from this tackiness agent hand-hole 119, axial one side of the annular gap 114 that forms between the outer diametric plane of the inner face 112c of shell 112 and outer ring 111a makes by the center line of bearing and the intersection point of wrapping angle elongation line, and will be that the plane, footpath at right angle and the crossing position of outer diametric plane of above-mentioned ball bearing have the assembling of magnitude of interference ground with respect to the axle direction of above-mentioned ball bearing, the throttling of the degree that bonding material do not run off is set at another side, inject bonding material at annular gap 114, outer ring 111a and shell 112 also can by bonding material is fixing.

Even only depend under the hypodynamic occasion of the maintenance of magnitude of interference, also can strengthen by adhesion.

In addition, as the inner ring side in the 4th example of representing among Fig. 7 and Fig. 8, also in advance bonding material is applied on the diameter reducing part 116 that is arranged on the axle, make by the center line of bearing and the intersection point of wrapping angle elongation line on axial one side of diameter reducing part 116, and will be the plane, footpath at right angle and crossing magnitude of interference ground, the position assembling of outer diametric plane of above-mentioned ball bearing with respect to the axle direction of above-mentioned ball bearing, at another side the throttling of the degree that bonding material do not run off is set, inner ring 111b and axle also can by bonding material is fixing.

In addition, as the 5th example of representing among Fig. 9 and Figure 10, the cylinder 120 of the tape of the magnetic force record of the driving video tape that will turn round on shell 112 etc. is provided with also passable integratedly.

In the 3rd example of representing among Fig. 5 and Fig. 6, the little diameter reducing part 116 in internal diameter footpath than inner ring 111b is set on the both sides of the department of assembly 115 of the inner ring 111b of assembling ball bearing 111 and axle S, in the 6th example as shown in figure 11, also can only diameter reducing part 116 be arranged on opposition side (center side of axle S) with the outer casing end of department of assembly 115.Preheating shell 112 in the bearing means that the 6th example relates to wherein inserts and parts that assembling obtains axle S and bearing 111 and helical spring 118 son assembling in advance.

In addition, the 7th example as shown in figure 12, by being provided with in the end of shell 112 than the big aperture surface 112d of the external diameter face diameter of outer ring 111a, can be in shell 112 assembling ball bearing 111 easily.

As the rolling bearing of supporting spindle S, use the deep groove ball bearing with inner ring 111b in the 1st to the 4th example, the 5th example as representing among Fig. 9 and Figure 10 also can use the deep groove ball bearing that does not have inner ring.Further, the rolling bearing as supporting spindle S in above-mentioned each example uses deep groove ball bearing 111, but also can instead use angular contact bearing (ア Application ギユラ Yu Shaft is subjected to).

Figure 13 is the sectional arrangement drawing of the 8th example of expression bearing means of the present invention.Have axle S that becomes running shaft and a pair of rolling bearing 211 that is loaded in axial 2 places of leaving a S in the bearing means 210.

Rolling bearing 211 is to possess following ball bearing: be pressed into the inner ring 213 of assembling in the periphery of axle S, outer ring 214 is as the retainer 217 at the interval of a plurality of balls 215 of the solid of rotation of equipping between those Internal and external cycles and restriction ball separately.In the bearing means of this example, a pair of rolling bearing 211 is identical rolling bearings.

In a pair of rolling bearing 211, be loaded between the outer ring S around reel compression helical spring (below, be called helical spring.) 216, the preload of helical spring 216 on the direction that effect on each the outer ring 214 is left mutually.

On a pair of rolling bearing 211, as among the figure with shown in two dot dot dash, outer embedding shell 212 is also passable.

Those rolling bearing 211 is for possessing, and 214 the two ends in the outer ring prevent the seal construction of the sealed member 214b that spills of the oiling agent of filling between the Internal and external cycle 213,214.Sealed member 214b, by peripheral part is being carried out elasticity assembling or fastening on the end difference 214a of the axial direction that forms spot-facing on the outer ring 214, thereby 214 end is fixed in the outer ring.In addition, among each sealed member 214b,, form circle-shaped along peripheral part as the groove 214c of end difference of the wire rod of the end of assembling compression helical spring 216.When each rolling bearing 211 is assembled in axle S, the position is in the groove 214c of the interior distolateral sealed member 214b of the outer ring 214 of mutual subtend, and being used for conduct will be at 211 spring seat with the end positioning and fixing of the compression helical spring 216 of compressive state assembling of a pair of rolling bearing.

In the bearing means 210 of this example, by utilizing compression helical spring 216 to make the preload of effect on each outer ring 214, can prevent in each rolling bearing 211 rocking to the axial direction of Internal and external cycle 213,214 and ball, the reduction of disturbing sound when therefore seeking the axle rotation (, solemn silence).

In the outer diametric plane of axle S, be pressed into assembling inner ring 213 aperture surface be pressed into department of assembly (below, be called the department of assembly) 218 in axle direction devices spaced apart and setting.What this was pressed into department of assembly 218 is pressed into assembling length W, is set at below 1/3 with respect to the footpath (diameter of axle) of axle S.In addition, for guaranteeing to be pressed into the breakaway force of department of assembly, the assembling length that is pressed into that is pressed into the department of assembly is preferably more than 1/10 of the diameter of axle.In this example, be pressed in the department of assembly 218, being pressed into assembling length W becomes 1/4 with respect to diameter of axle setting.Outside axle on the diametric plane, be provided as the tool withdrawal groove 219 of withdrawing portion in the axle direction both sides of separately department of assembly 218.Tool withdrawal groove 219 is compared the diameter of axle with department of assembly 218 and is become than microrelief, guarantees radial clearance between the diametric plane outside inner ring aperture surface and axle.The tool withdrawal groove 219 of department of assembly 218 by being arranged on the axle direction both sides is pressed into assembling length W and forms equably at axle Zhou Fangxiang.

In this example, department of assembly 218 is arranged on the intersection point P of the central axis of the wrapping angle elongation line that contains ball bearing and axle S, and is the position that the aperture surface of plane, the footpath R at right angle and ball bearing inner race intersects at axle direction.

In addition, in this example, the diameter of axle is got 2mm, the wide 3mm that gets of ball bearing, sphere diameter is got 1.2mm, and the pitch circle of ball is directly got about 3.9mm, is pressed into assembling length W and gets 0.5mm, and wrapping angle is got 21 °.Wrapping angle consider the inner radial gap of rolling bearing 211 deviation, plane of trajectory orbital radius of curvature size and be preferably scope about 11 °～25 °.It is the position at center that department of assembly 218 preferably is set in the position of axially departing from about 0.4mm～0.9mm with the rail slot center from inner ring 213, in this example, is that the center is set with the position of departing from 0.8mm.

If the formation by this example, bearing means 210, can prevent crooking of bending shaft etc. reliably for axle, the rolling bearing of wide variety of sizes, the runout when suppressing rotation and seek the raising of running accuracy.

When this bearing means uses in the spindle motor of recording device, because will be pressed into assembling length as below 1/3 of the diameter of axle, even the back adds the impact fall etc. so pack into when spindle mounted, in device, in record regenerating, do not produce in the scope of failure and can suppress bending shaft.

In addition, because department of assembly 218 is arranged on by the wrapping angle elongation line of rolling bearing 211 and the intersection point of shaft centre line, and at axle direction is the position that the aperture surface of the plane, footpath at right angle and inner ring 213 intersects, thus be not pressed into fixing inner ring 213 inclination a little etc. influence and keep running accuracy.

Further, be pressed into assembling length W because can adjust, so (not having withdrawing portion etc. at inner ring) rolling bearing of the standard of can packing into by the tool withdrawal groove 219 that on the outer diametric plane of axle S, is provided with.

Figure 14 is the sectional arrangement drawing of the bearing means 220 that relates to of expression the 9th example of the present invention.In the example of following explanation, for the 8th example in the parts that illustrated etc. have the parts etc. of identical formation effect, in the drawings by paying same-sign or respective symbol, simplify or omit explanation.

In this example, on the outer diametric plane of axle S, do not form concavo-convex, the outer diametric plane of axle formation barrel surface (flat shape).

On the aperture surface of inner ring 223, the department of assembly 28 that magnitude of interference is arranged with the external diameter mask of axle S is set.On the axial both sides of department of assembly 228, the withdrawing portion 229 that the footpath of setting 228 inner ring aperture surfaces than the department of assembly is set significantly.Be provided with in the inner ring aperture surface between the outer diametric plane of the local of withdrawing portion 229 and axle S and form radial clearance.In other words, inner ring 223 is with respect to axle S, and interference fit in department of assembly 228 is in the 229 intermediate gaps assembling of withdrawing portion.

At department of assembly 228 that inner ring 223 is provided with and the 8th example similarly, be arranged on the intersection point P at the axle center of the wrapping angle elongation line that contains ball bearing and axle S, and be the position that the outer diametric plane of plane, the footpath R at right angle and ball bearing intersects at axle direction.

The assembling length W that is pressed into of department of assembly 228 is set at below 1/3 of the diameter of axle (being 1/4) here.

If by the formation of this example, bearing means 220 can similarly prove effective with the 8th example.In addition, department of assembly 228 and withdrawing portion 229 are set in inner ring 223, so there is no need to process especially for axle S because constitute.For the diameter of axle is formed equably, do not limit the axle direction position of rolling bearing 221 with respect to axle S.By making so a kind of axle, can be applicable to the various bearing meanss that the position of bearings is different, can easily obtain the bearing means of various forms.

In addition, it is all to there is no need to process the inner ring aperture surface accurately because only with department of assembly 228 accurately abrasive machining just can, so the processing transfiguration of inner ring 223 is easy.

Further, by roughly processing the outer diametric plane of axle S equably, rolling bearing 221 all roughly forms definitely in the power that is pressed into of any position of axle S rolling bearing 221, and management is pressed into power and breakaway force becomes easy.

Figure 15 is the sectional arrangement drawing of the bearing means that relates to of expression the 10th example of the present invention.

In the bearing means 230, the position difference with respect to bearing of the department of assembly 238 on the diametric plane that is arranged on a S is identical with the formation of the bearing means 210 of the 8th example.

It is same to be pressed into assembling length W and the 8th example, is set at (being 1/4) below 1/3 here with respect to the diameter of axle.

As shown in figure 15, department of assembly 238 is arranged on from the axle direction position of the axle direction position deviation of point of contact with ball 235 and inner race track face.Here, department of assembly 238 is arranged on an opposite side of a side of the point of contact with ball 235 and inner ring 233.

Particularly, the department of assembly 238 of rolling bearing 231 on one side, from enclosing the center of 233 width within it, preferably being arranged on rolling bearing 231 1 sides to another side is the position at center in the position that axle direction departs from about 0.4mm～0.9mm, in this example, be arranged on the position of departing from 0.8mm.

If the formation by this example because department of assembly 238 is arranged on the axle direction position of departing from from the position of point of contact with ball 235 and inner race track face, is crooked so be difficult to generation in the running portion that the ball with the inner race track face contact.For this reason, can reduce the NRRO of bearing means 230.In addition, when the running of bearing means 230, the become influence of the out of roughness accuracy to shape that is difficult to be subjected to the outer diametric plane of axle, inner ring aperture surface of rotary driving part.Thereby, process axle S and inner ring 233 easily.

Figure 16 is the sectional arrangement drawing of the bearing means that relates to of expression the 11st example of the present invention.

In the bearing means 240,, identical with the formation of the bearing means 220 of the 9th example except the position difference for bearing of the department of assembly on the aperture surface that is arranged on inner ring 243 248.

As shown in figure 16, department of assembly 248 is arranged on from the axle direction position of the axle direction position deviation of point of contact with ball 245 and inner race track face.Here, department of assembly 248 is arranged on an opposite side of a side of the point of contact with ball 245 and inner ring.

Particularly, the department of assembly 248 of rolling bearing 241 on one side, from enclosing the center of 243 width within it, preferably being arranged on rolling bearing 241 1 sides to another side is the position at center in the position that axle direction departs from about 0.4mm～0.9mm, in this example, be arranged on the position of departing from 0.8mm.

At the outer ring of a pair of rolling bearing 241 244 China and foreign countries' embedding shells 244.

If the formation by this example can access the effect identical with the 10th example.

In addition, there is no need to process especially, can only carry out the processing of the department of assembly of inner ring for axle S.

Figure 17 is the sectional arrangement drawing of the bearing means that relates to of expression the 12nd example of the present invention.

Make the rolling bearing 251A with the 8th example same size, and than the bigger rolling bearing 251B of the external diameter of this rolling bearing 251A outer ring between axle direction from and in axle S, be pressed into assembling.Embedding shell 252a outside on a pair of rolling bearing 251A, 251B.The side of rolling bearing 251A one side of the another side of the outer ring of rolling bearing 251B, contact is on the end difference 252c that forms on the inner peripheral surface of shell 252a.In Figure 17,254c is illustrated in the end difference that the outer ring aperture surface forms, and 254d represents sealed member, and 254e represents the groove of sealed member 254d.End difference 254c and sealed member 254d and groove 254e are respectively with identical in the formation described in the above-mentioned example.

In axle S, the tool withdrawal groove 259 in footpath that becomes outer diametric plane than microrelief between axle direction from and be provided with 2.On the axle direction both sides of each tool withdrawal groove 259, in the place of the outer diametric plane of axle of adjacency, only be pressed into the part 258 of the inner ring aperture surface of running in bearings in the place on one side.The part of the remainder of inner ring aperture surface, the position on the tool withdrawal groove 259 and and tool withdrawal groove between form radial clearance.On the axle S of a pair of rolling bearing, be pressed into the part 258 of the inner ring aperture surface of assembling, be assemblied in a side that departs from from the rolling bearing of another side.The assembling length W that is pressed into of this part 258 and axle S is set at below 1/3 (for example 1/4) with respect to the diameter of axle.

Shell 252a with, the cylinder 252b that the magnetic force recording tape running of video tape etc. is driven constitutes also passable integratedly.

Figure 18 is the sectional arrangement drawing of the bearing means that relates to of expression the 13rd example of the present invention.

The bearing means 260 of this example is not by helical spring additional preload in rolling bearing, but by making outer ring 264 contacts add preload (fixed position preload) on the end difference 262d in being formed on shell 262a cylindraceous.S is identical with the 8th example for axle.

In the bearing means 260, at the outer circumferential side assembling engine housing 262b of shell 262a.On the inner peripheral surface of the cylindrical part of engine housing 262b, be arranged between axle direction from 2 fitting tab 262c.Fitting tab 262c has the magnitude of interference at the width of the Zhou Fangxiang of cylindrical part inner peripheral surface homogeneous.Then, those fitting tabs 262c, with a pair of rolling bearing 261 between in the corresponding place, be pressed into assembling at the outer circumferential face of shell 262a.

In the bearing means 260, the position that is pressed into assembling of shell 262a and engine housing 262b is the position from the position deviation that is pressed into assembling of rolling bearing 261 and shell 262a.For this reason, the influence that is pressed into assembling of shell 262a and engine housing 262b passes less than bearing 261.

Figure 19 is the sectional arrangement drawing of the bearing means that relates to of expression the 14th example of the present invention.Bearing means 270 is not by helical spring additional preload in rolling bearing, but adds preload (fixed position preload) by outer ring 274 contacts that make rolling bearing 271 in shell 272 cylindraceous.Department of assembly 278 and the tool withdrawal groove 279 of axle S are identical with the 10th example.Bearing means 270 is examples of reel cage pivot (スイ Application グア one system ピボ Star ト).

Particularly, on the inner peripheral surface of shell 272, form end difference 272a.On the inner peripheral surface of shell 272, form the face 272b at right angle between axle direction both sides and the end difference 272a with respect to inner peripheral surface.This face 272b is the top-joining part of the contacts side surfaces of outer ring 274.

The position forms assembly section (embedding generation) 272c in the both sides of top-joining part 272b and in the face of outside diameter depression in the mode with top-joining part 272b axle direction adjacency.The inner end of assembly section 272c diametric plane outside the outer ring of rolling bearing 271 (end of the space side of a pair of roller bearing shop) is pressed into assembling.The part that assembly section 272c is not set of concave face in the outside diameter of side face both end sides in the enclosure, on the external diameter face of outer ring by the footpath direction on the gap configuration of ring-type, close with the outer ring outside the gap of diametric plane.

If by above-mentioned formation, after the bearing means assembling, because can be crooked, so there is not the variation of the inclination of running shaft by axle such as impact S.

Figure 20 represents to use the rolling bearing 211 described in the 8th example, and fixedly the method for the axle runout a when S is rotated in the front and back of initial and bowing under load load, is measured in the outer ring 214 on both sides.

In the outer circumferential face of axle S, on one side the end on the contact displacement analyzer 280 (for example electric micrometers) the 280a of inspection portion.When a S was rotated, the displacement of the footpath direction of axle S was examined the 280a of portion and measures, and measured a runout based on the displacement of measuring by displacement analyzer 280.

In addition, Figure 21 represents one side of stationary axle S, and load load on the another side of the axle direction vertical with axle is estimated the method whether the axle runout changes.

Secondly, for confirming effect of the present invention, make to be pressed into relation that the axle runout before and after assembling length and the load load changes clearly by test described as follows with respect to the diameter of axle.

In this test,, prepare the ratio that is pressed into assembling length with respect to the diameter of axle and be 90%, 50%, 40%, 30%, 20% bearing means (among Figure 22 respectively as A～E as the bearing means of supplying with test usefulness.)。In the bearing means separately, the diameter of axle is got 2mm, and the width of rolling bearing is got 3mm, and the spacing between bearing ball is got 6.8mm, and shaft length is got 19mm.In addition, in the bearing means of supplying with test usefulness load as the 30N of flexural load F.Then, the axle runout that the front and back of bowing under load load carry out representing in Figure 20 in bearing means is measured.Be pressed into locomotivity and adjust magnitude of interference, all in the scope from 50N to 60N.

The result of this test is represented in the chart of Figure 22.

As shown in figure 22, before the load load separately bearing means A～E the axle runout do not have big difference.But, after the bowing under load load,, compare the variation of a runout with other bearing means A～C and almost can't see being pressed among 30%, 20% bearing means D, the E of assembling length as the diameter of axle.That is, will be pressed into 30%, 20% bearing means D, the E of assembling length as the diameter of axle, compare according to the influence of load load for a short time with other bearing means A～C, running accuracy is good.

Figure 32 is the sectional arrangement drawing of the 15th example of the bearing means that the present invention relates to of expression.

In this bearing means 1, the outer ring 3a of a pair of rolling bearing 3 possesses the sleeve cylindraceous 5 that is pressed into installation in week, by assembling installing sleeve 5 in the cylindrical portion 7a of the shell 7 of motor, and is supported by shell 7.

A pair of rolling bearing 3 is so-called ball bearings, possesses: outer ring 3a, inner ring 3b is equipped in a plurality of ball 3c between those Internal and external cycles, keeps the retainer 3d at the mutual interval of ball 3c and stops up the sealed member 3e of bearing openings at two ends portion.The main shaft 9 of motor is freely supported in the inner ring 3b rotation of this rolling bearing 3.

In the sleeve 5, the 5a of department of assembly, outer ring that is pressed into outer ring 3a is assemblied in the two ends in interior week.Week is compared undergauge with the 5a of department of assembly, outer ring in the sleeve between a pair of 5a of department of assembly, outer ring, forms the ladder 5b with the location, end of outer ring 3a.

The periphery of above-mentioned sleeve 5 is the certain simple structure of external diameter, and intermediate portion is formed for being assemblied in the 5c of device department of assembly on the cylindrical portion 7a.

Above-mentioned bearing means 1 as shown in figure 33, is pressed on sleeve 5 a pair of rolling bearing 3 is installed, and after the assembled state that makes a pair of rolling bearing 3 supporting spindles 9 forms, assembling installing sleeve 5 on cylindrical portion 7a.

But, in the sleeve 5 of above-mentioned bearing means 1, as shown in figure 34, because the influence of the expansion of the 5a of department of assembly, outer ring that is pressed into by outer ring 3a, occur in the sleeve periphery than the bulge 5d of the bigger outer diameter D 1 of the basic major diameter dimension D 0 of the device 5c of department of assembly.

For this reason, if basic major diameter size with the 5c of device department of assembly of sleeve 5, in advance by assembling with become and cylindrical portion 7a between can access the interference fit of sufficient adhesive strength mode set, bulge 5d is blocked by cylindrical portion 7a so, the occasion that just exists assembly manipulation to become extremely difficult.In addition, if assembling limpingly, the 5a of department of assembly, outer ring exceedingly oppresses outer ring 3a so, crooks in rolling bearing 3, has the danger of the verticity reduction that makes rolling bearing 3.

Thereby, for this embodiment who further considers in following explanation.

Figure 23 is the sectional arrangement drawing of the 16th example of the bearing means that the present invention relates to.

The bearing means 311 of the 16th example, support for example main shaft 309 of the drum spindle motor of VRC, tape stream usefulness, the outer ring 303a of a pair of rolling bearing 303 possesses the sleeve cylindraceous 313 that is pressed into installation in week, by assembling installing sleeve 313 in the cylindrical portion 307a of the shell 307 of motor, and supported by shell 307.In this example, sleeve 313 assembling is installed on the shell 307 of motor, also can be assemblied on the cylinder of for example motor stator, spindle motor.

A pair of rolling bearing 303 is so-called deep groove ball bearings, possess: outer ring 303a, inner ring 303b is equipped in a plurality of ball 303c between those Internal and external cycles, keeps the retainer 303d at the mutual interval of ball 303c and stops up the sealed member 303e of bearing openings at two ends portion.The main shaft 309 of motor is freely supported in the inner ring 303b rotation of this rolling bearing 303.

In the sleeve 313, the 313a of department of assembly, outer ring that is pressed into outer ring 303a is assemblied in the two ends in interior week.In week, compare undergauge in the sleeve between a pair of 313a of department of assembly, outer ring, form ladder 313b the location, end of outer ring 303a with the 313a of department of assembly, outer ring.

In the sleeve 313 of this example, intermediate portion in periphery, be assemblied in the 313c of device department of assembly on the cylindrical portion 307a by setting, constitute with the 313a of department of assembly, outer ring in week in the sleeve of assembling outer ring 303a with at the 313c of the device department of assembly of the sleeve periphery of assembling on the cylindrical portion 307a with on the axial direction of sleeve 313, misplacing.

In addition, under the occasion of this example, in the sleeve 313, because the influence of the expansion of the 313a of department of assembly, outer ring that is pressed into by outer ring 303a, do not appear at the mode of the periphery of sleeve 313 with bulge than the bigger external diameter of the basic major diameter dimension D 0 of the device 313c of department of assembly, remove the 313c of device department of assembly and on the peripheral part periphery of the sleeve 313 relative, have the diameter reducing part 313e of external diameter that reference dimension D0 with the device 313c of department of assembly is in a ratio of the D2 of path with the 313a of department of assembly, outer ring.

Above-mentioned bearing means 311 as shown in figure 24, is pressed on sleeve 313 a pair of rolling bearing 303 is installed, and after the assembled state of a pair of rolling bearing 303 supporting spindles 309 is formed, assembling installing sleeve 313 on cylindrical portion 307a.

In above-mentioned bearing means 311, if on sleeve 313, be pressed into the outer ring 303a of rolling bearing, as shown in figure 25, so because the influence of the expansion by this 313a of department of assembly, outer ring that is pressed into, on the periphery of the periphery of the sleeve relative with the 313a of department of assembly, outer ring, the bulge 314 that increases than initial size footpath size appears.

But, 313a of department of assembly, outer ring and the device 313c of department of assembly set in the axle direction staggered positions, and the scope that the bulge 314 of sleeve periphery occurs forms path than the reference dimension of the device 313c of department of assembly in advance, therefore by setting the degree of path aptly, can prevent that the external diameter of bulge 314 from surpassing the reference dimension D0 of the 313c of device department of assembly.

Thereby, on the cylindrical portion 307a of the crust of the device of motor etc. during assembling sleeve 313, because the bulge 314 that the influence of the expansion of the 313a of department of assembly, outer ring that is pressed into of the outer ring 303a by rolling bearing occurs is not blocked by housing 307, with can be directly with the build-up tolerance of the predefined device 313c of department of assembly, do not assemble not difficultly, can seek the raising of assembling operation.

In addition, the build-up tolerance between sleeve 313 and the device case 307 is set at suitable magnitude of interference in advance, can access sufficient adhesive strength by assembling.Thereby, can prevent to result from inappropriate generation of change, inclination etc. of rigging position of the lax sleeve 313 of assembling, the raising of the installation precision by sleeve 313 can be sought the raising of bearing performance.

In the sleeve of the bearing means that the present invention relates to, the configuration of department of assembly, outer ring, device department of assembly etc. are not limited to above-mentioned example.

For example, also can be used as the form of the 17th example of in Figure 26, representing.

Under the occasion of the bearing means 321 of the 17th example, by on the interior week at the two ends of sleeve 325 cylindraceous, equipment is pressed into the 325a of department of assembly, outer ring of the outer ring 323a that rolling bearing 323 is installed respectively, and will be pressed into the sleeve 325 that a pair of rolling bearing 323 is installed and on the cylindrical portion 307a of device case 307, assemble installation, and be supported by device case 307.

In addition, under the occasion of the bearing means 321 of the 17th example, the 325a of department of assembly, outer ring in week in the sleeve of assembling outer ring 323a, when on the axial direction of sleeve 325, misplacing and forming at the 325c of the device department of assembly of the sleeve periphery of assembling on the cylindrical portion 307a, remove the 325c of device department of assembly, and on the peripheral part periphery of the sleeve 325 relative, form the diameter reducing part 325e that is in a ratio of path with the reference dimension D0 of the device 325c of department of assembly with the 325a of department of assembly, outer ring.

But under the occasion of the 17th example, the 325a of department of assembly, outer ring constitutes near assembling entering the end of sleeve inboard of the outer ring 323a in the sleeve is kept.

Then, clamping the mode of the 325a of this department of assembly, outer ring, on each of the end of sleeve periphery and intermediate portion, the configuration external diameter is set to the 325c of device department of assembly of reference dimension D0.

Like this, even under the occasion of form of the configuration of the change 325a of department of assembly, outer ring, the device 325c of department of assembly, also can access above-mentioned action effect.

In above-mentioned example,, use to have the deep groove ball bearing of Internal and external cycle, but also can use deep groove ball bearing with inner ring as the rolling bearing of supporting spindle.Further, replace deep groove ball bearing, also can consider to use angular contact bearing, other rolling bearing.

As shown in figure 27, in the bearing means 410 of the 18th example, have along the 1st bearing portion 415 and the 2nd bearing portion 425 as axle 412 arranged coaxial of the drum spindle motor (figure is expression) of the VRC of an example, tape stream usefulness, when the inner track 413 of the 1st bearing portion 415 forms on the periphery of axle 412, the inner track 427 of the 2nd bearing portion 425 is formed on the inner ring 426 that is assemblied on the axle 412, and the helical spring 435 that is used for additional preload between 1 bearing portion 415 and the 2nd bearing portion 425 is loaded into.

In this bearing means 410, the 1st, the 2nd bearing portion 415,425 is assemblied in the pilot hole 441 of cylinder 440 etc. for example and is used.

In addition, in the bearing means 410 as shown in figure 28, the axle 412 and the assembling position 433 (rigging position) of inner ring 426 are located in the corresponding position of footpath direction plane with the intersection point 447 of the elongation line 446 of axis 445 by axle 412 and the wrapping angle α in the 2nd bearing portion 425.

In the axle 412, form on the periphery above the assembling position 433 internal diameter with inner ring 426 be in a ratio of path on minor diameter part 414A, on periphery below the assembling position 433, form and the internal diameter of inner ring 426 following minor diameter part 414B than path.Like this, can make the contacting part of inner ring 426 and axle 412 only be assembling position 433.

Like this, when forming assembling position 433, by the minor diameter part 414A about the formation separately up and down at assembling position 433,414B, even the inner ring 426 of the 2nd bearing portion 425 tilts with respect to the axis 445 of axle 412, because the core shift of outer ring 428 is minimum, so just can not core shift and whirling with respect to 440 412 on cylinder.

Therefore, there is no need for inner ring 426 being tilted with respect to axle 412 and improving machining accuracy, so can seek the reduction of cost.

In the 1st bearing portion 415, has outer ring 416 in pilot hole 441 assemblings of cylinder 440, a plurality of rotor 417 of configuration between this outer ring 416 and inner track 413, the retainer 418 that keeps a plurality of rotor 417 keeps the sealed member 419 and the spring seat 421 of oiling agent in bearing.

Inner track 413 is the profile of imitative rotor 417 on the periphery of axle 412 and the curved recessed portion that forms the ring-type of section circular arc.

In the 2nd bearing portion 425, has the inner ring 426 that embeds on the axle 412, the outer ring 428 that embeds on the wide diameter portion 442 in the pilot hole 441 of cylinder 440 (also can with reference to Fig. 7), a plurality of rotor 429 of configuration between inner ring 426 and outer ring 428, the retainer 431 that keeps a plurality of rotor 429 keeps the sealed member 432 of oiling agent in bearing.

The outer ring 416 of the 1st bearing portion 415, its outside dimension are compared lessly with the outside dimension of the outer ring 427 of the 2nd bearing portion 425 and are set.

Therefore, in the pilot hole 441 of the flange 440 that embeds in the 1st, the 2nd bearing portion 415,425, the position of corresponding the 2nd bearing portion 425 can be formed wide diameter portion 442.Like this, can end difference 443 be set on pilot hole 442, when on wide diameter portion 442, embedding the 2nd bearing portion 425,, bearing means 410 can be positioned simply the position of standard by apical grafting bearing portion 425 on the end difference 443 of wide diameter portion 442.

In addition, the rotor 429 of the rotor 417 of the 1st bearing portion 415 and the 2nd bearing portion 425 is set at same size.

Therefore, the rotor separately of the 1st, the 2nd bearing portion 415,425 can be constituted by same parts.Like this, because rotor separately that can shared the 1st, the 2nd bearing portion 415,425, so can reduce components number and seek the reduction of cost.

In the time of configuration helical spring 435 between the 1st, the 2nd bearing portion 415,425, the spring seat 421 of an end 436 contact the 1st bearing portion 415 of helical spring 435, the sealed member 432 of the other end 437 contacts the 2nd bearing portion 425 of helical spring 435.

Like this, between the 1st bearing portion 415 and the 2nd bearing portion 425, can add axial preload.

In this helical spring 435, the 1st bearing portion 415 sides, when promptly an end 436 sides form path, the 2nd bearing portion 425 sides, promptly the other end 437 sides form big footpath, become megarelief gradually into a cone shape from an end 436 to the other end 437 footpaths.Below, the reason that helical spring 435 is formed cone-shaped is described.

That is, in assembling during bearing means 410, enclose oiling agent when setting outer ring 416, a plurality of rotor 417, retainer 418 on the inner track 413 that on axle 412, forms, thereafter by sealed member 419 and spring seat 421 seal lubrication agent.

Secondly, after setting helical spring 435, outside the inner track of the inner ring 426 of the 2nd bearing portion 425, enclose oiling agent when setting outer ring 428, a plurality of rotor 429, retainer 431, to by the inner ring 426 of sealed member 432 seal lubrication agent on axle 412 embed thereafter.

Like this, by helical spring 435 is formed cone-shapeds, can by sealing plate the spring seat of recess double as the 2nd bearing portion 425 sides, can seek the reduction of cost.

And, be assemblied on the inner ring 426 of axle 412 by the inner track that forms the 2nd bearing portion 425, can improve the assembling performance of bearing means 410.

Further, on the periphery of axle 412, form, the external diameter of the outer ring 416 of the 1st bearing portion 415 can be formed path and form load capacity greatly by inner track 413 with the 1st bearing portion 415.

Secondly, based on Figure 29 the 19th example is described.In the 19th example, pay same-sign and omit explanation for the parts identical with the 18th example.

As shown in figure 29, in the bearing means 450 of the 19th example, forming too on this aspect of drum type different with the 18th example at the helical spring 455 of configuration between the 1st, the 2nd bearing portion 415,425.

That is, in the helical spring 455, when an end 456 of the 1st bearing portion 415 sides formed path, the other end 457 sides of the 2nd bearing portion 425 sides formed path, and central part 458 forms big footpath.

In the 1st bearing portion 415, when the spring seat 421 of an end 456 of contact helical spring 455 is set, in the 2nd bearing portion 425, the spring seat 461 of the other end 457 of contact helical spring 455 is set.

In addition, the helical spring between the 1st, the 2nd bearing portion 415,425 replaces forming the too helical spring 455 of drum type, the helical spring of the flat that also can using passes through forms identical path.

In above-mentioned example, example on the axle 412 of the relevant drum spindle motor that bearing means 410 is applied in VRC, tape stream usefulness is described, but be not limited to these, also can be enclosed in the magnetic disk memory spindle motor of LBP for example, on the rotation support part of the reel cage of HDD, other the motor with motor, HDD motor etc.

Further, among the present invention, be not limited to each above-mentioned example, can carry out suitable distortion, improvement etc., the material property of illustrative axle the 412, the 1st, the 2nd bearing portion 415,425, helical spring 435,455 grades in each above-mentioned example, shape, size, form, number, allocation position, if it just can be arbitrarily that thickness sizes etc. can be reached the present invention, unqualified.

Utilize possibility on the industry

As above-mentioned explanation, if by the present invention, even because the outer ring tilts with respect to the axle center, in the department of assembly of housing and outer ring outside core shift become minimum, so, do not have housing core shift and whirling with respect to the axle center.In addition, with respect to housing, the axle center does not tilt yet.Thereby, can tilt and highi degree of accuracy abrasive machining end difference with respect to the axle center in order not make the outer ring, so can seek the reduction of cost.

In addition,,, can suitably set and be pressed into assembling length, can provide to make to be applied to the bearing means that the stress on inner ring and the axle reduces and running accuracy is improved for the axle of various sizes and the combination of rolling bearing if by the present invention.

In addition, if by bearing means of the present invention, if on sleeve, be pressed into the outer ring of rolling bearing, because the influence of the expansion by this department of assembly, outer ring that is pressed into, on the periphery of the periphery of the sleeve relative with the department of assembly, outer ring, the bulge that increases than initial size footpath size occurs.

But, department of assembly, outer ring and device department of assembly are in axle direction staggered positions and setting, and the scope that the bulge of sleeve periphery occurs forms path than the reference dimension of device department of assembly in advance, so, can prevent that the external diameter of bulge from surpassing the reference dimension of device department of assembly by setting the degree of path aptly.

Thereby, on the cylindrical portion of the device case of motor etc. during the assembling sleeve, because the bulge that the influence of the expansion of the department of assembly, outer ring that is pressed into of the outer ring by rolling bearing occurs is not blocked by housing, direct build-up tolerance with predefined device department of assembly, can not assemble not difficultly, can seek the raising of assembling operation.

In addition, the build-up tolerance between sleeve and the device case is set at suitable magnitude of interference, can access sufficient adhesive strength by assembling.Thereby, can prevent to result from inappropriate generation of change, inclination etc. of rigging position of the lax sleeve of assembling, can seek the raising of bearing performance by the raising of installation precision.

In addition, if by the present invention, the position corresponding to the footpath direction plane of the axis that will be by axle and the intersection point of the elongation line of the wrapping angle in the 2nd bearing portion is as the rigging position of axle and inner ring assembling.

Like this, when the inner ring with the 2nd bearing portion embeds, can suppress core shift on axle with respect to the inner ring of axle.And, even at the inner ring of the 2nd bearing portion with respect to axle a little under the occasion of earth tilt, also the core shift of the outer ring of the 2nd bearing portion can be suppressed for minimum the axle runout to be suppressed for minimum.

Thereby, can be for inner ring being tilted with respect to axle and exceedingly improving machining accuracy, so can seek the reduction of cost.

In addition, form, in the pilot hole of the flange that embeds in the 1st, the 2nd bearing portion, the position of corresponding the 2nd bearing portion can be formed wide diameter portion by the outside dimension of the outer ring in the outside dimension of the outer ring in the 1st bearing portion and the 2nd bearing portion is compared tinily.

Like this, can end difference be set on pilot hole, when on wide diameter portion, embedding the 2nd bearing portion,, the 2nd bearing portion can be positioned simply the position of standard by apical grafting bearing portion on the end difference of wide diameter portion.Thereby, can bearing means be assembled simply with not taking time and energy.

In addition, by the rotor of the 1st bearing portion and the rotor of the 2nd bearing portion are set at same size.The rotor separately of the 1st, the 2nd bearing portion can be constituted by same parts.

Like this, because rotor separately that can shared the 1st, the 2nd bearing portion, so can reduce components number and seek the reduction of cost.

Detailed, the specific example of above reference has illustrated the present invention, as those skilled in the art, without departing from the spirit and scope of the present invention, can add all changes, correction.

The application is based on following application, Japan's special permission application of application on September 21 calendar year 2001 2001-288548 number, Japan's special permission application of application on February 25th, 2002 2002-047899 number, Japan's special permission application of application on February 22nd, 2002 2002-046326 number, Japan's special permission application of application on June 21st, 2002 2002-181639 number, its content is here taken as reference.

Claims

1. bearing means, wherein, assembling retainer shaft and a pair of rolling bearing that supports this on same axis, it is characterized in that, it at the intersection point of central axis by bearing and wrapping angle elongation line and with respect to the axle direction of above-mentioned rolling bearing the department of assembly that is provided with on the inner ring aperture surface of the plane, footpath at right angle and the above-mentioned rolling bearing position of intersecting with above-mentioned axle, and, be provided with diameter reducing part at the two ends of department of assembly.

2. bearing means as claimed in claim 1, it assembles maintenance on above-mentioned same axis, it is characterized in that, from the shaft outside diameter of above-mentioned department of assembly to the ball side, is provided with than the less diameter reducing part in footpath of the inner ring inside diameter of above-mentioned rolling bearing.

3. bearing means as claimed in claim 1 or 2, wherein, above-mentioned rolling bearing is a deep groove ball bearing.

4. bearing means as claimed in claim 1 or 2, wherein, above-mentioned rolling bearing is an angular contact bearing.

5. bearing means, have, axle and be pressed into the inner ring that is assemblied on this, it is characterized in that, make the assembling length that is pressed into that is pressed into the department of assembly between above-mentioned axle and above-mentioned inner ring become below 1/3 of the diameter of axle, axial length at above-mentioned shell is shorter than the axial length of outer ring, and the axial end of the department of assembly of shell is from axially seeing the inboard of the axial both ends of the surface that are positioned at foreign steamer.

6. bearing means as claimed in claim 5 is provided for adjusting the described withdrawing portion that is pressed into assembling length on the outer diametric plane of described axle.

7. bearing means as claimed in claim 5 is provided for adjusting the described withdrawing portion that is pressed into assembling length on the aperture surface of described inner ring.

8. a bearing means has, and axle is pressed into the rolling bearing that is assemblied in the inner ring on this with possessing, it is characterized in that, make the assembling length that is pressed into that is pressed into the department of assembly between above-mentioned axle and above-mentioned inner ring become below 1/3 of the diameter of axle, and, diameter reducing part be provided with at the two ends of department of assembly.

9. bearing means as claimed in claim 8, wherein, the described department of assembly that is pressed into is arranged on, and contains the wrapping angle elongation line of rolling bearing and the intersection point of central axis of axle, and is the position that the aperture surface of the plane, footpath at right angle and described inner ring intersects at axle direction.

10. bearing means as claimed in claim 8, wherein, the described department of assembly that is pressed into is arranged on, with respect to the axial position that deviates from of the intersection point of the central axis of the wrapping angle elongation line of rolling bearing and axle.

11., wherein, have the shell of the outer diametric plane of the outer ring of supporting described rolling bearing as each described bearing means in the claim 8～10.

12., wherein, on the outer diametric plane of axle, be provided for adjusting the withdrawing portion that is pressed into assembling length as each described bearing means in the claim 8～10.

13., wherein, on the aperture surface of inner ring, be provided for adjusting the withdrawing portion that is pressed into assembling length as each described bearing means in the claim 8～10.

14. bearing means, have, the 1st bearing portion and the 2nd bearing portion along the axle arranged coaxial, when the inner track of above-mentioned the 1st bearing portion forms on above-mentioned axle, the inner track of above-mentioned the 2nd bearing portion forms on the inner ring that is assemblied in above-mentioned axle, and the middle helical spring that additional preload between above-mentioned the 1st bearing portion and above-mentioned the 2nd bearing portion is housed, it is characterized in that, the rigging position of above-mentioned axle and above-mentioned inner ring, be with axis by above-mentioned axle with in the corresponding position, plane of the footpath direction of the intersection point of the elongation line of the wrapping angle of above-mentioned the 2nd bearing portion, and, be provided with diameter reducing part at the two ends of department of assembly.

15. bearing means as claimed in claim 14 is characterized in that, compares less at the outside dimension of the figure of China and foreign countries of above-mentioned the 1st bearing portion with the outside dimension of outer ring in the 2nd bearing portion.

16. bearing means as claimed in claim 14 is characterized in that, solid of rotation in above-mentioned the 1st bearing portion and the solid of rotation in above-mentioned the 2nd bearing portion are same sizes.