CN101103205A - Fluid dynamic bearing and a storage disk drive with a spindle motor having the fluid dynamic bearing - Google Patents
Fluid dynamic bearing and a storage disk drive with a spindle motor having the fluid dynamic bearing Download PDFInfo
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- CN101103205A CN101103205A CNA2005800149091A CN200580014909A CN101103205A CN 101103205 A CN101103205 A CN 101103205A CN A2005800149091 A CNA2005800149091 A CN A2005800149091A CN 200580014909 A CN200580014909 A CN 200580014909A CN 101103205 A CN101103205 A CN 101103205A
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Abstract
A hydrodynamic bearing having a bearing sleeve, a rotational shaft supported for rotation by the bearing sleeve, a bearing gap formed between the bearing sleeve and the rotational shaft, lubricating oil contained within the bearing gap, at least one hydrodynamic pressure-generating groove formed at an inner peripheral surface of the bearing sleeve; and an oil reservoir. The oil reservoir includes a gradually expanding section located in a position distanced from the pressure-generating groove and a first larger inner diameter, section located adjacently to the gradually expanding section. A second larger inner diameter section is located immediately below an opening of the bearing sleeve and an oil-repelling peripheral groove located between the first larger inner diameter section of the oil reservoir and the second larger inner diameter section. The oil-repelling peripheral groove and the second larger inner diameter section constitute an oil scatter and leakage prevention mechanism of the fluid dynamic bearing.
Description
The application requires all preference rights of Japanese patent application No.2004-142965 (unsettled) that submitted on May 12nd, 2004 and the Japanese patent application No.2005-115329 (unsettled) that submitted on April 13rd, 2005.
Technical field
Invention according to the application relates to fluid dynamic pressure bearing, is equipped with the spindle motor of this fluid dynamic pressure bearing, and the storage disk drive that utilizes this spindle motor.More specifically, the present invention relates to the leakproof structure of fluid dynamic pressure bearing, the lubricant oil that wherein is enclosed in the bearing can scattering or leakage owing to the influence of external force (such as various impacts or vibration) when spindle motor moves or do not move.
Background technique
Nearest technological improvement has improved significantly for littler, thinner and lighter but have the more demand of the data storage device of high density storage capacity.Generally disk and CD are used as memory device now.These new memory devices have caused that significant need is a kind of to be used for optimizing the rotational speed of the spindle motor that is used to rotate this disk and CD and the new technology of degree of accuracy.
In order to satisfy this demand, there has been gradually the trend that increases that the conventional ball bearing system that was used for supporting the axle of spinning disk or CD is in the past replaced with the hydrodynamic bearing system that utilizes oiling agent and/or air to produce the hydrodynamic pressure of supporting rotating shaft as its medium.
This hydrodynamic bearing is widely known by the people, and has known in its bearing that has been applied to spindle motor.(for example referring to Japan Patent prospectus No.2937833 and U.S. Patent No. 5,667,309).Figure 12-15 shows the example of conventional known fluid motive bearing.
Conventional hydrodynamic bearing 06 shown in Figure 12 is included in the axle 011 of rotation in the bearing sleeve 07.Axle 011 by the hydrodynamic bearing member supporting that is positioned at bearing sleeve 07 to rotate.Thrust plate 019 is connected to an end of running shaft.Bearing sleeve 07 comprises that formation receives the inner chamber of thrust plate 019.Anti-plate 018 surround bearing sleeve 07 inner chamber so that anti-plate and thrust plate locate with relation respect to one another.Continuous bearing slit 021,022,023 is formed on the one hand to have the running shaft 011 of thrust plate 019 and has on the other hand between the bearing sleeve 07 of anti-plate 018.Oiling agent 012 is included in this continuous bearing slit.
The radial fluid kinetic pressure produces groove 024 and is formed on the inner peripheral surface of bearing sleeve 07.First group of thrust hydrodynamic pressure produces top board that groove 025 is formed at the inner chamber of bearing sleeve 07 usually and sentences and make groove 025 relative with the end face of thrust plate 019.Second group of thrust kinetic pressure produces end face that groove 026 is formed at anti-plate 018 and sentences and make groove 026 relative with the bottom surface of thrust plate 019.
In described bearing arrangement, when running shaft 011 began to rotate, kinetic pressure produced groove 024,025 and 026 radially and produce the hydrodynamic pressure gradient on pushing to.Resulting hydrodynamic pressure with axle 011 be suspended on by around bearing sleeve 07 and the bearing space of anti-plate 018 formed thereby in.Running shaft is supported by the lubricant film that is formed in the bearing slit.
The oiling agent 012 that the common issue with of said system is included in the continuous slit 021-023 can let out from bearing, specifically passes through the open top of bearing sleeve 07.Several factors can cause the rise of the lubricant fluid height in the continuous bearing slit.For example, rise may be shunk because of the expansion that oiling agent itself causes owing to temperature variation and be produced; Can be because the bearing structure element be because the variation of caused capacity level is shunk in thermal expansion produces; Can be because start and the pumping action when ending the spindle motor operation and producing; And can produce because of centrifugal force that produces during motor operation and pressure.Because pump sucks the cause of mechanism (oiling agent is sucked back the into action of bearing), the unlikely leakage during the rotation of axle.Yet problem present in the prior art is, when spindle motor does not move (promptly axle 011 does not rotate) and such as impacting or the external force of vibration and so on when putting on this spindle motor, oiling agent 012 can be easy to flow out from the opening of bearing sleeve 07.
The situation of impacting or vibrating is common especially in portable computer, because it often falls when delivery.The spindle motor that is used for this portable machine is thinner, lighter and littler than the spindle motor that is used for non-pocket machine.This spindle motor experience a shock and the danger vibrated also higher.Therefore, be starved of protecting against shock and the vibrationproof ejector half structure that prevents that oiling agent from leaking.
Attempting shown in Figure 12-15 prevents that the sealing configuration that lubricant oil leaks is commonly referred to " cone-shaped seal structure " from conventional fluid dynamic pressure bearing.In this conventional structure, locate to be provided with conical surface 035 at the open part (open part of bearing sleeve 07) in bearing slit along the internal surface of bearing sleeve 07.Conical surface 035 tilts with specific inclined angle alpha and thereby widens the bearing slit gradually towards opening.Therefore, form gradually exhibition slotted section 029 at the place, top in bearing slit with wide opening.This gradually opens up slotted section 029 also as the reservoir of lubricant oil, and this is to be received and to be contained in this reservoir owing to surface tension because flow out the lubricant oil in bearing slit.As shown in figure 14, structure shown in Figure 12 and 13 also can be provided with the peripheral groove 036 that upcountry is formed up to conical surface 035 along the internal surface of bearing sleeve 07.
Be similar to existing bearing shown in Figure 13, above-mentioned Japan Patent No.2937833 discloses a kind of slit portion of gradually opening up modification, be formed with wide opening in the bearing slit in the radial bearing zone outside, wherein oil holds circumferential groove (being similar to all grooves 036 among Figure 13) and is formed on the internal surface of bearing sleeve.According to disclosing of No. 833 patents, the inclined angle alpha of gradually opening up the slit of modification is set to 0 or bigger.Inclined angle alpha be set to 0 or the bigger part of the inwall of bearing sleeve in the modification gap area of just representing can be parallel to running shaft.
As mentioned above, the lubricant oil reservoir 029 of conventional hydrodynamic bearing 06 shown in Figure 12-15 is general triangular and the part that forms the expansion in bearing slit.Yet the capacity that increases the reservoir with this structure is subject to the inclined angle alpha that increases wall or increases the length (promptly increase the height of reservoir in oil) of reservoir on axially.
In order to make spindle motor littler, thinner and lighter, just should shorten the axial length of hydrodynamic bearing.If the axial depth of modification expansion gap opening 029 is too big, so the radial pressure axial length that produces the zone compare produce the required length of enough kinetic pressure that supports this will be too short.Therefore, the modification that just needs restriction to hold oil is expanded the axial length of gap opening 029 to prevent the oiling agent outflow.Particularly, the axial height of modification expansion gap opening 029 must remain on it can not influence in the scope that bearing pressure produces regional required axial length.Structure thinner and lighter spindle motor also produces restriction to the inclined angle alpha of bearing slit wall.Therefore, requiring in the littler and thinner design of impacting or do not have during vibration the hydrodynamic bearing that oiling agent leaks, above-mentioned two consideration conditions make that the use of the slit reservoir 029 that modification is expanded is complicated.
In addition, oiling agent outflow prevent structure shown in the conventional design, the gap opening 029 of modification expansion is designed to reach overall dimensions at the opening of bearing sleeve 07, and does not have mechanism to forbid the scattering outflow of oiling agent here.Therefore, when running shaft when its stopping period is impacted or is vibrated, the oiling agent in the bearing slit of hydrodynamic bearing can not remain in the gap opening 029 of modification expansion and can splash the bearing outside.Thereby this conventional structure just allows oiling agent to scatter to gap opening 029 outside of modification expansion, and therefore scatters to the bearing outside.(referring to Figure 15.)
The oiling agent leakage problem of conventional spindle motor is the direct result of hydrodynamic bearing design, and wherein the capacity of lubricant reservoir is because multiple limiting factor and limited and can not prevent the oiling agent outflow.In addition, in this conventional oil reservoir, do not have when the axle that stops to be impacted or vibrates, to prevent that bearing from avoiding the protection walls that oiling agent leaks.Need under the requirement of littler, thinner and lighter spindle motor day by day, must solve the problem of the hydrodynamic bearing that produces littler, thinner but leakproof as much as possible.
Except the lubricant reservoir of above-mentioned conventional structure, the open No.3431723 of Japan Patent discloses a kind of hydrodynamic bearing, it has oiling agent blind between sleeve and running shaft and hydrodynamic pressure produces groove, expanded diameter section wherein is set on the internal surface of sleeve openings and is formed with circumferential groove in the neutral position of the expanded diameter section of sleeve.This structure attempts to control the outflow and the scattering thereof of lubricant oil.Yet, the but CONSTRUCTED SPECIFICATION of circumferential groove and expanded diameter section openly not.
Summary of the invention
One total aspect, the present invention is a kind of hydrodynamic bearing, its have bearing sleeve, by bearing sleeve be supported for rotation running shaft, be formed at bearing slit between bearing sleeve and the running shaft, be included in lubricant oil in the bearing slit, the hydrodynamic pressure at inner peripheral surface place that at least one is formed at bearing sleeve produces groove and oil reservoir.This oil reservoir comprise away from described pressure produce the gradually exhibition section section of groove and contiguous gradually exhibition section section first than the imperial palace diameter section.Be disposed immediately in second below the opening of bearing sleeve than the imperial palace diameter section and be positioned at oil reservoir first than imperial palace diameter section and second than all grooves of the oil of the retaining between the imperial palace diameter section, be provided to prevent the lubricant oil scattering and leak into outside the bearing slit.Keeping off the opening of oily all grooves widens gradually towards the inboard of bearing sleeve.First side that keeps off oily all grooves forms grease proofing sputter retaining wall surface.Oil reservoir is in first than the encirclement of the position in imperial palace diameter section lubricant oil in the inoperative liquid level of lubricant oil.Keep off oily all grooves and prevent that lubricated oil spill from crossing and scattering to outside, bearing slit, even afford at hydrodynamic shaft under the situation of external force.
The hydrodynamic bearing of structure allows at the hope volume that does not increase increase lubricant oil reservoir under the spindle motor axial dimension in the above described manner.For the restriction of conventional model, then no longer suitable such as the length reduction of pressure-generating element, therefore making to provide the little and thin hydrodynamic bearing that is applicable to littler, thinner and lighter spindle motor.
In addition, because a side that keeps off oily all grooves is as oily splashproof wall, even motor is subjected to also preventing overflowing and scattering of oil such as the external force of impacting or vibrating and so on when axle is static.Even without pumping into action, lubricant oil also is withdrawn in the bearing slit by the oily splashproof wall of the oily all grooves of retaining.
According to an aspect of the present invention, keep off oily all grooves and have the opening of widening gradually towards the bearing sleeve inboard.This structure allows the upper surface of all grooves that oiling agent is back in the bearing slit effectively, because the expansion of all grooves side helps the motion of oiling agent on the direction of bearing slit.
According to the present invention, all grooves of the retaining of above-mentioned hydrodynamic bearing oil can comprise a central axis angled side walls with respect to bearing sleeve.Be preferably acute angle by this sidewall and the formed tilt angle of central axis.
In another aspect of this invention, second than the inner diameter of imperial palace diameter section less than first the inner diameter than the imperial palace diameter section.
In still another aspect of the invention, first comprises the taper that increases the section inner diameter towards the opening of bearing sleeve gradually than the imperial palace diameter section.According to the present invention aspect this in bearing of structure, can under the prerequisite that does not increase the bearing axial dimension, enlarge markedly the volume of lubricant oil reservoir and can obtain wherein bubble with mix lubricant can be easy to from bearing slit ease from structure.
In another aspect of this invention, one deck oil-repellent solid film is applied to its end face along the edge of opening of bearing sleeve.Another layer oil-repellent solid film closely is applied to the outer circumferential face of running shaft on the opening of bearing sleeve.
Therefore, even oiling agent unexpectedly spills from the opening in bearing slit, oiling agent also will be pushed back by the oil-repellent solid film.
Of the present invention another total aspect in, the present invention is a kind of spindle motor, it comprises hydrodynamic bearing, this hydrodynamic bearing have bearing sleeve, by bearing sleeve be supported for rotation running shaft, be formed at bearing slit between bearing sleeve and the running shaft, be included in lubricant oil in the bearing slit, the hydrodynamic pressure at inner peripheral surface place that at least one is formed at bearing sleeve produces groove and oil reservoir.This oil reservoir comprise away from this pressure produce the gradually exhibition section section of groove and contiguous gradually exhibition section section first than the imperial palace diameter section.Be disposed immediately in second below the opening of bearing sleeve than the imperial palace diameter section and be positioned at oil reservoir first than imperial palace diameter section and second than all grooves of the oil of the retaining between the imperial palace diameter section, be provided to prevent lubricant oil scattering and leakage.Keeping off the opening of oily all grooves widens gradually towards the inboard of bearing sleeve.First side that keeps off oily all grooves forms grease proofing sputter retaining wall surface.Oil reservoir is in first than the encirclement of the position in imperial palace diameter section lubricant oil in the inoperative liquid level of lubricant oil.Keep off oily all grooves and prevent that lubricated oil spill from crossing and scattering to outside, bearing slit, even afford at hydrodynamic shaft under the situation of external force.
Another total aspect, the present invention is a kind of recording disc actuator device, and it has: recording disc, data are write the data head that reads data on the recording disc and/or from it and make the recording disc rotation and have the spindle motor of the hydrodynamic bearing of constructing as above-mentioned mode.Data head can be magnetic head or optical head.
Above-mentioned aspect, advantage and characteristics only are representational embodiments.Should be understood that they are not considered to be qualification of the present invention defined by the claims.In the following description, from accompanying drawing and during accessory rights requires, other characteristics of the present invention and advantage will become clearly.
Description of drawings
The present invention illustrates by way of example and is not limited, same same or corresponding parts of designated in the accompanying drawing, wherein:
Fig. 1 is the vertical cross-section view according to the spindle motor of first embodiment of the invention.
Fig. 2 is the vertical cross-section view of the stator module of spindle motor among Fig. 1.
Fig. 3 is the vertical cross-section view of hydrodynamic bearing that is used for the spindle motor of Fig. 1.
Fig. 4 is the partial enlarged view of hydrodynamic bearing among Fig. 3.
Fig. 5 is the partial enlarged view of hydrodynamic bearing among Fig. 3, wherein shows the operation of the oiling agent circumference retaining groove that is formed on the bearing sleeve internal surface.
Fig. 6 is the local vertical cross-section view of amplifying of hydrodynamic bearing that makes up according to second embodiment of the invention.
Fig. 7 is the local vertical cross-section view of amplifying of hydrodynamic bearing, and wherein oiling agent circumference retaining groove is an arc.
Fig. 8 a-8c shows the rigging position of conventional spindle motor on testing installation, and wherein " p " represents air pressure, and " g " represents gravity.
Fig. 9 shows first embodiment's the rigging position of spindle motor on testing installation, wherein " g " expression gravity.
Figure 10 is the chart that the comparative trial structure is shown.
Figure 11 shows the longitudinal cross-section schematic representation according to the hard disk drive structure of third embodiment of the invention.
Figure 12 is the vertical cross-section view that is used for the hydrodynamic bearing of conventional spindle motor.
Figure 13 is the local vertical cross-section view of amplifying of the conventional hydrodynamic bearing among Figure 12.
Figure 14 is the vertical cross-section view that amplify the part of conventional another example of hydrodynamic bearing.
Figure 15 is the local vertical cross-section view of amplifying of the hydrodynamic bearing among Figure 14, wherein schematically shows the operation of this conventional hydrodynamic bearing.
Embodiment
According to a preferred embodiment of the invention, a kind of hydrodynamic shaft bearing assembly comprises be supported for the running shaft that rotates in bearing sleeve, so that form the bearing slit between the internal surface of running shaft and bearing sleeve.Lubrication pockets is trapped among in the bearing slit of bearing sleeve and running shaft.At least one hydrodynamic pressure produces the internal surface place that groove is formed at bearing sleeve.Bearing sleeve comprise in the face of sleeve openings first than the imperial palace diameter section.This first is positioned at away from hydrodynamic pressure than the imperial palace diameter section and produces the position of groove one end so that first can not hinder pressure to produce the operation of groove than the imperial palace diameter section.Second closely is formed at below the opening of bearing sleeve than the imperial palace diameter section.Keep off oily all grooves be formed at first than imperial palace diameter section and second than between the imperial palace diameter section.The inner diameter that keeps off oily all grooves is greater than first and second inner diameters than the imperial palace diameter section.In addition, second bottom surface than the imperial palace diameter section forms the splashproof retaining wall that prevents the unexpected sputter of oiling agent.Oiling agent preferably be filled to when axle when static liquid level be in first than the level in the imperial palace diameter section.Therefore, can guarantee that lubricant oil may cause sputter or the volume that splashes increases the oily all grooves of retaining that can not overflow, though the external force of being applied with, impact or vibration, even perhaps capillary force, surface tension and barometric pressure equilibrium of forces are broken.
At least surround the zone at the edge that keeps off a side of oily all grooves and the central axis of bearing sleeve and form an acute angle.In a preferred embodiment, second than the inner diameter of imperial palace diameter section less than first the inner diameter than the imperial palace diameter section.The solid film of oil-repellent puts on the end face of bearing sleeve along the edge of sleeve openings.In addition, the solid film of oil-repellent also closely puts on the outer circumferential face of running shaft on the bearing sleeve opening.
Then, with reference to Fig. 1-5 first preferred embodiment of the present invention is described.
Fig. 1 shows first embodiment's who is used for driving the disk storage device (for example disk or CD) (being commonly referred to " recording disc driving arrangement " this moment) that is used for computer spindle motor 1 (hereinafter being called " motor 1 ").Spindle motor 1 comprises stator module 2 and rotor assembly 3.Stator module 2 has the framework 4 that is connected to the data recording equipment main body rigidly.Stator lamination 8 with coil winding 9 is installed on the outer circumferential face of vertical extension cylindrical part 5 at framework 4 middle parts.
When supplying power to coil 9, produce magnetic field by stator lamination 8.On the magnet 14 of the action of a magnetic field that is produced in placing magnetic field, make rotor assembly 3 rotate.The recording disc (such as disk or CD (not shown)) of rotation is fastened on the outer circumferential face of intermediate cylindrical part 15 of wheel hub 10.Disk is rotated by spindle motor 1 and stops, and is write and/or the read data operation by the data head execution, and data head can be magnetic head or optical head.
In the spindle motor 1 according to first embodiment, hydrodynamic bearing 6 is formed in the zone of bearing sleeve 7 supporting rotating shafts 11.Describe the structure of hydrodynamic bearing 6 below in detail.
As Figure 1-3, the bottom of bearing sleeve is provided with first chamber 16 and second chamber 17 that is disposed immediately on first chamber with ventricumbent major diameter opening.The inner diameter of second chamber is preferably less than the inner diameter of first chamber.Anti-plate 18 is fitted into first chamber 16 and is fixedly secured therein by welding, adhesive etc., so that the inboard of bearing sleeve 7 is in airtight conditions.
As shown in Figure 3, clutch shaft bearing slit 21 is formed between bearing sleeve 7 and the running shaft 11, and the second bearing slit 22 is formed between the top board of the thrust plate 19 and second chamber 17, and the 3rd bearing slit 23 is formed between thrust plate 19 and the anti-plate 18. Bearing slit 21,22 and 23 to each other mutually continuously and be filled with lubricant oil 12.Lubricant oil 12 is injected into the slit between bearing sleeve 7 and the running shaft 11.Clutch shaft bearing slit 21 is inserted between the second bearing slit 22 and the lubricant oil reservoir 29 (below will describe), and is to have the straight slot of consistent width along its whole axial length.
Be formed at the topmost part of bearing sleeve as the lubricant oil reservoir 29 of distinguishing characteristics of the present invention, between bearing sleeve 7 and running shaft 11.Lubricant oil reservoir 29 is the slits with special construction, and it is sealed in these continuous slits as the open part of continuous slit 21,22 and 23 and with oiling agent.
The first fluid kinetic pressure produces inner periphery 27 places that groove 24 is formed at bearing sleeve 7.The first fluid kinetic pressure produces groove 24 because the rotation of running shaft 11 produces kinetic pressure, and this kinetic pressure is kept out load diametrically.The first fluid kinetic pressure produces groove 24 and preferably is arranged in two positions, i.e. last position and upper/lower positions on the inner periphery 27 of sleeve 7.Two positions of this of groove 24 are all orientated as and are lower than lubricant oil reservoir 29.
Second hydrodynamic pressure produces groove 25 and is formed at the top board surface of second chamber 17 in the face of thrust plate 19 end faces.The three-fluid kinetic pressure produces groove 26 and is formed at anti-plate 18 in the face of on the end face of thrust plate 19 bottom surfaces.Second and the three-fluid kinetic pressure produces that groove 25 and 26 produces because the kinetic pressure that rotation caused of running shaft 11, it bears the load of pushing to.
Running shaft 11 is radially producing the kinetic pressure support that groove 24,25 and 26 is produced with pushing to by first, second and three-fluid kinetic pressure.Therefore, axle is in quick condition with respect to bearing sleeve rotation and anti-plate.
Shown in Fig. 3-5, lubricant oil reservoir 29 is to comprise gradually opening up the part 33 and first space than imperial palace diameter section 31a.Oil is packed into the bearing slit and is within first the volume than imperial palace diameter section 31a to guarantee oil level.Keeping off oily all grooves 32 and second closely is located on the oil reservoir 29 to prevent that oil is owing to applying oily sputter and the leakage that causes such as the external force of impacting or vibrating and so on than imperial palace diameter section 31b.All parts of lubricant oil reservoir and oily sputter and leakage-proof preventing structure all are formed in the top of internal surface 27 of bearing sleeve 7.In the present invention, total is called the line seal structure.
Gradually opening up part 33 is designated in Fig. 4 and is formed on the position of " m " on the internal surface 27 and towards opening (being designated " the w ") expansion of bearing sleeve.Position " m " produces groove 24 predetermined spacing at interval with top first fluid kinetic pressure.
First closely is formed on the internal surface 27 gradually opening up on the part 33 than imperial palace diameter section 31a.First than the inner diameter of the imperial palace diameter section 31a axial constant along bearing sleeve 7.
Shown in the cross section of Fig. 4, keep off oily all grooves 32 form U-shaped roughly towards bypass.Second than imperial palace diameter section 31b be formed at the retaining oily all grooves 32 on.One side (being designated numeral " 32b ") contiguous second of all grooves 32 of U-shaped is than the lubricant oil splashproof retaining wall surface of the axis perpendicular of imperial palace diameter section 31b and formation and bearing sleeve 7.U-shaped week groove 32 another side 32a contiguous first than imperial palace diameter section 31a and with the axis shape of bearing sleeve at an angle.Side 32a with respect to the angle of inclination of central axis preferably less than the angle of inclination of side 32b.In other words, the angle of inclination of side 32a is acute angle less than 90 °.The result is that the oily all grooves 32 of retaining have the opening of widening towards the bearing sleeve inboard.In the time of in running shaft 11 correctly is positioned at bearing sleeve 7, the central axis of the central axis of bearing sleeve 7 and running shaft 11 coincides.
Second than top edge 28 expansions of imperial palace diameter section 31b from the top edge that keeps off oily all grooves 32 towards bearing sleeve.Usually, consider manufacturability, first has identical diameter with second than imperial palace diameter section 31b than imperial palace diameter section 31a, and is parallel to the internal surface 27 of bearing sleeve 7.
As mentioned above, tilt by the side 32a of the oily all grooves 32 of retaining and the formed angle of central axis of bearing sleeve 7.Therefore, the shape of all grooves 32 has been quickened the outflow campaign of Lubricants and has been made fluid motion with bump side 32b.Side 32b utilizes and thisly excites being reflected on the direction of bearing inboard of bump that lubricant oil 12 is kept off back, to control overflowing of lubricant oil 12 effectively.(referring to Fig. 5.)
The shape of cross section that keeps off oily all grooves 32 is not limited to roughly U-shaped.It also can be roughly semicircle, roughly arc, essentially rectangular, trapezoidal, general triangular etc. roughly.Yet under the difform situation of any of these, the open part of all grooves should be widened towards the inboard of bearing sleeve and the part of surperficial at least 32a and 32b should be flat diametrically basically near the edge.
Notice that in certain embodiments, the cross section that keeps off oily all grooves 32 can be roughly U-shaped or essentially rectangular.Therefore, keep off oily all grooves and can be any one.When cross section during for roughly semicircle or arc, side 32b and side 32a are the zones that is equivalent to arc portion, and here the normal that extends along any point from arc portion sprays and breaks away from the oily all grooves 32 of retaining by the injection water that the outer circumferential face of running shaft 11 reflects symmetrically.
Shown in Figure 4 and 5, the liquid level SO of lubricant oil 12 is in first than imperial palace diameter section 31a when running shaft 11 is static, and lubricant oil 12 is in the bearing slit.As mentioned above, if when motor 1 is subjected to external force such as external impact or vibration and so on, and if the balance between capillary force, surface tension and the atmospheric pressure when being broken, lubricant oil 12 can also spill in scatterings.In the hydrodynamic bearing that provides at present, surround lubricant oil, so that can not overflow the oily all grooves 32 of retaining.When running shaft 11 is static, do not pump into effect, therefore when motor 1 was subjected to external force such as external impact or vibration and so on, the lubricant oil that is packed into continuous slit was understood scattering and spill more amount from opening portion.Yet, keep off the lubricant oil of oily all grooves 32 reception more amount and also it is depressed owing to the geometrical shape of side 32b, be back into bearing.When spindle motor was subjected to external force such as the unexpected variation and so on of the temperature and pressure except external impact and vibration, the hydrodynamic bearing of present described structure also was effective.
The solid layer 30a of oil-repellent puts on the edge of end face 28 of the opening in bearing slit " w ".Another solid layer 30b of oil-repellent puts on the outer circumferential face of running shaft 11 on bearing gap opening " w ".These solid films 30a and 30b reach under this unlikely situation of gap opening " w " at lubricant oil 12 and return to prevent that by it is kept off lubricant oil 12 from leaking or scattering to outside, bearing slit.
To explain the action of the oily all grooves 32 of retaining and first embodiment's effect below.
When running shaft 11 was static, the liquid level SO of lubricant oil 12 was arranged in first than imperial palace diameter section 31a, as shown in Figure 4.When motor 1 is subjected to breaking the external force of liquid level SO state of equilibrium, some lubricant oil will raise and will be drawn into the internal voids that keeps off oily all grooves 32.The liquid level of oiling agent will continue to raise and will be located with respect to side 32a and 32b up to it.Side 32b is used as lubricant oil splashproof retaining wall then and keeps off back lubricant oil 12 it is back in the bearing slit, as shown in Figure 5.Like this, just prevent lubricant oil 12 scatterings and leaked into the bearing outside.
The side 32a that keeps off oily all grooves 32 forms an acute angle with the central axis of bearing sleeve at least near its edge, it is less than side 32b and the formed 90 ° of angles of same axis.Therefore, compare with the structure that central axis forms the right angle, just quicken and encouraged oiling agent to leave the motion of all grooves with same side wherein.When lubricant oil 12 bump side 32b and side 32b utilize the reaction of this bump to push back lubricant oil 12 into the bearing slit, just suppressed overflowing of lubricant oil effectively.
Even be subjected to being better than the external impact of expection or vibrate under this unlikely situation and liquid level SO is elevated to when being higher than side 32b and reaching aperture position " w " at spindle motor 1, the oil effect of scolding of solid film 30a and 30b also will push back oil on the direction in bearing slit, thereby prevent lubricant oil 12 sputters or leak into the bearing outside.
According to first the size Selection, can under the prerequisite that does not increase whole bearing axial dimension, increase the volume of oil reservoir 29 than the inner diameter of imperial palace diameter section 31a.Because first is straight line than imperial palace diameter section 31a, so this structure is much simpler than conventional cone-shaped seal structure.In addition, by the structure of this lubricant oil reservoir 29, eliminated the reduction that occurs in the conventional sealing configuration and be used for the problem that kinetic pressure produces the space of groove.Therefore, can guarantee the lubricant oil reservoir of enough volumes and further increased the effect that prevents lubricant oil 12 scatterings and leak into bearing outside as mentioned above.
The invention described above first embodiment's effect is identified experimentally.Experimental result is summarised in the form of Figure 10 and below will makes an explanation.
When Figure 10 shows the impact load that applies varying level under the non-operating state about the contrast experiment's of lubricant oil anti-scatter and anti-leak effect result.Experiment is at the cone-shaped seal structure that is used for conventional hydrodynamic bearing structure, shown in Figure 12-14, and is used to form the line seal structure in the hydrodynamic bearing 6 in spindle motor 1 and carries out.
As experimental condition, in the contrast experiment, spindle motor with respect to the consideration of the rigging position of experimental facilities towards being: the direction that faces up, faced downwards to face side surface direction, shown in Fig. 8 (a)-8 (c), be used for conventional cone-shaped seal structure, and the side surface direction that faces that is used for the line seal structure as Fig. 9.Assembling towards " facing up ", " facing down " and " facing the side " expression fluid dynamic pressure bearing sleeve opening surface up, down or towards the side.Experiment is undertaken by applying to impact on direction from top to bottom, and wherein the impact size that records according to acceleration magnitude is divided into 5 grades, from 100G to 1000G.Therefore, carry out 15 kinds of tests altogether for each sample.Impact or the size of vibration because the amount of the lubricant oil that spills from hydrodynamic bearing depends on, and depend on fluid dynamic pressure bearing with respect to impact or direction of vibration towards, so above-mentioned test method is defined as these factors are taken into account.
For representative sample of the present invention, prepare to have three spindle motors (No.1 to No.3) of same straight line sealing configuration, and allow each sample repeatedly be subjected to 15 kinds of shock tests.For control sample corresponding to conventional cone-shaped seal structure, prepare five spindle motors (No.1 to No.5) of same cone-shaped seal structure, and be similar to the sample of line seal, be subjected to 15 kinds of shock tests respectively.
Note,, test by impact that at first applies minimum level and the impact that sequentially proceeds to maximum magnitude for each sample.In addition, for given impact magnitude (acceleration magnitude), assembling towards according to upwards, downward and sideways order changes.Process of the test adopts the reason of this rigging position order to be, in this order, the condition of keeping the stability in the hydrodynamic bearing of lubricant oil in being installed on spindle motor becomes strict more.Can understand this point better with reference to Fig. 8 (c).The side shown in Fig. 8 (c) towards in, the load of lubricant oil gross weight concentrates on the lowest part SL of pasta (meniscus).Therefore capillary force, surface tension and being responsible for kept pasta (meniscus) balance stable and that oil is remained between the atmospheric pressure p in the bearing slit and is easy to most be broken at pasta lowest part SL.For the situation among Fig. 9, wherein show embodiments of the invention, even balance is broken similarly, catch oiling agent and still can prevent its leakage by keeping off oily all grooves.The seriousness of considering oil leakage in the test of same sequence or scattering can increase, and for each sample, in case confirmed leakage of oil, then no longer carries out the residue test, because the test of back is self-evident.
Test result is very clear from the form of Figure 10.Sample with conventional cone-shaped seal structure can not bear 1000G and impact, and spills lubricant oil.Yet the sample that has according to the line seal structure of first embodiment of the invention can bear 1000G or bigger impact, and no matter assembly direction how, thereby proved the superiority that surpasses conventional cone-shaped seal structure.By demonstrate the effect that prevents lubricant oil scattering and leakage when being subjected to aforementioned impact load under running shaft is in quiescent conditions, all samples have all been confirmed superiority of the present invention.In the form of Figure 10, leakage of oil does not take place in word " O.K. " expression, in fact confirm leakage of oil has taken place in phrase " leakage of oil " the expression test, and hyphen ("-") but expression do not test clearly and in test leakage of oil will take place.
In addition, the comparison vibration test of adding between the cone-shaped seal structure of routine (being used for being formed at the scattering and the leakage that prevent lubricant oil in the fluid dynamic pressure bearing of conventional spindle motor) and line seal structure (be formed in the fluid dynamic pressure bearing 6 in the spindle motor 1 of first embodiment of the invention and be used for identical purpose) is verified when axle be in the ability that prevents lubricant oil scattering and leakage under the vibration that repeats under the quiescent conditions to apply.Test shows that oily scattering and leakage appear in the cone-shaped seal structure, and have prevented this phenomenon reliably in line seal structure according to the present invention.The example of a concrete vibration test condition that repeatedly applies under axle is static is, the acceleration range that is applied is 2.0Grms to 5.0Grms, vibration frequency range and swing condition are 10Hz to 2000Hz/30 minute, and assembling is oriented upwards, downward and side surface direction.
And, the checking sealing configuration is in the test result that is subjected to preventing when temperature and pressure changes suddenly the lubricant oil scattering and the ability of leakage, and the result of air curls inward (airinvolution) during the running test, confirmed that the line seal structure prevents that the ability of lubricant oil scattering and leakage is identical or better with the ability of cone-shaped seal structure.The test that temperature and pressure changes suddenly cone-shaped seal structure in the fluid dynamic pressure bearing in being formed at conventional spindle motor and being formed on the line seal structure of the fluid dynamic pressure bearing 6 in first embodiment's the spindle motor 1 under axle is static is carried out.The test of air curls inward is also carried out on cone-shaped seal structure and line seal structure under the axle rotation.
When comparing with conventional cone-shaped seal structure in the above described manner according to the line seal structure of first embodiment of the invention, line seal clearly of the present invention has significantly improved ability aspect lubricant oil scattering and the leakage in preventing fluid dynamic pressure bearing, and has identical aspect the ability that prevents the air curls inward or the more performance characteristic.In addition, line seal structure open at present and that require allows the hydrodynamic bearing size to reduce and has high reliability.Consider that the possibility that causes vibrating or impacting owing to misoperation increases in small computer device, and consider that the spindle motor that is installed in this equipment is just becoming littler, thinner and lighter, relatively increase its rigidity, the problem that the fluid dynamic pressure bearing of today is bigger becomes and prevents lubricant oil scattering and leakage.First embodiment's line seal structure has been brought important contribution for addressing this problem.
Notice, can second inner diameter than imperial palace diameter section 31b be set according to the shape of the oily all grooves 32 of retaining, to optimize effect, as first embodiment's improvement embodiment as the side 32b that prevents lubricant oil sputter retaining wall surface.For example, when the effect of side 32b was not enough to as lubricant oil sputter retaining wall surface, second inner diameter than imperial palace diameter section 31b can be set to less than first inner diameter than imperial palace diameter section 31a.Yet, the short of and contacted danger of running shaft 11 outer circumferential faces, second inner diameter than imperial palace diameter section 31b just can reduce.And, consider size of impacting or the structure of considering hydrodynamic bearing, on the contrary, second inner diameter than imperial palace diameter section 31b can be set to greater than first inner diameter than imperial palace diameter section 31a.
In above-mentioned example, second inner diameter than imperial palace diameter section 31b is set to not only further improve less than first inner diameter than imperial palace diameter section 31a and prevents to be formed at second than the lubricant oil scattering in the slit between the outer circumferential face of the inner peripheral surface of imperial palace diameter section 31b and running shaft 11 and the effect of leakage, but also the effect that reduces the air curls inward is provided.By from first than imperial palace diameter section 31a through retaining oily all grooves 32 and second than imperial palace diameter section 31b and scattering and the lubricant oil 12 that leaks into bearing outside are just kept off the side 32b of oily all grooves 32 and pushes back effectively into the bearing slit.Keep off oily all grooves 32 be connected to second than imperial palace diameter section 31b and widen towards the bearing sleeve inboard, thereby prevented diametrically from the first side 32b spill into the outside.In addition, restriction second effect than imperial palace diameter section 31b helps to control overflowing of lubricant oil 12, thereby more effectively prevent to leak, make the performance reliability that can improve lubricant oil scattering and leakage in the fluid dynamic pressure bearing that prevents little and thin specification extraly.
And, in another modified examples of first embodiment, replacement remains first inner diameter than imperial palace diameter section 31a along its axial constant, can provide inclination a little (being taper) with respect to running shaft 11 with the necessary volume of guaranteeing lubricant oil reservoir 29 and the effusion of being convenient to be mingled in the air in the lubricant oil in the axial direction.In addition, this taper configurations will reduce flow path resistance.In the case, inclination can be the inclination that increases gradually along with inclination that reduces gradually towards the mobile inner diameter of opening " W " or inner diameter.When inclination is when making that it reduces inner diameter gradually, to be easier to guarantee the volume of lubricant oil reservoir 29, and make that air is easier to overflow.In the case, second also can be less than inner diameter at the tapered end place than the inner diameter of imperial palace diameter section 31b.
To explain the second embodiment of the invention shown in Fig. 6 and 7 below.
Fig. 6 is according to the local vertical cross-section view of amplifying of second embodiment's hydrodynamic bearing, and the shape of cross section that wherein keeps off oily all grooves 32 is that the central axis of roughly trapezoidal and one of them side 32b and sleeve 7 forms acute angle.Fig. 7 is similar accompanying drawing, and wherein shape of cross section is arc roughly.
In Fig. 6, the shape of cross section of all grooves 32 of retaining oil of fluid dynamic pressure bearing 6 that is applied to spindle motor 1 as second embodiment is for roughly trapezoidal.And a side 32b is provided as lubricant oil splashproof retaining wall surface, and it keeps off back lubricant oil 12 to suppress lubricant oil 12 area scattering and leakage outside bearing towards bearing is inboard.Thereby, from keeping off the inboard of oily all grooves 32, at least near the tangent line the 32b edge, this side at a central axis of the transversal bearing sleeve 7 in P place to form acute angle with central axis.
And, according to second embodiment, first than the axial length of imperial palace diameter section 31a basically greater than second the axial length than imperial palace diameter section 31b.Optionally, second can prevent lubricant oil 12 scatterings with raising and leak into the effect (referring to dotted line) of bearing outside than first the little quantity X of radius than imperial palace diameter section 31a than the radius of imperial palace diameter section 31b.Other details is identical with first embodiment.
According to this second embodiment, a side (the lubricant oil splashproof retaining wall surface) 32b that keeps off oily all grooves 32 has an end, and this end comprises that at least the central axis of an encirclement and bearing sleeve 7 forms the zone at the edge of sharp angle.Therefore, will be kept off back reliably and back in the bearing by side 32b through the oily all grooves 32 of retaining and second lubricant oil 12 that leaks into bearing outside than imperial palace diameter section 31b from first than imperial palace diameter section 31a, thereby control overflowing of lubricant oil 12.Therefore, compare, more effectively prevented the scattering and the leakage of lubricant oil 12, and further improved performance and the reliability in littler and thinner hydrodynamic bearing 6 thereof that prevents lubricant oil scattering and leakage with first embodiment.
Be circular arc roughly according to the sectional shape of all grooves 32 of second embodiment's retaining oil as shown in Figure 7.And gradually exhibition portion 33 also has gradually arc.The side 32b and the second side 32a that keep off oily all grooves 32 face running shaft 11 directions ground opening with symmetrical manner.From keeping off the inboard of oily all grooves 32, equate by the formed angle of tangent line of the central axis of bearing sleeve 7 and side 32b end surface and by the central axis of bearing sleeve 7 and the formed angle of tangent line on 32a starting point surface, second side.
Except above-mentioned aspect, the structure of Fig. 7 is identical with antispraying structure with lubricant oil reservoir 29 structures shown in Figure 6, and therefore can obtain similar result.
Then, with the third embodiment of the invention of explaining as shown in figure 11.Figure 11 is the longitudinal cross-section schematic representation, and it shows the structure according to the hard disk drive of third embodiment of the invention.As shown in figure 11, hard disk drive 40 is provided with first embodiment's spindle motor 1.The 3rd embodiment's hard disk drive 40 following structures.The shell of hard disk drive 40 comprises housing 41 and the cap member 42 that holds spindle motor 1, and the inside of the described housing 41 of this cap member 42 sealings does not have the clean chamber of impurity with formation, the work that described impurity can the disturbance records disk.Be fit into the attachment hole 41a of housing 41 and be fastened to housing 41 with several attachment screw 52 by the central cylindrical portion 4a with framework 4, spindle motor 1 is fixed to housing 41, described attachment screw 52 is passed a plurality of through holes around the framework 41 outer periphery parts.Spindle motor 1 comprises that the main body of stator 2 and rotor 3 is contained in the shell of hard disk drive 40.
Alternatively, framework 4 and housing 41 can be integrated into single base component, wherein this base component comprises parts of the shell of attachment that the stator 2 of fluid dynamic pressure bearing 6 and spindle motor 1 is attached and hard disk drive 40.
Two hard disks (recording disc) 43 are installed on the outer circumferential face of intermediate cylindrical portion 15 of wheel hub 10 of rotor 3.Hard disk 43 is fastened to wheel hub 10 tightly by clamping element 44, and this clamping element 44 is fixed with a plurality of attachment screw 51, and described attachment screw 51 is threaded in a plurality of screw holes that axially are located on wheel hub 10 intermediate sections.Thereby hard disk 43 is along with wheel hub 10 rotates together.Although embodiment comprises two hard disks 43 that are installed on the wheel hub 10 as shown in figure 11, the quantity of hard disk 43 is not limited to two.
The hard disk drive 40 of as above constructing according to the 3rd embodiment be for conventional hydrodynamic bearing technology with regard to prevent lubricant oil scattering and leakage and prevent fluid dynamic pressure bearing 6 air involute with regard to substantial improvement, and especially when being used for the small portable computer equipment, hard disk drive 40 can be guaranteed higher levels of reliability, even it is subjected to the unexpected vibration of impacting or continuing when this small portable computer equipment of delivery.
Reader for convenience, foregoing description concentrates on the representative illustration that institute might embodiment, and an instruction principle of the invention is also passed on the example of planning for this invention optimal mode of execution.This description does not attempt to enumerate exhaustively all possible variation.Variation that other is not described or modification also are possible.For example, when describing a plurality of optional embodiment, different embodiments' element combinations can be got up under many circumstances, perhaps altogether embodiment's described here element and other modification of specially not describing or set of variations.A lot of all being in the literal scope of following claim in those variations of not describing, the modification, and other is equal to.
Claims (17)
1. hydrodynamic bearing comprises:
Bearing sleeve;
Be supported for the running shaft of rotation by described bearing sleeve;
Be formed at the bearing slit between described bearing sleeve and the described running shaft;
Be included in the lubricant oil in the described bearing slit;
At least one hydrodynamic pressure that is formed at the inner peripheral surface place of described bearing sleeve produces groove;
Oil reservoir, its also comprise away from described at least one pressure produce the gradually exhibition section section of groove and contiguous described gradually exhibition section section first than the imperial palace diameter section;
Be disposed immediately in second below the opening of described bearing sleeve than the imperial palace diameter section; With
Be positioned at described oil reservoir described first than imperial palace diameter section and described second than all grooves of the retaining between imperial palace diameter section oil,
The opening of the oily all grooves of wherein said retaining is widened gradually towards the inboard of described bearing sleeve, first side of the oily all grooves of wherein said retaining forms grease proofing sputter retaining wall surface, the inoperative liquid level that wherein said lubricant oil is filled to described lubricant oil is in described first than the position in the imperial palace diameter section, even and afford at described hydrodynamic shaft under the situation of external force, the shape of described first side of the oily all grooves of described retaining prevents that also described lubricated oil spill from crossing on described first side of the oily all grooves of described retaining and scattering.
2. according to the hydrodynamic bearing of claim 1, wherein from the inboard of the oily all grooves of described retaining, the tangent line of at least a portion of described first side of the oily all grooves of described retaining and the central axis of described bearing sleeve form acute angle.
3. according to the hydrodynamic bearing of claim 1, described second than the inner diameter of imperial palace diameter section less than described first the inner diameter than the imperial palace diameter section.
4. according to the hydrodynamic bearing of claim 1, wherein said first also comprises the taper that increases inner diameter towards the opening of described bearing sleeve gradually than the imperial palace diameter section.
5. according to the hydrodynamic bearing of claim 1, wherein one deck oil-repellent solid film is applied to its end face along the edge of opening of described bearing sleeve, and wherein one deck oil-repellent solid film closely is applied to the outer circumferential face of described running shaft on the described opening of described bearing sleeve.
6. spindle motor with hydrodynamic bearing, this hydrodynamic bearing comprises:
Bearing sleeve;
Be supported for the running shaft of rotation by described bearing sleeve;
Be formed at the bearing slit between described bearing sleeve and the described running shaft;
Be included in the lubricant oil in the described bearing slit;
At least one hydrodynamic pressure that is formed at the inner peripheral surface place of described bearing sleeve produces groove;
Oil reservoir, its also comprise away from described at least one pressure produce the gradually exhibition section section of groove and contiguous described gradually exhibition section section first than the imperial palace diameter section;
Be disposed immediately in second below the opening of described bearing sleeve than the imperial palace diameter section; With
Be positioned at described oil reservoir described first than imperial palace diameter section and described second than all grooves of the retaining between imperial palace diameter section oil,
The opening of the oily all grooves of wherein said retaining is widened gradually towards the inboard of described bearing sleeve, first side of the oily all grooves of wherein said retaining forms grease proofing sputter retaining wall surface, the inoperative liquid level that wherein said lubricant oil is filled to described lubricant oil is in described first than the position in the imperial palace diameter section, and, even afford at described hydrodynamic shaft under the situation of external force, the shape of described first side of the oily all grooves of described retaining prevents that also described lubricated oil spill from crossing on described first side of the oily all grooves of described retaining and scattering.
7. according to the spindle motor of claim 5, wherein from the inboard of the oily all grooves of described retaining, the tangent line of at least a portion of described first side of the oily all grooves of described retaining and the central axis of described bearing sleeve form acute angle.
8. according to the spindle motor of claim 5, described second than the inner diameter of imperial palace diameter section less than described first the inner diameter than the imperial palace diameter section.
9. according to the spindle motor of claim 5, wherein said first also comprises the taper that increases inner diameter towards the opening of described bearing sleeve gradually than the imperial palace diameter section.
10. according to the spindle motor of claim 5, wherein one deck oil-repellent solid film is applied to its end face along the edge of opening of described bearing sleeve, and wherein one deck oil-repellent solid film closely is applied to the outer circumferential face of described running shaft on the described opening of described bearing sleeve.
11. a recording disc actuator device, it comprises:
Recording disc;
The data head that reads and writes data from described recording disc; With
Spindle motor with hydrodynamic bearing, described hydrodynamic bearing also comprises:
Bearing sleeve;
Be supported for the running shaft of rotation by described bearing sleeve;
Be formed at the bearing slit between described bearing sleeve and the described running shaft;
Be included in the lubricant oil in the described bearing slit;
At least one hydrodynamic pressure that is formed at the inner peripheral surface place of described bearing sleeve produces groove;
Oil reservoir, its also comprise away from described at least one pressure produce the gradually exhibition section section of groove and contiguous described gradually exhibition section section first than the imperial palace diameter section;
Be disposed immediately in second below the opening of described bearing sleeve than the imperial palace diameter section; With
Be positioned at described oil reservoir described first than imperial palace diameter section and described second than all grooves of the retaining between imperial palace diameter section oil,
The opening of the oily all grooves of wherein said retaining is widened gradually towards the inboard of described bearing sleeve, first side of the oily all grooves of wherein said retaining forms grease proofing sputter retaining wall surface, the inoperative liquid level that wherein said lubricant oil is filled to described lubricant oil is in described first than the position in the imperial palace diameter section, even and afford at described hydrodynamic shaft under the situation of external force, the shape of described first side of the oily all grooves of described retaining prevents that also described lubricated oil spill from crossing on described first side of the oily all grooves of described retaining and scattering.
12. according to the recording disc actuator device of claim 11, the tangent line of at least a portion of described first side of all grooves of wherein said retaining oil and the central axis of described bearing sleeve form acute angle, from the inboard of the oily all grooves of described retaining.
13. according to the recording disc actuator device of claim 11, described second than the inner diameter of imperial palace diameter section less than described first the inner diameter than the imperial palace diameter section.
14. according to the recording disc actuator device of claim 11, wherein said first also comprises the taper that increases inner diameter towards the opening of described bearing sleeve gradually than the imperial palace diameter section.
15. recording disc actuator device according to claim 11, wherein one deck oil-repellent solid film is applied to its end face along the edge of opening of described bearing sleeve, and wherein one deck oil-repellent solid film closely is applied to the outer circumferential face of described running shaft on the described opening of described bearing sleeve.
16. according to the recording disc actuator device of claim 11, wherein said data head is a magnetic head.
17. according to the recording disc actuator device of claim 11, wherein said data head is an optical head.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2004142965 | 2004-05-12 | ||
| JP142965/2004 | 2004-05-12 |
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| CN101103205A true CN101103205A (en) | 2008-01-09 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNA2005800149091A Pending CN101103205A (en) | 2004-05-12 | 2005-05-11 | Fluid dynamic bearing and a storage disk drive with a spindle motor having the fluid dynamic bearing |
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| CN (1) | CN101103205A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103944302A (en) * | 2010-12-27 | 2014-07-23 | 日本电产株式会社 | Spindle motor, and disk drive apparatus including the spindle motor |
| CN104078065A (en) * | 2013-03-29 | 2014-10-01 | 日本电产株式会社 | Motor and disk drive apparatus |
| CN108799324A (en) * | 2017-04-27 | 2018-11-13 | 日本电产株式会社 | Hydrodynamic bearing device, motor and disk drive device |
| CN111749924A (en) * | 2019-03-29 | 2020-10-09 | 日本电产株式会社 | Gas dynamic pressure bearing, motor, and blower |
-
2005
- 2005-05-11 CN CNA2005800149091A patent/CN101103205A/en active Pending
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103944302A (en) * | 2010-12-27 | 2014-07-23 | 日本电产株式会社 | Spindle motor, and disk drive apparatus including the spindle motor |
| CN103944302B (en) * | 2010-12-27 | 2016-08-17 | 日本电产株式会社 | The spindle motor of dish driving and disk drive device |
| CN104078065A (en) * | 2013-03-29 | 2014-10-01 | 日本电产株式会社 | Motor and disk drive apparatus |
| CN108799324A (en) * | 2017-04-27 | 2018-11-13 | 日本电产株式会社 | Hydrodynamic bearing device, motor and disk drive device |
| CN111749924A (en) * | 2019-03-29 | 2020-10-09 | 日本电产株式会社 | Gas dynamic pressure bearing, motor, and blower |
| CN111749924B (en) * | 2019-03-29 | 2022-03-08 | 日本电产株式会社 | Gas dynamic pressure bearing, motor, and blower |
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