CN1831347A - Hydrodynamic bearing and method for manufacturing the same, and spindle motor and method for manufacturing the same - Google Patents

Abstract

The invention relates to a dynamic liquid bearing which can confirm axial space needed in working, and relative production, and main axle motor, wherein said bearing (101) at least comprises axle (7), an axle sleeve (8) rotationally relative to the axle (7), the first cam element (6) fixed on the axle (7), and the second cam element (9) fixed on the axle (7). In addition, said production comprises: 1, sheathing axle sleeve (8) on the axle (7); inserting second cam element (9) into axle (7); 2, pushing the axial upper end of second cam element (9); 3, holding said pushing operation, welding axle (7) and the second cam element (9), to fix the second cam element (9) on the axle (7).

Description

Hydrodynamic bearing and manufacture method thereof, spindle motor and manufacture method thereof

Technical field

The present invention relates to be used for Hydrodynamic bearing and manufacture method, spindle motor and the manufacture method thereof of spindle motor etc.

Background technique

In recent years, carry at hard disk drive (below, be called HDD) and wait the spindle motor on the disk drive device, employing can realize hanging down the fluid bearing electric machine of NRRO or low noise by the non-contact rotation.

About the electric machine structure of this fluid bearing electric machine, Hydrodynamic bearing in the past (for example, with reference to patent documentation 1) as shown in Figure 9, constitutes the parts of screw fixed axle 103 sides by axle 103, tapering part 106, axle sleeve 112, a taper bearing shell watt back of the body 108.In this example, on the axle 103 of tapering part 104 with double as radial bearing thrust-bearing, chimeric tapering part 106 with same tapering, fixing with fastening cover 114.In addition, on axle sleeve 112, the chimeric taper bearing shell watt back of the body 108.Then, between the tapering part of axle 103 and the taper bearing shell watt back of the body 108, be full of lubricating fluid.

When making so Hydrodynamic bearing, be pressed into or tackiness agent etc. engages between above-mentioned each parts by employing, have necessary strength, can realize miniaturization simultaneously.As concrete method, adopt and to utilize the chimeric method of hot pressing, or utilize the bonding construction from part etc. of tackiness agent.But all methods for example all exist because of the dimensional changes of component parts or to components interior to flow into tackiness agent, finally reduce the problem of bearing performance.

Therefore, in recent years Hydrodynamic bearing (for example, with reference to patent documentation 2) in, on the part of axle 7, form heavy caliber portion (the 1st vibrating part) 6 as the 1st sealed member, insert axle sleeve 8 here, keep the thrust clearance of regulation on one side, Yi Bian be pressed into the 2nd vibrating part 9 (for example, with reference to Fig. 2) as the 2nd sealed member.In addition, Fig. 2 is the diagram of the formation of expression Hydrodynamic bearing of the present invention, but is used to illustrate the formation of Hydrodynamic bearing in the past here for convenience.But also there is the burr that is pressed into formation in it when being pressed into the 2nd vibrating part 9 in axle 7, and this burr enters bearing part inside, reduces the problem of bearing performance, although the generation frequency of this problem is little, also is inherent.Therefore, for burr does not take place, generally adopt welded and installed method (for example, with reference to patent documentation 3).

In addition, in HDD, seek further miniaturization slimming.In order to make HDD miniaturization slimming, need make spindle motor miniaturization, the slimming of drive plate rotation.Figure 13 is as the sectional drawing (for example, with reference to patent documentation 4) of the spindle motor of example expression in the past.

In Figure 13, at the central part of housing 31 axle sleeve 33 is set, axle 34 rotatably inserts in the bearing hole of axle sleeve 33.By axle sleeve 33, axle 34 and thrust plate 35, be formed in the well-known Hydrodynamic bearing of this technical field, axle 34 rotates non-contactly with axle sleeve 33.Rotor propeller boss 32 is installed on axle 34.Magnet 36 is installed on the interior perimembranous of rotor propeller boss 32, disk 39 is installed at peripheral part.Axle 34 has screw 43, is screwed into the fastening screw 42 that is used for fixing secure component 41 in screw 43.Secure component 41 is the parts that are used to keep disk 39.Magnet 36 is accepted driving force from the stator core 37 that is fixed on the housing 31, makes rotor propeller boss 32 and axle 34 rotations.

In above-mentioned spindle motor, rotor propeller boss 32 need be fixedly mounted on the axle 34.In typical installation method, axle 34 is pressed in the hole of rotor propeller boss 32.But,, only can not carry out reliable and firm installation sometimes by being pressed into because the external diameter of the internal diameter in the hole of rotor propeller boss 32 and axle 34 has making error to a certain degree.Therefore, in the hole that axle 34 is pressed into rotor propeller boss 32 in, also weld both, to realize more reliable and more firm installation.Below, the installation method of above-mentioned rotor propeller boss 32 and axle 34 is described with reference to Figure 14.

Figure 14 (a) is an amplification profile of representing the rotor propeller boss 32 and the main position of the 1st installation method of axle 34.Bight in the upper end of axle 34 is pre-formed R (song) portion 44 or chamfered section 45.In addition, the bight in the upper end in the hole of rotor propeller boss 32 is pre-formed chamfered section 45.The internal diameter in the hole of rotor propeller boss 32 is slightly less than the external diameter of axle 34, just fixes both by secure fit if be pressed into axle 34 in the hole of rotor propeller boss 32.Then, to recess 46 irradiating lasers of the V font that formed by R portion 44 or chamfered section 45, near rotor propeller boss 32 the fusing recess 46 and axle 34 carry out laser bonding.

Figure 14 (b) is an amplification profile of representing the rotor propeller boss 32 and the main position of the 2nd installation method of axle 34.At first, around the hole of rotor propeller boss 32, the mode outstanding with the upper end portion 34a of axle 34 forms recess 47.When rotor propeller boss 32 is installed on axle 34, in the hole that axle 34 is pressed into rotor propeller boss 32 after, across corner 48 irradiating lasers weld.

In above-mentioned two kinds of installation methods, owing to, rotor propeller boss 32 is fixed on the axle 34, so can obtain high constant intensity by being pressed into and laser bonding.

Patent documentation 1: No. the 2525216th, Japanese Utility Model login communique

Patent documentation 2: Japanese patent of invention open communique spy open 2002-070849 number

Patent documentation 3: Japanese patent of invention open communique spy open 2002-369438 number

Patent documentation 4: No. the 3282945th, Japanese Gazette of Patent for Invention

Patent documentation 5: real the opening flat 6-21348 number of the open communique of Japanese Utility Model

But, in above-mentioned formation and method in the past, also have problem shown below.

That is, between weld assembly, produce and to follow the shrinking stress of the parts that welding solidifies to change, can not guarantee the problem of the part dimension stipulated.Especially, disclosed as patent documentation 3, when welding constituted the axle and flange of thrust-bearing part, flange moved to axial direction because of welding, and the heat that produces during in addition because of welding is in the above-below direction warpage.Therefore, the problem in the axial gap that thrust-bearing is required can not be fully guaranteed in existence.

In addition, in the 1st installation method, with near the rotor propeller boss the laser beam welding recess 46 32 and axle 34 o'clock, the crackle that length 1～2 μ m, dark 1～1.5 μ m take place on the surface of weld part is a fine crack.In fine crack, enter the small metallic that to remove easily with common cleaning.In the work of spindle motor, because of the vibration of spindle motor etc., this small metallic flies out from fine crack, on the surface attached to disk, sometimes to utilizing magnetic head record regenerating data to produce obstacle.The weld fume that takes place during laser bonding (micropowder of the oxide that generates from high-temperature metal during welding) enters screw 43 in addition, when assembling HDD, becomes pollutant, becomes the reason of polluting device.

In the 2nd installation method, if deepen the degree of depth of recess 47, prolong the outstanding length L of the upper end portion 34a of axle 34, just can prevent that dust from entering screw 43.But if the thickness of restriction spindle motor, the outstanding length L (with reference to Figure 14 (b)) of the upper end portion 34a of axle 34 is excessive, because the fastening force of axle 34 and rotor propeller boss 32 descends, can not satisfy impact resistance etc., so preferably shorten length L as far as possible.If but shortening length L, weld fume enters screw 43 easily.In addition owing to not avoiding taking place fine crack, so have the problem identical with the 1st method.

Summary of the invention

, the objective of the invention is to for this reason, a kind of Hydrodynamic bearing that can address the above problem and manufacture method, spindle motor and manufacture method thereof are provided.

The method of the 1st invention is the manufacture method that possesses the Hydrodynamic bearing of axle, axle sleeve, the 1st vibrating part, the 2nd vibrating part at least, wherein, has: the 1st step, on axle, be inserted in axle sleeve, and on this axle, be inserted in the 2nd vibrating part; The 2nd step pushes the axial upper-end surface of the 2nd vibrating part; The 3rd step, welding axle and the 2nd vibrating part are fixed on the 2nd vibrating part on the axle when keeping the state of pushing.Here, axle sleeve is can install by counterrotating state with respect to axle.The 1st vibrating part is fixed or is integrally formed on the axle.The 2nd vibrating part is fixed on the axle.

Here, be illustrated in welding the 2nd vibrating part and when axle, push the manufacture method of Hydrodynamic bearing of the axial upper-end surface of the 2nd vibrating part.

Usually, as the method that the 2nd vibrating part is fixed on the axle, adopt laser bonding.Laser bonding is to be pressed into or method that the defective of the previous methods of adhering part such as binder is introduced for solve adopting, and compares with method in the past, has the advantage of the bearing performance that does not reduce final Hydrodynamic bearing.But because in when welding, the 2nd vibrating part moves to axial direction, the heat of giving during in addition because of welding is in the above-below direction buckling deformation, so there is the problem that can not fully guarantee the axial gap of stipulating.Owing in axial gap, inject lubricating fluid, with working glibly of the Hydrodynamic bearing that guarantees to carry out the non-contact rotation, thus size manufacture component that can not be in accordance with regulations, and then reduce the performance of Hydrodynamic bearing.

For this reason, in the manufacture method of Hydrodynamic bearing of the present invention, when welding, push the axial upper-end surface of the 2nd vibrating part.For fixing the 2nd vibrating part, and suppress distortion, the pushing position is so long as the axial upper-end surface of the 2nd vibrating part is just passable.Especially, if consider the shrinking stress of welding part, also can be the outer circumferential side of above-mentioned upper-end surface.

Thus, owing to can prevent moving and distortion of the 2nd vibrating part, so when adopting welding, can fully guarantee the axial gap of stipulating to make Hydrodynamic bearing accurately simultaneously.Therefore, can guarantee the performance of Hydrodynamic bearing.

The method of the 2nd invention is the manufacture method of the described Hydrodynamic bearing of the 1st invention, wherein also has in the welding portion coating and has the 4th step of the resin of cementability.

Here, be illustrated in the operation of fixing on the axle behind the 2nd vibrating part.

Part in welding cracks (fine crack), because of from the metal microparticle that disperses here, so reduce the performance of Hydrodynamic bearing sometimes.

For this reason, after welding,, cover fine crack, suppress dispersing of metal microparticle with resin by in the weld part application of resin.

Thus, can guarantee the performance of Hydrodynamic bearing.

The method of the 3rd invention is the manufacture method of the described Hydrodynamic bearing of the 1st or the 2nd invention, wherein, in the 2nd step, also pushes axial upper-end surface when the axial upper-end surface of pushing the 2nd vibrating part.

Here, when being illustrated in welding the 2nd vibrating part and axle, not only push the 2nd vibrating part, also push the manufacture method of the Hydrodynamic bearing of axial upper-end surface.

As another problem in when welding, also there is a problem of floating in the influence because of the shrinking stress that is subjected to the welding part.Also with above-mentioned same, can not fully guarantee the axial gap of stipulating thus.Therefore, size manufacture component that can not be in accordance with regulations, and then reduce the performance of Hydrodynamic bearing.

Therefore, when welding, also push axial upper-end surface, stationary axle simultaneously.

Thus, owing to can prevent floating of axle, so when adopting welding, can fully guarantee the axial gap of stipulating to make Hydrodynamic bearing accurately simultaneously.Therefore, can guarantee the performance of Hydrodynamic bearing more.

The method of the 4th invention is the manufacture method of the described Hydrodynamic bearing of the 3rd invention, and wherein, axle has screw at end face, in the 2nd step, pushes axial upper-end surface while stop up screw.

Here, be illustrated in welding the 2nd vibrating part and when axle, the state of the screw that has with stem shaft, the manufacture method of the Hydrodynamic bearing of the upper-end surface of pushing axle simultaneously.

Usually, as the formation of Hydrodynamic bearing,, be designed for the fixing screw that covers the top lid of spindle motor with shape at axial upper-end surface opening.Under situation about so constituting, except that the floating of the moving of the 2nd above-mentioned vibrating part, distortion and axle, weld fume such as splash disperses when also having welding, enters the problem of screw.Therefore, finally reduce the accuracy of manufacturing of Hydrodynamic bearing.

For this reason, in manufacture method of the present invention, when the upper-end surface of pushing axle, the screw of stem shaft.Thus, dispersing of weld fume can be prevented, the decline of the accuracy of manufacturing of Hydrodynamic bearing can be suppressed.

The method of the 5th invention is the manufacture method of the described Hydrodynamic bearing of any invention in the 1st～the 4th invention, wherein, in the 2nd step, in the pushing of axial upper-end surface, adopts pressing element.

Here, the parts of the axial upper-end surface of expression pushing.

Pressing element, so long as pushing force can be passed to equably the axle shape just passable.

Thus, can push the upper-end surface of axle accurately.

The method of the 6th invention is the manufacture method of the described Hydrodynamic bearing of the 5th invention, and wherein, described pressing element has elasticity.

Here, the expression pressing element also can be the rubber-like object.

Pressing element for example, can adopt the rubber material of hard etc.

Thus, because pushing force can be provided equably, can push the upper-end surface of axle accurately.

The method of the 7th invention is the manufacture method of the described Hydrodynamic bearing of the 5th or the 6th invention, and wherein, pressing element has spheroid form at front end.

Here, expression is as the example of the shape of pressing element, and its top forms spheroid form.

The shape of pressing element is not preferably damaged the shape of axial upper-end surface.

For this reason, will be with the top of pressing element, be that the position that axial upper-end surface contacts forms spheroid form.

Thus, can not damage ground, the upper-end surface highi degree of accuracy pushing of axle.

The method of the 8th invention is the manufacture method of the described Hydrodynamic bearing of any invention in the 1st～the 7th invention, and wherein, the 1st vibrating part is fixed by welding on the axle.

Here, be illustrated in method when fixing the 1st vibrating part on the axle.

The 1st vibrating part is processed to form on axle by one sometimes, is fixed on the axle sometimes.Generally, the method as fixedly the time for example, is pressed into joint.But, exist to produce burr when being pressed into, influence the problem of the manufacturing of Hydrodynamic bearing.

Therefore, the same during with welding formation the 1st vibrating part on axle under the situation that adopts means of fixation, adopt welding.

Thus, burr ground highi degree of accuracy can not take place make Hydrodynamic bearing.

In addition, welding process, for example, so long as laser bonding just can.

The method of the 9th invention, be the manufacture method of the described Hydrodynamic bearing of any invention in the 1st～the 8th invention, wherein, the 2nd vibrating part has recess in interior all sides of axial upper-end surface, the axle in the 3rd step and the welding of the 2nd vibrating part are carried out near the boundary portion of recess and axle.

Here, be illustrated in the formation that recess is set on the upper-end surface of the 2nd vibrating part.

Usually, when welding the 2nd vibrating part and axle, the welding part is near the top contact of vibrating part and axle.But in the past, weld fume dispersed in the welding, influenced the accuracy of manufacturing of other parts sometimes.Therefore, finally cause the accuracy of manufacturing of Hydrodynamic bearing to descend.

For this reason, on the 2nd vibrating part, the interior all sides in axial upper-end surface are provided with recess, near the bottom surface of welding recess and the boundary portion of axle.The weld fume that produce this moment is trapped in the recess.

Thus, owing to can prevent dispersing of weld fume, so can suppress the decline of the accuracy of manufacturing of Hydrodynamic bearing.

The Hydrodynamic bearing of the 10th invention possesses: axle, axle sleeve, the 1st vibrating part, the 2nd vibrating part at least.Axle sleeve, with respect to axle with can be counterrotating state install.The 1st vibrating part is fixed or is integrally formed on the axle.The 2nd vibrating part is fixed on the axle.In addition, for stationary axle and the 2nd vibrating part, has the resin of cementability in the part coating of welding.

Here, a routine basic comprising of representing Hydrodynamic bearing of the present invention.

In the part application of resin of welding axle and the 2nd vibrating part, with not from the fine crack metal microparticle that disperses.

Thus, can be inhibited the dispersing of metal microparticle, Hydrodynamic bearing that operating accuracy is high.

The Hydrodynamic bearing of the 11st invention is the described Hydrodynamic bearing of the 10th invention, wherein, the 2nd vibrating part, the interior all sides in axial upper-end surface also have recess.The welding part, be recess the bottom surface and spool boundary portion near.

Here, represent the basic comprising of Hydrodynamic bearing of the present invention and, the example of recess is set in interior all sides of its axial upper-end surface for the shape of wherein the 2nd vibrating part.

Usually, when welding the 2nd vibrating part and axle, the welding part is near the top contact of vibrating part and axle.But so, weld fume etc. disperses in the welding sometimes, influences the precision of other parts.Therefore, finally cause reducing the operating accuracy of Hydrodynamic bearing.

So on the 2nd vibrating part, the interior all sides in axial upper-end surface are provided with recess, near the bottom surface of welding recess and the boundary portion of axle.So the weld fume that produce this moment is trapped in the recess.

In addition, by near the application of resin boundary portion of welding, covering resin on fine crack can suppress dispersing of metal microparticle.

Thus, can obtain the high Hydrodynamic bearing of operating accuracy.

The Hydrodynamic bearing of the 12nd invention is the described Hydrodynamic bearing of the 11st invention, and wherein, the 2nd vibrating part also has recess in interior all sides of axial lower end surface.

Here, represent that the 2nd vibrating part also has recess in its lower end surface.

Usually, if make Hydrodynamic bearing work, just the lubricating fluid from the gap that is injected into each parts produces bubble, hinders working glibly of Hydrodynamic bearing sometimes.

Therefore, interior all sides of obsolete axial lower end surface are provided with recess when laser bonding, form the bubble discharge portion.

Thus, flow into recess, can obtain to keep the Hydrodynamic bearing of working glibly by making bubble.

The Hydrodynamic bearing of the 13rd invention possesses axle, axle sleeve, the 1st vibrating part, the 2nd vibrating part at least.Axle sleeve, with respect to axle with can be counterrotating state install.The 1st vibrating part is fixed on or is integrally formed on the axle.The 2nd vibrating part is fixed on the axle.In addition, Hydrodynamic bearing of the present invention also possesses at least one side in the 1st sealed member and the 2nd sealed member.The 1st sealed member is fixed on the axle sleeve in the mode of the axial lower end surface that covers the 1st vibrating part.The 2nd sealed member is fixed on the axle sleeve in the mode of the axial upper-end surface that covers the 2nd vibrating part.

Here, expression is provided with the formation of the sealed member that covers vibrating part.

In the gap of each vibrating part and axle sleeve, inject lubricating fluid.About this gap, sneak into foreign matter from axial lower end surface sometimes, or spill lubricating fluid.In addition, also sneak into foreign matter from the upper-end surface sometimes.Its result hinders working glibly of Hydrodynamic bearing.

Therefore, to cover the shape of vibrating part, on axle, be fixed for forming the sealed member of the effect of playing lid.In addition because as long as the gap that covers each vibrating part and axle sleeve just can, so sealed member is erected at the outer circumferential side of the axial face of vibrating part at least.

Thus, can obtain to prevent sneaking into or the spilling of lubricating fluid, can keeping the Hydrodynamic bearing of working glibly of foreign matter.

The spindle motor of the 14th invention possesses at least as any one described Hydrodynamic bearing, propeller boss, magnet, base plate, stator core in the claim 9～13.Propeller boss is fixed on the Hydrodynamic bearing, can rotate Hydrodynamic bearing.Magnet is fixed on the propeller boss.Base plate is used for fixing Hydrodynamic bearing.Stator core and magnet are fixed on the base plate opposed to each other.

Here, the basic comprising of the spindle motor of Hydrodynamic bearing of the present invention is adopted in expression.

Usually, in spindle motor, adopt Hydrodynamic bearing.Hydrodynamic bearing, owing to can realize low NRRO or low noise by the non-contact rotation, so the performance of this bearing performance left and right sides spindle motor.Therefore, need employing correctly make and the Hydrodynamic bearing that precision is high of size in accordance with regulations.

Therefore by adopting Hydrodynamic bearing of the present invention, can obtain the stable bearing performance.This Hydrodynamic bearing, on the 2nd vibrating part, the interior all sides in axial upper-end surface are provided with recess.Near the contact of bottom surface corner by welding this recess and axle, weld fume can be stayed in the recess, can be obtained the Hydrodynamic bearing of favorable working performance.In addition, this Hydrodynamic bearing, interior all sides of also can be when laser bonding obsolete axial underpart are provided with recess, form the bubble discharge portion.

Thus, owing to, can obtain to keep the Hydrodynamic bearing of working glibly, so can obtain the spindle motor of favorable working performance by making bubble flow into recess.

The spindle motor of the 15th invention possesses at least as any one described Hydrodynamic bearing, propeller boss, magnet, base plate, stator core in the claim 9～13.Propeller boss is fixed on the Hydrodynamic bearing, can rotate Hydrodynamic bearing.Magnet is fixed on the propeller boss.Base plate is used for fixing described Hydrodynamic bearing.Stator core and magnet are fixed on the base plate opposed to each other.In addition, base plate has recess, the 1st vibrating part on the Hydrodynamic bearing and the lower end surface of axle sleeve, and base plate between keep being inserted in the recess in the predetermined gap.

Here, expression constitutes the Hydrodynamic bearing of spindle motor and the structural relation of base plate.

When constituting spindle motor, for guaranteeing the service behaviour of spindle motor, be preferably formed not to the gap that Hydrodynamic bearing has sneak into from the foreign matter of outside, and can prevent to the disperse formation of lubricating fluid of motor internal.

Therefore, be formed on the base plate of assembling Hydrodynamic bearing recess is set, in this recess, insert the formation of Hydrodynamic bearing.

Thus, compare when recess not being set, owing to have the recess of certain depth, and be difficult for causing sneaking into of foreign matter or dispersing of lubricating fluid from the outside.Therefore, can obtain the better spindle motor of service behaviour.

The spindle motor of the 16th invention possesses axle sleeve, propeller boss, resin, rotor magnet.Axle sleeve is back shaft rotatably.Propeller boss contains the hole that is pressed into axle, and the end regions in the hole has from the surface in accordance with regulations the recessed recess of distance and is located at the interior chamfered section of the interior perimembranous of recess, by internal chamfered section illuminating laser beam, is welded on the axle that is pressed into the hole.Resin has cementability, is coated on the part of welding.Rotor magnet is fixed on the propeller boss, and is opposed with stator coil, and this stator coil is installed on the housing that is fixed with axle sleeve.

Here, the basic comprising of expression another spindle motor of the present invention and the shape of relevant propeller boss wherein.

Usually, the flue dust that takes place during laser bonding enters screw, when assembling HDD, becomes pollutant, becomes the reason of polluting device.

Therefore, the end regions in the hole of propeller boss forms from the recess of the recessed predetermined distance in surface and is located at the interior chamfered section of the interior perimembranous of recess.If bottom illuminating laser beam to the V font of chamfered section in this, welding propeller boss and axle, because the weld fume that when welding takes place is difficult to get access in the screw of axle, even and overflow also at interior chamfered section molten metal and to stay in the recess, so can not flow to the surface of propeller boss.

Thus, can obtain to prevent the spindle motor that disperse, favorable working performance of weld fume towards the screw direction of axle.

The spindle motor of the 17th invention is the described spindle motor of the 16th invention, wherein, also has the annular slot that oozes out on the embedding part that is formed on axle and propeller boss, that be used to prevent lubricating fluid.

Here, another formation of expression spindle motor.

Usually, when adopting laser bonding to make spindle motor, only utilize chimeric axle of the mode that is pressed into and rotor propeller boss.This is because for example, if be pressed into bondingly, tackiness agent burning during welding becomes the reason of pollutant.But, if only be pressed into, the problem that the lubricating fluid that exists Hydrodynamic bearing to have oozes out.

Therefore,, form the annular slot that oozes out that prevents lubricating fluid, the lubricating fluid that oozes out is stayed in the annular slot at the embedding part of axle and propeller boss.In addition, annular slot also can be formed on any side of a side or propeller boss side.

Thus, can obtain the spindle motor of favorable working performance.

The manufacture method of the spindle motor of the 18th invention, have end face have the columned axle of screw, rotatably back shaft axle sleeve, have the band screw that is pressed into axle the end the hole and the end regions in hole have from the surface in accordance with regulations the recessed recess of distance and be located at recess interior perimembranous interior chamfered section propeller boss, be fixed on the propeller boss with the housing that is installed in fixed axle sleeve on the opposed rotor magnet of stator coil, wherein, have following steps: the end that will have a screw is pressed into the step in the hole; Utilize Sealing, the step of the end of the screw of temporary transient stem shaft; Internal chamfered section illuminating laser beam, the step of welding propeller boss and axle; After welding, apply the step of resin in the part of welding with cementability.

Here, expression can prevent the manufacture method of the spindle motor that disperses of weld fume.

Usually, the weld fume that takes place during laser bonding enters screw, when assembling HDD, becomes pollutant, becomes the reason of polluting device.In addition, sometimes because of the metal microparticle that disperses from fine crack, and the performance of reduction spindle motor.

Therefore, when welding axle and propeller boss,, prevent dispersing of weld fume by utilizing the screw of the temporary transient stem shaft of Sealing.In addition, because the welding back covers fine crack with resin, so can suppress dispersing of metal microparticle by application of resin on weld part.

Thus, can make spindle motor accurately.

The manufacture method of the spindle motor of the 19th invention is the manufacture method of the described spindle motor of the 18th invention, wherein, only in the step of application of resin, stops up screw with Sealing.

Stop up the manufacture method of the spindle motor of screw when being illustrated in application of resin here.

When application of resin, unnecessary sometimes resin enters screw, and the performance of spindle motor is reduced.

Therefore, by stopping up screw when the application of resin, can prevent entering of resin.

Thus, can make spindle motor accurately.

The manufacture method of the spindle motor of the 20th invention, this spindle motor has: end face have the columned axle of screw, rotatably back shaft axle sleeve, have the end that is pressed into end face with axle the hole and the end regions in hole have from the surface in accordance with regulations the recessed recess of distance and be located at recess interior perimembranous interior chamfered section propeller boss, be fixed on the propeller boss with the housing that is installed in fixed axle sleeve on the opposed rotor magnet of stator coil, wherein, have following steps: the step that the end with screw of axle is pressed into the hole; Internal chamfered section illuminating laser beam, the step of welding propeller boss and axle; After welding, with Sealing stop up screw, on one side in the part coating of welding have the step of the resin of cementability on one side.

Stop up the manufacture method of the spindle motor of screw when being illustrated in application of resin here.

When application of resin, unnecessary sometimes resin enters screw, reduces the performance of spindle motor.

Therefore, by stopping up screw when the application of resin, can prevent entering of resin.

Thus, can make spindle motor accurately.

Description of drawings

Fig. 1 is the diagram of formation of the spindle motor of the Hydrodynamic bearing of expression with embodiments of the present invention.

Fig. 2 is the diagram of the formation of the Hydrodynamic bearing in the expression one embodiment of the present invention.

Fig. 3 is the diagram of the manufacture method of the Hydrodynamic bearing in the expression one embodiment of the present invention.

Fig. 4 is the diagram of the welding part of the Hydrodynamic bearing in the expression one embodiment of the present invention.

Fig. 5 is the diagram of the oleophobic agent coating position of the Hydrodynamic bearing in the expression one embodiment of the present invention.

Fig. 6 (a) is the formation of spindle drive motor of Hydrodynamic bearing of expression another embodiment of the present invention and the diagram of welding part.Fig. 6 (b) is the partial enlarged drawing of the formation of the Hydrodynamic bearing in the another mode of execution of expression.

Fig. 7 is the diagram of formation of the spindle motor of expression another embodiment of the present invention.

Fig. 8 is the diagram of formation of the spindle motor of expression another embodiment of the present invention.

Fig. 9 is a diagram of representing the formation of Hydrodynamic bearing in the past.

Figure 10 is the sectional drawing of the spindle motor of another embodiment of the invention.

Figure 11 is the amplification profile at the main position of the axle of spindle motor and the assembly department of propeller boss.

Figure 12 is the amplification profile at the axle of spindle motor and the propeller boss main position when welding.

Figure 13 is the sectional drawing of spindle motor in the past.

Figure 14 is the amplification profile at the main position of the axle of expression spindle motor and the assembly department of propeller boss.

The synoptic diagram of the situation when Figure 15 is the expression laser bonding.

Figure 16 is the diagram that an example of expression another spindle motor of the present invention constitutes.

Among the figure: 1-base plate, 2-stator core, 3,59-coil (stator coil), the 4-insulation tube, 5-recess, 6-the 1st vibrating part, 7,34,53,103, the 353-axle, 8,33,52, the 112-axle sleeve, 9-the 2nd vibrating part, spherical of 10-(pressing element), 11,43, the 61-screw, 12,32,57,357-propeller boss (rotor propeller boss), the 13-rear magnetic yoke, 14-hermetic seal, 15,36,67-magnet (rotor magnet), 16-cylindrical wall portion, 17-the 2nd sealed member, 18-the 1st sealed member, the 19-access, 20-carriage, 21-bubble discharge portion, the 22-vent, the 31-housing, 39-disk, 46, the 47-recess, chamfered section in the 57c-, the 62-Sealing, 63-resin, 100,100 ', 200, the 300-spindle motor, 101,101 ', 102,302-bearing means (Hydrodynamic bearing), 104, the 106-tapering part, the 108-taper bearing shell watt back of the body, 114-fastening cover, the 116-lubricating fluid, the 320-annular slot.

Embodiment

Below, embodiments of the present invention are described.

(mode of execution 1)

Below, with reference to Fig. 1～Fig. 5, illustrate that adopting the Hydrodynamic bearing of present embodiment is the spindle motor 100 of bearing means 101.

[formation of spindle motor 100]

Spindle motor 100 roughly divides mainly to be made of static part and rotary component.

So-called static part for example, as shown in Figure 1, is base plate 1, stator core 2, coil 3, insulation tube the 4, the 1st vibrating part 6, axle the 7, the 2nd vibrating part 9, cylindrical wall portion 16.Base plate 1 is made of aluminum alloy etc.Silicon steel plates etc. are adopted in stator core 2, are the coil 3 that metal etc. constitutes by twining by copper, form the stator core builtup member.The stator core builtup member is fixed on the base plate 1 by being pressed into to engage to wait.Insulation tube 4, coil lead is inserted in the end of one side, and draw to the device outside its opposing party's end.In addition, about insulation tube 4, the heat-shrinkable tubes that constitute by polyolefin-based resins etc. that adopt more.Each vibrating part the 6, the 9th, the dynamic pressure generating unit is made of stainless steel etc.Axle 7 plays the effect of the pillar of the stability of guaranteeing bearing means 101 described later and then spindle motor 100.In addition, axle 7 is made of stainless steel etc., is pressed into to be bonded in the base plate 1.Cylindrical wall portion 16 forms recess on base plate 1.

So-called rotary component for example, as shown in Figure 1, is axle sleeve 8, rear magnetic yoke 13, hermetic seal 14, magnet 15.About axle sleeve, adopt at Cuprum alloy and carry out the axle sleeve that electroless nickel plating is handled.By the propeller boss 12 that aluminum alloy etc. constitutes, keep not shown recording medium etc., be fixed on the axle sleeve 8, integratedly rotation.Rear magnetic yoke 13 constitutes by Ferrious material being implemented magnetic material that electroless nickel plating handles etc., is fixed in the propeller boss 12 by being pressed into etc.Magnet 15 after being adhesively fixed on the rear magnetic yoke 13, is heated sclerosis.In addition, about magnet 15, adopt the resin magnet of Ne-Fe-Bo system usually.Hermetic seal 14, the main space of interdicting the space of the medium of holding the record and having the stator core builtup member.Magnet 15 disposes opposed to each other with the stator core builtup member, becomes the motive force of the rotation of rotary component.This recess is inserted in the lower end of the 1st vibrating part and axle sleeve 8, form so-called labyrinth seal structure.Here, the gap L 3 in week in axle sleeve 8 peripheries and the cylindrical wall portion 16 is for example as long as just can below 0.25mm.

In addition, between the lower end surface of base plate 1 and the 1st vibrating part 6, form predetermined gap L4.Gap L 4 when axle 7 is pressed into base plate 1, is used to adjust the height and position of axle 7.Simultaneously, at the lower end surface of base plate 1 and the 1st vibrating part 6 coating oleophobic agent 24 (details aftermentioned), need be provided with the gap of this part.Usually, gap L 4 is as long as just can about 0.2mm greatly.

In above-mentioned each parts, axle 7, vibrating part 6,9, axle sleeve 8, lubricating fluid 116, constituting Hydrodynamic bearing is bearing means 101.In addition, narrate the detailed formation of bearing means 101 below.

[formation of bearing means 101]

Below, illustrate that with reference to Fig. 2 an example of bearing means 101 constitutes.

Bearing means 101 as shown in Figure 2, constitutes by built-up shaft 7, vibrating part 6,9, axle sleeve 8, lubricating fluid 116.

Axle 7 is positioned at the center of bearing means 101, and base plate 1 (with reference to Fig. 1) is inserted in its lower end.In addition, axle 7 has screw 11 thereon on the end face, be used for fixing not shown lid, above this lid covering spindle motor 100 (with reference to Fig. 1).At the outer circumferential face of axle 7 or the inner peripheral surface of axle sleeve 8, form the radial dynamic pressure occurrence groove.The 1st vibrating part 6 also can be fixed on or be integrally formed on the axle 7.Opposed faces in the 1st vibrating part 6 sides of the opposed faces of axle sleeve 8 sides of the 1st vibrating part 6 or axle sleeve 8 forms the thrust dynamic pressure occurrence groove.The 2nd vibrating part 9 is fixed on the axle 7.Opposed faces in the 2nd vibrating part 9 sides of the opposed faces of axle sleeve 8 sides of the 2nd vibrating part 9 or axle sleeve 8 forms the thrust dynamic pressure occurrence groove.In the space that forms these dynamic pressure occurrence grooves is to inject lubricating fluid 116 in the bearing play.

On axle sleeve 8, form the access 19 that is communicated with above-mentioned 2 thrust dynamic pressure occurrence grooves, carry out the equilibrium of bearing pressure inside.Access 19 also can process by axle sleeve 8 is implemented holes, or axle sleeve 8 is divided into external axle sleeve and internal axle sleeve, and the part of internal axle sleeve periphery is the impartial cutting of D type, and they form chimeric again assembling.

[manufacture method of bearing means 101]

One example of the manufacture method of bearing means 101 then, is described with reference to Fig. 3.

At first, as shown in Figure 3, in having ground surperficial carriage 20, insert the lower end side of the axle 7 that is formed with the 1st vibrating part 6.Carriage 20 is to be used for stably and the pedestal of rigid bearing device 101 flatly.Then, forming mode, fall by deadweight, axle sleeve 8 is enclosed within on spools 7 by making axle sleeve 8 with respect to axle 7 rotatable states.

Face that the 1st vibrating part 6 contacts with carriage (A face) and the face (B face) that axle sleeve 8 contacts with carriage 20 are positioned on the same one side of carriage 20.But A face and B face also can be positioned on the different face on the carriage 20 according to the geomery of the 1st vibrating part 6 and axle sleeve 8.

Here, the distance setting of dynamic pressure face that will be from the B face to axle sleeve 8 sides is L1, will be L2 from the distance setting of the dynamic pressure face of A face to the 1 vibrating part 6 sides.At this moment, be made as L1＞L2.Suppose L1-L2=Gs, Gs is the distance in the gap of the 1st vibrating part 6 and axle sleeve 8, the i.e. gap of thrust-bearing.

Here, if Gs is wide, axial dynamic pressure imbalance, the thrust rigidity descends, and motor performance reduces.On the contrary, if Gs is narrow, the resistance of lubricating fluid increases, and bearing loss increases, and the current value of motor increases.Therefore, if consider operation and the thrust rigidity after the assembling and the current sinking of motor of assembling, Gs so long as the distance between 15～25 μ m just can.More preferably be limited in 20 μ m.

In the time of on the 2nd vibrating part 9 being welded on axle 7, push the upper-end surface of the 2nd vibrating part 9.Therefore, the 2nd vibrating part 9, preferably nestle up with the axial face of the 2nd vibrating part 9 opposed axle sleeves 8 fix.The axial gap of the 2nd vibrating part 9 and axle sleeve 8 is as long as form just passable by welding the back with respect to relatively move towards axial below axle sleeve 8 of axle 7.

So, the state of distance with control Gs inserts the 2nd vibrating part 9.

Below, Yi Bian push the peripheral part of the axial upper-end surface of the 2nd vibrating part 9,, pressing element is placed on axle 7 upper-end surface Yi Bian being spherical 10.This spherical 10 also can be sealed member.Therefore, seal screw 11 for spherical 10, and meanwhile the axial upper-end surface of pushing axle 7, full week or many places near the boundary portion of laser bonding axle 7 and the 2nd vibrating part 9.As long as this laser employing YAG laser etc. just can.The laser bonding position as shown in Figure 4.In addition, spherical 10, as long as owing to can seal in the mode of not damaging axle 7 screw 11, and equably pushing axle 7 just can, so with the surface of contact of axle 7 so long as spherical just passable.

Then, as shown in Figure 5, in the upper end side of bearing means 101, near the inner peripheral surface bearing means 101 opening portions of the upper-end surface peripheral part of the 2nd vibrating part 9 and axle sleeve 8, coating oleophobic agent 24.In addition, in the lower end side of bearing means 101, interior perimembranous or Zone Full coating oleophobic agent 24 in the lower end surface of the lower end surface peripheral part of the 1st vibrating part 6 and axle sleeve 8.Usually, as oleophobic agent 24, adopting fluorine is oleophobic agent.

Will utilize the bearing means 101 of said method assembling put into not shown vacuum chamber, being placed on, to the gap of the bearing lubricating fluid 116 that drips by the state under the environment under low pressure that vacuumizes formation.After the gap of bearing all is full of lubricating fluid 116, vacuum chamber is turned back to barometric pressure, place certain hour with this state.In addition, so-called lubricating fluid, for example, so long as lubricant oil just can.

Then, also can suit not shown top cover to be set by being adhesively fixed in the upper-end surface of the 1st vibrating part 6.

Utilize above method, even when adopting laser bonding, the gap that also can correctly keep each vibrating part 6,9 and axle sleeve 8 can be made bearing means 101 accurately.

[feature of this manufacture method]

(1)

The constitutive requirements of the bearing means made from present embodiment 101, comprise axle 7, with respect to axle 7 with the axle sleeve 8 can counterrotating state installed, be fixed on or be integrally formed in the 1st vibrating part 6 on the axle 7, be fixed on the 2nd vibrating part 9 on the axle 7 etc.The manufacturing process of this bearing means 101 comprises following operation: 1. after axle sleeve 8 is inserted axle 7, insert the 2nd vibrating part 9; 2. push the axial upper-end surface of the 2nd vibrating part 9; 3. keep the state of this pushing on one side, on one side welding axle the 7 and the 2nd vibrating part 9, the 2nd vibrating part 9 is fixed on the axle 7.

Thus, can avoid because of when welding the 2nd vibrating part move to axial direction, the heat that produces during in addition because of welding is in the above-below direction buckling deformation, can not fully guarantee the problem in the axial gap of stipulating.

Therefore, the axial gap of stipulating can be fully guaranteed, Hydrodynamic bearing can be made accurately simultaneously.

(2)

The manufacture method of the bearing means 101 of present embodiment, in above-mentioned the 2nd step, when the axial upper-end surface of pushing the 2nd vibrating part 9, the also axial upper-end surface of pushing axle 7.

When welding axle the 7 and the 2nd vibrating part, be subjected to the influence of the shrinking stress of welding part, also float with regard to connecting shaft, thereby have the problem that can not fully guarantee the axial gap of stipulating.

Therefore, stationary axle 7 in order to weld is as long as also the axial upper-end surface of pushing axle 7 is just passable.

Thus, the axial gap of stipulating can be fully guaranteed, Hydrodynamic bearing can be made accurately simultaneously.

(3)

The axle 7 of the bearing means 101 of present embodiment has screw 11 at end face, the manufacture method of the bearing means 101 of present embodiment, and in above-mentioned the 2nd step, Yi Bian stop up screw 11, Yi Bian the axial upper-end surface of pushing axle 7.

Thus,, can avoid weld fume etc. to disperse, enter the problem of screw in when welding.

Therefore, can suppress the decline of the accuracy of manufacturing of Hydrodynamic bearing.

(4)

The manufacture method of the bearing means 101 of present embodiment in the pushing of axial upper-end surface, adopts pressing element.

Thus, can push the upper-end surface of axle 7 accurately.

(5)

In the manufacture method of the bearing means 101 of present embodiment, above-mentioned pressing element has elasticity.

Thus, can apply pushing force equably to the upper-end surface of axle 7.

Therefore, can push the upper-end surface of axle 7 accurately.

(6)

In the manufacture method of the bearing means 101 of present embodiment, above-mentioned pressing element has spheroid form on the top.

Thus, can not damage ground, the upper-end surface highi degree of accuracy pushing of axle 7.

(7)

In the manufacture method of the bearing means 101 of present embodiment, the 2nd vibrating part 9 is fixed by welding on the axle 7.

As the fixation method of parts, generally be pressed into methods such as joint, but in the present invention, this method is inappropriate.This be because, need be on the outer circumferential face of axle 7, and adjacent part between the gap is set, to avoid engaging sneaking into of foreign matters such as burr that grade produces because of being pressed into.

In addition, as mentioned above, the manufacture method of bearing means 101, the problem in can avoiding welding.

Therefore, by adopting welding, can make bearing means 101 accurately.

(mode of execution 2)

With reference to Figure 10～Figure 12, the spindle motor 200 of present embodiment is described.

Figure 10 is the sectional drawing of spindle motor 200.

In Figure 10, housing 51 has cylindrical part 51a at central part, and axle sleeve 52 is installed on cylindrical part 51a.In the bearing hole 52a of axle sleeve 52, rotatably insert axle 53.At the lower end of axle 53 mounting flange 55.The opening of the lower end of axle sleeve 52 is sealed by thrust plate 54.Between axle 53 and axle sleeve 52, and between thrust plate 54 and flange 55, filling wet goods fluid is formed in the well-known Hydrodynamic bearing of this technical field.

In the present embodiment, about housing 51, adopt aluminum casting or iron material.About axle sleeve 52, adopt the axle sleeve of going up nickel plating at brass material (Cuprum alloy).About axle 53, adopt stainless steel material (for example, SUS420J2),, to adopt stainless steel material (for example, SUS304) about flange 55.About thrust plate 54, adopt stainless steel material (for example, SUS420J2),, to adopt stainless steel material (for example, DHS1) or aluminium about propeller boss 57.

On the upper end portion of axle 53, propeller boss 57 is installed by the method that describes in detail later.

At the central part of axle 53, the screw 61 of the axial parallel of setting and axle 53.In screw 61, be screwed into the fixing not shown screw of secure component by employing, the dish that keeps being installed in the peripheral part of propeller boss 57 is accepted the disk on the face 57g etc.In the inboard of propeller boss 57, rotor magnet 67 is set.Stator coil 59 is installed on the housing 51 opposed to each other with rotor magnet 67.

Below, the axle 53 and the installation method of propeller boss 57 are described.

Figure 11 is the amplification profile of the assembly department of axle 53 and propeller boss 57.When on axle 53, propeller boss 57 being installed, at first axle 53 is pressed in the hole 57b of propeller boss 57.The external diameter of axle 53 is than big 4～11 μ m of internal diameter of hole 57b, and the punching press intensity that is pressed into is approximately 10kgf.The upper-end surface 53a of the axle 53 after being pressed into and the upper-end surface 57a of propeller boss 57 are roughly identical height.In the bight of the periphery of axle 53, form the curved surface (below, be called the R face) of the about 0.1mm of radius.In the bight in interior week of the mounting hole 57b of propeller boss 57, carry out the interior chamfer machining of about 0.05mm, chamfered section 57c in forming.With the planar surface portion 57d that interior chamfered section 57c is connected, be the bottom surface that is approximately the recess 57f of 0.1mm apart from the degree of depth of upper-end surface 57a.The degree of depth of about 0.1mm of recess 57f, so long as small-sized spindle motor, no matter size how, preferably roughly is the identical degree of depth (approximately 0.1mm).Because the degree of depth of the 0.1mm of recess 57f is very small, so miniaturization, the slimming of spindle motor are not had big influence.Planar surface portion 57d and on facial 57a between, form inclined plane part 57e.

Then, utilize laser soldering devices such as adopting the YAG laser, welding axle 53 and propeller boss 57.Before welding, as shown in figure 12, diameter will be set on the top contact with screw 61, obstruction screw 61 than the big slightly metal ball body of the diameter of screw 61 or the Sealing 62 of cone.By stopping up screw,, can prevent that also weld fume from entering in the screw 61 even when welding, weld fume takes place with Sealing 62.But, when the weld fume that other is arranged is removed means, do not use Sealing 62 sometimes yet.

In welding process, towards bottom 60 illuminating laser beams of the paddy shape recess that forms by the outer circumferential face and the interior chamfered section 57c of axle 53.Laser bonding, as shown in figure 15, Yi Bian shine 3 laser welding heads simultaneously, Yi Bian rotate propeller boss 57.The rotational speed of propeller boss 57 is set between 200～300r/min.Laser is output as 1～2kW, shines with 20～30pulse/sec.Intensity of laser beam and exposure time are set near the axle 53 of bottom 60 and the metallic material fusing of propeller boss 57, and the deposite metal bury comprise in the degree of paddy shape recess of chamfered section 57c.Even overflow from paddy shape recess the deposite metal sometimes, because recess 57f is set, the deposite metal flows into recess 57f.Therefore, can prevent that the upper-end surface 57a that the deposite metal surpasses propeller boss 57 from overflowing.

After laser bonding finishes, adopt solvent for cleaning and brush to clean the weld part that comprises planar surface portion 57d.After evaporating solvent for cleaning fully, comprising application of resin 63 on the recess 57f of planar surface portion 57d.This operation is called " working procedure of coating ".By with resin 63 coatings, can cover the fine crack that takes place because of laser bonding.Therefore, can prevent in spindle motor work from the fine crack metal microparticle that flies out.As the material of resin 63, preferably after coating, harden in the short time, after sclerosis, do not emit the material of gas.As resin so, obtain easily and cheap resin is that thermosetting epoxy is a tackiness agent.For example, also can adopt the epoxy adhesion of two components.The coating amount of resin 63 in the spindle motor of shaft diameter 2mm, is approximately about 0.1mg.

Even in working procedure of coating, as long as adopt Sealing 62, when the coating of resin 63, stop up screw 61, just can prevent that unnecessary resin from entering in the screw 61.

In the spindle motor of making by above method, the axle 53 after the laser bonding and the impact strength of propeller boss 57 are approximately 80kgf, have obtained enough intensity.Owing to when welding, stop up screw 61, so weld fume can not enter screw 61 with Sealing 62.In addition, even in the working procedure of coating after welding,, can prevent that also unnecessary resin from entering screw 61 as long as adopt Sealing 62 to stop up screw 61.

As mentioned above, manufacturing method according to the invention can increase substantially the fabrication yield of spindle motor, can improve reliability and the life-span of the HDD that adopts spindle motor etc.

(other mode of execution)

(A)

In above-mentioned mode of execution 1, be example with Fig. 4, illustrated in order on axle 7, to fix the 2nd vibrating part 9, and near the example the boundary line of laser bonding axle 7 and the 2nd vibrating part 9.At this moment, the shape of the 2nd vibrating part 9 also is not limited to this.For example, shown in Fig. 6 (a), the 2nd vibrating part also can have recess in interior all sides of axial upper-end surface, and laser bonding also can be carried out near the boundary portion of the bottom surface of this recess 5 and axle 7.

As the effect of recess 5, the effect that prevents to weld the 2nd vibrating part 9 warpages of formation and prevent scattering foreign matter is arranged.

If by formation welding shown in Figure 4, just apply load towards the direction of the upper-end surface of the 2nd vibrating part 9 being introduced interior all sides.Therefore, the 2nd vibrating part 9 forms sometimes to the state of axially going up the direction warpage (peripheral part be higher than in the state of perimembranous).

In the above-described embodiment, for this warpage is suppressed within the limits prescribed, push the outer circumferential side of the axial upper-end surface of the 2nd vibrating part 9.In addition, if the recess 5 shown in Fig. 6 (a) is set, then apply because of fusing be incorporated in all sides load near the bottom surface of recess 5, can suppress influence to the upper-end surface.Therefore, can relax the warpage of the 2nd vibrating part 9.

In addition, in welding, usually, the scattering foreign matters such as welding slag that weld fume or welding sometimes produces influence the accuracy of manufacturing of other goods.Therefore, preferably after laser bonding, remove these foreign matters by wiping or air attraction etc., but even this moment foreign matter also disperse.

Therefore, shown in Fig. 6 (a), recess 5 is set, can suppresses dispersing of foreign matter by interior all sides at the 2nd vibrating part 9.

Thus, can provide the higher bearing means of performance 101.

(B)

In above-mentioned mode of execution 1 and above-mentioned (A), illustrated and adopted laser bonding that the 2nd vibrating part 9 is fixed on example on the axle 7.Thereafter, also can be in addition with coating laser bonding positions such as the resins (tackiness agent) with cementability.

This is the foreign matter (pollutant) that comes off and disperse for the tiny crackle (fine crack) that prevents to produce from the laser bonding position, the inside of stained bearing means 101 or spindle motor 100.

Thus, can provide the higher bearing means of performance 101.

(C)

In above-mentioned mode of execution 1 and above-mentioned (A), the shape of the 2nd vibrating part 9 has been described.But its shape also is not limited to this.For example, the 2nd vibrating part 9, shown in Fig. 6 (b), also can also have recess in interior all sides of axial upper-end surface is bubble discharge portion 21.

If make bearing means 101 work after manufacturing, the lubricating fluid from the gap that is injected into each parts 116 produces bubble sometimes, hinders bearing means 101 to work glibly.Suppose to be trapped in this boundary portion from the mobile bubble in axial thrust bearing zone, radial bearing zone.This be because, bearing is at work to lubricating fluid effect centrifugal force, heavy lubricating fluid moves to bearing foreign side radially, the little bubble of opposite proportion moves the side in bearing radially.In addition, the bubble that takes place in radial bearing zone, with above-mentioned same, the side moves in bearing radially.

Therefore, the interior all sides in the axial lower end surface of the 2nd vibrating part 9 are provided with recess as bubble discharge portion 21.In this recess, flow into, pile up bubble, not hinder working glibly of bearing means 101.

Thus, can keep working glibly of bearing means 101.

In addition, size about recess 5 and bubble discharge portion 21, for example, if with the diameter of axle 7 be set in Φ 3.5～Φ 4.5mm, with the thickness setting of the 2nd vibrating part 9 at about 2～4mm, the internal diameter of recess 5 just is approximately Φ 5.5mm (diameter of axle 1.5～2 times), the degree of depth is approximately 1mm (below 1/3 of the thickness of the 2nd vibrating part 9), the internal diameter of bubble discharge portion 21 is approximately Φ 3.7mm (sleeve diameter interior internal diameter above and the thrust-bearing slot part is following), and the degree of depth is approximately 1mm (more than the thrust clearance and below 1/3 of thickness of the 2nd vibrating part 9).

In addition, the position of bubble discharge portion 21 also is not limited to this.For example, bubble discharge portion 21 also can be formed on the 1st vibrating part 6 that is fixed on the axle 7.

(D)

In above-mentioned mode of execution 1 and above-mentioned (A)～(C), bearing means 101 of the present invention has been described.But the present invention also is not limited to this.For example, possess spindle motor 100 ' bearing means 101 ', also can be formation as shown in Figure 7.Promptly, bearing means 101 ', at least possess axle 7, with respect to axle 7 with can be counterrotating the axle sleeve 8 installed of state, be fixed on or be integrally formed in the 1st vibrating part 6 on the axle 7, be fixed on the 2nd vibrating part 9 on the axle 7, also can also have at least simultaneously mode with the axial lower end surface that covers the 1st vibrating part 6 be fixed on the axle sleeve 8 the 1st sealed member 18 and with the mode of the axial upper-end surface that covers the 2nd vibrating part 9 be fixed in the 2nd sealed member 17 on the axle sleeve 8 at least either party.

In the gap of each vibrating part 6,9 and axle sleeve 8, inject lubricating fluid 116.About this gap, sneak into foreign matter from axial lower end surface sometimes, or spill lubricating fluid 116.In addition, also sneak into foreign matter from the upper-end surface sometimes.Its result hinders bearing means 101 to work glibly.

In addition, usually, near base plate 1 ground configuration axle sleeve 8 and the 1st vibrating part 6, and base plate 1 between predetermined gap is set.The distance in this gap, in order to prevent foreign matter from the sneaking into of axial lower end surface, and the spilling of lubricating fluid 116, be small gap.Therefore, when making spindle motor, require highi degree of accuracy, also limit the degrees of freedom of the design of spindle motor.

Therefore, in order to seal the gap of each vibrating part 6,9 and axle sleeve 8, dispose each sealed member 17,18, be fixed on the axle sleeve 8 in the mode of each axial face of covering each vibrating part 6,9.As long as can seal above-mentioned gap, also can dispose each sealed member 17,18 in the mode of the outer circumferential side of each axial face of being erected at each vibrating part 6,9 at least.In addition, at this moment, each sealed member 17,18 is as long as be fixed on the axle sleeve 8 just passable by bonding grade.

By formation like this, not only can suppress sneaking into of foreign matter or spilling of lubricating fluid 116, nor necessarily need can also improve the degrees of freedom of design in addition near base plate 1 ground configuration bearing means 101 '.

Thus, can obtain the bearing means 101 of favorable working performance '.

(E)

In above-mentioned mode of execution 1, for example understand spherical the 10 directly method of pushing axle 7 that adopt.But, method that the present invention is not limited thereto.For example, also can be by other parts pushings such as vulcanites.

Thus, also can make bearing means 101 accurately.

(F)

In above-mentioned mode of execution 1 and above-mentioned (A)～(E), understand that for example axle 7 is examples of static part.But the present invention also is not limited to this formation.For example, as shown in Figure 8, also be applicable to the rotary-type bearing means 102 of so-called axle that as axle 7 ' be rotary component, axle sleeve 8 ' be static part, constitutes.

In bearing means 102, propeller boss 12 ' be fixed on axle 7 ' on, rotate with axle 7 ' one.Axle sleeve 8 ' be pressed into the recess that is bonded on base plate 1 is fixed on the base plate 1.In addition, at this moment, preferably base plate 1 and axle sleeve 8 ' between form vent 22 shown in Figure 8.Vent 22 plays the gap by stuffing box bearing device 102 and base plate 1, prevents the effect that lubricating fluid spills with the air of no floss hole.In addition, other parts, adopt with above-mentioned mode of execution 1 or above-mentioned (A)～(E) in any one identical formation.

Thus, also can access and above-mentioned mode of execution 1 and above-mentioned (A)～(E) identical effect.

(G)

In addition, about spindle motor of the present invention, also can be the formation that also has the annular slot that oozes out that is used to prevent lubricating fluid.Specifically be that as shown in figure 16, in spindle motor 300, axle 353 sides at the embedding part of axle 353 and propeller boss 357 form annular slot 320.

Usually, when adopting laser bonding to make spindle motor 300, only by being pressed into chimeric axle 353 and propeller boss 357, but the problem that the not shown lubricating fluid that so exists bearing means 302 to have oozes out.

Therefore,, be formed for the circular groove 320 that prevents that lubricating fluid from oozing out, the lubricating fluid that oozes out is stayed in the circular groove 320 at the embedding part of axle 353 and propeller boss 357.

Thus, can highi degree of accuracy make spindle motor 300.

In addition, circular groove 320 also can be formed on propeller boss 357 sides.

The present invention can be used in the motor with Hydrodynamic bearing, for example spindle motor.In addition, also can be applicable to the used both ends open fixed shaft type spindle motor of recording medium control gear with many dishes.

Claims (20)

1. the manufacture method of a Hydrodynamic bearing,

This Hydrodynamic bearing possesses:

Axle,

With can counterrotating state with respect to described axle be installed in axle sleeve on this,

Fixing or be integrally formed in the 1st vibrating part on the described axle,

Be fixed on the 2nd vibrating part on the described axle,

Wherein, the manufacture method of this Hydrodynamic bearing has:

The 1st step is inserted in described axle sleeve on described axle, be inserted in described the 2nd vibrating part on described axle;

The 2nd step pushes the axial upper-end surface of described the 2nd vibrating part;

The 3rd step, while keep described pushing state, weld described axle and described the 2nd vibrating part, and described the 2nd vibrating part is fixed on described.

2. the manufacture method of Hydrodynamic bearing as claimed in claim 1 wherein also has

The 4th step, it has the resin of cementability in the part coating of described welding.

3. the manufacture method of Hydrodynamic bearing as claimed in claim 1 or 2, wherein:

In described the 2nd step, when the axial upper-end surface of described the 2nd vibrating part of pushing, further also push described axial upper-end surface.

4. the manufacture method of Hydrodynamic bearing as claimed in claim 3, wherein:

On the end face of described axle, has screw;

In described the 2nd step, stop up described screw, and push described axial upper-end surface.

5. as the manufacture method of any one described Hydrodynamic bearing in the claim 1～4, wherein:

In described the 2nd step, adopt pressing element to push described axial upper-end surface.

6. the manufacture method of Hydrodynamic bearing as claimed in claim 5, wherein:

Described pressing element has elasticity.

7. as the manufacture method of claim 5 or 6 described Hydrodynamic bearings, wherein:

The top of described pressing element has spheroid form.

8. as the manufacture method of any one described Hydrodynamic bearing in the claim 1～7, wherein:

Described the 1st vibrating part is fixed on the described axle by welding.

9. as the manufacture method of any one described Hydrodynamic bearing in the claim 1～8, wherein:

Described the 2nd vibrating part has recess in interior all sides of axial upper-end surface;

The described axle in described the 3rd step and the welding of described the 2nd vibrating part are to carry out near the boundary portion of described recess and described axle.

10. Hydrodynamic bearing,

It possesses:

Axle,

With can counterrotating state with respect to described axle be installed in axle sleeve on this,

Fixing or be integrally formed in the 1st vibrating part on the described axle,

Be fixed on the 2nd vibrating part on the described axle,

Wherein, be coated with resin in the part of having carried out welding in order to fix described axle and described the 2nd vibrating part with cementability.

11. Hydrodynamic bearing as claimed in claim 10, wherein:

Described the 2nd vibrating part also has recess in interior all sides of axial upper-end surface;

The part of described welding is near the boundary portion of the bottom surface of described recess and described axle.

12. Hydrodynamic bearing as claimed in claim 11, wherein:

Interior all sides in the axial lower end surface of described the 2nd vibrating part also have recess.

13. a Hydrodynamic bearing,

Possess:

Axle,

With can counterrotating state with respect to described axle be installed in axle sleeve on this,

Fixing or be integrally formed in the 1st vibrating part on the described axle,

Be fixed on the 2nd vibrating part on the described axle,

Wherein, also possess at least one side in the 1st sealed member and the 2nd sealed member:

Described the 1st sealed member is fixed on the described axle sleeve in the mode of the axial lower end surface that covers described the 1st vibrating part;

Described the 2nd sealed member is fixed on the described axle sleeve in the mode of the axial upper-end surface that covers described the 2nd vibrating part.

14. a spindle motor, it possesses:

Any one described Hydrodynamic bearing in the claim 9～13;

Propeller boss, it is fixed on the described Hydrodynamic bearing, is used to make described Hydrodynamic bearing to rotate;

Be fixed on the magnet on the described propeller boss;

The base plate of fixing described Hydrodynamic bearing;

Stator core, itself and described magnet are fixed on the described base plate opposed to each other.

15. a spindle motor possesses,

Any one described Hydrodynamic bearing in the claim 9～13;

Propeller boss, it is fixed on the described Hydrodynamic bearing, is used to make described Hydrodynamic bearing to rotate;

Be fixed on the magnet on the described propeller boss;

The base plate of fixing described Hydrodynamic bearing;

Stator core, itself and described magnet are fixed on the described base plate opposed to each other,

Wherein, described base plate has recess,

Described the 1st vibrating part on the described Hydrodynamic bearing and the lower end surface of described axle sleeve, and described base plate between keep predetermined gap in, be inserted in the described recess.

16. a spindle motor possesses:

Back shaft and the axle sleeve that this can be rotated;

Propeller boss, it has the hole that is used to be pressed into described axle, end regions in described hole has from the recess of the recessed predetermined distance in surface and is located at the interior chamfered section of the interior perimembranous of described recess, by to chamfered section illuminating laser beam in described, and this propeller boss is welded on the described axle that is pressed in the described hole;

Resin with cementability is coated on the described part of welding;

Rotor magnet is fixed on the described propeller boss, and is opposed with stator coil, and this stator coil is installed on the housing, is fixed with described axle sleeve on this housing.

17. spindle motor as claimed in claim 16, wherein: the annular slot that prevents that lubricating fluid from oozing out of being used to that also has the embedding part that is formed at described axle and described propeller boss.

18. the manufacture method of a spindle motor,

This spindle motor has:

Columned axle has screw at its end face;

The axle sleeve that supports described axle and this can be rotated;

Propeller boss, it has the hole, and the end regions in described hole has from the recess of the recessed predetermined distance in surface and is located at the interior chamfered section of the interior perimembranous of described recess, and described hole is used to be pressed into the end with described screw of described axle;

Rotor magnet, it is fixed on the described propeller boss, and is opposed with stator coil, and this stator coil is installed on the housing, is fixed with described axle sleeve on this housing,

Wherein, the manufacture method of this spindle motor has:

The end with described screw of described axle is pressed into step in the described hole;

Utilize the Sealing step of the end face of the described screw of the described axle of obstruction temporarily;

To chamfered section illuminating laser beam in described, and the step of welding described propeller boss and described axle;

After described welding, has the step of the resin of cementability in the described part coating of having carried out welding.

19. the manufacture method of spindle motor as claimed in claim 18, wherein:

Only in the step of the described resin of coating, utilize described Sealing to stop up described screw.

20. the manufacture method of a spindle motor,

This spindle motor has:

Columned axle has screw at its end face;

Back shaft and the axle sleeve that this can be rotated;

Propeller boss, it has the hole, and the end regions in described hole has from the recess of the recessed predetermined distance in surface and is located at the interior chamfered section of the interior perimembranous of described recess, and described hole is used to be pressed into the end with described screw of described axle;

Rotor magnet, it is fixed on the described propeller boss, and is opposed with stator coil, and this stator coil is installed on the housing, is fixed with described axle sleeve on this housing,

Wherein, the manufacture method of this spindle motor has:

The end with described screw of described axle is pressed into step in the described hole;

To chamfered section illuminating laser beam in described, and the step of welding described propeller boss and described axle;

After described welding, with Sealing stop up described screw, on one side in the described part coating of having carried out welding have the step of the resin of cementability on one side.

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