CN101084384A - Method for forming dynamic pressure generating section - Google Patents

Abstract

A method for forming a dynamic pressure generating section on the flat surface of a material inexpensively with high precision by a simple process. Micro liquid drops (13) of UV-curing ink are shot or dripped from a nozzle head (11) to the upper end face (2b1) of the material (2b') by an inkjet method. The nozzle head (11) and a light source (14) for irradiating UV-rays are arranged sequentially in the advancing direction of the material (2b') and located oppositely to the material (2b'). A dynamic pressure generating section is formed by moving the shooting or dripping of ink from the nozzle head (11) and the curing of ink by irradiation with UV-rays from the light source (14) gradually in the advancing direction of the material (2b') while sliding the material (2b') relatively.

Description

Form the method for dynamic pressure generating section

Technical field

The present invention relates to a kind of method that forms dynamic pressure generating section.

Background technique

Hydraulic bearing is the bearing that the relative rotation of hydrodynamic effect by lubricant oil in the bearing play and bearing element by being positioned at the shaft component excircle produces pressure, this bearing by the pressure that produces with non-contact mode support shaft member.Hydraulic bearing has features such as high speed rotating, high running accuracy and less noise.In recent years, by utilizing these features, such bearing has been widely used in the spindle motor of information equipment, for example, disk unit such as HDD and FDD, compact disk equipments such as CD-ROM, CD-R/RW and DVD-ROM/RAM, MD and MO equimagnetic-compact disk equipment (magneto-optic apparatus), the multifaceted prism scan module of laser printer (LBP), and the micro-machine of electrical machinery and equipment, for example, the ring turbin generator of projector (collar wheel motor), axial-flow blower (axial fan) motor etc.

In such hydraulic bearing, a kind of known dynamic pressure generating section is arranged, this dynamic pressure generating section produces pressure by the hydrodynamic effect of the fluid in the bearing play, the aforementioned bearings gap comprises the dynamic pressure groove (for example, referring to the open communique No.2004-052850 of Japanese unexamined patent) of the helix shape that forms by transfer printing on thrust bearing surface.

In addition, in such hydraulic bearing, for example, the dynamic pressure generating section dynamic pressure groove of layouts such as man type (herringbone shape), spirality (for example, with) that is used to produce the hydrodynamic effect is formed on the outer peripheral surface of shaft component.The known method that accurately forms this specific and complicated dynamic pressure generating section comprises following method (1)-(3).

(1) for example when the dynamic pressure groove constitutes dynamic pressure generating section, on the part except that the dynamic pressure groove, be printed with China ink against corrosion (corrosion-resistant ink), utilize etching to erode not printing by on the excircle of shaft component, implementing the combinatorial electrochemistry method, thereby form the dynamic pressure groove.

(2) when printing mould (printing mold) formation of shaft component and printing equipment contacts, the single omnidistance rotation of shaft component (single full rotation), printing China ink against corrosion on the part except that the dynamic pressure groove on the excircle of shaft component.Then, printing is not carried out etch processes to form the dynamic pressure groove.

(3) when printing mould (printing mold) formation of shaft component and printing equipment contacts, the rotation of printing mould response axis member and moving, therefore on the part except that the dynamic pressure groove on the excircle of shaft component, be printed with China ink against corrosion, simultaneously, with light beam irradiates except that with part that the printing mould of shaft component contacts the position so that sclerosis China ink (for example, please refer to the Japan open communique No.S62-49351 of unexamined patent).

Summary of the invention

In the open communique No.2004-052850 of unexamined patent not, carry out the transfer printing that forms dynamic pressure generating section (dynamic pressure groove) according to following process usually.At first, China ink is ejected on the printing plate member that has corresponding to the depression of dynamic pressure groove shape, removes the China ink (printing plate preparation process) that overflows from depression with squeegee then.Secondly, push described printing plate member with mat member, the China ink that is filled in the depression just is transferred to (first transfer step) on the mat member.Subsequently, transfer printing has the mat member of China ink to be compressed on the element that forms thrust bearing surface, forms the dynamic pressure groove (secondary transfer printing step) of reservation shape by printing.At last, remove the China ink (ink removing step) that remains on the mat member with the ink removing member of preparing separately.

Yet, forming by transfer printing in the process of dynamic pressure generating section, the printing plate member (printing mould) that needs maintenance shape and size a lot of and dynamic pressure generating section to be complementary, and to carry out printing with the printing plate member that contacts with mat member, therefore, in a large amount of production, because the distortion of mat member, deterioration etc. can cause the reduction of printing precision.In the printing plate preparation process, the printing plate member need be supplied the China ink of additional quantity, and need remove the China ink of additional quantity with squeegee.In addition, because the China ink that remains in after transfer printing on the mat member will be removed, therefore a large amount of Mo Buhui is directly used in the formation dynamic pressure generating section.In addition, owing to implement printing by a lot of moulds (step), forming step is very complicated, and the difficulty that becomes reduces cost.In recent years, along with the development of low price information equipment, increase gradually for the demand of low-cost type dynamic pressure bearing device.In order to satisfy this demand, require consumingly to simplify the forming step of dynamic pressure generating section and produce dynamic pressure generating section cheaply.

In addition, in the patent disclosure communique No.S62-49351 of examination, method (1) is difficult to reasonably carry out owing to the step complexity.For method (2), when shaft component was finished whole rotation, not adequately hardened China ink can occur in the joint overlapped, therefore can destroy the shape of groove, causes needing to proofread and correct shape after printing.

On the contrary, in method (3), move, can wear and tear at contacting part because the printing mould contacts with the outer peripheral surface of shaft component.Therefore, in a large amount of production, the wearing and tearing of printing mould, distortion etc. can reduce printing precision.In addition, the China ink against corrosion of ink supply apparatus supply arrives the outer peripheral surface of shaft component through the printing mould, and with the plate extruding, makes China ink be fixed on the outer peripheral surface of shaft component, therefore needs to use the China ink against corrosion with the irrelevant additional quantity of the moulding of groove.This has increased the use amount of China ink against corrosion, and is uneconomical.

In addition, after printing, must etching corrode not printing and removal China ink against corrosion.This makes forming step complicated and too much, causes cost to increase.

Similarly, in the formation method of the dynamic pressure groove shown in the patent disclosure communique No.S62-49351 of examination, move, therefore can wear and tear at contacting part because the printing mould contacts with the outer peripheral surface of shaft component.Therefore, in a large amount of production, the wearing and tearing of printing mould, distortion etc. can reduce printing precision.In addition, the China ink against corrosion of ink supply apparatus supply arrives the outer peripheral surface of shaft component through the printing mould, and with the plate extruding, makes China ink be fixed on the outer peripheral surface of shaft component.Therefore the China ink against corrosion that needs the irrelevant additional quantity of the use and the moulding of groove.This has increased the use amount of China ink against corrosion, and is uneconomical.In addition, in press, need the material or the corresponding printing mould of shape of use and dynamic pressure groove, these numerous requirements can cause cost of investment to increase.

In addition, at present, the performance of information equipment improves significantly.Although the expectation dynamic pressure bearing device has more high-performance, the main trend that the information equipment demand side drops to price.Therefore, be badly in need of reducing the cost of dynamic pressure bearing device.Yet,, therefore be difficult to satisfy this demand because known method has above-mentioned technical problem.

First purpose of the present invention is by simple steps, low cost, forms dynamic pressure generating section accurately.

Second purpose of the present invention is to simplify forming step so that form the dynamic pressure generating section that cost is low, precision is high.

The 3rd purpose of the present invention provides a kind of formation and has dynamic pressure generating section method more cheaply.

In order to realize first purpose, the invention provides a kind of method that forms dynamic pressure generating section, this method comprises: form dynamic pressure generating section by print steps and cure step, the black aggregate of utilization trace, trace China ink is provided in non-contacting mode on a plurality of parts of plat surface of material in print steps, and the China ink that is provided in cure step is hardened.

In the present invention, term " dynamic pressure generating section " is meant that the hydrodynamic effect of the fluid that utilizes in the bearing play produces the part of pressure.For example, the part that comprises the boundary section (boundary section between these grooves and form the boundary of these grooves) of a plurality of grooves (groove that axial groove, tipper or spirality/man type are arranged or radial groove etc.) and rising, perhaps comprise a plurality of arc shaped surfaces, this arc shaped surface shrinks the bearing play with the shape of wedge shape on one or two circumferencial direction.The material that forms the element of dynamic pressure generating section is not crucial, and it can suitably select and use according to bearing characteristics, can use metallic material ferrous materials such as (, soft metals such as brass, sintering metal) stainless steels and resin compound.In addition, material shape can be that tabular, shell-like, bottom are cylindric etc., as long as they have plat surface.

According to above-mentioned forming method, can print with ink supply portions such as nozzles, and ink supply portion such as nozzle does not contact with material.Therefore, can realize the highi degree of accuracy printing, avoid the low problem of contact segment printing precision in the prior art.In addition, need not to remove the China ink of the additional quantity that is fed to the printing mould, China ink only is used for required part.Therefore, only need to use the China ink that forms the dynamic pressure generating section aequum, reduced black use amount.In addition, do not need to use and the corresponding a lot of printing moulds of dynamic pressure generating section required form, this has just saved a plurality of steps, has therefore simplified the structure of forming equipment.Comprise ink jet method (ink jet method) equipment from the exemplary of the black equipment of nozzle supply trace.

Forming by ink jet method in the method for dynamic pressure generating section, utilize the aggregate of falling or drop onto the black droplet on the material plat surface, can print out pattern with definite shape and thickness.In addition, by preestablishing pattern with program and according to position, the ink supply of program control nozzle with stop ink supply, can forming pattern with high precision.Therefore, the China ink of sclerosis self can form high-precision dynamic pressure generating section.

In this case, trace China ink is provided at print steps on a plurality of parts of plat surface of material in non-contacting mode after, before the cure step that the China ink that is provided is hardened, material relatively slides, the supply of China ink and sclerosis are carried out in succession, make it possible to form dynamic pressure generating section with simple device with in the step of short cycle.In addition, the material through print steps and cure step can be supplied to print steps once more so that carry out print steps and be supplied to cure step once more so that carry out cure step.Therefore, even when being supplied to print steps once more, owing to hardened fully through the China ink of once sclerosis, so can avoid by the problem of the black overlapping printing precision reduction that causes of sclerosis fully not.

For example, can use shower nozzle to carry out printing in the above-mentioned print steps, this shower nozzle comprises and is arranged to nozzle multirow, that discharge the trace China ink.In this case, ideally, be in heeling condition between the slide relative direction of the arranged direction of the nozzle on the shower nozzle and material.When the arranged direction of nozzle during perpendicular to the slide relative direction of material, a cycle period nozzle supply, and the interval of dropping on the China ink on the material naturally equal the arrangement interval of nozzle.On the contrary, if tilt between the slide relative direction of the arranged direction of nozzle and material, the nozzle supply and drop on the arrangement interval of the interval of the China ink on the material less than nozzle.Therefore, when the shower nozzle of the nozzle that a kind of mode is arranged after use has is carried out printing, can reduce the interval that China ink falls, guarantee to carry out more accurately printing.

Note that and by slide relative or by rotating material relatively material to be transported to cure step from print steps around axis.In this case, print steps is arranged on different circumferential positions with cure step, therefore can carry out the printing and the black cure step of material in a circumferential direction simultaneously.

The China ink that the present invention uses can still be considered cost and working environment etc. with electromagnetic wave and light beam irradiates sclerosis such as electron beams, the more satisfactory China ink that is to use light hardening China ink (light curable ink) and hardens by the light irradiation.Spendable light hardening China ink comprises UV cured type China ink and infrared cure type China ink, and visible light constrictive type China ink.It is desirable to use UV cured type China ink, because UV cured type China ink sclerosis cost is low, the sclerosis cycle short.

In order to realize second purpose of the present invention, the invention provides a kind of method that forms dynamic pressure generating section, this method comprises: the trace China ink is provided on the surface of material and utilizes the aggregate of this trace China ink to print the step of dynamic pressure generating section and the step of sclerosis China ink; Before the print steps of dynamic pressure generating section, use the surface of cleaning the cleaning means cleaning material of selecting (UV cleaning) and the ozone clean (ozone cleaning) from pickling, UV.The trace China ink is discharged from ink supply portion (for example, nozzle) by this way, for example impels its surface that falls or drop onto material, makes it possible to print under ink supply portion (nozzle) and the discontiguous situation of material.Therefore, can carry out the highi degree of accuracy printing, the technical problem that the printing precision of having avoided the contact segment wearing and tearing to cause reduces (this is the technical problem of existing method).In addition, need not to use plate, China ink only is used for required part, only needs to use the China ink that forms the dynamic pressure generating section aequum, so reduce the cost that comes material.In addition, (for example, netted printing screen frame etc.) retaining member also need not to use according to material and rotate the mechanism that moves the printing mould simultaneously, has therefore simplified the structure of forming equipment, makes cost further reduce to need not use printing mould and this printing mould of maintenance.From the exemplary of nozzle supply method for ink is ink-jet supply method.

In ink jet method, for example, printing pattern is that program is predefined, and according to position, the ink supply of program control nozzle with stop ink supply and carry out the pattern printing.At this moment, the surface condition of the material of fixing China ink has a strong impact on the formed precision of printing pattern.Surface material fixing China ink, that be used to form dynamic pressure generating section for example, is the shaft component, bearing housing etc. in the hydraulic bearing.For example, form the componentry of these hydraulic bearings by means such as cutting metals.Therefore, after cutting, can be at the impurity such as outer peripheral surface deposition cutting powder, machine oil, oil and grease of shaft component.If often be under this situation, the black shape of trace that drops on the material surface of surface condition bad (depositing impurity) will be different from the shape of the trace China ink that drops on the good material surface of surface condition.Therefore, the shape of trace China ink can change the contact angle of surface (for example with) after dropping on the bad material surface of surface condition, and this can cause the shape instability of the dynamic pressure generating section that the aggregate by the trace China ink forms.

In ink jet method, be that the shape (contact angle) of the trace China ink after falling according to hypothesis is controlled nozzle location.If the shape of the trace China ink after falling is unfixing, although control the position of nozzle accurately, but owing to will depend on that micro-ink droplet drops on the position of material surface, therefore the printing pattern (dynamic pressure generating section) that is formed by the black aggregate of trace can not have high accuracy to shape yet.Method with acetone and other organic solvent cleaning material surface is feasible, but the cleansing power of these organic solvents is poor, therefore is difficult to the material surface situation is improved to desired level.

Therefore, in the present invention, before the print steps of dynamic pressure generating section, adopt the cleaning means of from pickling, UV cleaning and ozone clean, selecting to come the surface of cleaning material.Like this, the impurity that is deposited on material surface during the material body forming step just has been removed, and therefore the material surface uniformity that just becomes can provide good surface condition.Therefore, in print steps subsequently, be provided at the shape of the trace China ink of material surface, for example with the contact angle of material surface, it is constant just to become, so has improved formability.In addition, the variation of the surface condition of each material is suppressed to very low-level, so improved the reproducibility of printing pattern.

Spendable material surface cleaning means comprise pickling, UV cleaning and ozone clean etc.For example, when material surface is metal, preferentially has the pickling of good solubility property.Like this, the impurity that is deposited on material surface can be removed, and simultaneously can remove the patina that is formed on material surface, makes the situation uniformity and better more of material surface.

For example, high-strength material such as stainless steel can be used as the shaft component of hydraulic bearing.In this case, in acid, because hydrochloric acid has good dissolubility to stainless steel, therefore preferred hydrochloric acid.

In addition, the pickling that utilizes the ultrasound effect to carry out material surface also can further improve the cleaning performance of material surface.Replacedly, can further improve cleaning performance by increasing the temperature (for example, about 50 ℃) of cleaning environment.

In order to realize the 3rd purpose, the invention provides a kind of method that forms dynamic pressure generating section, the bearing play that is used on the material surface that constitutes axial region produces the hydrodynamic effect, and described method comprises: the trace China ink is provided under the situation that a plurality of materials axially connect; Utilize the aggregate of trace China ink on each material, to form dynamic pressure generating section.

In the present invention, under the situation that a plurality of materials connect, on each material, form dynamic pressure generating section.Therefore, in a print steps, can on a plurality of materials, form dynamic pressure generating section simultaneously.Therefore, for example, reduce quantity such as preparation process, shortened cycle time, reduced the cost of production of dynamic pressure generating section.

In the process that forms dynamic pressure generating section, provide the possible ad hoc approach of trace China ink to comprise: for example, so-called ink jet method falls or is dropped on the material surface by this method China ink from nozzle; Cause the method for black phoresis; No nozzle type method (no nozzle ink jet method) in the method, is not from the little ink droplet of nozzle ejection, but from the flow surface of China ink; Discharge the method for China ink continuously through microtubule, rather than with the form of drop; Perhaps shorten to the method for fixed surface distance, this method drops on the fixed surface China ink by discharging China ink.Perhaps other method.Note that in the following description these methods are generically and collectively referred to as " ink jet method etc. ".

Forming in the method for dynamic pressure generating section by ink jet method etc., preestablish pattern with program with definite shape and thickness, and according to position, the ink supply of program control ink supply portion (for example, nozzle) with stop ink supply.Therefore can form any pattern with high precision.In addition, by accurately controlling the output speed of China ink, every part of pattern can form has any thickness.Therefore, the sclerosis China ink self can be guaranteed the required form of dynamic pressure generating section.

In addition, can under nozzle and the discontiguous situation of material, carry out the printing of ink jet method etc., the technical problem that the printing precision of having avoided the contact segment wearing and tearing to cause reduces (this is the technical problem of existing method).In addition, need not to remove with plate the China ink of the additional quantity that is fed to the printing mould, China ink only is used for required part, only needs to use the China ink that forms the dynamic pressure generating section aequum, has reduced black use amount.In addition, do not need to use the mechanism of printing mould and moving this printing mould according to the rotation of shaft component.Therefore simplified forming equipment.So printing methodes such as employing ink jet method can reduce the cost of production of dynamic pressure bearing device.

Axially connecting in a plurality of materials, for each material no change, accurately form for the dynamic pressure generating section, the alignment when material connects is very important.Therefore, in the present invention, on material, be provided with axial hole,, therefore guaranteed alignment by fixed block being inserted in the described through hole.Like this, only just can keep alignment with common fixed block.So, can uniformity ground on all connected materials, form high-precision dynamic pressure generating section at low cost.

Please note, each material can use above-mentioned fixing piece, perhaps, connect each material by following manner, that is: projection is set, depression is set at an end that is connected material at the other end, the projection that cooperates with the aforementioned depression that is connected material in an end setting of an adjacent materials, and the depression that cooperates with the aforementioned projection that is connected material in an end setting of another adjacent materials.

In existing known method, under material (shaft component) and printing mould situation about contacting, print.At this moment, if when a plurality of material axially connects, because the contact segment applied pressure can cause the bending that is connected material, therefore the alignment that is connected between the material is lowered, and makes to be difficult to guarantee the required precision of dynamic pressure generating section.On the contrary, the ink jet method of the application of the invention etc. allow to print under material and the discontiguous situation of nozzle.Therefore, can avoid above-mentioned situation, so form high-precision dynamic pressure generating section on each that can be in a plurality of materials.

Irradiation such as the black available electron bundle of the formation dynamic pressure generating section that uses among the present invention, light beam sclerosis.But consider economic aspect and working environment etc., the China ink that hardens is shone in more satisfactory being to use by light.As the light hardening China ink, can use UV cured type China ink and infrared cure type China ink, and visible light constrictive type China ink.It is desirable to use UV cured type China ink, because UV cured type China ink sclerosis cost is low, the sclerosis cycle short.

As mentioned above, according to the present invention, can use simple equipment to form to have highi degree of accuracy, dynamic pressure generating section cheaply.

In addition,, can simplify forming step according to the present invention, and can high precision, form dynamic pressure generating section at low cost.

In addition, according to the present invention, can form the highi degree of accuracy dynamic pressure generating section at low cost.

Description of drawings

Fig. 1 is the summary side view that shows the ink jet method printing equipment of the first embodiment of the present invention;

Fig. 2 A is that shower nozzle is configured to the figure vertical with the feeding direction of material; Fig. 2 B is the figure that shower nozzle is arranged to become with the feeding direction of material predetermined angle with being tilted;

Fig. 3 is the plan view of the upper-end surface of lip part;

Fig. 4 A is that boundary section (demarcation portion) B is formed directly into the partial enlarged drawing on the material end face; Fig. 4 B is that the China ink layer is formed on the material end face, boundary section B is formed on the partial enlarged drawing on the described China ink layer;

Fig. 5 is the side view that shows another structure of ink jet method printing equipment;

Fig. 6 is the sectional view of spindle motor that is integrated with the information equipment of dynamic pressure bearing device;

Fig. 7 is the sectional view that shows the dynamic pressure bearing device example constructions;

Fig. 8 is the sectional view that shows another example constructions of dynamic pressure bearing device;

Fig. 9 is the sectional view that shows another example constructions of dynamic pressure bearing device;

Figure 10 A is the plan view of another form that shows the upper-end surface of lip part; Figure 10 B is the X-X partial enlarged drawing of boundary section B when boundary section B is integrated into dynamic pressure bearing device;

Figure 11 is the schematic representation of the forming equipment of the root second embodiment of the present invention;

Figure 12 is the figure that shows another form of the method that forms dynamic pressure generating section;

Figure 13 is the sectional view of dynamic pressure bearing device;

Figure 14 is the sectional view that shows another example constructions of dynamic pressure bearing device;

Figure 15 is the sectional view that shows another example constructions of dynamic pressure bearing device;

Figure 16 is the sectional view that shows another example constructions of dynamic pressure bearing device;

Figure 17 is the spindle motor example sectional view that is integrated with dynamic pressure bearing device;

Figure 18 is display material surface clean test result figure;

Figure 19 is the schematic representation of example that shows the ink jet method printing equipment of a third embodiment in accordance with the invention;

Figure 20 is the schematic representation that shows the ink jet method printing equipment of another form;

Figure 21 is the sectional view of example constructions with dynamic pressure bearing device of the present invention structure;

Figure 22 is the sectional view that shows another structure example of dynamic pressure bearing device;

Figure 23 is the sectional view that shows another structure example of dynamic pressure bearing device;

Figure 24 is the schematic representation that shows the motor example that is integrated with dynamic pressure bearing device.

Embodiment

Below with reference to Fig. 1-10 explanation first embodiment of the present invention.

Fig. 1 shown and uses ink jet printing device to carry out the concise and to the point forming step of dynamic pressure generating section, as the example of the method for formation dynamic pressure generating section of the present invention.Example shown in Figure 1 has shown concise and to the point step and the concise and to the point forming equipment of going up the formation dynamic pressure generating section at the upper-end surface of material 2b ' 2b1, the lip part 2b of shaft component 2 in the 2b1 pie graph 5 of this upper-end surface.

In this forming equipment, material 2b ' is transmitted by conveying meanss such as conveyer 15.This conveying means 15 transmits material 2b ' by slide relative along the straight line of (curing step) from the print steps to the cure step.For example, material 2b ' has the shape of the plate that metallic material such as corrosion resistant plate make.Be relatively set with a pair of shower nozzle 11 and light source 14 with the plat surface (for example upper-end surface 2b1) of material 2b '.In the present embodiment, by shower nozzle 11 and the zone (conveying means 15) relative with shower nozzle 11, China ink is provided on a plurality of parts of upper-end surface 2b1 of material 2b ' (print steps), and by light source 14 and the zone (conveying means 15) relative with light source 14, the China ink on a plurality of parts hardened (cure step).Therefore, shower nozzle 11 and light source 14 are provided with in regular turn along the glide direction of material 2b '.

In shower nozzle 11 ends, the nozzle 12 of ink-jet is with the form setting of a plurality of horizontal line and a plurality of vertical row.The China ink that holds is supplied to shower nozzle 11 through ink supply pipe 17 in the China ink jar, and under the driving of shower nozzle drive part 16, at once with each nozzle 12 ejection from shower nozzle 11 of the form of droplet 13.The venting system of nozzle 12 is not particularly limited, and can select various types of venting system, as piezoelectric system (piezosystem), hot nozzle system (thermal ink jet system) and air-injection system (air jet system) etc.In addition, printing method can be continuous system printing method or Request System (on-demandsystem) printing method.

Shower nozzle 11 is configured to intersect with the slide relative direction of material 2b ' (conveying means 15).At this moment, shown in Fig. 2 A, shower nozzle 11 can be configured to the arranged direction vertical with the slide relative direction of material 2b ' (Vertical direction shown in Fig. 2 A) of each nozzle 12, shown in Fig. 2 B, simultaneously, it also can be provided with by predetermined angle θ obliquely, and this predetermined angle θ is the angle between the arranged direction of the slide relative direction of material 2b ' and each nozzle 12.Under the situation shown in Fig. 2 A, the landing of the droplet 13 of discharge (landing interval) t2 at interval equals the arrangement interval t1 of nozzle 12.On the contrary, under the situation shown in Fig. 2 B, t2 is less than the arrangement interval t1 of nozzle 12 at interval in the landing of droplet 13, and its advantage is to print more accurately.

In the present embodiment, use ultraviolet radiator as light source 14.The employed China ink of ink jet printing is commercial UV cured type China ink.Cause that by ultraviolet irradiation polymerisation is fixed UV cured China ink.As long as can discharge from nozzle 12, liquid polymer material or the liquid polymer material that comprises solvent all can be used as aforementioned UV cured China ink.As long as have the characteristic of the UV cured China ink of dissolving, any organic solvent all can be used as aforementioned solvents.

The example of ultraviolet hardening resin of base resin that constitutes UV cured China ink also comprises imido acrylate and mercaptan-alkene compound such as ring-type polyenic compounds and poly-thiol compound except that the monomer of the monomer that comprises free redical polymerization or oligomer and cationically polymerizable.Wherein, preferably use outside the monomer of the monomer of free redical polymerization or oligomer and cationically polymerizable.The example of the monomer of free redical polymerization comprise have simple function group, difunctional or multi-functional acrylate and methacrylate.The example of the monomer of free redical polymerization comprises urethane acrylate, epoxy acrylate, polyester acrylate and unsaturated polyester.The example of the monomer of cationically polymerizable comprises that bisphenol A epoxide resin, phenol phenolic resin varnish, alicyclic ring epoxide resin and oxetane resin for example can use 3-ethyl-3-hydroxymethyl-oxetanes, 1, two { [(3-ethyl-3-oxa-cyclobutyl) methoxyl group] methyl } benzene of 4-, 3-ethyl-3-(benzene oxygen methyl) oxetanes, two [1-ethyl (3-oxa-cyclobutyl)] methyl ether, 3-ethyl-3-(the own oxygen methyl of 2-ethyl) oxetanes, 3-ethyl-3-{[3-(triethoxy-silicyl) propoxyl group] methyl } oxetanes.These ultraviolet hardening resins can be used alone as base resin, also can two or more combinations be used as base resin.

In these base resins, can use the Photoepolymerizationinitiater initiater such as radical photopolymerization initator, cationic photopolymerization initator that causes polymerisation by ultraviolet irradiation.The example of radical photopolymerization initator comprises the following hydrogen-abstraction Photoepolymerizationinitiater initiater of classifying representative as: the ammonium salt of ammonium salt, isopropyl thioxanthone, diethyl thioxanthone and the thioxanthones of benzophenone, adjacent diphenylhydroxyethanone benzoic acid formicester, 4 benzoic acid base-4 '-dimethyl diphenyl sulfide, benzophenone.Alternatively, the example of radical photopolymerization initator comprises the following intermolecular type Photoepolymerizationinitiater initiater that splits of classifying representative as: diphenylhydroxyethanone derivative, benzyldimethylketal, alpha-hydroxyalkyl benzene ketone (phenon), α-aminoalkyl benzene ketone, acyl group phosphorous oxide, monoacyl phosphorous oxide, two acyl group phosphorous oxide, acyl group phenyl dihydroxy acetic acid fat, diethoxy acetophenone and two cyclopentadiene titanium compounds.The example of cationic photopolymerization initator comprises the following polyaryl sulfonium salt of classifying representative as: hexafluoro-antimonic acid triphenylsulfonium, hexafluorophosphoric acid triphenylsulfonium, SP-170 and SP-150 (both are by Asahi Denka Co., and Ltd. produces), FC-508 and FC-512 (both produce by 3M Company) and UVE-1014 (being produced by General Electric Company); Below classify the triallyl hexafluorophosphate of the mixing of representative: Uvacure 1590 and 1591 (both are by DAICEL-UCB Co., and Ltd. produces) as; Metallocenic compound such as Irg-261 (producing) by Ciba-Geigy Corporation; With the following polyaryl iodonium salt of classifying representative as: hexafluoro-antimonic acid diphenyl iodnium, hexafluoro-antimonic acid are to nonyl phenyl base iodine father-in-law and hexafluoro-antimonic acid 4,4 '-diethoxy phenyl-iodide father-in-law.These Photoepolymerizationinitiater initiaters can use separately or be used in combination.

In said structure, when conveying means 15 is driven and the direction of the arrow of material 2b ' in Fig. 1 when sliding, black droplet 13 goes out from nozzle ejection.Therefore, the boundary section B that forms black droplet 13 aggregate projections is formed on a plurality of parts of upper-end surface 2b1 of material 2b '.On the contrary, except boundary section B, China ink can regions coated not become dynamic pressure groove Bb.By using these boundary section Ba and dynamic pressure groove Bb, for example, as shown in Figure 3, be printed as the dynamic pressure groove pattern of the helix shape of dynamic pressure generating section.At this moment, at each nozzle 12 place,, therefore can print accurately owing to suitably switching the supply of China ink with the scheduled time in advance and stopping.After being completed for printing, material 2b ' arrives the zone relative with light source 14, thereby the China ink generation polymerisation of having accepted ultraviolet irradiation is hardened.At this moment, because shower nozzle 11 and light source 14 are provided with on feeding direction away from each other, the ultraviolet ray of shining from light source 14 can not shine nozzle 12, therefore, can prevent that the matter mouth 12 that ultraviolet irradiation causes from stopping up or other problems.

By this way after the through-hardening, material 2b ' further slides so that withdraw from conveying means at China ink.At this moment, if a plurality of material 2b ' is fed to conveying means 15 continuously, can produce in a large number be printed with dynamic pressure groove pattern by hardened material 2b '.In the time dynamic pressure groove pattern will being formed on the lower end surface 2b2 of material 2b ', can be provided for the forming equipment of lower end surface 2b2 separately, this forming equipment has shower nozzle 11 and light source 14, and this shower nozzle 11 and light source 14 are positioned at the downstream of forming equipment shown in Figure 1.Material 2b ' can be fed to two forming equipments in order.Otherwise forming equipment shown in Figure 1 will reciprocally be used for printing and sclerosis dynamic pressure groove pattern on two end face 2b1,2b2.In this case, printed on arbitrary end face after dynamic pressure groove pattern and the sclerosis, material 2b ' is reversed and is fed to once more forming equipment shown in Figure 1, carries out printing and sclerosis dynamic pressure groove pattern then on another end face.

In the foregoing description, example carry out the situation of the printing of dynamic pressure groove pattern by stationary nozzle 11 and sliding material 2b '.On the other hand, when material 2b ' transfixion, can carry out printing by the shower nozzle 11 that reciprocatingly slides.In addition, as mentioned above, can be at one time on the end face of material 2b ', carry out the printing and the sclerosis of dynamic pressure groove pattern, or be divided into a plurality of steps and carry out.In this case, fully hardened,, can be avoided the not reduction of the overlapping printing precision that causes of adequately hardened China ink if carry out when printing once more owing to once experienced the China ink of cure step.

Shower nozzle 11 is accurately discharged and the corresponding black droplet 13 of predefined shape.Therefore, can print dynamic pressure groove pattern as high-precision dynamic pressure generating section.In addition, shown in Fig. 4 A, because the China ink self of sclerosis can be guaranteed the desired depth (several microns to tens microns) of dynamic pressure groove, so it can be used as the shaft component 2 with dynamic pressure groove, because it need not to experience steps such as etching subsequently.

In addition, because printing by black ejecting system does not have the part of (as is well known in the transfer printing) contact pad designed member, it carries out printing under contactless state, therefore can avoid the deterioration of contacting part or the reduction of the printing precision that other problem causes, in production in enormous quantities, can reliably guarantee the precision of dynamic pressure groove.In addition, owing to need not to provide the China ink of additional quantity, therefore need not to remove the China ink of additional quantity and remove the China ink that remains on the cushion member with scraper plate, the China ink amount of required use is only for forming the required amount of dynamic pressure groove pattern.Therefore, can reduce employed China ink amount, so that reduce cost.In addition, can only form the dynamic pressure generating section of reservation shape in a step, therefore, dynamic pressure generating section need not through a plurality of steps just plastic.This also need not to use the printing mould, so is shortened cycle time, and the moulding cost is lowered.In addition, equipment can be very little, makes the price of printing equipment reduce greatly.

In Fig. 4 A, although it has shown the example that forms dynamic pressure groove Bb from the part of uncoated China ink,, shown in Fig. 4 B, dynamic pressure groove Bb also can form from the part that applies China ink (China ink layer) 25.In the later case, the whole end face of material 2b ' is coated with China ink, and the boundary section Ba of rising is integrally formed on the material 2b '.In this structure, to compare with the example of Fig. 4 A, the China ink amount of use increases, but the adhesive area of material 2b ' also increases, the reduction of the fatigue life that problem such as therefore can suppress that China ink is peeled off causes.

The example of spendable black fusing system not only comprises aforesaid black ejecting system, also comprise and utilize electrophoresis to discharge the method for drop, promptly, not from nozzle ejection ink droplet but from the no nozzle type China ink discharge system of black liquid level (ink fluid level) ejection, also can comprise through microtubule (micropipette) not with the drop form but continuously ink-jet to the lip-deep system of material, and also can comprise the distance that shortens between material surface and the photographic fixing surface and when ink-jet with the surperficial system that contacts of photographic fixing.Can both be used in shower nozzle drive part 16 with every kind of corresponding structure of discharge system.

Fig. 5 has shown the another kind of configuration example of the equipment that forms dynamic pressure groove pattern.In this example of structure, material 2b ' is relatively rotated so that forming dynamic pressure groove pattern on the end face or on two end faces.

In structure shown in Figure 5, use the axle shape fixture 21 and the lower end surface of pushing to come blocking materials 2b ' from the upper-end surface.Fixture 21 is supported rotationally by rolling bearing 23.The rotation that comprises motor etc. drives on 22 one of being connected in the fixture 21.Drive 22 by starting rotation, material 2b ' thus accept rotary driving force through fixture 21 drives with being rotated.It is relative with the upper-end surface 2b1 of material 2b ' that shower nozzle 11 and light source 14 are arranged to, and their circumferential locations difference, preferably, is positioned at (shower nozzle 11 and light source 14 are positioned at the both sides of fixture 21) on relative two side positions that cross fixture shown in Figure 5 21.Note that in this structure, represent with identical reference character, and omitted repeat specification and their function with structural elements shown in Figure 1.

In said structure, when material 2b ' rotated, China ink was discharged so that printing dynamic pressure groove pattern from the nozzle 12 of shower nozzle 11, and this dynamic pressure groove pattern comprises boundary section Ba and the dynamic pressure groove Bb on the upper-end surface 2b1 of material 2b '.In this example of structure, the rotation of responsive materials 2b ' and carry out printing by this way, i.e. mode little by little to carry out in a circumferential direction.When being printed part when proceeding to a certain degree in a circumferential direction (shown in Figure 5 half), be printed part and reach the zone relative with light source 14, accepting the China ink of ultraviolet irradiation so can polymerization reaction take place and hardened.

In example shown in Figure 5, shown the example that uses a shower nozzle 11, but also can radially or a plurality of positions of circumferencial direction a plurality of shower nozzles 11 are set.In addition, when the omnidistance individual pen rotation of material 2b ' (full single rotation), or when material 2b ' rotated more times (for example two to tens change), dynamic pressure groove pattern can be printed on the whole surface, makes dynamic pressure groove pattern can be formed on the whole material 2b '.

Fig. 6 shows the spindle motor of the information equipment that is used to be integrated with dynamic pressure bearing device (fluid motive bearing equipment) 1 briefly.The spindle motor of information equipment is used for disc drive units such as HDD, and it comprises dynamic pressure bearing device 1, is connected to the rotor of the shaft component 2 of dynamic pressure bearing device 1 (hereinafter referred to as disk hub 3), crosses gap stator coil 4 respect to one another, rotor magnet 5 and support 6 diametrically.Stator coil 4 is connected to the periphery of support 6, and rotor magnet 5 is connected to the interior week of disk hub 3.Disk hub 3 keeps disc D such as one or more disks on its periphery.Housing 7 is connected the interior week of support 6.When stator coil 4 was excited, rotor magnet 5 rotated under the electromagnetic force effect that produces, so disk hub 3 and shaft component 2 rotations.

Fig. 7 has shown the example of the dynamic pressure bearing device 1 that uses in the aforementioned spindle motor.This dynamic pressure bearing device 1 comprises the main structure element, has the cover component 28 and the sealing component 9 of the end opening part of the bearing element 27 of sleeve shape part, the shaft component 2 that is inserted in the interior week of bearing element 27, closing axle fixed bearing element 27.In this form, bearing element 27 is made of bearing housing 8 and circular cylindrical shell 7, and bearing housing 8 is fixed on the interior week of circular cylindrical shell 7.To note that in order illustrating, in the following description, to be called upside, be called downside by the sidepiece of cover component 28 sealings of housing 7 by the sidepiece of sealing component 9 sealings of housing 7.

For example, shaft component 2 is made by stainless steel and other metal materials, and is made of axial region 2a and lip part 2b, and lip part 2b integrally or independently is arranged on an end of shaft component 2.On the outer peripheral surface 2a1 of axial region 2a, as dynamic pressure generating section, for example, include the radial bearing surface A of the boundary section Aa of the dynamic pressure groove Ab and the formation of man type layout and the dynamic pressure groove Ab that demarcates, be formed on the position of leaving each other.On the radial bearing surface A of top, the relative axle center m of dynamic pressure groove Ab axially asymmetricly forms, and the axial dimension X1 of the upper area of above-mentioned axle center m is greater than the axial dimension X2 of the lower zone of above-mentioned axle center m.Therefore, when shaft component 2 rotated, the traction of the lubricant oil of top radial bearing surface A (pump driving force) was greater than the traction of the lubricant oil of the radial bearing surface A of bottom symmetry.The quantity that note that radial bearing surface A is selectable, and a position that can be in the axial direction forms or forms radial bearing surface A three above positions.

On the upper-end surface 2b1 of the lip part 2b of shaft component 2, be formed with dynamic pressure generating section, for example, with the dynamic pressure groove Bb and the first thrust bearing surface B helix shape shown in Figure 3, by aforementioned ink jet printing, the first thrust bearing surface B comprises boundary section Ba, and boundary section Ba forms and boundary dynamic pressure groove Bb.In addition, for example, by above-mentioned ink jet printing with the dynamic pressure groove Bb of helix shape as upper-end surface 2b1, on the 2b2 of the lower end surface of lip part 2b, be formed with the second thrust bearing surface C (not shown), the second thrust bearing surface C comprises boundary section Ba, and boundary section Ba forms and boundary dynamic pressure groove Bb.

Note that on the radial bearing surface A that is formed on the outer peripheral surface 2a1 of axial region 2a, can form dynamic pressure generating section, as upper-end surface 2b1 and the lower end surface 2b2 of lip part 2b by ink jet printing.Otherwise, form radial bearing surface A by mechanical means such as plastotype technological method such as the operation of rolling (rolling processing), forging and pressing process, pressing process or cuttings.

For example, bearing housing 8 is formed by porous body, and this porous body is the oil-containing sintering metal porous body of being made by sintering metal, particularly comprises with copper for mainly forming, be soaked with the sintering metal of lubricant oil (or lubricating grease).Shaft component 2 is inserted in the inner peripheral surface 8a of axle sleeve 8.In this example structure, the lower end surface 8b of axle sleeve 8 forms level and smooth and smooth surface, and inner peripheral surface 8a forms cylinder arcuate surface completely.

Housing 7 is formed by resin material or metallic material cylindrical shape ground.The open part of the lower end of housing 7 is closed with cover component 28, and cover component 28 is formed by metallic material such as soft metal or resin materials.Cover component 28 is fixed to the open part of the lower end of housing 7 by fixing means such as press fit or Bonds.Otherwise housing 7 and cover component 28 are integrally formed by metallic material or resin material.

Sealing component 9 is formed by metallic material or ring resin material cylindrical shape ground.Sealing component 9 forms independently with housing 7, and is fixed to the upper end open part of housing 7 by means such as press fit or Bonds.The diameter of the inner peripheral surface 9a of sealing component 9 becomes big gradually in the mode with taper on the direction on top.Be formed with the ring packing space S between the outer peripheral surface 2a1 of inner peripheral surface 9a and the axial region 2a relative with inner peripheral surface 9a, the ring packing space S is broadening on the direction on top gradually.For example, in the inner space of the dynamic pressure bearing device 1 that sealing component 9 is sealed, lubricant oil is injected into, and as lubricating fluid, being full of in the inside of dynamic pressure bearing device 1 has lubricant oil.In this state, the pasta of lubricant oil remains in the scope of seal space S.In order to reduce number of components and assembling manually, sealing component 9 can integrally form with housing 7.

In the dynamic pressure bearing device 1 with said structure, when shaft component 2 rotated, the radial bearing surface A of the outer peripheral surface 2a1 of the axial region 2a relative with the inner peripheral surface 8a of axle sleeve 8 crossed the radial bearing gap respectively.According to relative rotation, the lubricant oil that is full of each radial bearing gap produces the hydrodynamic effect, and shaft component 2 is supported rotationally in non-contacting mode under the effect of radial pressure.Therefore, formed the first radial bearing part R1 and the second radial bearing part R2, this first radial bearing part R1 and the second radial bearing part R2 are diametrically with non-contacting mode support shaft member 2 rotatably.

In addition, the first thrust bearing surface B of upper-end surface 2b1 of axial region 2a that is formed on shaft component 2 is relative with the lower end surface 8b of axle sleeve 8, crosses the first thrust-bearing gap.The second thrust bearing surface C that is formed on the lower end surface 2b2 of lip part 2b is relative with the upper-end surface 28a of cover component 28, crosses the second thrust-bearing gap.According to the relative rotation of shaft component 2 and bearing housing 8, the lubricant oil that is full of two thrust-bearing gaps produces the hydrodynamic effect, and shaft component 2 is supported rotationally in non-contacting mode under the effect at pressure on the thrust direction.Therefore, formed on two thrust directions with non-contacting the mode first thrust-bearing part T1 and the first thrust-bearing part T2 of support shaft member 2 rotationally.

When the pressure of the thrust-bearing gap of two thrust-bearing part T1, T2 between dynamic pressure bearing device 1 on-stream period and seal space S occurs when uneven, lubricant oil flows by the loop 10 of communicating space.Therefore, the initial stage has just solved pressure difference.Therefore prevented the leakage of the lubricant oil that pressure reduction causes and the formation of bubble, and generation of vibration.In Fig. 7, example the loop 10 that forms by axial groove 10a and radial groove 10b, axial groove 10a comprises the outer peripheral surface of the axle sleeve 8 that forms thereon, radial groove 10b is formed on the lower end surface 9b of sealing component 9, but axial groove 10a can be formed on the inner peripheral surface of housing 7, and radial groove 10b can be formed on the upper-end surface 8c of axle sleeve 8.

Please note, in the above description, example thrust bearing surface B, C be formed on situation on two end face 2b1, the 2b2 of lip part 2b by ink jet printing, but thrust bearing surface B, C can be formed on two end face facing surfaces with lip part 2b by ink jet printing, for example constitute on the upper-end surface 28a of the lower end surface 8b of bearing housing 8 of bearing element 27 and cover component 28.In these two thrust bearing surface B, C, can on arbitrary thrust bearing surface, form dynamic pressure groove pattern by another kind of technological methodes such as pressing process.

The present invention can not only be applied to dynamic pressure bearing device shown in Figure 71, and in the dynamic pressure bearing device example shown in below can being applied to.Note that in the following description the element and the device that structurally have identical function with Fig. 7 are represented with same reference character substantially, and omitted repeated description.

Different is for dynamic pressure bearing device 31 shown in Figure 8 and dynamic pressure bearing device shown in Figure 71: cone seal space A is formed between the outer peripheral surface 7c of the inner peripheral surface 33b1 of disk hub 33 and housing 7; The second thrust-bearing part T2 is formed between the lower end surface 33a1 of the upper-end surface 7b of housing and disk hub 33.On the first thrust-bearing part T1, the thrust bearing surface B that has carried out ink jet printing is formed on the lower end surface 8b of bearing housing 8 of a part of bearing element 27.On the second thrust-bearing part T2, the thrust bearing surface C that has carried out ink jet printing is formed on the lower end surface 33a1 as the disk hub 33 of rotor.Also thrust bearing surface B can be formed on the upper-end surface 2b1 of lip part 2b, thrust bearing surface C be formed on the upper-end surface 7b of the housing 7 that constitutes bearing element 27.

Different is for dynamic pressure bearing device 41 shown in Figure 9 and dynamic pressure bearing device shown in Figure 71: bearing element 27 integrally constitutes with bearing housing 8 and housing 7; The cylinder element 28b of Tu Chuing is arranged on the periphery of cover component 28 up; Cylinder element 28b forms with the end face 27a1 of cover member 227 (corresponding to the bearing housing 8 of bearing element) and contacts.On the first thrust-bearing part T1, the thrust bearing surface B that has carried out ink jet printing is formed on the end face 27a1 of cover member 227 of bearing element 27; Simultaneously, on the second thrust-bearing part T2, the thrust bearing surface C that has carried out ink jet printing is formed on the upper-end surface 28a of cover component 28.Also thrust bearing surface B can be formed on the upper-end surface 2b1 of lip part 2b, thrust bearing surface C be formed on the lower end surface 2b2 of lip part 2b.

In the above-described embodiments, used a kind of bearing as hydraulic bearing, dynamic pressure generating section comprises the dynamic pressure groove in this bearing, and the dynamic pressure groove has man type or spirality etc., and hydraulic bearing is made of radial bearing part R1, R2 and thrust-bearing part T1, T2.Yet the structure of dynamic pressure generating section is not limited thereto.For example, as radial bearing part R1, R2, can use so-called step bearing and leafy bearing (multilobe bearing).So-called step bearing is such bearing, promptly in this bearing, the dynamic pressure groove of a plurality of axial flute profiles along the circumferential direction is set on as the zone of bearing surface with predetermined interval; Leafy bearing is such bearing, promptly in this bearing, on the inner peripheral surface 8a of the outer peripheral surface 2a1 of axial region 2a and bearing housing 8 a plurality of arc shaped surfaces is set, and these a plurality of arc shaped surfaces shrink the bearing play with wedge shape on one or two circumferencial direction.

In addition, for example, one or two among thrust-bearing part T1, the T2 can be made of step bearing, or by so-called waveform bearing formations such as (step bearings of waveform).

Figure 10 A has shown a kind of example of bearing, and in this bearing, the step bearing face is formed on the upper-end surface 2b1 of material 2b '.In example shown in Figure 10, be provided at predetermined intervals the dynamic pressure groove Bb of a plurality of radially flute profiles in a circumferential direction, form and the boundary section Ba of the described dynamic pressure groove Bb that demarcates is formed by above-mentioned ink jet printing method.The upper surface Ba1 of boundary section Ba is the taper shown in Figure 10 B.In this part, the thrust-bearing gap is a wedge shape.When rotating on the direction shown in the arrow in Figure 10 B of lip part (shaft component 2) 2b, lubricant oil is extruded the narrower side to wedge gap.Therefore, according to its hydrodynamic effect, shaft component 2 is supported in the non-contact mode on thrust direction, thereby forms the first thrust-bearing part T1.

Below with reference to Figure 11-18 explanation second embodiment of the present invention.

According to a second embodiment of the present invention, as the method that forms dynamic pressure generating section, shaft component 102 shown in Figure 13 is used as the example that forms the step of dynamic pressure generating section on the outer peripheral surface 102a1 of axial region 102a.

In this embodiment, the cure step (c) of the China ink that the cleaning process (a) of the outer peripheral surface of process axial region, the print steps (b) that the trace China ink is provided and sclerosis are provided forms dynamic pressure generating section on the outer peripheral surface 102a1 of axial region 102a.

(a) cleaning process

At first, clean the material surface formation dynamic pressure generating section and that be used to be provided China ink.In the present embodiment, metals such as stainless steel are used as the material 102a ' of axial region 102a, and are formed a shape by machinings such as grindings.In addition, as washing unit, use chlorohydric acid pickling.

Material 102a ' is placed in the container of the hydrochloric acid that into is full of predetermined concentration, and the surface of material 102a ' (particularly outer peripheral surface) is dipped in the hydrochloric acid solution under the effect of ultrasound effect.After the predetermined immersion time, take out material 102a ' in experience, and remove and be deposited on lip-deep hydrochloric acid, for example, utilize the ultrasound ultra-pure water to clean or other device from hydrochloric acid solution.

Therefore, the impurity that is deposited on the outer peripheral surface 102a1 of material 102a ' such as cutting powder, oil ﹠ fat is removed.In addition, the patina that is formed on the outer peripheral surface 102a1 of stainless steel prepared material 102a ' is removed.Therefore, the surface condition of outer peripheral surface 102a1 becomes fine and even.

(b) print steps and (c) cure step

Figure 11 shows the simplified diagram of the printing equipment of the dynamic pressure generating section that forms by ink jet printing method.The black cure step (c) of trace that this printing equipment is carried out the print steps (b) that the trace China ink is provided continuously and hardened and provided.As shown in figure 11, printing equipment mainly comprises rotation driving 113, single or multiple shower nozzle 110 and stiffened members 111, single or multiple shower nozzles 110 are relative with the outer peripheral surface 102a1 of material 102a ', material 102a ' drives 113 by rotation and drives rotatably, stiffened members 111 is arranged at different positions in a circumferential direction with respect to shower nozzle 110, preferably as shown in figure 11, crossing material 102a ' relatively is provided with shower nozzle 110.A plurality of nozzles 114 of the discharge trace ink droplet 112 at shower nozzle 110 places are set up in the axial direction.At direction top nozzle 114 row perpendicular to material 102a ' can be delegation or multirow.For example, China ink 112 can be based on the resin composition of light-hardening resin, is preferably ultraviolet hardening resin.If desired, for example, use the organic solvent of the photopolymerization priming composition that comprises appropriate amount.Stiffened members 111 is light sources, and its emission light is used for sclerosis China ink 112.For example, use ultraviolet lamp.

The example that constitutes the ultraviolet hardening resin of China ink 112 comprises free yl polymerizating monomer (radicalpolymerizable monomer), radical polymerization oligomer (radical polymerizable oligomer) and cationic polymerization monomer (cationic polymerizable monomer), and typically comprise propylene imide acid esters (imide acrylate), the mercaptan compound (en-thiol compound) of ring polyenic compounds (cyclic polyene compound) and poly-thiol compound (polythiol compound).In these materials, free yl polymerizating monomer, radical polymerization oligomer and cationic polymerization monomer can be fit to use.These ultraviolet hardening resins can singly be planted and be used or be used in combination.In addition, above-mentioned single kind resin or two or more hybrid resin can be used as base resin.

In these base resins, can use radical photopolymerization initator (radicalphotopolymerization initiator) and cationic photopolymerization initator Photoepolymerizationinitiater initiaters such as (cationicphotopolymerization initiator).These Photoepolymerizationinitiater initiaters can singly be planted and be used or be used in combination.

In said structure, be under the rotation drive condition at material 102a ', China ink 112 is discharged from nozzle 114, so that trace China ink 112 drops on the precalculated position of the outer peripheral surface 102a1 of material 102a ' with the drop form.By assembling the trace China ink 112 of a lot of formation drops, a plurality of dynamic pressure groove Eb go up as dynamic pressure generating section with the outer peripheral surface 102a1 that man type is arranged in material 102a ', dynamic pressure groove pattern (as the zone of radial bearing surface E) with boundary section Ea is formed, and boundary section Ea forms and boundary dynamic pressure groove Eb (please refer to Figure 11 and 13).In the present embodiment, only boundary section Ea is formed by above-mentioned micro-black 112 aggregate.

In this embodiment, the printing of dynamic pressure groove pattern is carried out by this way, i.e. mode of little by little carrying out in a circumferential direction with the rotation of responsive materials 102a '.When be printed part arrive the zone relative with stiffened members 111 (in Figure 11, when arrive from the position relative with shower nozzle 110 half) time, accepted the China ink 112 generation polymerisations of ultraviolet irradiation, hardened subsequently.When the supply of the China ink 112 that suitably switches each nozzle 114 with when stopping, material 102a ' is rotated one to less than 100 times, and the boundary section Ea of the dynamic pressure generating section of constituent material 102a ' is formed on the whole circumference face of material 102a '.At this moment, because shower nozzle 110 and stiffened members 111 are arranged on the position respect to one another of crossing material 102a ', the ultraviolet ray of stiffened members 111 emissions is blocked by material 102a ', therefore the Mo Buhui of nozzle 114 ejections is applied the induration of polymerisation.Therefore, prevent that China ink 112 sclerosis from causing problems such as nozzle 114 obstructions, so that can form boundary section Ea effectively.

In this printing, shower nozzle 110 can be arranged on the fixed position, or slides axially going up of material 102a '.In addition, in Figure 11, shown the example of using single shower nozzle 110, but can be provided with a plurality of positions on axial or circumferencial direction.In addition, for example, as shown in figure 12, a plurality of material 102a ' are connected in series and rotate simultaneously, and they slide in the axial direction, are acted on so that dynamic pressure groove pattern can be formed on each material 102a ' by one or more shower nozzles 110.In this case, for example, fitting projection 102a2 by being arranged on an axle head and the depression that is arranged on another axle head are guaranteed the alignment between the material 102a '.In addition, in the present embodiment, material 102a ' is driven by rotation as described above, but material 102a ' can maintain static, and shower nozzle 110 and stiffened members 111 drive around material 102a ' with being rotated.

Therefore, in ink jet method, it is consistent with the shape pattern of program setting in advance accurately to regulate trace China ink 112 that output speed makes the drop form.In addition, at cleaning process (a), the outer peripheral surface 102a1 of material 102a is cleaned by pickling, thus its surface condition to be enhanced into whole surface all be uniformity.Therefore, drop on and drop in the shape that trace China ink 112 on the outer peripheral surface 102a1 of material 102a forms uniformities, for example, at the contact angle that falls formation uniformity between back it self and the outer peripheral surface 102a1.The dynamic pressure groove pattern that is formed by micro-black 112 aggregate can be formed accurately.In addition, according to the kind of forming method, the China ink 112 of sclerosis self can be guaranteed the desired depth (a few μ m are to tens μ m) of dynamic pressure groove.This can save processes such as turning, etching after printing, so that allow material as the shaft component 102 with dynamic pressure generating section.For example, when forming the outer peripheral surface 102a1 (carrying out above-mentioned cleaning process thereon) of material 102a by machinings such as grindings, after this process, the line decision table surface roughness on the grinding direction that causes of the grinding of Cun Zaiing still.These lines are never desired, because they can cause that the China ink 112 that provides with the drop form flow to the photographic fixing position along these lines from the position is provided.As mentioned above, by pickling, particularly chlorohydric acid pickling can solve such problem.Yet if clean time (leaching time) is oversize, cycle period will increase, and the surface of material 102a ' is fully dissolved, and causes the surface condition (for example, rough surface) that quite worsens.Therefore to suitably select required clean time according to the cleansing power (solvability) of employed washing unit.As guidance, the surface roughness Ra of cleaning back outer peripheral surface 102a1 is 0.05 μ m or lower, preferably is 0.03 μ m or lower.

In addition, in the present embodiment, carry out print steps (b) and cure step (c), still, for example, between cleaning process (a) and print steps (b), can insert the surface treatment step of utilizing coupling agent (coupling agent) in cleaning process (a) back.After cleaning outer peripheral surface 102a1, to form coupling agent system coating (not shown) on the outer peripheral surface 102a1 at material 102a before the drop form supply China ink 112.Can carry out such coating by the supply coupling agent and form (surface treatment), aforementioned coupling agent is diluted to predetermined concentration (0.1 to 5% weight percentage), for example utilize alcohol/alcohol mixed solution and water/toluene equal solvent dilution, on the outer peripheral surface 102a1 of material, carry out such coating by the device of spray method or infiltration method and form.Above-mentioned coupling agent can be any in the multiple material.Consider industrial reliability, preferably metatitanic acid alkali coupling agent.Therefore, before utilizing China ink 112 printing dynamic pressure groove patterns, on the outer peripheral surface 102a1 of material 102a, form coupling agent system coating, so can improve the shortcoming of the poor adhesion between the organic materials such as inorganic material such as metal and China ink.Therefore, after China ink 112 is by sclerosis, cause with the sliding contact meeting of bearing element and to peel off and break away from, and the dynamic pressure generating section of this shape can keeps for a long time reliably.Especially, in the present embodiment, on the surface of material 102a ', carry out surface treatment with coupling agent, because the surface of material 102a ' is the persalt cleaning process, therefore can avoid coupling agent system coating to form part and fail, such coating can uniformity and is formed on reliably on the outer peripheral surface 102a1.

Note that in the present embodiment pickling such as application hydrochloric acid are as the cleaning means of material 102a ', but the combination that can use UV cleaning, ozone clean or two kinds of cleaning processes.Because these cleaning methods are feasible under the environment of drying, therefore after cleaning process, can save to remove and be deposited on the lip-deep acid of material 102a ' or drying and be deposited on material outer peripheral surface 102a1 and go up moisture, cause job step simple.

The front has illustrated that the outer peripheral surface 102a1 by being printed on axial region 102a (material 102a ') goes up the situation that forms dynamic pressure generating section.Preceding method may be used on equally by being printed on bearing element (as shown in figure 13, corresponding to axle sleeve 108.Below please refer to Figure 13 for each structural element) inner peripheral surface on form the situation of dynamic pressure generating section.Bearing element constitutes the hydraulic bearing between shaft component 102 and the bearing element.In addition, utilize similarity method, the dynamic pressure generating section (for example, dynamic pressure groove) that produces hydrodynamic in thrust direction can be formed on the lip part 102b of shaft component 102, the bottom end face 107c of housing 107 etc.

In addition, in the above description, illustrated with the example of ink-jet system as black fusing system, but be not limited to this system, for example, can use the system that discharges drop and make it to fall, the promptly so-called no nozzle type system that is used to discharge drop, also can use through micro-pick-up tube (micropipette) not with the drop form but continuously ink-jet to the lip-deep system of material, with also can use the distance that shortens to the photographic fixing surface and when the ink-jet with the surperficial system that contacts of photographic fixing.

The shaft component 102 that forms through above-mentioned steps constitutes hydraulic bearings, for example, uses this shaft component 102 and bearing element so that with non-contacting mode support shaft member 102, bearing element himself with shaft component 102 between the gap in generation hydrodynamic effect.Be integrated with the topology example of the dynamic pressure bearing device of shaft component 102 below with reference to Figure 13 explanation.

Figure 13 has shown first topology example of the dynamic pressure bearing device 101 that is integrated with the shaft component 102 that forms by above-mentioned steps.This dynamic pressure bearing device 101 comprises shaft component 102, bearing housing 108, housing 107 and sealing component 109.Shaft component 102 has the axial region 102a that is positioned at rotating center, and bearing housing 108 has the interior week that can insert shaft component 102, and housing 107 comprises the bearing housing 108 on fixing week within it, and sealing component 109 is arranged on an end of the opening side of housing 107.In the present embodiment, bearing element is made of housing 107 and bearing housing 108.Note that in order to explain in the following description, a side at sealing component 109 places is called upside, a side relative with sealing component 109 is called downside.

Shaft component 102 has axial region 102a and lip part 102b, and lip part 102b integrally or independently is arranged on an end of shaft component 102.On the outer peripheral surface 102a1 of axial region 102a, for example, in the axial direction two independently the position form dynamic pressure groove Eb and the radial bearing surface E that a plurality of man types are arranged, as dynamic pressure generating section.Radial bearing surface E comprises the boundary section Ea that forms and demarcate dynamic pressure groove Eb.

On the radial bearing surface E of top, the relative axle center m of dynamic pressure groove Eb (central core region between the upper and lower tipper) axially asymmetricly forms, and the axial dimension X1 of the upper area of above-mentioned axle center m is greater than the axial dimension X2 of the lower zone of above-mentioned axle center m.

For example, bearing housing 108 is formed by porous body cylindrical shape ground, and this porous body is copper (comprising Cuprum alloy) and aluminium soft metals such as (comprising aluminum alloy), or sintering metal.The inner peripheral surface 108a of axle sleeve 108 forms smooth and the cylinder arcuate surface.Although in Figure 13, do not show, on ground, the inner circumference area top of the lower end surface of bearing housing 108 108b or fully form a plurality of dynamic pressure grooves and the first thrust bearing surface F, as dynamic pressure generating section, the first thrust bearing surface F comprises the boundary section Ba that forms and demarcate the dynamic pressure groove to the dynamic pressure groove with helix shape.Note that also but user's font is as dynamic pressure groove pattern.

Housing 107 comprises roughly cylinder sidepiece 107b, is positioned at the bottom 107c of the lower end of sidepiece 107b, and bottom 107c and sidepiece 107b integrally or independently form.In the present embodiment, bottom 107c be formed as with the element of sidepiece 107b independent separate, and with bonding (comprising loose bonding, being press-fitted bonding), (for example be press-fitted, weld, ultrasonic welding), welding (for example, laser bonding) etc. means are fixed on the lower end of sidepiece 107b with it, and sidepiece 107b and bottom 107c are made of metal.Certainly, any among sidepiece 107b and the bottom 107c can be formed or all be formed by resin by resin.

On all or part of annular region of the upper-end surface of bottom 107c 107c1, form first thrust bearing surface G and the boundary section as dynamic pressure generating section, the first thrust bearing surface G draws together a plurality of dynamic pressure grooves (although Figure 13 does not show) with helix shape, and boundary section forms and these dynamic pressure grooves of demarcating.Note that also but user's font is as dynamic pressure groove pattern.

On the interior week of the open part 107a of housing 107, metallic material or resin material system annular seat component 109 are by being press-fitted, boning and means such as welding being fixed.The inner peripheral surface 109a of sealing component 109a towards the top axially on become wideer gradually in the mode of taper.Be formed with seal space S between the outer peripheral surface 102a1 of inner peripheral surface 109a and axial region 102a on the other side, seal space S is increasing on the direction on top gradually.

Lubricant oil is filled in the inside (zone that the point of Figure 13 is represented) of the dynamic pressure bearing device 101 with said structure, and the pasta of lubricant oil remains in the seal space S.Note that sealing component 109 can integrally form (comprising inner moulding, outside moulding) with housing 107 in order to reduce number of components and assembling manually.Replacedly, as substituting of sealing component 109, zone on the upper end open side of the inner peripheral surface 108a of bearing housing 108 can be formed to such an extent that have than the bigger diameter in zone as radial bearing surface, or the diameter bigger than the zone that broadens gradually, make to form seal space between the outer peripheral surface 102a1 of aforementioned areas and the axial region 102a relative with this zone.

When shaft component 102 rotations, it is relative with the inner peripheral surface 108a of bearing housing 108 that the radial bearing surface E of the outer peripheral surface 102a of shaft component 102 (forming upper and lower dynamic pressure groove Eb in this zone) crosses the radial bearing gap.Along with the rotation of axial region 102a, the lubricant oil in the above-mentioned radial bearing gap is pulled to the center axis of the dynamic pressure groove Eb of each radial bearing surface E, and its pressure increases.Thereby constituting the first radial bearing part R11 and the second radial bearing part R12 respectively, the first radial bearing part R11 and the second radial bearing part R12 utilize the hydrodynamic effect of dynamic pressure groove Eb to support axial region 102a in non-contacting mode diametrically.

Simultaneously, in the thrust-bearing gap between the upper-end surface 102b1 of the thrust bearing surface F of bearing housing 108 (forming the dynamic pressure groove) and lip part 102b on the other side and utilize the hydrodynamic effect of dynamic pressure groove to form the oil film of lubricant oil in the thrust-bearing gap between the lower end surface 2b2 of the thrust bearing surface G of bottom 107c and lip part 102b on the other side in this zone.Utilize the pressure of this oil film to constitute on thrust direction the first thrust-bearing part T11 and the second thrust-bearing part T12 with the non-contact mode supporting lip 102b of portion.

Note that in this dynamic pressure bearing device 101 during shaft component 102 rotations, the lubricant oil in the radial clearance between shaft component 102 and bearing housing 108 is pulled to the bottom 107c side of housing 107.Therefore, the pressure in the thrust-bearing gap of thrust-bearing part T11, T12 just all increases, and causes may forming bubble, oil leak or vibration when lubricated.In this case, lubricant oil the path that is communicated with thrust-bearing gap (the particularly thrust-bearing gap of the first thrust-bearing part T11) and seal space S can be set, so that can circulate by the path of the type between thrust-bearing gap and seal space S.Therefore, just can solve pressure difference in the early stage, so just can prevent disadvantageous situation.For example, as shown in figure 13, on the outer peripheral surface 108d of bearing housing 108, form path 110a, on the 109b of the lower end surface of sealing component 109, form path 110b.

Like this, in the present embodiment, the first thrust bearing surface F is on the 108b of the lower end surface of bearing housing 108, and the second thrust bearing surface G is formed on the upper-end surface 107c1 of bottom 107c of housing 107.These thrust bearing surfaces F, G can be formed on the face with aforementioned end face opposite side (the both ends of the surface 102b1 of lip part 102b, 102b2).Please note, the not only available method of forming forms each thrust bearing surface F, G, also cleaning process → the printing of available dynamic pressure generating section and cure step or as the cleaning process of radial bearing surface E → utilize the surface treatment step → printing of coupling agent and cure step to form each thrust bearing surface F, G.

The structure that constitutes the shaft component 102 of dynamic pressure generating section of the present invention is not limited to said structure.Shaft component applicable to have other structure dynamic pressure bearing device.In the description of the dynamic pressure bearing device of Figure 14 below-16, represent with identical reference character with routine position and the element of first structure shown in Figure 13, and omitted repeated explanation with same configuration and effect.Note that following described form of ownership, on the outer peripheral surface 102a1 of the axial region 102a of shaft component 102, form radial bearing surface E with dynamic pressure generating section by above-mentioned ink jet method.

Figure 14 has shown another structure example of dynamic pressure bearing device 101.Main difference point between the dynamic pressure bearing device of the structure of dynamic pressure bearing device shown in Figure 14 and the first structure example is: seal space S is formed on the outer diameter side of housing 107; The second thrust-bearing part T12 be formed on housing 107 sidepiece 107b upper-end surface 107b1 and constitute between the lower end surface 103a1 of board member 103a of disk hub 103.

Figure 15 shows another structure example of dynamic pressure bearing device 101.Main difference point between the dynamic pressure bearing device of the structure of dynamic pressure bearing device 101 shown in Figure 15 and the first structure example is: bearing element (bearing element 127) is made of bearing housing 108 and housing 107 integral body; Cylinder element 128a protruding upward is arranged on the periphery as the cover component 28 of bottom, and this cylinder element 128a contacts with the lower end surface 127a1 than the cylinder element 127a of minor diameter corresponding to the bearing housing 108 of bearing element 127.Therefore, integrate, can reduce number of components and assembling manually by the component that makes bearing apparatus.

Figure 16 shows another structure example of dynamic pressure bearing device 101.In this dynamic pressure bearing device 101, shaft component 102 is provided with lip part 122b, and lip part 122b is positioned at the top of the lower end of axial region 122a.During shaft component 102 rotations, between the upper-end surface 108c of the lower end surface of lip part 122b 122b2 and bearing housing on the other side 108, form the thrust-bearing gap of thrust-bearing part T13.Sealing component 129 is fixed on week in the upper end of housing 107, and seal space S ' is formed between the outer peripheral surface 122a1 of the inner peripheral surface 129a of sealing component 129 and shaft component 122.The 129b trans-axial gap, lower end surface of sealing component 129 is relative with the upper-end surface 122b1 of lip part 122b.When shaft component 122 moves up, by engaging, thereby has the function that prevents that shaft component 122 from throwing off with the upper-end surface 122b1 of lip part 122b.

The shape that is included in the dynamic pressure generating section among the radial bearing surface E that shows in the structure example only is an example, can form the dynamic pressure groove pattern (for example spirality) of arranging structure corresponding to other groove, as long as this shape can be by the ink jet method printing.In addition, although it is not shown, as the dynamic pressure generating section that is included among the radial bearing surface E, can form so-called stepped shaft dynamic pressure generating section or so-called multi sphere shape dynamic pressure generating section by the similar methods printing, axially groove forms in a plurality of positions along the circumferential direction in so-called stepped shaft dynamic pressure generating section, and a plurality of arc shaped surfaces along the circumferential direction form in so-called multi sphere shape dynamic pressure generating section.

In addition, in the above description, example radial bearing surface E form in the axial direction two positions independently, but the quantity of radial bearing surface E is selectable, radial bearing surface E can be formed on a position or three above positions altogether.

In addition, on reasoning bearing surface F, G, can form above-mentioned a plurality of dynamic pressure grooves of helix shape, so-called stepped shaft dynamic pressure generating section and so-called waveform (ladder belongs to a kind of waveform) dynamic pressure generating section as dynamic pressure generating section.In so-called stepped shaft dynamic pressure generating section, the dynamic pressure groove of a plurality of radially flute profiles along the circumferential direction is provided at predetermined intervals.

In addition, in the above-described embodiments, the lubricant oil conduct is full of the inside of dynamic pressure bearing device 101 and forms the example of the fluid of lubricating film in each bearing play.Yet other fluid also can form lubricating film in each bearing play, for example, can use oiling agents such as gas, the magnetic fluid with flowability and lubricating grease such as air.

For example, above-mentioned dynamic pressure bearing device 101 can be used for the spindle motor of information equipment and therein integrated, and information equipment typical case representative has disc drive units such as HDD.Figure 17 shows its a kind of structure example.Spindle motor comprises dynamic pressure bearing device 101, be connected on the shaft component of dynamic pressure bearing device 101 disk hub 103, (for example, diametrically) cross gap stator coil 104 respect to one another and rotor magnet 105 and electric machine support 106.Stator coil 104 is connected to the periphery of electric machine support 106, and rotor magnet 105 is connected to the interior week of disk hub 103.Disk hub 103 keeps disc D such as one or more disks in its periphery.When stator coil 104 was excited, rotor magnet 105 rotated by the electromagnetic force that produces between stator coil 104 and the rotor magnet 105, and this makes disk hub 103 and the disc D that remains on the disk hub 103 integrally rotate with shaft component 102 again.Durable longevity of the motor here and rotation are accurately.

[example 1]

For advantage of the present invention is described, by using the shaft component made from stainless steel (SU420) as material, and this material immersed have in two kinds of hydrochloric acid (hydrochloric acid of the hydrochloric acid of 15% weight percentage, 30% weight percentage) of variable concentrations, cleaning is carried out on the surface of material.Carry out cleaning several times with different clean time (immersion time).After cleaning, determine roughness and the roughness and the relation between the immersion time of material surface.

The result who cleans test is presented among Figure 18.Horizontal axis is represented the immersion time [min], and vertical shaft is represented the surface roughness Ra [um] of material.In Figure 18, shown the situation of different concentration of hydrochloric acid equally, surface roughness Ra increased with the immersion time.For example, the time when concentration of hydrochloric acid is 15% weight percentage during roughness Ra=0.05um, the chances are 9 minutes, and the chances are 6 minutes the time during roughness Ra=0.05um when concentration of hydrochloric acid is 30% weight percentage.

Below with reference to Figure 19-24 explanation third embodiment of the present invention.

The material 202 ' that constitutes axial region 202 is formed by stainless steel and other metal materials.Material 202 ' is formed cylindrical shape roughly and has through hole 202b, and through hole 202b is axial and passes its axle.

As the example of the method that forms dynamic pressure generating section of the present invention, Figure 19 shows the summary of the dynamic pressure generating section printing equipment that uses ink jet method.This printing equipment has such mode, and the cure step of the print steps of trace China ink and the trace China ink that sclerosis is provided promptly is provided.

As shown in figure 19, printing equipment comprises: as one or more shower nozzles 217 of body element, this shower nozzle 217 is with driven fixed block 216 (the outer peripheral surface 202a of material 202 ') is relative rotatably; Supporting member 213, the two ends of these supporting member 213 support fixation parts 216, and drive fixed block 216 rotatably; With one or more stiffened members 215, stiffened members 215 is arranged on different circumferential locations with respect to shower nozzle 217, preferably as shown in figure 19, crosses fixed block 216 and is oppositely arranged with shower nozzle 217.At least one supporting member 213 is provided with rotation drivings 214 such as motor.Note that in the present embodiment shower nozzle 217 and stiffened members 215 are positioned at two axial positions separately.

Fixed block 216 is formed by the contour rigid metallic material of stainless steel.A plurality of materials 202 ' are connected in series on the outer peripheral surface of fixed block 216.

In shower nozzle 217, a plurality of nozzles of discharging the droplet of China ink 212 are provided with in the axial direction.For example, China ink 212 is the resin compounds that comprise light-hardening resin, Photoepolymerizationinitiater initiater, and preferred ultraviolet hardening resin is as base resin.If necessary, resin compound further comprises the organic solvent of appropriate amount.Stiffened members 215 is light sources, is used to launch the light of sclerosis China ink 212.For example, can use ultraviolet lamp.

The example that constitutes the ultraviolet hardening resin of employed China ink in the print steps also comprises imido acrylate and mercaptan-alkene compound such as ring-type polyenic compounds and poly-thiol compound except that the monomer of the monomer that comprises free redical polymerization or oligomer and cationically polymerizable.Wherein, preferably use outside the monomer of the monomer of free redical polymerization or oligomer and cationically polymerizable.The example of the monomer of free redical polymerization comprise have simple function group, difunctional or multi-functional acrylate and methacrylate.The example of the monomer of free redical polymerization comprises urethane acrylate, epoxy acrylate, polyester acrylate and unsaturated polyester.The example of the monomer of cationically polymerizable comprises that bisphenol A epoxide resin, phenol phenolic resin varnish, alicyclic ring epoxide resin and oxetane resin for example can use 3-ethyl-3-(the own oxygen methyl of 2-ethyl) oxetanes, 3-ethyl-3-hydroxymethyl-oxetanes, 1, two { [(3-ethyl-3-oxa-cyclobutyl) methoxyl group] methyl } benzene of 4-, 3-ethyl-3-(benzene oxygen methyl) oxetanes, two [1-ethyl (3-oxa-cyclobutyl)] methyl ether, 3-ethyl-3-{[3-(triethoxy-silicyl) propoxyl group] methyl } oxetanes.These ultraviolet hardening resins can be used alone as base resin, also can be used in combination.

For these base resins, can use Photoepolymerizationinitiater initiaters such as radical photopolymerization initator, cationic photopolymerization initator.The example of radical photopolymerization initator comprises the following hydrogen-abstraction Photoepolymerizationinitiater initiater of classifying representative as: the ammonium salt of ammonium salt, isopropyl thioxanthone, diethyl thioxanthone and the thioxanthones of benzophenone, adjacent diphenylhydroxyethanone benzoic acid formicester, 4 benzoic acid base-4 '-dimethyl diphenyl sulfide, benzophenone.Alternatively, the example of radical photopolymerization initator comprises the following intermolecular type Photoepolymerizationinitiater initiater that splits of classifying representative as: diphenylhydroxyethanone derivative, benzyldimethylketal, alpha-hydroxyalkyl benzene ketone (phenon), α-aminoalkyl benzene ketone, acyl group phosphorous oxide, monoacyl phosphorous oxide, two acyl group phosphorous oxide, acyl group phenyl dihydroxy acetic acid fat, diethoxy acetophenone and two cyclopentadiene titanium compounds.The example of cationic photopolymerization initator comprises the following polyaryl sulfonium salt of classifying representative as: hexafluoro-antimonic acid triphenylsulfonium, hexafluorophosphoric acid triphenylsulfonium, SP-170 and SP-150 (both are by AsahiDenka Co., and Ltd. produces), FC-508 and FC-512 (both produce by 3M Company) and UVE-1014 (being produced by General Electric Company); Below classify the triallyl hexafluorophosphate of the mixing of representative: Uvacure 1590 and 1591 (both are by DAICEL-UCB Co., and Ltd. produces) as; Metallocenic compound such as Irg-261 (producing) by Ciba-Geigy Corporation; With the following polyaryl iodonium salt of classifying representative as: hexafluoro-antimonic acid diphenyl iodnium, hexafluoro-antimonic acid are to nonyl phenyl base iodine father-in-law and hexafluoro-antimonic acid 4,4 '-diethoxy phenyl-iodide father-in-law.These Photoepolymerizationinitiater initiaters can use separately or be used in combination.

In above-mentioned structure, fixed block 216 is supported by supporting member 213 at its two ends, and rotation simultaneously.At this moment, set the outer peripheral surface of fixed block 216 and the inner peripheral surface of material 202 ' and make it to cooperate with such degree, promptly can be with the degree of fixed block 216 synchronous rotations with material 202 '.Otherwise the cooperation between the outer peripheral surface of fixed block 216 and the inner peripheral surface of material 202 ' may be very loose, and available rotation drives 214 direct driving material rotatably.

When material rotates by this way, discharge China ink 212 from shower nozzle 211 and make the droplet of China ink 212 drop on the precalculated position of the outer peripheral surface 202a of material 202 '.Utilize the aggregate of these droplets on the outer peripheral surface 202a of material 202 ' to form dynamic pressure groove pattern as dynamic pressure generating section.For example, in this dynamic pressure groove pattern, the boundary section Ha of rising and the zone of uncoated China ink (being dynamic pressure groove Hb) arranges with man type.At this moment, at each nozzle 211 place, suitably switch China ink 212 supply and stop with the predefined moment.With the rotation of fixed block 216, carry out the formation of dynamic pressure groove pattern in the mode of on the excircle direction of the outer peripheral surface 202a of material 202 ', little by little carrying out.When being printed part and proceeding to a certain degree (halfway shown in Figure 19) at circumferencial direction, be printed part and arrive and the relative zone of stiffened members 215 (cure step), having accepted the China ink 212 that ultraviolet irradiation causes polymerisation will sequentially be hardened.With the rotation of material 202 ', the sclerosis of China ink is little by little carried out in a circumferential direction.

When the part individual pen that at first is printed rotates and arrival and nozzle 217 are relative when regional fully, shower nozzle 217 slides into the zone relative with the outer peripheral surface 202a of adjacent materials 202 '.When fixed block 216 continues rotation, on adjacent materials 202 ', form dynamic pressure groove pattern in a similar manner.Such circulation continues until whole printings of finishing material 202 ' always.Confirm that then all China inks 212 are whether by the zone relative with stiffened members 11 with whether hardened.Afterwards, stop the rotation, remove fixed block 216 from supporting member 213.

When not using structure of the present invention, only when single material 202 ' was gone up the execution printing, rotating the necessity that drives (idle running) continuously can increase, and hardens fully until China ink, and this can cause rising cycle time.In addition, when it needed repeatedly to carry out connection and removes, can prolong the ineffective time not directly related with the printing dynamic pressure generating section.

On the contrary, the present invention can carry out continuous printing by a plurality of materials 202 ' that are connected in series, and therefore can carry out the formation of dynamic pressure groove very efficiently.When finishing the printing of single material, shower nozzle 217 is slidably so that begin to print adjacent material 202 '.At this moment, during the next adjacent material 202 ' of printing, can carry out the China ink sclerosis of previous material 202 ' simultaneously.Therefore, can implement print steps and cure step simultaneously, carry out the formation of dynamic pressure groove pattern effectively.In addition, be connected to printing equipment material 202 ' and the number of times that removes from printing equipment material 202 ' and prepare number of times and can significantly reduce.Therefore, can shorten greatly cycle time, and the manufacture cost of dynamic pressure generating section can reduce greatly.

In addition, a plurality of materials 202 ' are connected in series to guarantee alignment by fixed block 216, can prevent to influence the vibration of the formed precision of each material, can go up at all materials 202 ' and form high-precision dynamic pressure groove pattern.Please note, being connected when guaranteeing alignment of a plurality of materials 202 ', also can utilize the depression 202a2 of the protruding 202a1 of the axle head that is arranged on one of them material 202 ' and an adjacent material 202 ' and by using above-mentioned fixing piece 216 to assemble, for example, as shown in figure 20.

In example shown in Figure 20, example two shower nozzles 217, but can be, or a plurality of positions along the circumferential direction are provided with shower nozzle in a position or three above positions vertically.In addition, dynamic pressure groove pattern will be printed on the whole circumference when material rotates one time fully, perhaps (for example rotates twice to tens times) dynamic pressure groove pattern and can be printed on the whole circumference of material 202 ' when material 202 ' rotates repeatedly.

In addition, as spendable stiffened members 215, for example, have the fixedly use of stiffened members 215 of high light diffusibility, having the concentrative stiffened members 215 of high light can be with shower nozzle 217 use of sliding in the axial direction.In addition, in the above description, designed so a kind of structure: when being completed for printing of the dynamic pressure groove pattern on the single material 202 ', promptly begin the printing of adjacent materials 202 '.But, can carry out the printing of a plurality of materials 202 ' simultaneously by slip shower nozzle 217.

By ink jet method, according to predefined shape pattern, black 212 droplets are accurately discharged.Therefore, can be as the dynamic pressure groove pattern of dynamic pressure generating section by the printing of high precision ground.In addition, the China ink 212 of sclerosis self can guarantee the desired depth (several microns to tens microns) of dynamic pressure groove, can be used as the axial region 202 with dynamic pressure groove to guarantee this part.

In addition, in the printing of ink-jet system, screen process press is the same just as is known, does not have contact segment between printing mould and the material 202 '.This can be avoided when a large amount of production the reduction of the printing precision that the wearing and tearing by contact segment cause.In addition, when a plurality of materials 202 ' connect as described above in the axial direction, be applied to pressure on the material 202 ' from nozzle and do not have what influence, therefore can avoid being connected the reduction of the crooked printing precision that causes of material 202 '.In addition because need not to print mould, the maintenance that is used to print mould is with the printing net etc., it is also necessary to be used for the mechanism of mobile printing mould according to the rotation of material 202 ' simultaneously, so can simplify the structure of printing equipment.In addition,, reduced black consumption, realized the reduction of cost because therefore the required China ink that uses, is compared with the equipment of known use squeegee only as the needed amount of formation of dynamic pressure groove pattern.

In addition, owing to be provided with print steps and cure step independently on the circumferencial direction of material 202 ', the part that at first is printed is UV cured by stiffened members 215, turns back to the position relative with shower nozzle 217 then.Therefore, cover not adequately hardened China ink to avoid the destruction of dynamic pressure groove pattern.In addition, because shower nozzle 217 and stiffened members 215 are arranged on and pass across on material 202 ' and the position respect to one another, therefore material 202 ' has covered the ultraviolet ray of stiffened members 215, so ultraviolet induration can not influence nozzle 211, the problems such as nozzle 211 obstructions that ultraviolet irradiation causes have therefore been prevented.

Material 202 ' (fixed block 216) drives with being rotated in the above description, but material 202 ' can maintain static, and shower nozzle 217 and stiffened members 215 can be driven rotatably around material 202 '.

Figure 21 has shown the example of dynamic pressure bearing device, is integrated with rotating member 203 in this dynamic pressure bearing device, and rotating member 203 has the axial region of making by above-mentioned steps 202.This dynamic pressure bearing device 201 comprises: as the housing 207 of critical piece, housing 207 has sidepiece 207a and base material 207b, and base material 207b separates the also end opening of closed side 207a with sidepiece 207a; Week is complete 208, is fixed on the interior week of housing 207; With rotating member 203, rotating member 203 comprises that also housing 207 and bearing housing 208 relatively rotate the axial region 202 that is positioned at rotating center relatively.To note that in order illustrating in the following description, base material 207b side is known as downside, to be known as upside with the axial relative side of base material 207b.

For example, rotating member 203 is made of hub member 209 and axial region 202, the top of hub member 209 covering shells 207, and axial region 202 is inserted in the interior week of bearing housing 208.Axial region 202 has through hole 202b to be passed through with the axis that allows it.In the present embodiment, hub member 209 and axial region 202 independent formation, and by be press-fitted, bonding and welding etc. suitably means fix.

Hub member 209 comprises disk segment 209a, cylindrical portions may 209b, disk load surface 209c and edge 209d.Disk segment 209a is arranged on the housing 207, and cylindrical portions may 209b extends downwards vertically from the outer peripheral surface of disk segment 209a, and disk load surface 209c and edge 209d are arranged on the outer peripheral surface of cylindrical portions may 209b.The disc-shaped information recording carrier of Xian Shiing is not assembled on the periphery of disk segment 209a, and is installed on the disk load surface 209c.By the suitable holding device that does not show disc-shaped information recording carrier is remained on the hub member 209.

Axial region 202 comprises the lip part 210 of conduct at the anti-slip device of its lower end independently.Lip part 210 is made of metal, and is fixed to axial region 202 by means such as be threaded, therefore, and the closed lower end of through hole 202b.At the upper end of through hole 202b, by means mounting fixture (not shown) such as being threaded, these anchor clamps remain on disc-shaped information recording carrier between the upper end and hub member 209 of through hole 202b.

Radial bearing surface H is set on the outer peripheral surface 202a of axial region 202 vertically independently, and this radial bearing surface H comprises the boundary section Ha as the man type dynamic pressure groove Hb of dynamic pressure generating section and formation and boundary dynamic pressure groove Hb.On the radial bearing surface H of top, dynamic pressure groove Hb axially asymmetricly forms with respect to axle center m, and the axial dimension X1 of axle center m upper area is greater than the car cun X2 of axle center m lower zone.Therefore, when axial region 202 rotation, the lubricant oil traction (suction force) that dynamic pressure groove Hb produces in the top radial bearing surface is relatively greater than the lubricant oil traction that produces in the lower shaft bearing surface.

Bearing housing 208 is formed by sintering metal or brass and aluminium soft metal system porous body cylindrical shapes such as (aluminum alloys) ground, and concrete, the sintering metal of porous body comprises with copper being main component.The inner peripheral surface 208a of bearing housing 208 is formed smooth and cylinder arcuate surface.Although not shown, on the part annular region of the lower end surface of bearing housing 208 208b, for example, be formed with thrust bearing surface I, this thrust bearing surface I comprises the boundary section of dynamic pressure groove and the formation and the boundary dynamic pressure groove of a plurality of helix shape.Care for meaning, the shape of dynamic pressure groove can be other shapes such as above-mentioned shape or man type.

In addition, form single or multiple axial groove 208d1 vertically on the whole length of the outer peripheral surface 208d of bearing housing 208, these single or multiple axial groove 208d1 are used for the two ends of connection shaft bearing sleeve 208.In the present embodiment, be formed with three axial groove 208d1 in a circumferential direction at regular intervals.

Housing 207 constitutes the opening of the end of base material 207b closed side 207a by general cylindrical shape sidepiece 207a with base material 207b as the bottom of separating with sidepiece 207a.For example, sidepiece 207a is formed by resin material, and base material 207b is made by metallic material such as stainless steel and brass.Base material 207b is fixed to the lower end of sidepiece 207a by means such as bonding, as to be press-fitted.

On the part annular region of the upper-end surface of sidepiece 207a 207a1, although not shown, be formed with thrust bearing surface J, this thrust bearing surface J comprises the dynamic pressure groove and the formation of a plurality of helix shape and the boundary section of this dynamic pressure groove of demarcating.The shape that note that the dynamic pressure groove can be other shapes such as above-mentioned shape or man type.

Be formed with outer wall 207a2 on the periphery of sidepiece 207a, this outer wall 207a2 extends towards the top gradually in the taper mode.This conical outer wall 207a2 forms the ring packing space S, and the radial dimension of sealing space S diminishes to (between the inner peripheral surface 209b1 at himself and cylindrical shape part 209b) top gradually from the lower end side of housing 207.When axial region 202 and 209 rotations of hub member, the sealing space S is communicated with the thrust-bearing gap of thrust-bearing part T22.

Next, the following describes the installation step of the dynamic pressure bearing device of present embodiment.

At first, by being press-fitted means such as bonding bearing housing 208 is fixed on the inner peripheral surface 207a3 of the sidepiece 207a that constitutes housing 207.Next, axial region 202 insertions that integrally form with hub member 209 are fixed in the bearing housing 208 of sidepiece 207a.Then, for example lip part 210 is placed on the axial region 202 by being threaded.Then, for example, by be press-fitted with the bonding lower end side that base material 207b is fixed to sidepiece 207a on week.

When aforementioned assembling was finished, the axial region 202 of rotating member 203 was inserted on the inner peripheral surface 208a of bearing housing 208, and lip part 210 is included in the space between the upper-end surface 207b1 of the lower end surface 208b of bearing housing 208 and base material 207b suitably.Then, for example, be poured as the lubricant oil of fluid (lubricating fluid) in the inner space of dynamic pressure bearing device 201 into, dynamic pressure bearing device 201 comprises the endoporus that is positioned at bearing housing 208.At this moment, the pasta of lubricant oil remains in the scope of seal space S.

In the dynamic pressure bearing device 201 with said structure, when rotating member 203 (axial region 202) rotated, it is relative with the inner peripheral surface 208a of bearing housing 208 that the radial bearing surface H that is formed independently by the outer peripheral surface 202a of axial region 202 crosses the radial bearing gap.With the rotation of axial region 202, the lubricant oil that charges into each radial bearing gap produces the hydrodynamic effect, and axial region 202 is supported in the non-contact mode under the effect of radial pressure.Therefore, formed the first radial bearing part R21 and the second radial bearing part R22, the first radial bearing part R21 and the second radial bearing part R22 support axial region 202 diametrically rotatably in the non-contact mode.

In addition, between the upper-end surface 210a of the lower end surface of bearing housing 208 208b and lip part 210, form thrust-bearing gap (not shown).Lubricant oil produces the hydrodynamic effect in this thrust-bearing gap, thereby forms the first thrust-bearing part T21, and this first thrust-bearing part T21 supports rotating member 203 rotatably in the non-contact mode on thrust direction.Similarly, at the upper-end surface 207a1 of the sidepiece 207a of housing 207 and constitute between the lower end surface 209a1 of hub member 209 of rotating member 203 and form the thrust-bearing gap.Rotation with rotating member 203, lubricant oil produces the hydrodynamic effect in this thrust-bearing gap, thereby form the first thrust-bearing part T22, this first thrust-bearing part T22 utilizes pressure to support rotating member 203 rotatably in the non-contact mode on thrust direction.

Dynamic pressure bearing device with the dynamic pressure generating section that utilizes method formation of the present invention not only can be used for the said equipment ideally, and can be used for having the dynamic pressure bearing device of other structures.In the description taken in conjunction with the accompanying drawings below, structure shown in Figure 21 and same configuration element are represented with same tag, and have been omitted duplicate explanation.

Figure 22 shows another structure example of dynamic pressure bearing device 201.Compare with dynamic pressure bearing device shown in Figure 21, the main difference point of dynamic pressure bearing device 201 shown in Figure 22 is: the shaft component 222 that is formed by axial region 202 and lip part 210 forms complicated metal structure and complicated resin material structure, the second thrust-bearing part T22 is formed between the upper-end surface 207b1 of the lower end surface 210b of lip part 210 and base material 207b on the other side, and the annular seat component 219 of separating with housing 207 was fixed in the upper end of sidepiece 207a on week; Seal space S is formed between the outer peripheral surface 202 of inner peripheral surface 219a and axial region on the other side 202.

Axial region 202 comprises the material 202 ' that uses among Figure 19 and is formed on dynamic pressure generating section (radial bearing surface H) on the outer peripheral surface 202a by above-mentioned ink jet method.The axial hole 202b that is formed on axial region 202 passes the whole length of resin material 220 in the axial direction, and integrally forms entire flange portion 210, and this lip part 210 overhangs out to the outer diameter side from the lower end of axial region 202.What can be used as resin material 220 has PA66 (66 nylon), LCP (liquid-crystalline polymer), polyphenylene sulfides PPS thermoplastic resins such as (polyphenylene sulfide), if necessary, can add packings such as glass fibre in these resin materials.

In this structure example, make metallic material and resin material 220 be in jointing state in order to prevent separating of axial region 202 (metallic material) and resin material 220, to embed in the lip part 210 and conical surface 202d is set on all sides in the upper end of axial region 202 by lower end 202c with axial region 202.

By axial region 202 is used as the portion that is inserted into, with resin injection molding (insertion moulding) manufactured shaft component 222.In the shaft component 222 of the type, in view of the function of bearing apparatus, high dimensional accuracy is necessary, and aforementioned high dimensional accuracy comprises the parallelism between two end faces of up rightness between axial region 202 and the lip part 210 and lip part 210.Insert moulding if adopt, only just can guarantee required precision by increasing the mould precision and accurately will being positioned in the mould as the axial region 202 that is inserted into part, simultaneously, only just can realize low-cost mass production by increasing the mould precision and accurately will being positioned in the mould as the axial region 202 that is inserted into part.In addition, the part annular region on two end face 210a, 210b of lip part 210 forms the first thrust bearing surface I and the second thrust bearing surface J respectively, adopts injection molding equally.

Compare with the shaft component 222 that forms with metallic material, the shaft component 222 with said structure can reduce the weight of axial region and lip part greatly.Therefore, when shaft component 222 collides with bearing housing 208 or base material 207b, can reduce the impact that causes, collide the possibility that is partially damaged like this and just reduce greatly.In addition,, therefore improved the sliding properties of the lower end surface 208b of the upper-end surface 207b1 of base material 207b and metallic bearing housing 208, guaranteed the reduction of torque because lip part 210 is formed from a resin.

In addition, in dynamic pressure bearing device as implied above 210, bearing housing 208 and housing 207 (sidepiece 207a) are formed independently, but also can integrally form.Figure 23 has shown the example of this structure, and the bearing housing 208 that forms independently in Figure 22 and the sidepiece 207a of housing 207 are made of the bearing element 227 of an integral body.In this structure example, can reduce number of components and artificial, and cost that can be lower forms dynamic pressure bearing device 201.

Bearing element 227 has general cylindrical shape, and is made by metallic material or resin material.Bearing element 227 comprises cover member 227a, sealing and fixing member 227b and base material fixed component 227c.Shaft component 222 is inserted into the interior week of cover member 227a, and sealing and fixing member 227b is used for fixing from the upwardly extending sealing component 219 of the outer circumferential side of cover member 227a, and base material fixed component 227c extends downwards from the outer circumferential side of cover member 227a.In addition, the first thrust-bearing part T21 is formed between the upper-end surface 210a of the lower end surface 227a1 of cover member 227a and lip part on the other side 210.

In addition, in the structure shown in Figure 22 and 23, sealing component 219 forms mutually independently with housing 207 and bearing element 227, but they also can integrally form, can reduce number of components and artificial like this, also can form dynamic pressure bearing device 201 simultaneously with lower cost.

In the above description, dynamic pressure bearing device has used the axial region 202 with axial hole 202b, as shown in figure 19.Yet, can be used on the axial region 202 formation dynamic pressure bearing devices 201 (not shown) that the one end has protruding 202a1 and has depression 202a2 at its other end.

Like this, the above-mentioned shape that is formed on the dynamic pressure generating section on the radial bearing surface H is only used for example, and the dynamic pressure groove pattern of the dynamic pressure groove of available other shapes of formation is as dynamic pressure generating section, as long as this shape can enough ink jet method printings.Radial bearing surface H can so-called ladder dynamic pressure generating section (step hydrodynamic pressure producing part) form form, or form with the form of so-called leafy dynamic pressure generating section (multirobe hydrodynamic pressure producing part).In the ladder dynamic pressure generating section, axial dynamic pressure groove a plurality of positions in a circumferential direction form.In many shells dynamic pressure generating section, with similarity method a plurality of bow shaped surface of favourite at the court in a circumferential direction.

In addition, in the foregoing description, example radial bearing surface H form independently in two axial positions.Yet the quantity of radial bearing surface H is selectable, and radial bearing surface H can be formed on axial a position or three above positions.

In addition, can on thrust bearing surface I, J, form the dynamic pressure generating section that has with the dynamic pressure groove of above-mentioned spirality or other arrangements, and for example stepped shaft dynamic pressure generating section and so-called waveform dynamic pressure generating section (stepped shaft belongs to waveform), as dynamic pressure generating section.

Figure 24 has summarily shown the example constructions of the spindle motor of the information equipment that is integrated with dynamic pressure bearing device shown in Figure 21 201.The spindle motor that is used for information equipment is used for disc drive units such as HDD, dynamic pressure bearing device 201 supports rotating member 203 rotatably in the non-contact mode, and dynamic pressure bearing device 201 comprises axial region 202, stator coil 204 and crosses gap rotor magnet 205 respect to one another with it and electric machine support (retaining member) 206.Stator coil 204 is connected to the periphery of support 206, and rotor magnet 205 is connected to the periphery of rotating member 203.Rotating member 203 keeps discs such as one or more disks in its periphery.Housing 207 is fixed to the interior week of electric machine support 206, for example, and by being press-fitted modes such as combination.When stator coil 204 was excited, under the effect of the electromagnetic force that produces, the rotating member 203 between stator coil 204 and the rotor magnet 205 was rotated.Therefore, rotating member 203 and axial region 202 rotate together.Motor has high durable life-span and high running accuracy.

Claims (13)

1. method that forms dynamic pressure generating section, this method comprises: form dynamic pressure generating section by experience print steps and cure step, the black aggregate of utilization trace, trace China ink is provided in non-contacting mode on a plurality of parts of plat surface of material in print steps, and the China ink that is provided in cure step is hardened.

2. the method for formation dynamic pressure generating section according to claim 1, wherein said material relatively slides, so that described material is sent to cure step from print steps.

3. the method for formation dynamic pressure generating section according to claim 2, wherein in print steps, provide shower nozzle, described shower nozzle comprises the nozzle of discharging the trace China ink, and described arrangement of nozzles becomes multirow, and the slide relative direction of the arranged direction of described nozzle and material tilts.

4. the method for formation dynamic pressure generating section according to claim 1, wherein said material relatively rotates around its axis, so that described material is sent to cure step from print steps.

5. according to the method for each described formation dynamic pressure generating section among the claim 1-4, wherein said China ink has light hardening, and carries out the sclerosis of China ink by the irradiation of light beam.

6. method that forms dynamic pressure generating section, this method comprises: the trace China ink is provided on the surface of material and utilizes the step of aggregate printing dynamic pressure generating section of this trace China ink and the step of sclerosis China ink;

Before the print steps of dynamic pressure generating section, use the surface of the cleaning means cleaning material of from pickling, UV cleaning and ozone clean, selecting.

7. the method for formation dynamic pressure generating section according to claim 6 wherein in above-mentioned cleaning means, is carried out pickling by using hydrochloric acid.

8. the method for formation dynamic pressure generating section according to claim 6 wherein in above-mentioned cleaning means, utilizes the ultrasound effect to carry out pickling.

9. method that forms dynamic pressure generating section, be used for producing the hydrodynamic effect in the bearing play of the material surface that constitutes axial region, described method comprises: the trace China ink is provided under the situation that a plurality of materials axially connect, and utilizes the aggregate of trace China ink to form dynamic pressure generating section on each material.

10. the method for formation dynamic pressure generating section according to claim 9, wherein said material is provided with axial hole, by connecting each material in each through hole that fixed block is inserted a plurality of materials.

11. the method for formation dynamic pressure generating section according to claim 9, wherein an end of material is provided with projection, and the other end is provided with depression, by incompatible each material that is connected that projection on the adjacent materials and the depression on another material are joined.

12. according to the method for each the described formation dynamic pressure generating section among the claim 9-11, wherein dynamic pressure generating section is formed by the China ink that falls or drip from nozzle.

13. according to the method for each the described formation dynamic pressure generating section among the claim 9-12, wherein said China ink is a light-hardening resin.

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