JP4528682B2 - Manufacturing method of hydrodynamic bearing parts - Google Patents

Description

  The present invention relates to a method of manufacturing a hydrodynamic bearing part having a dynamic pressure generating groove formed on the inner surface, and is high-speed and high-precision, such as a hard disk spindle motor or a polygon mirror laser scanning motor. Applicable to bearing parts of rotating motors.

  In this type of high-speed motors, dynamic pressure bearings are used in which radial and / or thrust bearing surfaces are formed by herringbone and other groove pattern dynamic pressure generating grooves. The dynamic pressure generating groove is formed by processing the outer surface on the shaft side and when forming the inner surface on the bearing side. is there.

For example, as the former prior art for forming the dynamic pressure generating groove by processing the outer surface on the shaft side, there are those disclosed in Patent Documents 1 to 3 and the like.
JP 2000-120695 A Japanese Patent Laid-Open No. 11-093945 Japanese Patent Application Laid-Open No. 08-2833953

Further, as the latter prior art for forming the dynamic pressure generating groove formed by processing the inner surface on the bearing side, there are those disclosed in Patent Documents 4 to 6 and the like.
JP 2004-324673 A JP 2001-146914 A JP 2000-312943 A

  In the former prior art, as disclosed in Patent Documents 1 to 3 and the like, the outer surface of the thin shaft is subjected to a chemical treatment such as plating or etching, so that it can be moved by a fine herringbone or the like. The pressure generating groove can be formed relatively easily and inexpensively with high accuracy. However, stable thrust levitation characteristics can be achieved by reducing the dead weight due to the groove processing and the working fluid flowing out of the groove by centrifugal force. Was damaged.

  In the latter prior art, as disclosed in Patent Documents 4 to 6 and the like, a dynamic pressure generating groove is formed on the inner surface of a small bearing part using a tool for groove processing by ball rolling. Although it is plastically processed, stable thrust levitation characteristics can be obtained compared to the former prior art, but it is easy to perform plastic processing by positioning the dynamic pressure generating groove due to fine herringbone etc. concentrically with the shaft center Rather, it hindered production in large quantities and at low cost with good yield.

  Therefore, the present invention provides a method of manufacturing a hydrodynamic bearing component that can solve the problems of the conventional technology, and does not use plastic working by ball rolling as in the prior arts of Patent Documents 4 to 6 and the like. The new manufacturing method enables easy and high-precision machining of the dynamic pressure generating groove on the inner surface of the small-diameter bearing component, thereby enabling the production of the dynamic pressure bearing component with a high yield and a large amount at a low cost. This is the main purpose.

  The method of manufacturing a hydrodynamic bearing component according to the present invention includes a step of providing a transfer member on the outer surface of the bearing core, a step of groove forming the outer surface of the transfer member, and performing a transfer groove processing using a reverse pattern of the dynamic pressure generating groove, and a transfer A step of providing a metal bearing member on the transfer surface of the member to form a master shaft, a step of inserting the master shaft into the mold and integrally molding a resin molded member on the outer surface of the metal bearing member, A step of removing the bearing core material from the transfer member by removing the molded product from the mold, and a step of removing the transfer member to form a dynamic pressure generating groove on the inner surface of the metal bearing member. To produce a hydrodynamic bearing part in which a metal bearing member forming a hydrodynamic groove is integrated. (Claim 1)

  In the method of manufacturing a hydrodynamic bearing component according to claim 1, a form using a cylindrical shaft made of hard metal can be adopted as the bearing core material. (Claim 2)

  In the method for manufacturing a hydrodynamic bearing component according to claim 1 or 2, the transfer member may be formed of a soft metal plating layer. (Claim 3)

  In the method for manufacturing a hydrodynamic bearing part according to any one of claims 1 to 3, it is possible to adopt a form in which a rolling process is performed on a transfer member in the process of performing the transfer groove process. (Claim 4)

  5. The method of manufacturing a hydrodynamic bearing component according to claim 1, wherein the metal bearing member is formed of a hard metal plating layer having high surface hardness and corrosion resistance. (Claim 5)

  In the method for manufacturing a hydrodynamic bearing component according to any one of claims 1 to 5, it is possible to adopt a form in which a housing of a motor that uses the bearing component in the step of integrally molding the resin molded member is simultaneously molded. (Claim 6)

  In the method for manufacturing a hydrodynamic bearing component according to any one of claims 1 to 6, it is possible to adopt a form in which the bearing core is pulled out and removed in the step of removing the bearing core material. (Claim 7)

  In the method for manufacturing a hydrodynamic bearing part according to any one of claims 1 to 7, a mode in which the transfer member is dissolved and removed by a dissolving liquid in the step of removing the transfer member can be employed. (Claim 8)

  In the method of manufacturing a hydrodynamic bearing part according to claim 1, since the reverse pattern formed by grooving on the outer surface of the transfer member is transferred to the metal bearing member to form the hydrodynamic pressure generating groove, Compared to the conventional technology that directly performs dynamic pressure groove machining on the shaft hole of the bearing component, the groove machining operation is easy at each stage and the machining accuracy can be increased. Can be produced in large quantities and at low cost with a high yield.

  Moreover, since the manufactured hydrodynamic bearing part is reinforced by the metal bearing member on the shaft center side of the resin molded member, and the metal bearing member is held by the shaft member through the transfer member in the manufacturing process, Despite being a resin molded product, the shaft hole and the dynamic pressure generating groove can be manufactured with roundness and dimensional accuracy ensured.

  In the method for manufacturing a hydrodynamic bearing part according to claim 2, when a transfer groove is formed by rolling or the like on a transfer member by adopting a form using a cylindrical shaft made of hard metal such as stainless steel as a bearing core material. In addition to preventing deformation of the transfer member due to rolling pressure, it is possible to prevent deformation of the transfer member and the metal bearing member due to injection molding pressure when insert molding the resin molded member.

  In the method of manufacturing a hydrodynamic bearing part according to claim 3, by adopting a form in which the transfer member is formed of a soft metal plating layer such as copper plating, the groove processing of the transfer groove by rolling or the like is easy and the melting is performed. It can be easily separated and removed from the metal bearing member by liquid or the like.

  In the method of manufacturing a hydrodynamic bearing part according to claim 4, by adopting a form in which the transfer member is rolled in the transfer groove machining process, the shaft hole of the hydrodynamic bearing part is formed by ball rolling or the like. On the other hand, compared with the prior art that directly performs dynamic pressure grooving, the grooving operation is easy at each stage and the machining accuracy can be increased.

  In the method of manufacturing a hydrodynamic bearing component according to claim 5, the metal bearing member is formed of a hard metal plating layer such as nickel plating, so that the bearing surface of the hydrodynamic bearing component has high surface hardness and corrosion resistance. can do.

  In the method of manufacturing a hydrodynamic bearing component according to claim 6, the housing of the hydrodynamic bearing component motor is configured by simultaneously forming the housing of the motor using the bearing component in the step of integrally molding the resin molded member. Compared with the case of manufacturing individually, the productivity can be improved and the cost can be reduced, and the positioning accuracy with the motor parts mounted on the housing can also be improved.

  In the method of manufacturing a hydrodynamic bearing component according to claim 7, the pattern surface of the dynamic pressure generating groove transferred to the metal bearing member is formed by removing the bearing core material from the transfer member in the step of removing the bearing core material. The bearing core material can be removed in a state protected by.

  In the method of manufacturing a dynamic pressure bearing part according to claim 8, the pattern surface of the dynamic pressure generating groove transferred to the metal bearing member is formed by adopting a form in which the transfer member is dissolved and removed by the dissolving liquid in the step of removing the transfer member. The transfer member can be easily removed without loss.

  Hereinafter, a method for manufacturing a hydrodynamic bearing component according to the present invention will be described in detail with reference to the accompanying drawings showing a preferred embodiment to which the present invention is applied. In FIGS. 1 to 10, radial bearing surfaces parallel to the axial direction are described. FIG. 11 and FIG. 12 show a dynamic pressure generating groove on a radial bearing surface parallel to the axial direction and a dynamic pressure on a thrust bearing surface perpendicular to the axial direction. The 2nd Example which provided the generating groove | channel is shown.

  In any of the embodiments, the process A for providing the transfer member on the outer surface of the bearing core, the process B for processing the transfer groove on the transfer member, the process C for providing the metal bearing member on the outer surface of the transfer member, and the transfer member And a step D of injection molding a resin molding member with the bearing core provided with the metal bearing member as an insert shaft, a step E of removing the bearing core material from the molded product, and a step of removing the transfer member from the resin molding member and the metal bearing member. F is sequentially performed, and a dynamic pressure bearing part in which a metal bearing member that forms a dynamic pressure generating groove on the axial center side of the resin molded member is integrated can be manufactured.

  Step A is a step of providing a transfer member with a thickness larger than the inner diameter of the bearing component on the outer surface of the bearing core material having a diameter smaller than the inner diameter of the bearing component. The non-plated portion is masked by printing or other known means, and a plating process is performed over a predetermined length range set in advance. As shown in FIG. The soft metal plating layer 2 is provided locally.

  The bearing core material is a material that can be easily and satisfactorily attached when a transfer member is provided by electroless plating, electroforming, etc., and the shaft core hole of the bearing component is determined by the outer peripheral surface, so that the roundness is high. And a material capable of obtaining dimensional accuracy of the outer diameter, not being altered or deformed during the plating process, being easily and smoothly separated when removed from the transfer member in the step E of removing the bearing core material, and the like. Required.

  In this embodiment, a cylindrical shaft 1 made of a solid shaft formed by quenching stainless steel into a straight cylindrical shape is used as a bearing core material. Particularly, stainless steel has high hardness and is resistant to acid and corrosion. It is desirable to use SUS420J, which is also excellent, but it is not limited to stainless steel, but other hard metal materials having equivalent performance (for example, nickel chrome steel and other nickel alloys and chrome alloys) and ceramic surfaces are hard. It is also possible to use a metal coating.

  The bearing core material can be adapted to various uses and can take various sizes. The cylindrical shaft 1 according to this embodiment has an outer diameter of about 0.3 to 1.5 mm and a length of at least Although it can be set to a desired length sufficiently longer than the width dimension of the transfer member, in the case of the cylindrical shaft 1 according to this implementation, the length dimension is set to about 7.5 mm.

  Further, the bearing core material can be not only a solid cylindrical shaft but also a hollow shaft pipe, or can be reinforced by filling a resin material into the pipe. Although the shape is a cylindrical axis formed in a cylindrical shape, it is possible to adopt a polygonal shape or other non-circular shape if the shape of the cross section is constant, and the end is gradually reduced in diameter to a truncated cone shape or the like. You may make it into a shape.

  The transfer member is a material that can be easily joined to the bearing core material, and in the process B of processing the transfer groove, the transfer member is a material that can easily transfer the dynamic pressure generating groove with a desired pattern on the outer peripheral surface, metal In the step C of providing the bearing member, the outer peripheral side of the transfer groove processed is a material that can be firmly joined to the metal bearing member serving as the bearing component, and in the step F of removing the transfer member, the inner periphery of the metal bearing member serving as the separation surface The material is required to be a material that can be easily removed from the metal bearing member without impairing the smoothness of the side.

  In this embodiment, as the transfer member, the transfer groove processing by rolling is easy in the process B, the metal bearing member can be firmly joined in the process C, the dissolution removal by the solution in the process F is easy, and the cost is low. For this reason, a soft metal plating layer 2 is formed by electroforming a soft metal material such as copper or a copper alloy, and the soft metal plating layer 2 has a width of about 3.0 mm. The film thickness is set to about 10 to 30 μm.

  In this transfer member, the soft metal plating layer 2 can be formed by electroless plating instead of electroforming (electrolytic plating), and a soft metal such as brass, gold or silver other than copper as a metal material to be plated. It is also possible to perform electroforming or electroless plating using a material, and when groove processing is performed by a known means other than rolling, the metal bearing member can be firmly joined with a material suitable for the groove processing means. In addition, a material that can be removed in the step F can be used.

  For example, when the dynamic pressure generating groove is provided on the outer peripheral surface of the dynamic pressure bearing shaft, the resist layer applied to the outer peripheral surface of the shaft is subjected to electrolytic or chemical etching or laser irradiation in addition to the above-described plastic working by rolling. There are known techniques for removing and processing dynamic pressure generating grooves of a predetermined pattern. In the method of manufacturing a hydrodynamic bearing part according to the present invention, these known techniques are applied to Step A and Step B, and these resist layers are transferred to a transfer member. It can also take the form.

  It is also possible to adopt a form in which the transfer member is formed of a water-soluble resin. In this case, the cylindrical shaft 1 as a bearing core material is inserted into a mold, and the transfer member made of the water-soluble resin is injection-molded. After that, the transfer groove processing in the next step B can be carried out. However, if the dynamic pressure generating groove is provided in this injection mold, the transfer groove processing in the next step B is performed. Can be performed simultaneously.

  Process B is a process in which the outer surface of the transfer member is grooved to a depth that matches the inner diameter of the bearing component, and the transfer groove is processed by the reverse pattern of the dynamic pressure generating groove. As shown in FIG. 2, the outer peripheral surface of the metal plating layer 2 is subjected to a rolling process, and the transfer concave portion 3a and the transfer convex portion 3b form the transfer surface 3 with the reverse pattern of the dynamic pressure generating groove. Is grooved at a depth (5 μm) that is about ½ of the thickness of the film.

  The transfer surface 3 can be easily rolled using a known prior art dynamic pressure groove rolling device, such as the prior art disclosed in Japanese Patent Application Laid-Open No. 11-13746. Similarly, a flat die which is engraved with a dynamic pressure generating groove in an unfolded state above the cylindrical shaft 1 while two rollers provided on a horizontal moving table are rotatably supported below the cylindrical shaft 1. When the horizontal movement table and the flat die are horizontally moved in the same direction, the transfer surface 3 with a reverse pattern is rolled on the outer peripheral surface of the soft metal plating layer 2.

  Further, the transfer surface 3 can be processed by known rolling means other than the rolling means described above, and as described above in Step B, the resist layer as a transfer member is subjected to electrolytic or chemical etching or laser. Irradiation or the like can be performed to perform groove processing of a predetermined pattern. These groove processing is adapted to a dynamic pressure generating groove by a desired herringbone pattern, V-shaped pattern or spiral pattern, and the dynamic pressure generating groove. The transfer groove is processed by the reverse pattern.

  Step C is a step of providing a metal bearing member on the transfer surface of the transfer member with a thickness that matches at least the outer diameter of the bearing component, and is formed by the transfer concave portion 3a and the transfer convex portion 3b on the outer peripheral surface of the soft metal plating layer 2. A hard metal plating layer 4 which is a metal bearing member thicker than the soft metal plating layer 2 as shown in FIG. 3 and FIG. On the inner peripheral side of the hard metal plating layer 4, a dynamic pressure groove pattern surface 5 complementary to the transfer surface 3 is formed by a dynamic pressure concave portion 5a and a dynamic pressure convex portion 5b.

  The metal bearing member is made of a material that can be easily and firmly joined to the transfer member, and the transfer member can be easily removed in the process F, and the inner peripheral side movement formed on the separation surface when removed. A material that does not impair the shape of the pressure generating groove, roundness and dimensional accuracy as dynamic pressure bearing parts, high surface hardness, and corrosion resistance are required.

  In this embodiment, the metal bearing member can be easily and firmly joined with copper or a copper alloy of the soft metal plating layer 2 by electroforming plating, the cylindrical shaft 1 can be drawn and removed in the process E, and the soft metal can be removed by the solution in the process F. The removal of the plating layer 2 is easy, and the shape of the dynamic pressure generating groove on the inner peripheral side is not damaged when it is dissolved and removed, the roundness and dimensional accuracy are ensured, the surface hardness is high, and the corrosion resistance is high. For some reason, a hard metal plating layer 4 is formed by electroforming a hard metal material such as nickel or a nickel alloy, and the thickness of the coating is set to about 100 μm, which is sufficiently thicker than the soft metal plating layer 2. It is meaty.

  In this metal bearing member, the hard metal plating layer 4 can be formed by electroless plating with a hard metal material instead of electroforming (electrolytic plating), and carbon is added to nickel or a nickel alloy as a metal material to be plated. Thus, it is possible to apply a known technique for enhancing the conductivity or adding a self-lubricating fine particle such as polytetrafluoroethylene (PTFE) or graphite to enhance the slidability and wear resistance.

  Process D is a process in which a bearing core material provided with a metal bearing member on the transfer surface of the transfer member is used as a master shaft, and this master shaft is inserted into an injection mold to integrally mold a resin molded member on the outer surface of the metal bearing member. In this embodiment, a master shaft 6 in which a soft metal plating layer 2 and a hard metal plating layer 4 are laminated is inserted on the outer peripheral surface of the cylindrical shaft 1, and injection molding is performed on the outer peripheral surface of the hard metal plating layer 4, As shown in FIG. 5, a resin sleeve 7 which is a resin molding member is integrally molded.

  In this embodiment, the resin molded member is formed in the cylindrical resin sleeve 7 so as to be adapted to the radial bearing surface. However, the mold cavity is set as desired according to the application and adapted to the radial and thrust bearing surfaces. It can be formed into a bottomed cylindrical body as in a second embodiment to be described later, or formed integrally with a housing to which other motor components are mounted, and applied to a bearing device of a high-speed spindle motor, for example.

  In this insert molding, the laminated transfer member, the soft metal plating layer 2 as the metal bearing member and the hard metal plating layer 4 are held by the cylindrical shaft 1 as the bearing core material. In addition, the inner and outer diameters can be prevented from being deformed, and after the injection molding, the cylindrical shaft 1 is taken out from the mold, and after the thermal contraction is completed, the bearing core material removing step, which is the next step, is performed. It is possible to ensure the roundness of parts and the dimensional accuracy of inner and outer diameters.

  Molded resin materials are excellent in mechanical strength and dimensional stability, so it is desirable to use liquid crystal polymer (LCP), or in addition to liquid crystal polymer, crystals such as polyphenylene sulfide (PPS) resin, polyacetal resin and polyamide resin are used. It is possible to use a functional polymer or a highly functional resin material that exhibits the same function other than these, and if necessary, additives such as a fiber reinforcing agent and a lubricant may be added to these resin materials. good.

  Step E is a step of removing the bearing core material from the inner side and the metal bearing member, and is a bearing core material in a state where the soft metal plating layer 2 and the hard metal plating layer 4 which are the inner side and the metal bearing member are held in a locked state. The cylindrical shaft 1 can be removed as shown in FIGS. 6 and 7 by pulling the cylindrical shaft 1 in the axial direction or slightly hitting it in the axial direction, and the shaft formed by the removal hole 8 after being pulled out. The inner peripheral surface of the soft metal plating layer 2 is exposed in the core hole.

  In this bearing core material removal, the dynamic pressure groove pattern surface 5 formed on the inner peripheral side of the hard metal plating layer 4 is protected by the soft metal plating layer 2 formed by electroforming copper or copper alloy or the like. Since tensile stress acts on the outer side of the axis as a characteristic of the cast plating layer, a fine gap is generated between the soft metal plating layer 2 and the cylindrical shaft 1 that are formed thin, and the cylindrical shaft 1 is pulled out. Removal can be performed easily.

  If necessary, the outer peripheral surface of the bearing core material 1 is mirror-finished, the outer peripheral surface of the bearing core material 1 is coated with a slidable film in advance, or the soft metal plating layer 2 is coated with polytetrafluoroethylene (PTFE). ) Or the like to improve releasability, or temporarily heat or cool the soft metal plating layer 2 and the hard metal plating layer 4 or the bearing core cylindrical shaft 1 to Removal can be made easier by using various known means such as utilizing the difference in thermal expansion coefficient.

  Step F is a step of removing the transfer member from the metal bearing member. In this embodiment, the soft metal formed by electroforming copper or copper alloy from the hard metal plating layer 4 formed by nickel or nickel alloy by electroforming. The metal plating layer 2 is dissolved and removed. In this case, copper is dissolved in at least one of a ferric chloride solution, a copper chloride solution, a mixed solution of hydrogen peroxide and sulfuric acid, an aqueous solution of ammonium persulfate, or aqueous ammonia. Use liquid.

  As a result, it is possible to manufacture a dynamic pressure bearing part in which a metal bearing member that forms a dynamic pressure generating groove is formed on the axial center side of the resin molded member. This dynamic pressure bearing part 9 is shown in FIGS. As shown in the figure, since the axial center side of the resin sleeve 7 which is a resin molded member is reinforced by the hard metal plating layer 4 which is a metal bearing member, roundness and dimensional accuracy are ensured and surface hardness is high and corrosion resistance is ensured. In addition, the dynamic pressure groove pattern surface 5 transferred from the soft metal plating layer 2 as a transfer member is easily and accurately formed on the inner peripheral side as shown in a development view shown in FIG.

  The transfer member is removed in the process F when the transfer member is formed of a resist layer other than the soft metal plating layer 2, for example, by removing a solvent that can dissolve the resist layer or laser irradiation. When the member is formed of a water-soluble resin, an appropriate form can be adopted depending on the properties of the material used as the transfer member, unless the water-soluble resin is removed with pure water or the like.

  Next, a method for manufacturing a hydrodynamic bearing component according to the second embodiment having a radial bearing surface parallel to the axial direction and a thrust bearing surface perpendicular to the axial direction will be described with reference to FIGS. In this embodiment, as in the case of the first embodiment, the process A to the process F are sequentially performed to manufacture the hydrodynamic bearing part. The explanation will focus on the parts to be performed.

  First, in step A, a transfer member is provided on the bearing core. Since the region is an outer surface on one end side including the one end surface of the bearing core, one of the cylindrical shafts 1 (bearing core) is shown in FIG. A soft metal plating layer 12 (transfer member) is provided in a bottomed cylindrical shape on the outer surface on one end side including the side end surfaces, and in step B, the soft metal plating layer 12 is individually transferred to the outer peripheral surface side and the end surface side of the soft metal plating layer 12. Groove processing is performed by manufacturing or the like, and transfer grooves are processed by a reverse pattern of the dynamic pressure groove pattern surfaces 5 and 15 shown in FIG. 12 (not shown).

  In Step C, a hard metal plating layer 14 (metal bearing member) is provided in a bottomed cylindrical shape so as to cover the transfer groove on the soft metal plating layer 12 (transfer member), and in Step D, the soft metal plating layer is provided. The cylindrical shaft 1 (bearing core material) in which 12 (transfer member) and the hard metal plating layer 14 (metal bearing member) are stacked is used as an insert shaft, and is injection molded outside the hard metal plating layer 14 (metal bearing member) in the mold. The bottomed cylindrical resin sleeve 17 (resin molding member) is integrally molded.

  Further, in step E, the cylindrical shaft 1 (bearing core material) is removed from the injection molded product taken out from the mold by drawing to the other end side, and in step F, the soft metal plating layer 12 (transfer member) is dissolved. As shown in FIG. 12, the hydrodynamic bearing component 19 is manufactured by integrating the metal bearing member 14 forming the dynamic pressure generating groove on the axial center side of the resin sleeve 17 (resin molding member). be able to.

  The dynamic pressure bearing part 19 is transferred from the soft metal plating layer 12 (transfer member) to the inside of the hard metal plating layer 14 (metal bearing member) by removing the soft metal plating layer 12 (transfer member) in the process F. The dynamic pressure generating grooves are formed by the dynamic pressure groove pattern surfaces 5 and 15. The dynamic pressure generating grooves are the dynamic pressure groove pattern surface 5 serving as the radial bearing surface on the shaft peripheral side and the thrust bearing surface on the shaft end side. The dynamic pressure groove pattern surface 15 is formed.

  In the dynamic pressure bearing parts 9 and 19 according to the first and second embodiments, for example, the dissolution removal in the process F is insufficient, or the dynamic pressure generating grooves by the dynamic pressure groove pattern surfaces 5 and 15 for other reasons. If it is necessary to correct this, it is also possible to correct it by post-processing, in which case the groove processing by ball rolling widely used as the prior art can be used. No new groove processing is performed, and correction processing is performed while tracing the hydrodynamic groove pattern surfaces 5 and 15 that have already been grooved. Therefore, the machining operation is extremely easy.

It is process explanatory drawing of the manufacturing method of the dynamic pressure bearing components by 1st Example to which this invention is applied, Comprising: Explanatory drawing of the process A which provides a transfer member in the outer surface of a bearing core material. Similarly, explanatory drawing of process B which processes a transfer groove on a transfer member. Similarly, explanatory drawing of the process C which provides a metal bearing member in the outer surface of a transfer member. Explanatory drawing which expanded the principal part of the process C of FIG. Similarly, explanatory drawing of the process D which carries out the injection molding of the resin molding member to the insert shaft from the bearing core material which provided the transfer member and the metal bearing member. Similarly, explanatory drawing of the process E which removes a bearing core material from a molded article. Explanatory drawing which expanded the principal part of the process E of FIG. Similarly, explanatory drawing of process F which removes a transfer member from a resin molding member and a metal bearing member. Explanatory drawing which expanded the principal part of the process F of FIG. 8 is a development view of the dynamic pressure groove pattern in the dynamic pressure bearing part completed in the process F. FIG. It is process explanatory drawing of the manufacturing method of the dynamic pressure bearing components by 2nd Example to which this invention is applied, Comprising: Explanatory drawing of the process A which provides a transfer member in the outer surface of a bearing core material. Similarly, explanatory drawing of process F which removes a transfer member from a resin molding member and a metal bearing member.

Explanation of symbols

1 Cylindrical shaft (bearing core material)
2,12 Soft metal plating layer (transfer member)
3 Transfer surface 4,14 Hard metal plating layer (metal bearing member)
5,15 Dynamic pressure groove pattern surface 6 Master shaft (insert member)
7, 17 Resin sleeve (resin molding member)
8 Removal hole (axial hole)
9,19 Hydrodynamic bearing parts

Claims (8)

A step of providing a transfer member on the outer surface of the bearing core, a step of performing groove processing on the outer surface of the transfer member to perform transfer groove processing by a reverse pattern of the dynamic pressure generating groove, and a metal bearing member on the transfer surface of the transfer member to provide a master A step of forming a shaft, a step of inserting a master shaft into the mold and integrally molding a resin molded member on the outer surface of the metal bearing member, and taking out the molded product from the mold integrally with the master shaft and bearing from the transfer member A metal bearing member comprising a step of removing a core material and a step of removing a transfer member to form a dynamic pressure generating groove on the inner surface of the metal bearing member, and forming a dynamic pressure generating groove on the axial center side of the resin molded member. A method of manufacturing a hydrodynamic bearing part, characterized by being integrated.   The method for manufacturing a hydrodynamic bearing component according to claim 1, wherein a hard metal cylindrical shaft is used as the bearing core.   The method for manufacturing a hydrodynamic bearing component according to claim 1, wherein the transfer member is formed of a soft metal plating layer.   The method for manufacturing a hydrodynamic bearing part according to claim 1, wherein in the step of performing the transfer groove processing, a rolling process is performed on the transfer member.   The said metal bearing member is a manufacturing method of the hydrodynamic bearing components in any one of Claims 1-4 formed with a hard metal plating layer.   The method for manufacturing a hydrodynamic bearing component according to any one of claims 1 to 5, wherein in the step of integrally molding the resin molded member, a housing of a motor that uses the bearing component is also molded simultaneously.   The method for producing a hydrodynamic bearing component according to claim 1, wherein the bearing core material is removed from the transfer member in the step of removing the bearing core material.   The method for manufacturing a hydrodynamic bearing component according to claim 1, wherein in the step of removing the transfer member, the transfer member is dissolved and removed by a dissolving liquid.

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