CN1690459A - Fluid bearing device and spindle motor - Google Patents
Fluid bearing device and spindle motor Download PDFInfo
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- CN1690459A CN1690459A CN 200510067379 CN200510067379A CN1690459A CN 1690459 A CN1690459 A CN 1690459A CN 200510067379 CN200510067379 CN 200510067379 CN 200510067379 A CN200510067379 A CN 200510067379A CN 1690459 A CN1690459 A CN 1690459A
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Abstract
A fluid bearing device capable of responding to miniaturization while preventing an operating fluid such as a lubricating oil from leaking out to the outside. The fluid bearing device includes a shaft and a sleeve arranged on an outer periphery with respect to the shaft with a microscopic gap in between, and has an operating fluid filled in between the shaft and the sleeve. The shaft is formed by a sintered body, a radial dynamic pressure generating groove is formed on an outer peripheral surface of the shaft, and the sleeve is formed by a material not allowing the operating fluid to pass through. The shaft is thus covered by the sleeve formed by a material that does not penetrate the operating fluid such as lubricating oil from the outer periphery side, so that the operating fluid does not leak out to the outside even when the shaft is a porous body made of a sintered body.
Description
Technical field
The present invention relates to the spindle motor that utilizes the hydrodynamic bearing device of hydrodynamic and have this hydrodynamic bearing device.In addition, hydrodynamic bearing device of the present invention is specially adapted to the middle hydrodynamic bearing devices that use such as the spindle motor of hard disk unit and other disk apparatus, but also is applicable to miscellaneous equipment.
Background technique
Bearing means as middle spindle motors that uses such as hard disk units uses hydrodynamic bearing device better than ball bearing unit running accuracy, that low noise is also good more and more, to replace employed in the past ball bearing unit.
Figure 11 represents the sectional view (opening 2003-65323 communique (being called patent documentation 1) and Japanese patent laid-open 7-63220 communique (being called patent documentation 2) with reference to the Japan Patent spy) of the major component of traditional hydrodynamic bearing device.In traditional hydrodynamic bearing device shown in Figure 11, constitute by sintering body, the inner peripheral surface of bearing hole is formed with the periphery of the sleeve 52 of radial dynamic pressure occurrence groove 51, being provided with by working fluid is the formed framework 53 of the intransitable material of lubricant oil.Axle 54 is inserted in the bearing hole of sleeve 52, has constituted the radial fluid bearing by these sleeves 52 and axle 54.At the bottom opening place of framework 53, fixing the thrust plate 56 that is formed with axial hydrodynamic occurrence groove 55.In the underpart of axle 54, be provided with the thrust flanges 57 with thrust plate 56 opposed shapes, constituted the axial flow of fluid bearing by above-mentioned thrust flanges 57 and above-mentioned thrust plate 56.The gap that comprises formation radial fluid bearing and axial flow of fluid bearing is interior, and between sleeve 52 and axle 54 and between thrust flanges 57 and the thrust plate 56, the lubricant oil as working fluid in filling.
In above-mentioned traditional hydrodynamic bearing device structure, sleeve 52 is made of the sintering body that uses sintered metal materials.Sintering body is that the shaping thing behind the sintering is put into metal pattern, can form radial dynamic pressure occurrence groove 51 by drawing, so but highi degree of accuracy and form radial dynamic pressure occurrence groove 51 by simple operation.That is, the sleeve in that the solid metal material that uses non-sintering body is made must form groove by methods such as precision cutting processing in the operation of back, compare with it, sleeve 52 by sintering body constitutes even it is also passable not implement groove processing in the operation of back, can reduce manufacture cost.
Sintering body portion within it has many little emptying apertures, and when sleeve 52 was made of sintering body, can produce working fluid was the problem that lubricant oil spills to the outside by the emptying aperture of sleeve 52.Its result brings sometimes because of the problem of lubricant oil minimizing overslaugh as the FDB function.Again, during the motor rotation, the pressurized lubricant oil that is present in the radial dynamic pressure occurrence groove 51 flows in the emptying aperture of sleeve 52, can reduce the pressure that the dynamic pressure occurrence groove is taken place, and reduces the bearing rigidity as the radial fluid bearing.
At these problems, in the hydrodynamic bearing device of above-mentioned patent documentation 1, utilize the framework 53 that forms by the intransitable material of lubricant oil, will surround by the sleeve 52 that sintering body forms, spill to the outside by the emptying aperture of sleeve 52 to stop lubricant oil.In patent documentation 2 in the traditional hydrodynamic bearing device of disclosed another kind, implement blocking microporous processing and emptying aperture is blocked at the inner peripheral surface of the sleeve of sintering body again.Like this, can prevent during rotation that lubricant oil from spilling in the emptying aperture of sleeve from power occurrence groove radially, to reach the purpose of the bearing rigidity that does not reduce the radial fluid bearing.
Again, open in the 2003-333792 communique (being called patent documentation 3), disclose and a kind ofly formed axle, in the axle of this sintering body, contain the structure of lubricant oil by the sintering body behind the sintered metal materials sintering the Japan Patent spy.The sleeve that is inserted with this axle is made of the metal solid that lubricant oil can not soak into, and in sleeve, the axle that is being supported is rotated under the lubricating status of the lubricant oil that is subjected to wherein containing.This bearing is not a hydraulic bearing, is called positive slick and sly dynamic bearing.In its structure, be not sleeve but axle has adopted sintering body formation, but since sleeve formed by the material that lubricant oil can not soak into, so the lubricant oil that is included in the axle can not spill to the outside of sleeve.
Yet, in the traditional hydrodynamic bearing device shown in above-mentioned patent documentation 1 and the patent documentation 2, must set the framework that forms by the intransitable material of lubricant oil in the outside of all sleeves that form by sintering body.Therefore increase part number, increased manufacturing assembling procedure number and manufacture cost.Again, aspect desirable hard disk unit miniaturization in recent years, because of needing 2 kinds of members of sleeve and framework, so be difficult to realize miniaturization.
Again, disclosed traditional hydrodynamic bearing device in the above-mentioned patent documentation 3 is because of merely having constituted positive slick and sly dynamic bearing, if strengthen the void content of the sintering body of the porous matter that constitutes running shaft, the rigidity of bearing is descended, exist and to tackle the problem that this bearing rigidity descends.
Summary of the invention
The present invention makes in order to address the above problem, its purpose is, provide a kind of working fluid that prevents lubricated wet goods to spill, and can reduce part number, reduce hydrodynamic bearing device and spindle motor that the miniaturization of making assembling procedure number and manufacture cost, can tackle hard disk unit again can well maintained bearing rigidity to the outside.
Hydrodynamic bearing device of the present invention, have axle and accompany micro-gap, be configured in sleeve on the periphery with respect to described axle, working fluid in filling between axle and sleeve, it is characterized in that, axle is formed by sintering body, outer circumferential face at this is formed with the radial dynamic pressure occurrence groove simultaneously, and sleeve is formed by the intransitable material of working fluid.
Adopt said structure, because the sleeve that has used material that the working fluid by lubricated wet goods can not soak into to form surrounds axle from outer circumferential side, therefore, although a porous plastid of being made up of sintering body does not worry that working fluid spills to the outside yet.Again, also can not set framework etc., can form the function of sleeve, compare, can reduce part number, worker ordinal number and manufacture cost with traditional hydrodynamic bearing device that framework must be arranged by 1 member in the outside of sleeve.And, because of can reducing part number, so can obtain tackling the small-sized spindle motor that the miniaturization of hard disk unit requires.During manufacturing, by modes such as drawings, can highi degree of accuracy and time-consumingly do not make shaft and radial dynamic pressure occurrence groove thereof.Again, axle is surrounded by working fluid, and outer circumferential face is formed with the radial dynamic pressure occurrence groove, so add the generation pressure of radial dynamic pressure occurrence groove equably to the inside of axle from periphery, when dynamic pressure took place, can prevent also that working fluid from partly flowing out and making from porous plastid pressure takes place descended.
Again, the present invention is characterized in that on the basis of said structure, has: the thrust flanges of protruding from axle towards radial direction foreign side; With respect to described thrust flanges, be configured in thrust plate on the relative position with accompanying micro-gap, working fluid in filling between axle and the sleeve and even between thrust flanges and sleeve and the thrust plate, sleeve and thrust plate are formed by the intransitable material of working fluid.Adopt said structure, constituted the axial flow of fluid bearing, the footpath upwards also can position limit.
Again, thrust flanges is formed by sintering body, is formed with the axial hydrodynamic occurrence groove on the surface of this thrust flanges simultaneously, and sleeve and thrust plate are formed by the intransitable material of working fluid.
Adopt said structure, also can axle and thrust flanges is integrally formed, can reduce part number, thereby the precision of can further improve, owing to, radial dynamic pressure occurrence groove and axial hydrodynamic occurrence groove are formed simultaneously by stamping processes and sintering circuit, so can further save time, can reduce manufacture cost.In addition, even axle and thrust flanges are being separated when making separately, also have can with highi degree of accuracy and lower cost produce the advantage of thrust flanges with axial hydrodynamic occurrence groove.
Again, also can implement blocking microporous processing or coating processing or electroplating processes on the inner peripheral surface of this sleeve when forming sleeve by sintering body, thrust plate is formed by the intransitable material of working fluid.Adopt said structure, because of further sleeve also being formed by sintering body, so can further reduce cost.
And, also thrust flanges can be set, but form axial hydrodynamic occurrence groove and trunnion bearing at the end face of axle, can further make simple structureization thus, can reduce manufacture cost.
Again, hydrodynamic bearing device of the present invention, have the axle that forms by sintering body and with respect to the outer circumferential face of described axle, be configured to can counterrotating sleeve with guaranteeing to have micro-gap, working fluid in filling between described axle and described sleeve, it is characterized in that, described sleeve is formed by the intransitable material of described working fluid, and the inner peripheral surface of while in the hole of the described axle of being inserted with of described sleeve is formed with the radial dynamic pressure occurrence groove.
Adopt the present invention, because the sleeve that the material that can not be soaked into by the working fluid that lubricates wet goods having on every side of axle forms, therefore, although axle is the sintering body of porous matter, working fluid can not spill to the outside yet.In the hole of the axle of porous matter, almost seamlessly contain and be soaked with working fluid.During the action of this hydrodynamic bearing device, the radial dynamic pressure occurrence groove that utilizes the inner peripheral surface in the hole that is inserted with axle of sleeve to form is equably to the outer circumferential face additional pressure of axle.Thus, working fluid is come in and gone out in the axle of porous matter and is made pressure decline takes place in the time of can preventing that dynamic pressure from taking place.
Adopt said structure, because of axle is formed by sintering body, thus when making this, the high-precision processing method of applicable drawing etc., processing is simply.Owing on the inner peripheral surface of sleeve, can wait by rollforming, corrosion or electrolytic machining and form high-precision radial dynamic pressure occurrence groove, can obtain high-precision hydrodynamic bearing device again.Owing to reduced part number, if adopt this FDB, the small-sized spindle motor that then can obtain tackling the hard disk unit miniaturization again.
Again, sleeve and thrust plate also can be formed by the intransitable material of working fluid, and thrust flanges is formed by sintering body, is formed with the axial hydrodynamic occurrence groove on the surface of this thrust flanges.Thus, can axle and thrust flanges is integrally formed and constitute, can reduce part number, thereby the precision of can further improve, because by punching press and sintering circuit, can form simultaneously and not need specific diameter,, can reduce manufacture cost so manufacturing procedure is simplified to the dynamic pressure occurrence groove axial hydrodynamic occurrence groove of high manufacturing accuracy more.Even axle and thrust flanges are being separated when making separately, also have can with highi degree of accuracy and lower cost produce thrust flanges with axial hydrodynamic occurrence groove.
Again, hydrodynamic bearing device of the present invention, have the axle and the outer circumferential face that form by sintering body with respect to described, be configured to can counterrotating sleeve with guaranteeing micro-gap, working fluid in filling between described axle and described sleeve, it is characterized in that, described sleeve is made of the intransitable material of described working fluid, the inner peripheral surface of while in the hole of the described axle of being inserted with of described sleeve is formed with the radial dynamic pressure occurrence groove, also have: be configured to a square end with described axle in the face of putting shape with guaranteeing micro-gap, by the formed thrust plate of the intransitable material of working fluid, has the axial hydrodynamic occurrence groove the either party of the opposing side of described axle.
Like this, thrust flanges need not be set, directly form the axial hydrodynamic occurrence groove, can further make simple structureization, can reduce manufacture cost, can make the hydrodynamic bearing device miniaturization at the end face of axle.
Description of drawings
Fig. 1 is the sectional view of spindle motor with hydrodynamic bearing device of embodiments of the invention 1.
Fig. 2 is the sectional view of spindle motor with hydrodynamic bearing device of embodiments of the invention 2.
Fig. 3 is the sectional view of spindle motor with hydrodynamic bearing device of embodiments of the invention 3.
Fig. 4 is the sectional view of spindle motor with hydrodynamic bearing device of embodiments of the invention 4.
Fig. 5 is the sectional view of spindle motor with hydrodynamic bearing device of embodiments of the invention 5.
Fig. 6 is the sectional view of spindle motor with hydrodynamic bearing device of embodiments of the invention 6.
Fig. 7 has the left-half sectional view of spindle motor of the hydrodynamic bearing device of embodiments of the invention 7 for expression.
Fig. 8 has the left-half sectional view of spindle motor of the hydrodynamic bearing device of embodiments of the invention 8 for expression.
Fig. 9 has the left-half sectional view of spindle motor of the hydrodynamic bearing device of embodiments of the invention 9 for expression.
Figure 10 has the left-half sectional view of spindle motor of the hydrodynamic bearing device of embodiments of the invention 10 for expression.
Figure 11 is the sectional view with spindle motor of traditional hydrodynamic bearing device.
Embodiment
Hydrodynamic bearing device in the embodiments of the invention is described with reference to the accompanying drawings and has the spindle motor of this hydrodynamic bearing device.
(embodiment 1)
As shown in Figure 1, the hydrodynamic bearing device of the spindle motor in the present embodiment 1 comprises: axle 1; From this 1 thrust flanges of protruding to radial direction foreign side 2; Accompany micro-gap, be configured in sleeve 3 on the periphery with respect to axle 1; Accompany micro-gap, be configured in thrust flanges 2 relative positions on thrust plate 4.
In this hydrodynamic bearing device, especially axle 1 sintering body of being made up of the metal sintering material is formed.At this outer circumferential face of 1, the radial dynamic pressure occurrence groove 7 of helical or herring-bone form figure etc. forms by punch process, has constituted the radial fluid bearing.As the metal sintering material, constitute such as the sintering metal that can use the metallic that contains iron or copper to form, but be not limited to this.Can use also that to have stainless iron be that the iron of particle is the sintering metal that particle is formed.In addition, sintering body is the porous plastid that inside has many emptying apertures.As its manufacture method, with the regulation ratio metal powder is cooperated with lubriation material, after mixing, be filled in the metal pattern, the compression forming by punching press is placed on the powder compact of compression that heating stipulated time sintering manufacturing forms in the high temperature below the fusing point then.In this production process, radial dynamic pressure occurrence groove 7, compress once more in the metal pattern and form, but be not limited to this such as also sintering body being reentered into, also can be before sintering form in the compression forming operation of initial impact style.
In the present embodiment, axle 1 is formed by sintering body, and sleeve 3, thrust flanges 2 and thrust plate 4, then is by lubricant oil 6 intransitable materials, promptly the material by the metal solid of non-porous plastid and synthetic resin etc. is formed.As shown in Figure 1, in the present embodiment,, the radial fluid bearing that is made of radial dynamic pressure occurrence groove 7 is set respectively in the close inboard zone on the outer circumferential face of axle 1 and near on 2 positions in opening portion zone.
On the face of at least one side on the opposing side of thrust flanges 2 and thrust plate 4, be formed with the axial hydrodynamic occurrence groove 8 of helical or herring-bone form figure etc., constituted the axial flow of fluid bearing.And at least one side on the face of the sleeve 3 relative with this face with the face of the thrust flanges 2 of the inner end portion adjacency of axle 1 also forms axial hydrodynamic occurrence groove 8, has constituted the axial flow of fluid bearing.Among Fig. 1, expression be that axial hydrodynamic occurrence groove 8 is respectively formed at situation with the face of the face of thrust flanges 2 opposed sleeves 3 and thrust plate 4.
On the protrusion side end 1a that protrudes from the opening portion of sleeve 3 on the axle 1, be wheel hub 9 to be pressed into that the outer embedding of state on its periphery such as the rotating member that is fixed with the magnetic recording disc.In the present embodiment, on the close base part periphery of wheel hub 9, rotor magnet 10 is installed.On pedestal 5, be installed be wound with stator coil 11 and with rotor magnet 10 opposed stator cores 12.Constituted the drive portion that the spindle motor of rotary driving force is provided by this rotor magnet 10 and stator core 12 between axle 1 and sleeve 3.
Usually, wheel hub 9 and pedestal 5 are formed by the metallic material of aluminium and stainless steel etc., but also synthetic resin etc., and the kind of material is not limited.
At the drive portion by this spindle motor wheel hub 9, axle 1, thrust flanges 2 are rotated when driving, diametrically by radial dynamic pressure occurrence groove 7, in the axial direction by axial hydrodynamic occurrence groove 8, making separately, the lubricant oil 6 at position produces dynamic pressure, utilize these FDB (radial fluid bearing and axial flow of fluid bearing), with respect to sleeve 3 and thrust plate 4, with the contactless state of guaranteeing micro-gap with axle 1 and thrust flanges 2 swivel bearings.
Adopt said structure, use the sleeve 3 that forms by lubricant oil 6 intransitable materials axle 1 to be surrounded, although spool 1 porous plastid of being made up of sintering body does not worry that lubricant oil 6 spills to the outside from outer circumferential side.Therefore, can not cause lubricant oil 6 to reduce, can not keep good reliability because of this bad phenomenon convection cell bearing brings obstruction because of spilling to the outside.And, can not setting framework etc. in the outside of sleeve 3 yet, available 1 member is realized the function of sleeve 3.Like this, compare, can reduce part number, can reduce and make assembling procedure number and manufacture cost with the tradition formation that framework must be arranged.Again, during manufacturing, can be by drawing, highi degree of accuracy and time-consumingly do not make shaft 1 and radial dynamic pressure occurrence groove 7 thereof, even it is also passable not use the groove of the modes such as the sort of precision cutting processing of common metallic material occasion to process, can further reduce manufacture cost in the operation of back.And, because of reducing part number, so can obtain tackling the small-sized spindle motor of hard disk unit miniaturization requirement.
Again, axle 1 lubricated oily 6 surrounds, and periphery is formed with radial dynamic pressure occurrence groove 7, so add the generation pressure of radial dynamic pressure occurrence groove 7 equably from the inside of outer circumferential axis 1.Like this, when dynamic pressure took place, can prevent also that lubricant oil 6 from partly flowing out and making from porous matter pressure takes place descended.Again, owing on the axle 1 that forms by sintering body, be formed with radial dynamic pressure occurrence groove 7, therefore can strengthen the area that radial dynamic pressure occurrence groove 7 forms the position, can freely design the shape of radial dynamic pressure occurrence groove 7, bearing rigidity can be well kept thus, high reliability can be kept.
(embodiment 2)
As shown in Figure 2, in the hydrodynamic bearing device of the spindle motor of present embodiment 2, thrust flanges 2 is formed by sintering body with axle 1, in the manufacturing process, with axle 1 and thrust flanges 2 integrally formed manufacturings.
Not only the outer circumferential face formation radial dynamic pressure occurrence groove 7 at axle 1 constitutes the radial fluid bearing, and constitutes the axial flow of fluid bearing at the circular flat portion formation axial hydrodynamic occurrence groove 8 of thrust flanges about in the of 2.
In addition, sleeve 3 and thrust plate 4 are by lubricant oil 6 intransitable materials, promptly the material by the metal solid of non-porous plastid or synthetic resin etc. forms.
Adopt said structure, because of axle 1 and thrust flanges 2 integrally formed, so can reduce part number, thereby the precision of can further improve.Again,, therefore, can further save time, can reduce cost owing to formed radial dynamic pressure occurrence groove 7 and axial hydrodynamic occurrence groove 8 simultaneously by punching press and sintering circuit.
Again, reason sleeve 3 and thrust plate 4 surround axle 1 and thrust flanges 2 from outer circumferential side, although axle 1 and thrust flanges 2 are porous plastids, do not worry that also lubricant oil 6 spills to the outside.And axle 1 and thrust flanges 2 lubricated oily 6 surround, and axle 1 the periphery and the top and bottom of thrust flanges 2 are formed with dynamic pressure occurrence groove 7,8, so add the generation pressure of dynamic pressure occurrence groove 7,8 equably to the inside of the inside of axle 1 and thrust flanges 2.Like this, when dynamic pressure took place, can prevent also that lubricant oil 6 from partly flowing out and making from porous matter pressure takes place descended.Can not cause reliability decrease because of rigidity reduces yet.
In addition, also axle 1 and thrust flanges 2 can be separated separately and make, this occasion has highi degree of accuracy and cost produce the thrust flanges 2 with axial hydrodynamic occurrence groove 8 than the lowland advantage.
(embodiment 3)
As shown in Figure 3, in the hydrodynamic bearing device of the spindle motor of present embodiment 3, axle 1 is formed by sintering body, and the outer circumferential face of axle 1 is formed with radial dynamic pressure occurrence groove 7, and while sleeve 3 is also formed by sintering body.Wherein, the inner peripheral surface of sleeve 3 (inserting hole 3a) has been implemented blocking microporous processing or coating processing or electroplating processes, and lubricant oil 6 can not flow to inner from the inner peripheral surface of sleeve 3.
Adopt said structure, sleeve 3 is also formed by sintering body owing to further incite somebody to action at least, so can further reduce cost.Again, because the inner peripheral surface (inserting hole 3a) of sleeve 3 has been implemented blocking microporous processing or coating processing or electroplating processes, so, do not worry that also lubricant oil 6 spills even sleeve 3 is porous plastids.
(embodiment 4)
As shown in Figure 4, in the hydrodynamic bearing device of the spindle motor of present embodiment 4, do not have thrust flanges 2, and the internal diameter of sleeve 3 is made necessarily.Be formed with axial hydrodynamic occurrence groove 8 in the bottom surface of axle 1.In addition, on the protrusion side end 1a of axle 1, form stepped part, the drop-proof component 13 of axle 1 is installed on the sleeve 3, form the shape that this stepped part is covered from the top, deviate from from sleeve 3 to prevent axle 1.
Adopt said structure, because of the internal diameter of sleeve 3 certain, so have the advantage that is convenient to blocking microporous processing.
In addition, also drop-proof component 13 can be set, that utilizes that the lid 14 that motor driving part is covered is used for axle 1 prevents deviating from function.Whether for preventing deviating from and this place being set, the present invention does not limit.
(embodiment 5)
As shown in Figure 5, in the hydrodynamic bearing device of the spindle motor of present embodiment 5, axle 1 is formed by sintering body, is formed with radial dynamic pressure occurrence groove 7 at the outer circumferential face of axle 1, and the while is formed with trunnion bearing 15 in the lower end of axle 1.
Adopt said structure, because of the part of axial flow of fluid bearing has been altered to trunnion bearing 15, so simple structure can further reduce manufacture cost.
(embodiment 6)
As shown in Figure 6, in the hydrodynamic bearing device of the spindle motor of present embodiment 6, axle 1 is formed by sintering body, and the outer circumferential face of axle 1 is formed with radial dynamic pressure occurrence groove 7, and the while is formed with trunnion bearing 15 in the lower end of axle 1.Sleeve 3 is also formed by sintering body, and the inner peripheral surface of sleeve 3 has been implemented blocking microporous processing or coating processing or electroplating processes.
Adopt said structure, because of the part of axial flow of fluid bearing has been altered to trunnion bearing 15, sleeve 3 is also formed by sintering body at least, so can further reduce manufacture cost.
(embodiment 7)
The hydrodynamic bearing device of the spindle motor in the embodiments of the invention 7 is described below with reference to Fig. 7.Fig. 7 has the left-half sectional view of spindle motor of embodiment 7 hydrodynamic bearing device for expression, and right half part is symmetry with respect to center line C, the Therefore, omited diagram.Among Fig. 7, the hydrodynamic bearing device of present embodiment comprises: axle 1; Be installed in the lower end among this figure of 1, the thrust flanges of protruding from axle 1 towards radial direction foreign side 2; Have to guarantee the sleeve 3 of micro-gap ground, on sleeve 3, be installed with to guarantee micro-gap ground and thrust flanges 2 opposed thrust plates 4 with the inserting hole 3a of axle 1 insertion.
In this hydrodynamic bearing device, axle 1 is formed by the sintering body behind the metal sintering material sintering.As the metal sintering material, constitute such as the sintering metal that can use the metallic that contains iron or copper to form, but be not limited to this, also can use the iron with stainless steel etc. is that the iron of particle is sintering metal.Sintering body is the porous plastid that inside has many emptying apertures, and the white round dot of illustrated size is represented the emptying aperture of sintering body on the surface of axle 1.Because of axle 1 is a porous plastid, so,, just can not continue again to soak in case soak into to all emptying apertures saturatedly though lubricant oil 6 soaks into to the emptying aperture of axle 1.As the manufacture method of axle 1, with the regulation ratio metal powder is cooperated with lubriation material and to mix, mixture is filled in the metal pattern compression forming by punching press.The formed body of compression forming is placed on heating stipulated time sintering manufacturing forms in the temperature below the fusing point.
In the present embodiment, axle 1 is formed by sintering body, but sleeve 3, thrust flanges 2 and thrust plate 4, by lubricant oil 6 intransitable materials, promptly the material by the metal solid of non-porous plastid or synthetic resin etc. forms.At the inner peripheral surface of the inserting hole 3a of sleeve 3, by traditional known method, be rollforming, burn into electrolytic machining etc., form radial dynamic pressure occurrence groove 7A, the 7B of well-known shape such as helical or herring-bone form figure.Among Fig. 7, illustrating 2 radial dynamic pressure occurrence groove 7A, 7B in the analysing and observe of sleeve 3, in practice, then is on the inner peripheral surface of the inserting hole 3a of sleeve 3 a plurality of radial dynamic pressure occurrence groove 7A, 7B to be set respectively.Want on the inner peripheral surface 3a of sleeve 3, to illustrate radial dynamic pressure occurrence groove 7A, 7B and be difficult to see clearly, so ideograph has been shown as form shown in Figure 7.
On at least one side's of thrust flanges 2 and thrust plate 4 opposing side separately face (above the thrust plate 4 among Fig. 7), constituted the axial hydrodynamic occurrence groove 8A of well-known shape such as helical or herring-bone form figure, constituted the axial flow of fluid bearing.And, at least one side's the face on thrust flanges 2 and below the sleeve 3 relative (sleeve 3 among Fig. 7 below), also be formed with axial hydrodynamic occurrence groove 8B with this face, constituted the axial flow of fluid bearing.
On the protrusion side end 1a of the axle 1 that the opening portion from sleeve 3 protrudes, to be pressed into the wheel hub 9 that state is installed with rotating member.Periphery at wheel hub 9 is installed with such as magnetic recording disc 20.In this spindle motor, on the periphery of close pedestal 5 parts of wheel hub 9, rotor magnet 10 is installed.On pedestal 5, be installed be wound with stator coil 11 and with rotor magnet 10 opposed stator cores 12.Utilize rotor magnet 10 and stator core 12, constituted the drive portion that the spindle motor of rotary driving force is provided between axle 1 and sleeve 3.
When the drive portion by spindle motor makes wheel hub 9, axle 1 and thrust flanges 2 rotations, utilize radial dynamic pressure occurrence groove 7A, 7B that radially dynamic pressure takes place in lubricant oil 6, utilize axial hydrodynamic occurrence groove 8A, 8B that axial dynamic pressure takes place, rely on these dynamic pressures to form FDB (radial fluid bearing and axial flow of fluid bearing), axle 1 and thrust flanges 2 are rotated with the contactless state of guaranteeing micro-gap with respect to sleeve 3 and thrust plate 4.
Adopt present embodiment, the unnecessary elephant sets framework 53 etc. in the outside of sleeve 52 traditional hydrodynamic bearing device shown in Figure 11, and available 1 member forms sleeve 52.Like this, compare, can reduce part number, can reduce worker ordinal number and manufacture cost with traditional hydrodynamic bearing device formation that framework must be arranged.
During manufacturing, can be by drawing, highi degree of accuracy and make shaft 1 with simple operation.Again, owing on the inner peripheral surface of the sleeve 3 of non-sintering body, can wait by rollforming, corrosion or electrolytic machining and form radial dynamic pressure occurrence groove 7A, 7B, so the machining accuracy height of radial dynamic pressure occurrence groove 7A, 7B.As mentioned above, in the present embodiment, because of reducing part number, so can obtain to tackle the small-sized spindle motor of hard disk unit miniaturization.
Again, because the inner peripheral surface at the inserting hole 3a of sleeve 3 is formed with radial dynamic pressure occurrence groove 7A, 7B, therefore, so be additional to by the equalization pressure of radial dynamic pressure occurrence groove 7A, the formed lubricant oil 6 of 7B in the periphery and inner lubricant oil 6 of lubricated oily 6 axles 1 that surround.Therefore, come in and go out because of lubricant oil 6 in the time of can preventing that dynamic pressure from taking place and partly waits the generation pressure decline that causes in porous matter.Its result is thus because of can well keeping the bearing rigidity of radial fluid bearing and axial flow of fluid bearing, so can keep the high reliability of hydrodynamic bearing device.
(embodiment 8)
The hydrodynamic bearing device of the spindle motor in the embodiments of the invention 8 is described below with reference to Fig. 8.Fig. 8 has the left-half sectional view of spindle motor of embodiment 8 hydrodynamic bearing device for expression, and right half part is symmetry with respect to center line C, the Therefore, omited diagram.The axle 1 of present embodiment, underpart in the drawings has the thrust flanges 2 with axle 1 integrally formed sintering body.In manufacturing process, axle 1 is made simultaneously with thrust flanges 2.Other structure is identical with the foregoing description 7 shown in Figure 7.That is, sleeve 3 and thrust plate 4 are by lubricant oil 6 intransitable materials, promptly the material by the metal solid of non-porous plastid or synthetic resin etc. forms.At the inner peripheral surface of the inserting hole 3a of sleeve 3, by traditional processing method, be rollforming, burn into electrolytic machining etc., form well-known radial dynamic pressure occurrence groove 7A, 7B.On the face of the sleeve 3 relative, be formed with axial hydrodynamic occurrence groove 8B, on the face of thrust plate 4, be formed with axial hydrodynamic occurrence groove 8A, constituted the axial flow of fluid bearing with thrust flanges 2.
Adopt the structure of present embodiment, integrally formed because of axle 1 and thrust flanges 2, so can reduce part number, and can improve precision.
Again, reason sleeve 3 and thrust plate 4 surround axle 1 and thrust flanges 2 from outer circumferential side, although axle 1 and thrust flanges 2 are porous plastids, do not worry that also lubricant oil 6 spills to the outside.And, contain and be soaked with lubricant oil 6 in axle 1 and the thrust flanges 2.Inner peripheral surface at the inserting hole 3a of sleeve 3 is formed with dynamic pressure occurrence groove 7A, 7B, below the sleeve 3 relative with thrust flanges 2 and be formed with dynamic pressure occurrence groove 8B, 8A above the thrust plate 4 respectively.During action, to the inside of axle 1 and the additional equably dynamic pressure occurrence groove 7A in inside, 7B, 8A, the formed pressure of 8B of thrust flanges 2.Like this, when dynamic pressure took place, can prevent that lubricant oil 6 from partly flowing out and making from porous matter pressure takes place descended.Can not reduce the decline that causes the FDB reliability because of the rigidity of bearing.
Also axle 1 and thrust flanges 2 can be separated to make separately again both are made up, this occasion also has the advantage that cost is made than the lowland.
(embodiment 9)
The hydrodynamic bearing device of the spindle motor in the embodiments of the invention 9 is described below with reference to Fig. 9.Fig. 9 has the left-half sectional view of spindle motor of embodiment 9 hydrodynamic bearing device for expression, and right half part is symmetry with respect to center line C, the Therefore, omited diagram.As shown in Figure 9, in the hydrodynamic bearing device of this spindle motor, axle 1 and thrust flanges 2 are formed by sintering body.Axle 1 and thrust flanges 2 integrally formed manufacturings.On the upper and lower surfaces of thrust flanges 2 peripheries (circular flat portion), be formed with axial hydrodynamic occurrence groove 8A, 8B respectively, constituted the axial flow of fluid bearing.Other structure is identical with the foregoing description 7 shown in Figure 7, omits the explanation of its repetition.
In this hydrodynamic bearing device, integrally formed because of axle 1 and thrust flanges 2, so can reduce part number, and can improve precision.Again, can form axial hydrodynamic occurrence groove 8A, 8B simultaneously, manufacturing process is simplified, can reduce cost by punching press and sintering circuit.Compare with radial dynamic pressure occurrence groove 7A, 7B, axial hydrodynamic occurrence groove 8A, 8B do not need high machining accuracy like that.Like this, even the sintering body that axial hydrodynamic occurrence groove 8A, 8B are arranged on porous plastid is on the thrust flanges 2, in function aspects also no problem.
(embodiment 10)
The hydrodynamic bearing device of the spindle motor in the embodiments of the invention 10 is described below with reference to Figure 10.Figure 10 has the left-half sectional view of spindle motor of embodiment 10 hydrodynamic bearing device for expression, and right half part is symmetry with respect to center line C, the Therefore, omited diagram.As shown in figure 10, the axle 1 of the hydrodynamic bearing device of this spindle motor is not provided with the thrust flanges of radially protruding 2 as shown in Figure 9 below axle 1.The axial hydrodynamic occurrence groove 8 that constitutes the axial flow of fluid bearing is formed on the bottom surface 1c of axle.In order to prevent that axle from 1 deviating from from sleeve 3, on the protrusion side end 1a of axle 1, be formed with stepped part 1d, drop-proof component 13 is installed on the sleeve 3, form the shape that this stepped part 1d is covered from the top.Other structure is identical with the structure of the foregoing description 9.
In the structure of this hydrodynamic bearing device, because of the internal diameter of the inserting hole 3a of sleeve 3 certain, so have the advantage that the interior Zhou Jiagong that is convenient to sleeve 3 and radial dynamic pressure occurrence groove 7A, 7B form.
Also drop-proof component 13 can be set, prevent axle 1 function of deviating from, be used for both but the lid 14 that covers motor driving part is had.The present invention does not limit having or not drop-proof component and configuration place thereof.
Claims (19)
1. hydrodynamic bearing device has axle and accompanies micro-gap, is configured in sleeve on the periphery with respect to described axle, and working fluid in filling between axle and sleeve, it is characterized in that,
Axle is formed by sintering body, and the outer circumferential face at this is formed with the radial dynamic pressure occurrence groove simultaneously, and sleeve is formed by the intransitable material of working fluid.
2. hydrodynamic bearing device as claimed in claim 1 is characterized in that,
Have: the thrust flanges of protruding from axle towards radial direction foreign side; With respect to described thrust flanges, be configured in thrust plate on the relative position with accompanying micro-gap,
Working fluid in filling between axle and the sleeve and even between thrust flanges and sleeve and the thrust plate,
Sleeve, thrust flanges and thrust plate are formed by the intransitable material of working fluid.
3. hydrodynamic bearing device as claimed in claim 1 is characterized in that,
Have: the thrust flanges of protruding from axle towards radial direction foreign side; With respect to described thrust flanges, be configured in thrust plate on the relative position with accompanying micro-gap,
Working fluid in filling between axle and the sleeve and even between thrust flanges and sleeve and the thrust plate,
Thrust flanges is formed by sintering body, is formed with the axial hydrodynamic occurrence groove on the surface of this thrust flanges simultaneously,
Sleeve and thrust plate are formed by the intransitable material of working fluid.
4. hydrodynamic bearing device as claimed in claim 1 is characterized in that,
Have: the thrust flanges of protruding from axle towards radial direction foreign side; With respect to described thrust flanges, be configured in thrust plate on the relative position with accompanying micro-gap,
Working fluid in filling between axle and the sleeve and even between thrust flanges and sleeve and the thrust plate,
The surface of thrust flanges or with the face of the surperficial opposed sleeve of thrust flanges or with at least 1 face of the face of the surperficial opposed thrust plate of thrust flanges on, be formed with the axial hydrodynamic occurrence groove,
Sleeve is formed by sintering body, simultaneously implements blocking microporous processing or coating processing or electroplating processes on the inner peripheral surface of this sleeve at least,
Thrust plate is formed by the intransitable material of working fluid.
5. hydrodynamic bearing device as claimed in claim 1 is characterized in that,
Have end face, be configured in thrust plate on the relative position with accompanying micro-gap with respect to axle,
Between axle and the sleeve so that the axle end face and thrust plate between filling working fluid,
On the end face of axle or thrust plate, be formed with the axial hydrodynamic occurrence groove,
Sleeve and thrust plate are formed by the intransitable material of working fluid.
6. hydrodynamic bearing device as claimed in claim 1 is characterized in that,
Have end face, be configured in thrust plate on the relative position with accompanying micro-gap with respect to axle,
Between axle and the sleeve so that the axle end face and thrust plate between filling working fluid,
On the end face of axle or thrust plate, be formed with the axial hydrodynamic occurrence groove,
Sleeve is formed by sintering body, simultaneously on the inner peripheral surface of this sleeve at least, implements blocking microporous processing or coating processing or electroplating processes,
Thrust plate is formed by the intransitable material of working fluid.
7. hydrodynamic bearing device as claimed in claim 1 is characterized in that,
Have the thrust plate that the end face with respect to axle is configured,
Between axle and the sleeve so that the axle end face and thrust plate between filling working fluid,
End face at axle is formed with trunnion bearing,
Sleeve and thrust plate are formed by the intransitable material of working fluid.
8. hydrodynamic bearing device as claimed in claim 1 is characterized in that,
Have the thrust plate that the end face with respect to axle is configured,
Between axle and the sleeve so that the axle end face and thrust plate between filling working fluid,
End face at axle is formed with trunnion bearing,
Sleeve is formed by sintering body, simultaneously on the inner peripheral surface of this sleeve at least, implements blocking microporous processing or coating processing or electroplating processes,
Thrust plate is formed by the intransitable material of working fluid.
9. hydrodynamic bearing device, have the axle that forms by sintering body and with respect to the outer circumferential face of described axle, be configured to can counterrotating sleeve with guaranteeing to have micro-gap, working fluid in filling between axle and sleeve, it is characterized in that,
Described sleeve is made of the intransitable material of described working fluid, and the inner peripheral surface of while in the hole that is inserted with axle of described sleeve is formed with the radial dynamic pressure occurrence groove.
10. hydrodynamic bearing device as claimed in claim 9 is characterized in that,
Axle has in this radial direction foreign side the thrust flanges of protruding to foreign side, and on described thrust flanges, have and be configured to relative thrust plate with guaranteeing micro-gap,
Working fluid in filling between described axle and the described sleeve, between described thrust flanges and the described sleeve and between described thrust flanges and the described thrust plate,
Described sleeve, described thrust flanges and described thrust plate are made of the intransitable material of working fluid.
11. hydrodynamic bearing device as claimed in claim 9 is characterized in that,
The thrust flanges that forms by sintering body that has the axle that forms by sintering body, on radial direction, protrudes from described axle and guarantee the thrust plate that micro-gap is arranged is configured with respect to described thrust flanges to foreign side,
Working fluid in filling between described axle and the described sleeve, between described thrust flanges and the described sleeve and between described thrust flanges and the described thrust plate,
Described sleeve and described thrust plate are made of the intransitable material of working fluid.
12. hydrodynamic bearing device as claimed in claim 10 is characterized in that, with the face of thrust flanges one side's the opposed sleeve of face and with at least 1 face of the face of the opposing party's of thrust flanges the opposed thrust plate of face on, be formed with the axial hydrodynamic occurrence groove.
13. hydrodynamic bearing device as claimed in claim 11 is characterized in that, with the face of thrust flanges one side's the opposed sleeve of face or with at least 1 face of the face of the opposing party's of thrust flanges the opposed thrust plate of face on, be formed with the axial hydrodynamic occurrence groove.
14. hydrodynamic bearing device as claimed in claim 10 is characterized in that, at least one side at two faces of thrust flanges is formed with the axial hydrodynamic occurrence groove.
15. hydrodynamic bearing device as claimed in claim 11 is characterized in that, at least one side at two faces of thrust flanges is formed with the axial hydrodynamic occurrence groove.
16. a hydrodynamic bearing device, have the axle that forms by sintering body and with respect to the outer circumferential face of described axle, be configured to can counterrotating sleeve with guaranteeing to have micro-gap, working fluid in filling between described and described sleeve,
Described sleeve is made of the intransitable material of described working fluid, and the inner peripheral surface of while in the hole that is inserted with axle of described sleeve is formed with the radial dynamic pressure occurrence groove, it is characterized in that,
Also have: be configured to the opposed form of a square end face of described axle, by the formed thrust plate of the intransitable material of working fluid with guaranteeing micro-gap,
Working fluid in filling between a square end face of described and described thrust plate,
Either party at the opposing side of square end face of described axle and described thrust plate is provided with the axial hydrodynamic occurrence groove.
17. a spindle motor comprises:
Have axle and accompany micro-gap, with respect to described axle be configured in sleeve on the periphery, the hydrodynamic bearing device of working fluid in filling between axle and sleeve;
The drive portion of rotary driving force is provided between axle and sleeve, it is characterized in that,
Axle is formed by sintering body, is formed with the radial dynamic pressure occurrence groove simultaneously on this outer circumferential face, and sleeve is formed by the intransitable material of working fluid.
18. a spindle motor comprises:
Have the axle that forms by sintering body and with respect to the outer circumferential face of described axle, guaranteeing micro-gap is arranged to be configured to can counterrotating sleeve, the hydrodynamic bearing device of working fluid in filling between axle and sleeve;
The drive portion of rotary driving force is provided between axle and sleeve, it is characterized in that,
Described sleeve is made of the intransitable material of described working fluid, and the while is formed with the radial dynamic pressure occurrence groove on the inner peripheral surface in the hole that is inserted with axle of described sleeve.
19. a spindle motor comprises: by sintering body form the axle; With respect to the outer circumferential face of described axle, be configured to can counterrotating sleeve with guaranteeing to have micro-gap; Be configured to with guaranteeing micro-gap with the axle a square end in the face of put shape, by the formed thrust plate of the intransitable material of working fluid; The drive portion of rotary driving force is provided between axle and sleeve, it is characterized in that,
Working fluid in filling between described axle and described sleeve, and described sleeve is made of the intransitable material of described working fluid, and the while is formed with the radial dynamic pressure occurrence groove on the inner peripheral surface in the hole that is inserted with axle of described sleeve,
Working fluid in filling between a square end face of described and described thrust plate,
Either party at the opposing side of square end face of described axle and described thrust plate is provided with the axial hydrodynamic occurrence groove.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2004119681 | 2004-04-15 | ||
| JP2004119681A JP2005299862A (en) | 2004-04-15 | 2004-04-15 | Fluid dynamic bearing device and spindle motor |
| JP2004186433 | 2004-06-24 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1690459A true CN1690459A (en) | 2005-11-02 |
| CN100374744C CN100374744C (en) | 2008-03-12 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB2005100673799A Expired - Fee Related CN100374744C (en) | 2004-04-15 | 2005-04-13 | Fluid bearing device and spindle motor |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JP2005299862A (en) |
| CN (1) | CN100374744C (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101210585B (en) * | 2006-12-29 | 2010-05-12 | 富准精密工业(深圳)有限公司 | Dynamical pressure bearing, rotary shaft and manufacturing method thereof |
| CN101210586B (en) * | 2006-12-29 | 2010-11-10 | 富准精密工业(深圳)有限公司 | Dynamical pressure bearing manufacturing method |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3158857B2 (en) * | 1994-04-26 | 2001-04-23 | ティアック株式会社 | Motor and disk device |
| JP2003333792A (en) * | 2002-05-09 | 2003-11-21 | Mitsumi Electric Co Ltd | Motor and disc drive |
| JP2006347492A (en) * | 2005-06-20 | 2006-12-28 | Calsonic Kansei Corp | Air-conditioning control device for vehicle |
-
2004
- 2004-04-15 JP JP2004119681A patent/JP2005299862A/en active Pending
-
2005
- 2005-04-13 CN CNB2005100673799A patent/CN100374744C/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101210585B (en) * | 2006-12-29 | 2010-05-12 | 富准精密工业(深圳)有限公司 | Dynamical pressure bearing, rotary shaft and manufacturing method thereof |
| CN101210586B (en) * | 2006-12-29 | 2010-11-10 | 富准精密工业(深圳)有限公司 | Dynamical pressure bearing manufacturing method |
| US7857516B2 (en) | 2006-12-29 | 2010-12-28 | Foxconn Technology Co., Ltd. | Hydrodynamic bearing with bearing surface having branched grooves |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2005299862A (en) | 2005-10-27 |
| CN100374744C (en) | 2008-03-12 |
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