CN101400912B - Fluid bearing device - Google Patents
Fluid bearing device Download PDFInfo
- Publication number
- CN101400912B CN101400912B CN200780008497XA CN200780008497A CN101400912B CN 101400912 B CN101400912 B CN 101400912B CN 200780008497X A CN200780008497X A CN 200780008497XA CN 200780008497 A CN200780008497 A CN 200780008497A CN 101400912 B CN101400912 B CN 101400912B
- Authority
- CN
- China
- Prior art keywords
- bearing
- shell
- sleeve
- main body
- bearing sleeve
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
- 239000012530 fluid Substances 0.000 title claims abstract description 15
- 238000002347 injection Methods 0.000 claims abstract description 12
- 239000007924 injection Substances 0.000 claims abstract description 12
- 239000011148 porous material Substances 0.000 claims description 35
- 229920005989 resin Polymers 0.000 claims description 26
- 239000011347 resin Substances 0.000 claims description 26
- 230000002093 peripheral effect Effects 0.000 claims description 24
- 230000001050 lubricating effect Effects 0.000 claims description 11
- 230000015572 biosynthetic process Effects 0.000 claims description 8
- 238000007493 shaping process Methods 0.000 claims description 6
- 238000000465 moulding Methods 0.000 abstract 1
- 239000002184 metal Substances 0.000 description 38
- 229910052751 metal Inorganic materials 0.000 description 38
- 238000001746 injection moulding Methods 0.000 description 32
- 239000000314 lubricant Substances 0.000 description 23
- 239000000463 material Substances 0.000 description 16
- 230000000694 effects Effects 0.000 description 15
- 239000007769 metal material Substances 0.000 description 13
- 238000005245 sintering Methods 0.000 description 13
- 238000000034 method Methods 0.000 description 10
- 239000011230 binding agent Substances 0.000 description 6
- 230000033228 biological regulation Effects 0.000 description 6
- 229910001369 Brass Inorganic materials 0.000 description 5
- 239000010951 brass Substances 0.000 description 5
- 238000004891 communication Methods 0.000 description 5
- 238000010586 diagram Methods 0.000 description 5
- BGPVFRJUHWVFKM-UHFFFAOYSA-N N1=C2C=CC=CC2=[N+]([O-])C1(CC1)CCC21N=C1C=CC=CC1=[N+]2[O-] Chemical compound N1=C2C=CC=CC2=[N+]([O-])C1(CC1)CCC21N=C1C=CC=CC1=[N+]2[O-] BGPVFRJUHWVFKM-UHFFFAOYSA-N 0.000 description 4
- 230000015556 catabolic process Effects 0.000 description 4
- 238000006731 degradation reaction Methods 0.000 description 4
- 238000003754 machining Methods 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 4
- 125000006850 spacer group Chemical group 0.000 description 4
- 230000004323 axial length Effects 0.000 description 3
- 230000014759 maintenance of location Effects 0.000 description 3
- 150000002739 metals Chemical class 0.000 description 3
- 238000012545 processing Methods 0.000 description 3
- 229910000838 Al alloy Inorganic materials 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 2
- 229920000106 Liquid crystal polymer Polymers 0.000 description 2
- 229910000861 Mg alloy Inorganic materials 0.000 description 2
- 239000004696 Poly ether ether ketone Substances 0.000 description 2
- 239000004734 Polyphenylene sulfide Substances 0.000 description 2
- 239000000853 adhesive Substances 0.000 description 2
- 230000001070 adhesive effect Effects 0.000 description 2
- 238000004873 anchoring Methods 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 2
- 238000010276 construction Methods 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- 239000010949 copper Substances 0.000 description 2
- 238000013213 extrapolation Methods 0.000 description 2
- 239000004519 grease Substances 0.000 description 2
- 230000003993 interaction Effects 0.000 description 2
- 239000011553 magnetic fluid Substances 0.000 description 2
- 239000011159 matrix material Substances 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 239000008041 oiling agent Substances 0.000 description 2
- 235000015927 pasta Nutrition 0.000 description 2
- 229920002492 poly(sulfone) Polymers 0.000 description 2
- 229920002530 polyetherether ketone Polymers 0.000 description 2
- 229920000069 polyphenylene sulfide Polymers 0.000 description 2
- 238000011176 pooling Methods 0.000 description 2
- 239000010935 stainless steel Substances 0.000 description 2
- 229910001220 stainless steel Inorganic materials 0.000 description 2
- 229920012266 Poly(ether sulfone) PES Polymers 0.000 description 1
- 229920006127 amorphous resin Polymers 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 229920006038 crystalline resin Polymers 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 230000003467 diminishing effect Effects 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 238000012856 packing Methods 0.000 description 1
- 229920012287 polyphenylene sulfone Polymers 0.000 description 1
- 239000012779 reinforcing material Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000010023 transfer printing Methods 0.000 description 1
Images
Landscapes
- Sliding-Contact Bearings (AREA)
- Mounting Of Bearings Or Others (AREA)
Abstract
A fluid dynamic bearing device capable of exercising high bearing performance is provided at low cost. A housing 7 is injection molded with a bearing sleeve 8 as an insert. Accordingly, the molding of the housing 7 and the assembly of the housing 7 and the bearing sleeve 8 can be performed in a single step. In addition to this, by simply increasing the die precisions the housing 7 and the bearing sleeve 8 can be fixed easily with high precision. Since the housing 7 is opened at both ends, it is possible to sandwich the bearing sleeve 8, and accordingly, the bearing sleeve 8 can be accurately positioned inside the dies with reliability.
Description
Technical field
The present invention relates to hydrodynamic bearing device.
Background technique
Hydrodynamic bearing device is that the axle that need support by the lubricating film of the fluid that produces in the bearing play is supported for relative rotation bearing means freely.This hydrodynamic bearing device has features such as high speed rotating, high running accuracy, low noise.In recent years, use its feature, with its as information equipment, for example, the spindle motor that magneto-optical disc apparatus such as optical disk unit, MD, MO such as disk such as HDD, FDD device, CD-ROM, CD-R/RW, DVD-ROM/RAM etc. go up to carry with or personal computer (PC) wait to go up and carry, the bearing that the blower motor that carries out the cooling of heat releasing source is used etc. is widely-used.
For example, be provided with radial bearing portion that spindle unit is supported diametrically and the thrust bearing division that supports in the axial direction embedding the hydrodynamic bearing device of HDD with spindle motor, radial bearing portion is in the majority by the situation that the hydraulic bearing of the dynamic pressure generating section that possesses the lubricating fluid generation dynamic pressure effect that is used in the radial bearing gap constitutes.Constituting with hydraulic bearing under the situation of radial bearing portion, forming dynamic pressure groove (for example, with reference to patent documentation 1) as dynamic pressure generating section the either party of the outer circumferential face of the inner peripheral surface of bearing sleeve or opposed spindle unit.
Usually, above-mentioned bearing sleeve is fixed in the fixed position in week in the shell.At this moment, as the bearing sleeve that is fixed in shell, for example, that knows has interior week at a bearing sleeve, is provided with the structure (with reference to above-mentioned patent documentation 1) of two place's dynamic pressure generating sections at axially spaced-apart.That knows in addition has, for the purpose that further enlarges the bearing play of radial bearing portion, the structure of arranging two dynamic pressure generating sections in the axial direction and disposing (for example, with reference to patent documentation 2) or between two bearing sleeves, accompany the Spacer structure of (also being called liner) (for example, with reference to patent documentation 3).
Patent documentation 1: the spy opens communique 2003-No. 232353
Patent documentation 2: the spy opens flat 11-No. 269475 communiques
Patent documentation 3: the spy opens flat 11-No. 155254 communiques
In above-mentioned hydrodynamic bearing device, bearing sleeve directly determines bearing performance in other words to the width accuracy of the assembly precision of shell decision bearing play, therefore, needs highi degree of accuracy to carry out assembling to the bearing sleeve of shell.Yet, be not easy highi degree of accuracy and carry out described assembling, expensiveization that may cause the reduction of manufacturing efficiency to cause.Especially, as described in the structure of record in the above-mentioned patent documentation 2,3, under the situation of using a plurality of bearing sleeves, except assembly precision to the bearing sleeve of shell, positional accuracy between bearing sleeve (coaxality etc.) also becomes problem, but has tolerance of size respectively on shell or bearing sleeve, therefore, day by day be difficult to carry out these assembling, may cause further expensiveization.
Summary of the invention
The objective of the invention is to provides the assembly precision of raising to the bearing sleeve of shell with low cost, can bring into play the hydrodynamic bearing device of high bearing performance thus.
In order to solve described problem, the invention provides a kind of hydrodynamic bearing device, it possesses: the shell of both ends open; Be fixed in the bearing sleeve in the interior week of shell; Insert the spindle unit in the interior week of bearing sleeve; Be arranged at spindle unit lip part; The radial bearing gap that forms between the inner peripheral surface of the outer circumferential face of spindle unit and bearing sleeve is formed with seal space between the inner peripheral surface of the outer circumferential face of lip part and shell, it is characterized in that, with bearing sleeve as built in items, the injection moulding shell.
As mentioned above, if with bearing sleeve as built in items injection moulding shell, then only by bearing sleeve is properly positioned in the forming metal mould, just can precision securing two components well, the precision that can realize the bearing play improves even the raising of bearing performance.Especially, the both ends open of shell can form location in the metal pattern from axial both end sides, therefore, can carry out further correct positioning.In addition, can omit the set casing that in the past needed and the operation of bearing sleeve, therefore, enhance productivity.
For example, by in forming die with bearing sleeve location, simultaneously, under the state in its at least one distolateral space (gap) that is provided with regulation, carry out injection moulding, at least one side's of lining bearing sleeve the lining portion of end face can be set.If described structure, even then causing taking place under the uneven situation on the axial dimension of each goods at bearing sleeve owing to machining error, also can absorb described inequality by lining portion, therefore, can relax machining accuracy, realize the further cost degradation of hydrodynamic bearing device the bearing sleeve requirement.In addition, limit moving axially of bearing sleeve by lining portion is set, i.e. therefore lining portion, easily obtains high-intensity assembling part as the performance function that comes off that prevents of bearing sleeve.
The end face of bearing sleeve is sometimes towards the thrust-bearing gap, and the surface accuracy of (below, be called thrust bearing surface) is poor if this face, and then the width accuracy in thrust-bearing gap reduces, and may cause axial bearing performance.Therefore, need be with the fine finishing of thrust bearing surface highi degree of accuracy.Bearing sleeve is in the majority by the situation that sintering metal forms usually, but with regard to sintering metal, there is the limit in the raising of surface accuracy, and high-precision processing causes the reduction of manufacturing efficiency or cost to improve.
In this respect, if in above-mentioned lining portion with form the thrust-bearing gap with it between the end face of opposed lip part, then can realize the high precision int in thrust-bearing gap by form the high precision int of the lining end surface that lining portion brings with injection moulding.Especially, if form lining portion, then compare with sintering metal etc. with resin, obtain wearability, therefore, during low speed rotation when the starting that can be suppressed at bearing stops etc., contact the wearing and tearing that cause with moving via the slip of the end face of the opposed lip part in thrust-bearing gap.
When being shaped above-mentioned lining portion,, in the time of then can be,, therefore preferred at lining end surface transfer printing shaping dynamic pressure generating section with the shaping of lining portion if in forming metal mould, mould portion corresponding to the dynamic pressure generating section shape is set corresponding to the position of lining end surface.
Also have, in this hydrodynamic bearing device, negative pressure takes place in the part in bearing sometimes, and the generation that causes bubble of described negative pressure or the generation of vibration reduce bearing performance.Described imappropriate situation can form axial groove by for example above-mentioned patent documentation 1 the same periphery at bearing sleeve, and the intercommunicating pore of the both ends of the surface that are communicated with bearing sleeve is set, and guarantees that in bearing inside the circulation stream of lubricating fluid is eliminated.
Yet if will embed and injection moulding at the bearing sleeve that outer circumferential face is provided with axial groove, axial groove is by the injection material landfill.Therefore, in the present invention,, formed the intercommunicating pore between the both ends of the surface that are communicated with bearing sleeve by this intermediate sleeve at the periphery of bearing sleeve configuration intermediate member.If this bearing sleeve and intermediate sleeve are made as built in items, then the both ends open portion of intercommunicating pore is sealed by metal pattern, and therefore, intercommunicating pore is not by landfill.
In addition, as other structures that are used to finish the problems referred to above, in the present invention, provide a kind of hydrodynamic bearing device, it possesses: shell; Be fixed in the bearing main body in the interior week of shell; With the inner peripheral surface of bearing main body towards the lubricating film and supporting diametrically of the fluid that forms of radial bearing gap need the radial bearing portion of the axle that supports, bearing main body is formed by a plurality of bearing sleeves of arranging in the axial direction, it is characterized in that, shell is to have opening portion at two ends, and the injection-molded article that bearing main body is embedded.
Like this, by by bearing main body is embedded and the injection moulding shell, even constituting with a plurality of bearing sleeves under the situation of bearing sleeve, also as long as raising mould precision just can easily improve the mutual assembly precision of parts.Especially, as the application, the injection moulding two ends have under the situation of shell of opening portion, form the location of the bearing main body in the mould from axial both end sides, therefore, can carry out more accurate location.In addition, shaping, and the assembling of shell and bearing main body of shell can be carried out, therefore, cheapization of manufacture cost can be realized by an operation.
For example, by in forming die with bearing main body location, simultaneously, under the state in its at least one distolateral space that is provided with established amount, carry out injection moulding (embed and be shaped), at least one side's of lining bearing main body the lining portion of end face can be set.If there is inequality in described structure even then constitute each bearing sleeve of bearing main body on axial dimension, also can easily obtain absorbing the described inequality high-precision assembling part that becomes by this lining portion.In addition, this lining portion also as the performance function that comes off that prevents of sleeve part, therefore, can easily obtain high-intensity assembling part.
As mentioned above, in this hydrodynamic bearing device, local negative pressure takes place sometimes in bearing, the generation that causes bubble of described negative pressure or the generation of vibration reduce bearing performance.Described imappropriate situation can guarantee that in bearing inside the circulation stream of lubricating fluid is eliminated by the intercommunicating pore of the both ends of the surface that are communicated with bearing main body is set.
This intercommunicating pore is as described in the above-mentioned patent documentation 1, for example can form by being assembled in shell at the bearing sleeve that outer circumferential face is provided with axial groove, but in that bearing main body is embedded in the application's of injection moulding shell the structure, landfill groove when injection moulding.As the method for avoiding it, for example, consider to insert injection moulding shell under the state of selling, the method for extracting pin then at axial groove.Yet intercommunicating pore is set at the small aperture about hundreds of μ m usually, and therefore, when extracting, pin fractures easily, and especially, in the said structure of the total length of rectangularization bearing main body, its possibility uprises.For fear of described situation, also consider to enlarge communication aperture, but between the end face of bearing main body and opposed with it parts end face thrust bearing division sometimes, inquire under the situation of this countermeasure, the bearing area of having in the design dwindle may cause bearing rigidity to reduce thus.
Therefore, in the present invention, the axial region that is provided at the fixing part that becomes bearing main body of shell is provided with than other positions to the side-prominent minor diameter part of internal diameter, is provided with the structure of intercommunicating pore at this minor diameter part.If this structure then can enlarge communication aperture under the situation that does not reduce bearing rigidity.
In addition, in the present invention, also provide to be provided with the intermediate sleeve of accommodating bearing main body, between this intermediate sleeve and bearing main body, be provided with the structure of intercommunicating pore.Like this, between intermediate sleeve and bearing main body intercommunicating pore is set, under the situation of these annex product as the built in items use, the both ends open portion of intercommunicating pore is sealed by the forming die of shell, and therefore, intercommunicating pore is not by the injection material landfill.
The hydrodynamic bearing device of said structure can preferably be used in the motor with this hydrodynamic bearing device, stator coil and rotor magnet, wherein follows the weightization of high speed rotating or solid of rotation, especially needs the motor of high torque rigidity.
The invention effect
As known from the above, according to the present invention, can provide at low cost and improve the assembly precision of bearing main body, and can bring into play the hydrodynamic bearing device of high bearing performance thus with respect to shell.
Description of drawings
Fig. 1 is that conception represents to embed the sectional drawing of the facility information of hydrodynamic bearing device with first structure example of spindle motor.
Fig. 2 is the sectional drawing of first structure example of the hydrodynamic bearing device of expression first mode of execution.
Fig. 3 is the longitudinal sectional drawing of bearing sleeve.
Fig. 4 is the figure of the upside end face of expression bearing sleeve.
Fig. 5 is the figure of the downside end face of expression bearing sleeve.
Fig. 6 is the sectional drawing that conception is represented the injection forming process of shell.
Fig. 7 is the sectional drawing of second structure example of the hydrodynamic bearing device of expression first mode of execution.
Fig. 8 is the sectional drawing of the 3rd structure example of the hydrodynamic bearing device of expression first mode of execution.
Fig. 9 is that conception represents to embed the sectional drawing of the facility information of hydrodynamic bearing device with second structure example of spindle motor.
Figure 10 is the sectional drawing of first structure example of the hydrodynamic bearing device of expression second mode of execution.
Figure 11 (A) is the figure of the upside end face of clutch shaft bearing sleeve, and (B) figure is the longitudinal sectional drawing of bearing main body, (C) is the figure of the downside end face of second bearing sleeve.
Figure 12 is the longitudinal sectional drawing of other structure example of expression bearing main body.
Figure 13 is the sectional drawing of second structure example of the hydrodynamic bearing device of expression second mode of execution.
Figure 14 is the sectional drawing of the 3rd structure example of the hydrodynamic bearing device of expression second mode of execution.
Figure 15 is the sectional drawing of the 4th structure example of the hydrodynamic bearing device of expression second mode of execution.
Figure 16 is the sectional drawing of the 5th structure example of the hydrodynamic bearing device of expression second mode of execution.
Figure 17 is the sectional drawing that conception represents to embed the blower motor of hydrodynamic bearing device.
Among the figure: 1,101-hydrodynamic bearing device; 2,102-spindle unit; 3,103-dish hub; 6,106-carriage; 7,107-shell; 8-bearing sleeve; 9,109-the first lip part; 10,110-the second lip part; 12,112-the second seal space; 13,113-intermediate sleeve; But 20-dynamic model; 21-axial region; 30-fixed die; 34-elastic member; 71,72,171,172-lining portion; 108-bearing main body; 181-clutch shaft bearing sleeve; 182-the second bearing sleeve; 183-distance member; A1, A2-radial bearing surface; B1, B2-thrust bearing surface; R1, R2-radial bearing portion; T1, T2-thrust bearing division; S1, S2-seal space.
Embodiment
Below, based on accompanying drawing, embodiments of the present invention are described.
Fig. 1 represents to embed the structure example of the facility information of hydrodynamic bearing device with spindle motor with conception.This facility information is used in the disk drive device of HDD etc. with spindle motor, possesses: hydrodynamic bearing device 1; Be installed on the rotor (dish hub) 3 of the spindle unit 2 of hydrodynamic bearing device 1; For example, via opposed stator coil 4 in slit radially and rotor magnet 5; With carriage 6.Stator coil 4 is installed on the periphery of carriage 6, and rotor magnet 5 is installed on the interior week of dish hub 3.Dish hub 3 keeps dish D such as one or more pieces disks in its periphery.If to stator coil 4 energising, then rotor magnet 5 rotates by the electromagnetic force that produces between stator coil 4 and the rotor magnet 5, follow in this, dish hub 3, and spindle unit 2 be integral rotation.
Fig. 2 shows in detail the structure that embeds hydrodynamic bearing device 1 on the spindle motor shown in Figure 1, represents first structure example of first mode of execution of hydrodynamic bearing device of the present invention.This hydrodynamic bearing device 1 possesses as the main composition important document: spindle unit 2; Be arranged at the lip part of spindle unit 2; Insert the bearing sleeve 8 of spindle unit 2 in interior week; Shell 7 at interior all rigid bearing sleeves 8.In the mode of illustrated example, as lip part, first lip part 9 and second lip part 10 are disposed at the both ends open portion of bearing sleeve 8.Also have, below, for convenience of explanation, the end of spindle unit 2 is called upside from the outstanding side of the opening portion of shell 7, its axial opposed side is called downside and describes.
Between the outer circumferential face 2a of the inner peripheral surface 8a of bearing sleeve 8 and spindle unit 2, be provided with first R1 of radial bearing portion and second R2 of radial bearing portion in the axial direction at interval.In addition, between the downside end face 9b of the upside end face 8b of bearing sleeve 8 and first lip part 9, be provided with the first thrust bearing division T1, between the upside end face 10b of the downside end face 8c of bearing sleeve 8 and second lip part 10, be provided with the second thrust bearing division T2.
The porous body that bearing sleeve 8 for example is made of sintering metal especially is that the porous body of the sintering metal of primary coil forms cylindric with copper.Also have, bearing sleeve 8 also can be formed by the soft metal materials such as brass beyond the sintering metal.
Inner peripheral surface 8a at bearing sleeve 8, be provided with at interval two zones up and down of the radial bearing surface A2 of the radial bearing surface A1 that becomes first R1 of radial bearing portion and second R2 of radial bearing portion in the axial direction, in these two zones, for example, be formed with dynamic pressure groove 8a1, the 8a2 of herringbone shape shown in Figure 3 respectively.Also have, radial bearing surface A1 and radial bearing surface A2 also can be arranged at the outer circumferential face 2a of opposed diametrically spindle unit 2, and in addition, the dynamic pressure groove shape as being formed at radial bearing surface also can adopt known other shapes such as spiral-shaped.
Be provided with the zone of the thrust bearing surface B1 that becomes the first thrust bearing division T1 at part or all annular section of the upside end face 8b of bearing sleeve 8, for example be formed with spiral-shaped dynamic pressure groove 8b1 shown in Figure 4 in this zone.In addition, be provided with the zone of the thrust bearing surface B2 that becomes the second thrust bearing division T2, for example be formed with spiral-shaped dynamic pressure groove 8c1 shown in Figure 5 in this zone at part or all annular section of the downside end face 8c of bearing sleeve 8.Also have, the side of thrust bearing surface B1 and B2 or both also can be arranged at the downside end face 9b of opposed in the axial direction first lip part 9, the upside end face 10b of second lip part 10 respectively, in addition, as the dynamic pressure groove shape that should be formed at thrust bearing surface, also can adopt known other shapes such as herringbone shape.
Shell 7 forms the roughly cylindric of both ends open, and inner circumferential surface 7a becomes same diameter and straight barrel surface.The inner peripheral surface of carriage shown in Figure 16 by be pressed into, bonding or be pressed into the outer circumferential face of method set casing 7 such as bonding.
Like this, by shell 7 with bearing sleeve 8 as built in items and injection moulding, utilize an operation to finish the forming process of shell 7, and the assembling procedure of shell 7 and bearing sleeve 8, therefore, make and oversimplify.
In addition, therefore the axial both ends open of shell 7, when the injection moulding of shell 7, can utilize metal pattern 20,30 to become the bearing sleeve 8 of built in items from axial sandwich, therefore, can be in die cavity 40 with bearing sleeve 8 location reliably in the axial direction.Thus, if precision processing metal mould 20,30 well, precision set casing 7 and bearing sleeve 8 well then.
When above-mentioned matched moulds, the both ends of the surface 8b of bearing sleeve 8, the axial dimension between the 8c and and the bearing surface 22,32 of the metal pattern of both ends of the surface 8b, 8c butt between the inconsistent situation of axial dimension under, following appropriate situation takes place.For example, the former produces axial gap than under the little situation of the latter between bearing sleeve 8 and metal pattern, cause the location of bearing sleeve 8 incomplete.In addition, under the former situation bigger than the latter, when matched moulds, bearing sleeve 8 is applied big axial pressure, bearing sleeve 8 may be out of shape.For fear of so appropriate situation, precision processing metal mould and bearing sleeve 8 well is good, is unpractical but make both axial dimension in full accord as described above.
In view of this point, in the present embodiment, as shown in Figure 6, but the spindle unit 2 by making dynamic model 20 and the upside end face 8b butt of bearing sleeve 8, bearing sleeve 8 is located in the axial direction, and, will form with the face 32 usefulness elastic members 34 of the downside end face 8c butt of bearing sleeve 8 in the fixed die 30.Thus, the enough elastic members 34 of energy absorb the error of the axial dimension of metal patterns 20,30 and bearing sleeve 8.That is, by the axial dimension with 22,32 of the bearing surfaces of metal pattern be set at both ends of the surface 8b than bearing sleeve 8, axial dimension between 8c is smaller, can utilize elastic member 34 elasticity to absorb its size error, can avoid aforesaid appropriate situation.
In addition, usually under the situation of parts by bonding fixing resin system such as grade and metal parts, compare the retention force pin between parts with situation about for example being adhesively fixed between the metal parts.With respect to this, the bearing sleeve 8 of form metal system and shell 7 integratedly can improve the retention force between two parts as described above.And then, if form bearing sleeve 8 with porous bodies such as sintering metals, then put into resin material by surface vacancies portion at bearing sleeve 8 as present embodiment, the performance anchoring effect can further improve the retention force between two parts.
Also have, shell 7 also can form the injection-molded article of metallic material except being formed as described above the injection-molded article for resin.In this case, as the metallic material that should inject, can suitably use low melting point metal materials such as magnesium alloy or aluminum alloy.
The integrally formed product of bearing sleeve 8 that forms like this and shell 7 interior week insert spindle unit 2 after, first lip part 9 and second lip part 10 are fixed in the outer circumferential face of spindle unit 2.First lip part 9 and second lip part 10 all form ring-type by soft metals such as brass or other metallic material or resin material, for example use the assigned position of adhesive securement in the outer circumferential face 2a of spindle unit 2.As binder, can use the Thermocurable binder, in this case, carry out location with respect to the lip part 9,10 of spindle unit 2 after, spindle unit 2 is carried out heat treated (curing), lip part 9,10 can be fixed in spindle unit 2 reliably thus.At this moment, the binder that is coated on spindle unit 2 is filled in as binder and accumulates the circumferential groove 2c of portion and solidify, and improves the bonding strength with respect to spindle unit 2 of lip part 9,10 thus.
The outer circumferential face 9a of first lip part 9 and the inner peripheral surface 7a of the upper end open portion of shell 7 between form the first seal space S1 of volume with regulation, the outer circumferential face 10a of second lip part 10 and the inner peripheral surface 7a of the lower ending opening portion of shell 7 between form the second seal space S2 of volume with regulation.In this embodiment, the outer circumferential face 10a of the outer circumferential face 9a of first lip part 9 and second lip part 10 forms respectively towards the outer side of bearing means and the conical surface shape of hole enlargement gradually.Therefore, two seal space S1, S2 are diminishing cone-shaped on approaching mutually direction.When the rotation of spindle unit 2, the graviational interaction that the centrifugal force when introducing effect that the lubricating fluid (for example, lubricant oil) in two seal space S1, the S2 produces by capillary force and rotation produces, the direction that becomes narrow to seal space is introduced into.Thus, prevent that effectively lubricant oil from spilling from the inside of shell 7.In order to prevent leakage of oil reliably, can the upside end face 9c of the upside end face 7b of shell 7 and downside end face 7c, first lip part 9, and the downside end face 10c of second lip part 10 form the tunicle of oleophobic agent respectively.
First and second seal space S1, S2 have the pooling feature of the volume-variation amount that absorbs the temperature variation of following the lubricant oil that fills up in the inner space of shell 7.In the scope of the temperature variation of imagining, pasta is positioned at two seal space S1, S2 often.In order to realize it, the summation of the volume of two seal space S1, S2 is set at bigger than the volume-variation amount of the temperature variation of following the lubricant oil that is filled in the inner space at least.
In this structure example, seal space S1, S2 are formed at lip part 9,10, therefore, for example compare with the situation that forms seal space at the outer circumferential side of spindle unit 2, can enlarge the volume of seal space S1, S2.That is, can under the state of keeping identical spatial volume, shorten the axial dimension of seal space S1, S2, therefore, can dwindle the axial dimension of hydrodynamic bearing device 1.And then, in this structure example, be shaped as the shell 7 of seal space S1, S2 with resin-shaped, therefore, to compare with for example metal shell, the hole enlargement quantitative change of the inner peripheral surface 7a during high temperature is big, and the volume of seal space S enlarges.Thereby, can absorb the Volume Changes of the thermal expansion generation of lubricant oil by the seal space of this expansion, therefore, can dwindle the volume of seal space S1, S2, can further dwindle the axial dimension of hydrodynamic bearing device 1.
If finish like this assembling, then in the inner space of the shell 7 airtight, comprise in the internal porosity of bearing sleeve 8 and fill up lubricant oil by lip part 9,10.
When the rotation of spindle unit 2, radial bearing surface A1, the A2 of inner peripheral surface 8a that is formed at bearing sleeve 8 is opposed via the outer circumferential face 2a of radial bearing gap and spindle unit 2 respectively.In addition, the thrust bearing surface B1 of upside end face 8b that is formed at bearing sleeve 8 is opposed via the downside end face 9b of thrust-bearing gap and first lip part 9 of regulation, and the thrust bearing surface B2 of downside end face 8c that is formed at bearing sleeve 8 is opposed via the upside end face 10b of the thrust-bearing gap of stipulating and second lip part 10.Also have, the oil film of following the rotation of spindle unit 2 and producing in described radial bearing gap is by the dynamic pressure groove 8a1 that forms respectively at two radial bearing surface A1, A2, the dynamic pressure effect of 8a2, improve its oil film rigidity, spindle unit 2 non-contact diametrically is supported for rotation freely.Thus, constitute spindle unit 2 is supported for rotation first R1 of radial bearing portion and second R2 of radial bearing portion freely in non-contact radially.Simultaneously, the oil film that produces in described thrust-bearing gap improves its oil film rigidity by the dynamic pressure effect of the dynamic pressure groove 8b1 that forms respectively at two thrust bearing surface B1, B2, and spindle unit 2 non-contact on two thrust directions is supported for rotation freely.Thus, formation is supported for the rotation first thrust bearing division T1 and the second thrust bearing division T2 freely with spindle unit 2 non-contact on two thrust directions.
More than, first structure example in first mode of execution of hydrodynamic bearing device of the present invention at length is illustrated, but the present invention does not limit and is applicable to the said structure example.Below, describe being suitable for other structure example of the present invention, but in the following description,, mark identical reference marks for structure, effect position and the parts substantially the same with first structure example, omit repeat specification.
Fig. 7 represents second structure example in first mode of execution of hydrodynamic bearing device of the present invention.In hydrodynamic bearing device shown in Figure 71, be provided with the upside end face 8b of lining bearing sleeve 8 and the lining portion 71 and 72 of downside end face 8c.This lining portion 71 and 72 is shaped bearing sleeve 8 integratedly as built in items and shell 7 with resin injection.Also have, when injection moulding, bearing sleeve 8 positions (omit and illustrate) by chamfered section 8e, the 8f that is provided with metal pattern Zhou Yuan in its two ends of axial sandwich.Between the downside end face 9b of the upside end face 71a of lining portion 71 and first lip part 9, form the thrust-bearing gap of the first thrust bearing division T1, between the upside end face 10b of the downside end face 72a of lining portion 72 and second lip part 10, form the bearing play of the second thrust bearing division T2.In this structure example, form the dynamic pressure groove identical at the upside end face 71a of lining portion 71 with structure shown in Figure 4, this dynamic pressure groove forms the zone and becomes thrust bearing surface B1.In addition, form the dynamic pressure groove identical with structure shown in Figure 5 at the downside end face 72a of lining portion 72, this dynamic pressure groove forms the zone and becomes thrust bearing surface B2.
Like this, in this structure example, form thrust bearing surface B1, B2 with resin, therefore, can be simply and with low-cost and high-precision thrust bearing surface B1 and B2.In addition, even, also can absorb this inequality by lining portion 71 and 72 because foozle etc. cause the axial dimension of the bearing sleeve 8 of each goods to take place under the uneven situation.Thereby, can guarantee high-precision thrust-bearing gap, can relax the machining accuracy of bearing sleeve 8, thereby realize cost degradation.
In addition, by lining portion 71,72 is set, therefore axial the moving of restriction bearing sleeve 8, can prevent that bearing sleeve 8 departs from the axial direction with respect to shell 7 when applying impact load etc. to hydrodynamic bearing device 1.In the present embodiment, by with the injection moulding of bearing sleeve 8, form lining portion 71 and 72 and shell 7, therefore, further carry out bearing sleeve 8 axial fixing of aforesaid utilization lining portion 71 and 72 reliably as built in items.
And then, dynamic pressure groove that the thrust bearing surface B2 of the thrust bearing surface B1 of lining portion 71 and lining portion 72 forms can with the injection moulding of shell 7 and lining portion 71,72 in carry out.Specifically, if the position that forms presumptive area with the dynamic pressure groove of the downside end face 72a of the upside end face 71a of lining portion 71 and lining portion 72 in forming metal mould forms the mould portion corresponding to the dynamic pressure groove shape, form the dynamic pressure groove in the time of then with the injection moulding of shell 7.Thus, and compare in the situation that metallic material forms the dynamic pressure groove by machining etc., can be easily and precision form the dynamic pressure groove well.
And then, by forming thrust bearing surface B1, B2 with resin, and thrust bearing surface is compared with the situation that sintering metal forms, obtain superior wearability.Thus, in the starting of hydrodynamic bearing device 1, when stopping etc. during low speed rotation, can suppress to contact the wearing and tearing that cause with moving via the slip of the end face of the opposed lip part 9,10 in thrust-bearing gap.
In addition, bearing sleeve 8 and lining portion 71,72 form the composite structure of sintering metal and resin, therefore, for example, are all compared by the situation that resin forms with these, can suppress poor with the linear expansion coeffcient of spindle unit 2.Thereby, can suppress to follow the thermal expansion of temperature variation or the gap width of each bearing play that thermal shrinkage causes.Thus, even the Environmental Conditions temperature variation of bearing means also can be kept superior bearing performance.
Also have, in above-mentioned hydrodynamic bearing device, local negative pressure takes place sometimes in bearing, the generation that causes bubble of described negative pressure or the generation of vibration reduce bearing performance.Described imappropriate situation can guarantee that the circulation stream of the lubricating fluid of bearing inside is eliminated by the intercommunicating pore of the both ends of the surface that are communicated with bearing sleeve 8 is set.
This intercommunicating pore for example is provided with the one or more axial groove 8d1 to both ends of the surface 8b and 8c opening by the outer circumferential face 8d at bearing sleeve 8 sometimes and forms.But, if the bearing sleeve 8 that will have axial groove 8d1, is then used injection material (being resin at this) landfill axial groove 8d1 as built in items injection moulding shell 7.
Imappropriate situation like this can be exposed axial groove and avoid by the outer circumferential face at bearing sleeve 8.For example, in hydrodynamic bearing device shown in Figure 81, have the bearing sleeve 8 extrapolation intermediate sleeves 13 of axial groove 8d1, form intercommunicating pore 12 with this intermediate sleeve 13 and axial groove 8d1 at outer circumferential face.If this bearing sleeve 8 and intermediate sleeve 13 as the built in items injection moulding, are then sealed the both ends open portion of intercommunicating pore 12 with metal pattern, therefore, resin can landfill intercommunicating pore 12.Also have, the outer circumferential face of bearing sleeve 8 is made as barrel surface, at the inner peripheral surface of intermediate sleeve 13 axial groove is set and also can.
Perhaps, intercommunicating pore 12 is set, can prevents the situation of resin landfill intercommunicating pore 12 by inside at bearing sleeve 8.
In addition, for fear of above-mentioned appropriate situation, also axial groove 8d1 can be set by the outer circumferential face at bearing sleeve 8, at the forming pin of axial groove 8d1 embedding corresponding to the shape of this axial groove 8d1, injection moulding prevents that resin from entering under this state.The forming metal mould of such forming pin and shell 7 be provided with integratedly also can, be set to separate component and also can.
Also have, under the situation that intercommunicating pore 12 is set as described above, for example form asymmetrical shape in the axial direction, can also make the lubricant oil pump circulation (omitting diagram) that is filled in bearing inside by dynamic pressure groove 8a1 with radial bearing surface A1.
In the hydrodynamic bearing device 1 that has carried out above explanation, lip part is arranged at axial two places of spindle unit 2, but only being arranged at an axial place, lip part also can.
In addition, in the structure example of the hydrodynamic bearing device 1 shown in above, utilize hydraulic bearing to constitute the dynamic pressure generating section of the radial bearing R1 of portion, R2 or thrust bearing division T1, T2 as being used to, adopt herringbone shape or spiral-shaped dynamic pressure groove, but the shape of dynamic pressure generating section is not limited thereto.For example, also can pass through so-called arc bearing, not only bearing or cone bearing constitute the side of the radial bearing R1 of portion, R2 or both, in addition, a side that also can be by so-called not only bearing or wave mode bearing formation thrust bearing division T1, T2 or both.And then, also can constitute the either party of the radial bearing R1 of portion, R2 or both by the so-called positive circular journal bearing that does not have dynamic pressure generating section, in addition, the so-called pivot bearing of a end that also can be by contact shaft member 2 constitutes thrust bearing division.
In addition, in the above description, lubricating fluid as the inside that is filled in hydrodynamic bearing device 1, show lubricant oil, but in addition, also can use the fluid that can produce the dynamic pressure effect in each bearing play, for example, gas such as air or magnetic fluid etc. have mobile oiling agent or lubricant grease etc.
Fig. 9 conception represents to embed second structure example of the facility information of hydrodynamic bearing device with spindle motor.This spindle motor is used in disk drive devices such as HDD, possesses: spindle unit 102 non-contacts are supported for rotation hydrodynamic bearing device 101 freely; Be assemblied in the rotor (dish hub) 103 of spindle unit 102; For example via opposed stator coil 104 in slit radially and rotor magnet 105.Stator coil 104 is installed on the periphery of carriage 106, and rotor magnet 105 is installed on the interior week of dish hub 103.The shell 107 of hydrodynamic bearing device 101 is assemblied in the interior week of carriage 106.Keep dish D such as one or more pieces disks at dish hub 103.If to stator coil 104 energisings, then rotor magnet 105 rotates by the electromagnetic force between stator coil 104 and the rotor magnet 105, thus, dish hub 103 and spindle unit 102 are integral rotation.
Figure 10 represents the hydrodynamic bearing device 101 that embeds on the spindle motor shown in Figure 9, represents first structure example of second mode of execution of hydrodynamic bearing device of the present invention.This hydrodynamic bearing device 101 possesses as the main composition important document: the spindle unit 102 of rotary side; The shell 107 of fixed side; And be fixed in the bearing main body 108 in the interior week of shell 107.In illustrated example, bearing main body 108 comprises: arrange in the axial direction and the clutch shaft bearing sleeve 181 and second bearing sleeve 182 that dispose.Also have, for the ease of the following description, with the end of spindle unit 102 from the outstanding side of the opening portion of shell 107 as upside, its axial opposed side is described as downside.
Constitute porous body that the bearing sleeve 181,182 of bearing main body 108 all constitutes by sintering metal, especially be that the porous body of the sintering metal of primary coil forms cylindric with copper.Illustrated bearing sleeve 181,182 forms identical in the axial direction length.Also can form a side of bearing sleeve 181,182 or both with soft metals such as brass.
The inner peripheral surface 181a that is disposed at the clutch shaft bearing sleeve 181 of axial upside in bearing main body 108 is provided with the zone of the radial bearing surface A1 that becomes first R1 of radial bearing portion, the dynamic pressure groove 181a1 that forms the herringbone shape shown in Figure 11 (B) for example in the zone that becomes this radial bearing surface A1 is as dynamic pressure generating section, and this dynamic pressure groove 181a1 divides and forms by being arranged at the 181a2 of massif portion between this groove.The radial bearing surface A1 of clutch shaft bearing sleeve 181 be formed at from second bearing sleeve 182 away from the end of a side (upside).In addition, the inner peripheral surface 182a that is positioned at second bearing sleeve 182 of downside in bearing main body 108 is provided with the zone of the radial bearing surface A2 that becomes spindle unit 2, the dynamic pressure groove 182a1 that forms the herringbone shape shown in Figure 11 (B) for example in the zone that becomes this radial bearing surface A2 is as dynamic pressure generating section, and this dynamic pressure groove 182a1 divides and forms by being arranged at the 182a2 of massif portion between each groove.The radial bearing surface A2 of second bearing sleeve 182 be formed at from clutch shaft bearing sleeve 181 away from the end of a side (downside).
Also have, in illustrated example, each dynamic pressure groove 181a1,182a1 are formed the shape with respect to the axial centre symmetry, but for example, by forming flute length with respect to the axial width of the groove of the upper-side area of axial centre among the upside dynamic pressure groove 181a1 than underside area, can also be when the rotation of spindle unit 102, give the power that is pressed into (suction force) to lubricant oil towards axial below.Dynamic pressure groove 181a1,182a1 also can be formed at the outer circumferential face 102a of opposed diametrically spindle unit 102, in addition, as its shape, also can form known other shapes, and be for example, spiral-shaped etc.
Be formed with the thrust bearing surface B1 of the first thrust bearing division T1 at part or all annular section of the upside end face 181b of clutch shaft bearing sleeve 181, for example shown in Figure 11 (A), be formed with spiral-shaped dynamic pressure groove 181b1 at this thrust bearing surface B1.In addition, be formed with the thrust bearing surface B2 of the second thrust bearing division T2, for example shown in Figure 11 (C), be formed with spiral-shaped dynamic pressure groove 182c1 at this thrust bearing surface B2 at part or all annular section of the downside end face 182c of second bearing sleeve 182.Be formed at a side or the downside end face 109b that both also can be formed at opposed in the axial direction first lip part 109, the upside end face 110b of second lip part 110 of dynamic pressure groove 181b1, the 182c1 of thrust bearing surface B1, B2, in addition, as its shape, also can form known other shapes, for example, herringbone shape.
This shell 107 is for example by being pressed into fixing pin in interior week, with arranged coaxial first, second bearing sleeve 181,182 (bearing main body 108) built in items and the injection moulding before of two radial bearing surface A1, A2 (181a2 of massif portion, 182a2).As injection material, except low melting point metal materials such as aluminum alloy or magnesium alloy, can use resin material.In this structure example, use resin material to come injection moulding, as matrix resin, so long as can injection moulding, just do not limit especially, for example, not only can use liquid-crystalline polymer (LCP), polyphenylene sulfide (PPS), polyether-ether-ketone crystalline resins such as (PEEK), can also use polysulfones (PSU), polyether sulfone (PES), Polyphenylene Sulfone amorphous resins such as (PPSU).Feature as requested cooperates one or more reinforcing materials or conductive material, and various packing materials such as lubriation material in matrix resin.
The outer circumferential face 109a of first lip part 109 and the inner peripheral surface 107a of the upper end open side of shell 107 between form the first seal space S1 of specified volume, in addition, the outer circumferential face 110a of second lip part 110 and the inner peripheral surface 107a of the lower ending opening side of shell 107 between form the second seal space S2 of specified volume.In illustrated example, the outer circumferential face 110a of the outer circumferential face 109a of first lip part 109 and second lip part 110 forms respectively towards the outer side of the bearing means conical surface shape of undergauge gradually.Therefore, two seal space S1, S2 are on approaching mutually direction (internal direction of shell 107) cone-shaped of undergauge gradually.When the rotation of spindle unit 102, lubricating fluid in two seal space S1, the S2 (for example, lubricant oil) graviational interaction that produces of the centrifugal force when introducing effect that produces by capillary force and rotation, the direction (internal direction of shell 107) that becomes narrow to seal space is introduced into.Thus, prevent that effectively lubricant oil from spilling from the inside of shell 107.In order to prevent leakage of oil reliably, can be in the upper and lower end face of shell 107, the upside end face 109c of first lip part 109, and the downside end face 110c of second lip part 110 form the tunicle (omitting diagram) that constitutes by oleophobic agent respectively.
First and second seal space S1, S2 have the pooling feature of the volume-variation amount that absorbs the temperature variation of following the lubricant oil that fills up in the inner space of shell 107.In the scope of the temperature variation of imagining, pasta is positioned at two seal space S1, S2 often.In order to realize it, the summation of the volume of two seal space S1, S2 is set at bigger than the volume-variation amount of the temperature variation of following the lubricant oil that is filled in the inner space at least.
The assembling of the hydrodynamic bearing device 101 that is made of said structure is for example carried out as described below.
In the hydrodynamic bearing device 101 of said structure, if spindle unit 102 rotation, then the radial bearing surface A1 of the inner peripheral surface 181a of clutch shaft bearing sleeve 181, and the radial bearing surface A2 of second bearing sleeve 182 opposed via the outer circumferential face 102a of radial bearing gap and spindle unit 102 respectively.Also have, the lubricant film of following the rotation of spindle unit 102 and producing in described radial bearing gap improves its oil film rigidity by the dynamic pressure effect of the dynamic pressure groove 181a1, the 182a1 that form respectively two radial bearing surface, and spindle unit 102 non-contact diametrically is supported for rotation freely.Thus, form at interval in the axial direction spindle unit 102 non-contact diametrically is supported for rotation first R1 of radial bearing portion and second R2 of radial bearing portion freely.
In addition, if spindle unit 102 rotations, the zone of thrust bearing surface B1 of upside end face 181b that then becomes clutch shaft bearing sleeve 181 is opposed via the thrust-bearing gap and the downside end face 109b of first lip part 109 of regulation, in addition, it is opposed via the thrust-bearing gap and the upside end face 110b of second lip part 110 of regulation to become the zone of thrust bearing surface B2 of downside end face 182c of second bearing sleeve 182.Also have, the lubricant film of following the rotation of spindle unit 102 and producing in each thrust-bearing gap improves its oil film rigidity by the dynamic pressure effect of the dynamic pressure groove 181b1, the 182c1 that form respectively at thrust bearing surface B1, B2, and spindle unit 102 non-contact on two thrust directions is supported for rotation freely.Thus, formation is supported for the rotation first thrust bearing division T1 and the second thrust bearing division T2 freely with spindle unit 102 non-contact on two thrust directions.
In the hydrodynamic bearing device 101 of above explanation, shell 107 with bearing main body 108 as built in items and injection moulding.Be shaped if embed, then constitute bearing main body 108 by a plurality of bearing sleeves 181,182, even under the situation of the assembly precision that is difficult to guarantee expect, also only by improving the mould precision, just can improve the assembly precision of 181,182 of each bearing sleeves and with respect to the assembly precision of the bearing main body 108 of shell 107.Especially, therefore the both ends open of shell 107, can more correctly position from the bearing main body 108 of axial both end sides clamping as built in items.In addition, shaping, and the assembling of shell 107 and bearing main body 108 of shell 107 can be carried out, therefore, cheapization of manufacture cost can be realized by an operation.
In addition, if with bearing main body 108 as built in items injection moulding shell 107, then with bearing main body 108 compare by the situation that method such as bonding, as to be pressed into is assembled in shell 107, can easily improve the combination force of 108 of shell 107 and bearing main bodies.Especially, if will constitute first and second bearing sleeve 181,182 of bearing main body 108 as sintering metal system, then injection material enters the surface vacancies of bearing sleeve 181,182, therefore, can further improve between the two combination force by so-called anchoring effect.
In addition, omit diagram, but in order to realize further cost degradation, also can be with carriage 106 and shell 107 injection moulding integratedly.
In addition, in structure shown in Figure 10, the structure that forms thrust bearing division with the both end sides of the lip part that is provided with at an end of spindle unit (for example, with reference to patent documentation 1) compare, the axially spaced-apart distance of thrust bearing division can be increased, therefore, torque rigidity can be improved.
Also have, in the above description, illustration from second bearing sleeve 182 away from the end of a side (upside) formed the radial bearing surface A1 of clutch shaft bearing sleeve 181, in addition, from clutch shaft bearing sleeve 181 away from the end of a side (downside) formed the situation of the radial bearing surface A2 of second bearing sleeve 182, but in this case, the internal diameter size of bearing sleeve is inequality in upper-side area and underside area, therefore, be difficult to sometimes to guarantee between the upper and lower end face of bearing sleeve separately, and two bearing sleeves between coaxality.In this case, for example shown in Figure 12, by will be arranged at respectively with protuberance 181a3, the 182a3 of the roughly the same diameter of radial bearing surface A1, the A2 181a2 of massif portion, the 182a2 of groove (divide dynamic pressure) from radial bearing surface in the axial direction away from the zone, can eliminate the problems referred to above.At this moment, for torque improves, preferred protuberance 181a3,182a3 form the band shape that does not have dynamic pressure generation function of illustrated example and so on etc.Also have, in illustrated example, show the situation that protuberance is formed at two bearing sleeves 181,182, also can but protuberance only is arranged at either party's bearing sleeve.
Also have, as above-mentioned structure example, under the identical situation of the axial length of first and second bearing sleeve 181,182, both apparent difference is few, and therefore, when injection moulding shell 107, the operating personnel may embed the turned upside down of two sleeves.Therefore, omit diagram, but, also can make the axial length of the clutch shaft bearing sleeve 181 and second bearing sleeve 182 inequality in order to prevent this artificial mistake.
More than, first structure example in second mode of execution of hydrodynamic bearing device of the present invention at length is illustrated, but the present invention does not limit and is applicable to the said structure example.Below, other structure example are described, but in the following description,, mark identical reference marks for structure, effect position and the parts substantially the same with first structure example, omit repeat specification.
Figure 13 represents second structure example of the hydrodynamic bearing device 101 of second mode of execution.This hydrodynamic bearing device 101 mainly forms on this point with the structure of hydrodynamic bearing device shown in Figure 10 inequality at the lining portion 171,172 of the downside end face 182c of the upside end face 181b of lining clutch shaft bearing sleeve 181 and second bearing sleeve 182 and shell 7.In this structure example, between the downside end face 109b of the upside end face 171a of lining portion 171 and first lip part 109, be provided with the first thrust bearing division T1, between the upside end face 110b of the downside end face 172b and second lip part 110, be provided with the second thrust bearing division T2.
In the hydrodynamic bearing device 101 of said structure, lining portion 171,172 with bearing main body 108 as built in items and with shell 107 injection moulding integratedly.In this structure, uneven even the axial dimension of each bearing sleeve 181,182 exists, also can absorb described inequality by lining portion 171,172, can further easily obtain high-precision assembling part.In other words, the forming accuracy of each bearing sleeve 181,182 (especially, axial dimension) is rough in a way, also can not become problem, can also realize cost degradation thus.
In addition, lining portion 171,172 also as bearing main body 108 axially on Drop-proof performance function, therefore, obtain further superior assembling part of adhesive strength easily and with low cost.
Also have, in above-mentioned hydrodynamic bearing device 101, sometimes in the local generation of the lubricant oil that fills up bearing inside negative pressure, the generation that causes bubble of described negative pressure or the generation of vibration.Described imappropriate situation can guarantee that in bearing inside the circulation stream of lubricant oil is eliminated by the intercommunicating pore between the both ends of the surface that are communicated with bearing main body 108 is set.
This intercommunicating pore for example can be assembled in shell and form by the bearing main body that will be provided with axial groove, but as the application, under the situation of bearing main body 108 as built in items injection moulding shell 107, injection material enters axial groove, causes the landfill groove.Described situation for example can by insert at axial groove be integral with forming die or the state of the pin of separate component under, the injection moulding shell is extracted pin and is avoided after shaping.Yet intercommunicating pore 112 is set at the small aperture about hundreds of μ m usually, and therefore, when extracting, pin fractures easily, and especially, in the said structure of the total length of rectangularization bearing main body 108, its possibility uprises.For fear of described situation, also consider to enlarge communication aperture, but form dynamic pressure groove shown in Figure 11 at upside end face 181b, the 182c of bearing main body 108 sometimes, if enlarge communication aperture, then bearing area narrows down, and may cause bearing rigidity to reduce.
Figure 14 represents to be provided with an example of the hydrodynamic bearing device 101 of the intercommunicating pore 112 between the both ends of the surface that are communicated with bearing main body 108, the 3rd structure example of the hydrodynamic bearing device 101 of expression the application's second mode of execution.In hydrodynamic bearing device shown in Figure 14 101, the problems referred to above during in view of formation intercommunicating pore 112, the axial region that becomes the fixing part of bearing main body 108 in shell 117 is provided with than other positions to the side-prominent minor diameter part 117a of internal diameter, and 117a is provided with intercommunicating pore 112 at this minor diameter part.This minor diameter part 117a is and the irrelevant position of thrust bearing division T1, T2, therefore, can more freely sets communication aperture.Also have, in illustrated example, intercommunicating pore 112 is formed same diameter on entire axial length, but also can be diameter inequality in the axial direction.
Problem when in addition, above-mentioned intercommunicating pore forms can be by exposing axial groove outer circumferential face at bearing main body 108, can avoiding an example of its concrete countermeasure product shown in Figure 15 to the open surface of die cavity.In hydrodynamic bearing device shown in Figure 15 101, the periphery extrapolation intermediate sleeve 113 in that outer circumferential face 181d, 182d have the bearing sleeve 181,182 of axial groove 181d1,182d1 forms intercommunicating pore 112 by this intermediate sleeve 113 and axial groove.If built in items before this annex is come injection moulding, then the both ends open portion of intercommunicating pore 112 is sealed by metal pattern, and therefore, intercommunicating pore 112 is not by the injection material landfill.Also have, the inner peripheral surface that axial groove is arranged at intermediate sleeve 113 also can.
In the above description, constitute bearing main body 108 by two bearing sleeves 181,182 of arranging in the axial direction, but for example shown in Figure 6, also can between two bearing sleeves 181,182, insert installation sleeve tubular Spacer parts 183, constitute bearing main body 108.In this case, if by soft metal material such as brass or other metallic material, resin material etc. the non-porous bodily form different thing parts 183 at interval with sintering metal (porous body), then can reduce do not infiltrate Spacer parts 183 also can the lubricants capacity of range degree, dwindle the axial width of seal space S1, S2, can be with hydrodynamic bearing device 101 compactness in the axial direction.Certainly, also this structure can be used in Figure 13～hydrodynamic bearing device 101 shown in Figure 15.
In the above description, as the R1 of radial bearing portion, R2 and thrust bearing division T1, T2, show by herringbone shape or dynamic pressure groove such as spiral-shaped and produce the structure of the dynamic pressure effect of lubricant oil, but the present invention is not limited to this.
For example, omit diagram, but the side of the R1 of radial bearing portion, R2 or both for example can adopt also in the zone that becomes radial bearing surface and uniformly-spaced to be provided with stepping bearings a plurality of axial grooves, so-called with circumferencial direction or to be provided with many arc bearings a plurality of arc surfaces, so-called in the zone that becomes radial bearing surface.In addition, the side of thrust bearing division T1, T2 or both for example also can adopt in the zone that becomes thrust bearing surface and be provided with stepping bearing a plurality of radial grooves, so-called, so-called wave mode bearing (stepping type becomes the bearing of wave mode) etc. with the circumferencial direction predetermined distance.
In addition, in the above description, illustration constitute first R1 of radial bearing portion and second both modes of the R2 of radial bearing portion by hydraulic bearing, but also can constitute the side of first R1 of radial bearing portion and second R2 of radial bearing portion or both by positive circular journal bearing.In addition, thrust bearing division also can constitute by the so-called pivot bearing that an end in contact of spindle unit is supported.
In addition, in the above description, to being illustrated by the situation that has disposed bearing sleeve 181,182 or bearing sleeve 181,182 and Spacer parts 183 formation bearing main bodies 108 at two axial places, but also can more than three axial places, dispose bearing sleeve, constitute bearing main body 108.
In addition, in the above description, as the lubricating fluid of the inside that should be filled in hydrodynamic bearing device 101, illustration lubricant oil, but in addition, also can use fluid such as air or magnetic fluid etc. to have mobile oiling agent or lubricant grease etc.
In above, illustration embed hydrodynamic bearing device with spindle motor and the mode used at the dish device, but the hydrodynamic bearing device with structure of the present invention except facility information with the spindle motor, also can preferably be used in motor, for example blower motor of demanding torque rigidity.
Figure 17 conception is represented hydrodynamic bearing device of the present invention, is especially embedded the blower motor of hydrodynamic bearing device shown in Figure 10 101, wherein makes an example of stator coil 104 and rotor magnet 105 opposed so-called radial gap type blower motors via the slit of (radial direction) radially.The motor of illustrated example mainly the outer circumferential face of the fixing rotor 133 of the upper end of spindle unit 102 periphery have the blade this point, and carriage 136 inequality with the structure of spindle motor shown in Figure 9 on as the shell performance function this point of each component parts of accommodating motor.Also have, other component parts are identical with function, the effect of each component parts of motor shown in Figure 9, therefore, mark common reference marks, omission repeat specification.
Claims (10)
1. hydrodynamic bearing device, it possesses: the shell of both ends open; Be fixed in the bearing sleeve in the interior week of shell; Insert the spindle unit in the interior week of bearing sleeve; Be arranged at spindle unit and be configured in two lip parts of the axial both sides of bearing sleeve; The radial bearing gap that forms between the inner peripheral surface of the outer circumferential face of spindle unit and bearing sleeve is formed with seal space between the inner peripheral surface of the outer circumferential face of each lip part and the shell relative with it, it is characterized in that,
As built in items, by resin injection shaping shell, and two faces of the formation seal space of shell are same diameter with bearing sleeve.
2. hydrodynamic bearing device according to claim 1, wherein,
Be provided with at least one side's of lining bearing sleeve the lining portion of end face.
3. hydrodynamic bearing device according to claim 2, wherein,
Lining portion and and the end face of this opposed lip part of lining portion between be formed with the thrust-bearing gap.
4. hydrodynamic bearing device according to claim 3, wherein,
Be formed with dynamic pressure generating section in described lining portion.
5. hydrodynamic bearing device according to claim 1, wherein,
Form the intercommunicating pore that the both ends of the surface that make bearing sleeve are communicated with by intermediate sleeve in the configuration of the periphery of bearing sleeve.
6. hydrodynamic bearing device, it possesses: shell; Be fixed in the bearing main body in the interior week of shell; Insert the spindle unit in the interior week of bearing main body; Be arranged at spindle unit and be configured in two lip parts of the axial both sides of bearing main body; The lubricating film of the fluid that forms with the radial bearing gap between the outer circumferential face of the inner peripheral surface of bearing main body and spindle unit and the radial bearing portion of shaft member diametrically, bearing main body is formed by a plurality of bearing sleeves of arranging in the axial direction, between the inner peripheral surface of the outer circumferential face of each lip part and the shell relative, be formed with seal space with it, it is characterized in that
Shell is to have opening portion at two ends, and the injection-molded article of the resin that bearing main body is embedded, and two faces of the formation seal space of shell are same diameter.
7. hydrodynamic bearing device according to claim 6, wherein,
Be provided with at least one side's of lining bearing main body the lining portion of end face.
8. hydrodynamic bearing device according to claim 6, wherein,
Be provided with the intercommunicating pore of the both ends of the surface connection that makes bearing main body.
9. hydrodynamic bearing device according to claim 8, wherein,
Be provided with than other positions to the side-prominent minor diameter part of internal diameter in the axial region of the fixing part that becomes bearing main body of shell, be provided with described intercommunicating pore at this minor diameter part.
10. hydrodynamic bearing device according to claim 8, wherein,
Be provided with the intermediate sleeve of accommodating bearing main body, between this intermediate sleeve and bearing main body, be provided with described intercommunicating pore.
Applications Claiming Priority (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2006064506A JP5247987B2 (en) | 2006-03-09 | 2006-03-09 | Hydrodynamic bearing device |
| JP064506/2006 | 2006-03-09 | ||
| JP2006102259A JP2007278325A (en) | 2006-04-03 | 2006-04-03 | Fluid bearing device |
| JP102259/2006 | 2006-04-03 | ||
| PCT/JP2007/053728 WO2007102359A1 (en) | 2006-03-09 | 2007-02-28 | Fluid bearing device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101400912A CN101400912A (en) | 2009-04-01 |
| CN101400912B true CN101400912B (en) | 2010-11-10 |
Family
ID=38585658
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN200780008497XA Expired - Fee Related CN101400912B (en) | 2006-03-09 | 2007-02-28 | Fluid bearing device |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JP5247987B2 (en) |
| CN (1) | CN101400912B (en) |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1453481A (en) * | 2002-04-23 | 2003-11-05 | Ntn株式会社 | Fluid bearing apparatus |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH048909A (en) * | 1990-04-27 | 1992-01-13 | Canon Inc | Dynamic pressure fluid bearing rotating device |
| JP3637632B2 (en) * | 1995-05-25 | 2005-04-13 | 松下電器産業株式会社 | Electric motor |
| JP3578948B2 (en) * | 1999-10-01 | 2004-10-20 | 日本電産株式会社 | motor |
| JP4145068B2 (en) * | 2002-04-16 | 2008-09-03 | シチズンホールディングス株式会社 | Support device and motor using this bearing device |
| JP2004052999A (en) * | 2002-05-30 | 2004-02-19 | Ntn Corp | Fluid bearing device |
| JP2004028174A (en) * | 2002-06-24 | 2004-01-29 | Sony Corp | Bearing unit and motor having bearing unit |
| JP3864942B2 (en) * | 2003-08-25 | 2007-01-10 | ソニー株式会社 | Bearing unit and motor using the bearing unit |
| JP2005321089A (en) * | 2004-04-09 | 2005-11-17 | Ntn Corp | Dynamic pressure bearing device |
| JP2007192316A (en) * | 2006-01-19 | 2007-08-02 | Ntn Corp | Dynamic pressure bearing device |
-
2006
- 2006-03-09 JP JP2006064506A patent/JP5247987B2/en active Active
-
2007
- 2007-02-28 CN CN200780008497XA patent/CN101400912B/en not_active Expired - Fee Related
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1453481A (en) * | 2002-04-23 | 2003-11-05 | Ntn株式会社 | Fluid bearing apparatus |
Non-Patent Citations (5)
| Title |
|---|
| JP特开2004-218804A 2004.08.05 |
| JP特开2004-28174A 2004.01.29 |
| JP特开2005-321089A 2005.11.17 |
| JP特开2005-69382A 2005.03.17 |
| JP特开平8-322191A 1996.12.03 |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2007239920A (en) | 2007-09-20 |
| JP5247987B2 (en) | 2013-07-24 |
| CN101400912A (en) | 2009-04-01 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101438068B (en) | Fluid bearing device and its manufacturing method | |
| US8782901B2 (en) | Dynamic bearing device | |
| CN101868636B (en) | Fluid dynamic-pressure bearing device | |
| CN101006280B (en) | Fluid dynamic pressure bearing device | |
| US8356938B2 (en) | Fluid dynamic bearing apparatus | |
| CN101258014B (en) | Method for forming dynamic pressure groove | |
| CN1807908B (en) | Fluid lubrication bearing apparatus | |
| KR101527398B1 (en) | Fluid bearing device and process for manufacturing the same | |
| KR101347146B1 (en) | Fluid bearing device | |
| KR101405075B1 (en) | Fluid bearing device and its manufacturing method | |
| CN101405512B (en) | Fluid bearing device | |
| CN102414464A (en) | Dynamic-pressure bearing device | |
| KR20080102304A (en) | Fluid bearing device | |
| WO2005017380A1 (en) | Fluid bearing device and method of producing the same | |
| CN101400912B (en) | Fluid bearing device | |
| JP4790586B2 (en) | Hydrodynamic bearing device and manufacturing method thereof | |
| JP2004190786A (en) | Dynamic-pressure bearing device and manufacturing method therefor | |
| JP2004316926A (en) | Dynamic pressure-type bearing unit and method for manufacturing the same | |
| CN100480522C (en) | Dynamic pressure bearing device | |
| JP2007113778A (en) | Fluid bearing device and motor equipped with the same | |
| JP2007263225A (en) | Fluid bearing device | |
| JP2005188747A (en) | Hydrodynamic bearing device and its manufacturing method | |
| CN101331332B (en) | Fluid bearing device | |
| JP2005130699A (en) | Spindle motor of disk unit | |
| JP2007327546A (en) | Fluid bearing device manufacturing method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20101110 Termination date: 20200228 |
|
| CF01 | Termination of patent right due to non-payment of annual fee |