WO2019139007A1 - Dispositif de palier fluide dynamique et moteur le comportant - Google Patents

Dispositif de palier fluide dynamique et moteur le comportant Download PDF

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Publication number
WO2019139007A1
WO2019139007A1 PCT/JP2019/000242 JP2019000242W WO2019139007A1 WO 2019139007 A1 WO2019139007 A1 WO 2019139007A1 JP 2019000242 W JP2019000242 W JP 2019000242W WO 2019139007 A1 WO2019139007 A1 WO 2019139007A1
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WO
WIPO (PCT)
Prior art keywords
bearing
bearing sleeve
housing
fluid dynamic
lubricating oil
Prior art date
Application number
PCT/JP2019/000242
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English (en)
Japanese (ja)
Inventor
慎治 小松原
Original Assignee
Ntn株式会社
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Publication date
Application filed by Ntn株式会社 filed Critical Ntn株式会社
Publication of WO2019139007A1 publication Critical patent/WO2019139007A1/fr

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C17/00—Sliding-contact bearings for exclusively rotary movement
    • F16C17/02—Sliding-contact bearings for exclusively rotary movement for radial load only
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C17/00—Sliding-contact bearings for exclusively rotary movement
    • F16C17/04—Sliding-contact bearings for exclusively rotary movement for axial load only
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C17/00—Sliding-contact bearings for exclusively rotary movement
    • F16C17/10—Sliding-contact bearings for exclusively rotary movement for both radial and axial load
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C33/00—Parts of bearings; Special methods for making bearings or parts thereof
    • F16C33/02—Parts of sliding-contact bearings
    • F16C33/04—Brasses; Bushes; Linings
    • F16C33/06—Sliding surface mainly made of metal
    • F16C33/10—Construction relative to lubrication
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C35/00—Rigid support of bearing units; Housings, e.g. caps, covers
    • F16C35/02—Rigid support of bearing units; Housings, e.g. caps, covers in the case of sliding-contact bearings

Definitions

  • the present invention relates to a fluid dynamic bearing device and a motor provided with the same.
  • the fluid dynamic pressure bearing device is a bearing device for a motor mounted on various electric devices including an information device, specifically, for a fan motor incorporated in a PC or the like, or a laser beam printer ( It is suitably used as a bearing device for a polygon scanner motor incorporated in LBP).
  • This fluid dynamic pressure bearing device has a bottomed cylindrical (a shape integrally having a cylindrical portion and a bottom portion closing one end in the axial direction) a housing, a bearing sleeve disposed on the inner periphery of the housing, and a bearing A shaft member inserted into the inner periphery of the sleeve, a radial bearing portion supporting the shaft member in the radial direction by an oil film of lubricating oil formed in a radial bearing gap, a thrust bearing portion supporting one end of the shaft member, a housing And an annular member (seal member) fixed to the inner periphery of the opening of
  • This fluid dynamic pressure bearing device is used in a so-called full fill state in which the entire inner space of the housing is filled with lubricating oil, and a seal space (the inner peripheral surface of the annular member and the outer peripheral surface of the shaft member A radial gap) having a larger gap width than the radial bearing gap is provided.
  • the seal space has a buffer function to absorb the volume change caused by the temperature change of the lubricating oil, and is designed to always keep the oil surface of the lubricant within the seal space within the assumed temperature change range. There is. As a result, it is possible to prevent the deterioration of the bearing performance due to the external leakage of the lubricating oil and the contamination of the surrounding environment.
  • the fluid dynamic bearing includes: a bottomed cylindrical housing; a bearing sleeve disposed on the inner periphery of the housing; a shaft member inserted on the inner periphery of the bearing sleeve; and an upper end surface of the bearing sleeve
  • An annular seal member fixed to the inner periphery of the housing in a contact state and forming a seal space with the outer peripheral surface of the shaft member, and a radial between the inner peripheral surface of the bearing sleeve and the outer peripheral surface of the shaft member
  • the part is filled with lubricating oil, and the remaining part is a void part not filled with lubricating oil.
  • the amount of lubricating oil filled in the internal space of the housing becomes smaller than the total volume of the internal space, and An area not filled with lubricating oil is provided.
  • the present invention provides a fluid dynamic bearing device capable of maintaining a required bearing rigidity while reducing the axial dimension of the entire device, and capable of being assembled at low cost. , And technical issues to be solved.
  • this bearing device has a bottomed cylindrical housing closed at one end in the axial direction and open at the other end in the axial direction, a bearing sleeve disposed on the inner periphery of the housing, and a bearing that can be inserted and removed.
  • the shaft member is radially oriented by an oil film of lubricating oil formed in a radial bearing gap between an inner peripheral surface of the bearing sleeve and an outer peripheral surface of the shaft member, and a shaft member having a shaft portion inserted into the inner periphery of the sleeve
  • a fluid dynamic bearing device comprising a radial bearing portion to support and a thrust bearing portion to support one end of a shaft member in a thrust direction
  • a part of the internal space of the housing is filled with lubricating oil and the remaining part is lubricated
  • An axial end surface of the bearing sleeve which is an oil-free gap and is an opening side of the housing is open to the atmosphere, and an axial portion is formed between the inner peripheral surface of the bearing sleeve and the axial end surface.
  • the “thrust bearing portion” referred to here may be, for example, a pivot bearing portion which contacts and supports one end of the shaft member in the thrust direction.
  • the bearing on the opening side of the housing is adopted while adopting an oil-impregnated structure in the form of a so-called partial fill in which a part of the internal space of the housing is filled with lubricating oil.
  • An inclined surface portion is formed between the inner peripheral surface of the bearing sleeve and the axial end surface to form an oil buffer space between the inner peripheral surface of the bearing sleeve and the axial end surface, with one end surface in the axial direction of the sleeve being open to the atmosphere.
  • the seal member which is essential in the fluid dynamic bearing having the oil-impregnated structure in the form of the conventional partial fill can be eliminated, the entire shaft of the fluid dynamic bearing can be obtained without changing the axial dimension of the bearing sleeve.
  • Directional dimensions can be shortened.
  • the oil buffer space of sufficient volume can be obtained only by utilizing a part of axial direction one end side of a bearing sleeve as formation of an oil buffer space as a slope part.
  • the inclined surface portion is continuous with the chamfered portion continuous with the inner peripheral surface of the bearing sleeve and the chamfered portion, and the inclination angle with respect to the central axis of the bearing sleeve is smaller than the chamfered portion. It may consist of a large, large inclined surface.
  • the insertion of the shaft portion is smooth when the shaft portion is inserted into the inner periphery of the bearing sleeve. There is a possibility that can not be done. If the inclination angle of the inclined surface is reduced for the purpose of smooth insertion of the shaft, there arises a problem that the oil buffer space is reduced. Therefore, as described above, by forming the inclined surface portion with the chamfered portion and the large inclined surface having a larger inclination angle than the chamfered portion, it is possible to smoothly insert the shaft portion, but with a sufficient volume of oil. It is possible to form the buffer space with the outer peripheral surface of the shaft portion.
  • the inclination angle with respect to the central axis of the large inclined surface may be larger than 45 ° and smaller than 90 °.
  • the bearing sleeve has a receding surface portion between the axial one end surface and the outer peripheral surface, which is receded to the axial center side of the bearing sleeve than the axial one end surface.
  • the bearing sleeve may be held between the pressing member and the housing by pressing the receding surface portion in the axial direction by the pressing member.
  • the bearing sleeve is fixed to the housing at the same time as fixing the pressing member to the housing. It can be fixed. Therefore, the effort required for the assembly of members (especially the assembly of a bearing sleeve and a housing) can be reduced.
  • the bearing sleeve is provided with a receding surface portion receding to the axial center side of the bearing sleeve from one end surface in the axial direction, and the bearing surface is held by pressing the receding surface portion by the pressing member. A part or all of the axial direction can be accommodated on the axial center side of the bearing sleeve rather than the upper end surface. Therefore, the axial dimension of the fluid dynamic bearing can be shortened as much as possible while using the pressing member.
  • the pressing member may be fixed to the housing by press-fitting the outer peripheral surface thereof into the inner peripheral surface of the housing.
  • the pressing member when the pressing member is fixed to the housing by press-fitting the outer peripheral surface of the pressing member to the inner circumferential surface of the housing, the axial direction of (the retreating surface portion of) the bearing sleeve by the pressing member The center can be pushed in.
  • the pressing member, the bearing sleeve and the housing can be fixed to each other with a minimum of work.
  • the bearing sleeve may be made of a porous body in which the inner holes are impregnated with the lubricating oil.
  • the bearing sleeve is formed of a porous body and the internal pores thereof are impregnated with the lubricating oil
  • the radial bearing clearance and the thrust bearing are generated due to the bleeding of the lubricating oil from the surface opening of the bearing sleeve.
  • the area around the department can be filled with ample lubricating oil. Therefore, the bearing performance of the radial bearing portion and the thrust bearing portion can be stably maintained.
  • the bearing sleeve impregnated with lubricating oil can be fixed to the housing in advance, the amount of lubricating oil injected into the internal space of the housing can be reduced accordingly. Therefore, it becomes possible to perform the oiling operation to the inside of a housing more simply.
  • the lubricating oil may be an ester type, a PAO type or a fluorine type lubricating oil.
  • the fluid dynamic bearing device can maintain the required bearing rigidity while reducing the axial dimension of the entire device, and can be assembled at low cost.
  • a motor provided with the above-mentioned fluid dynamic pressure bearing device it can be suitably provided especially as a fan motor etc. which are required to be thinned.
  • FIG. 3 It is a sectional view of a fan motor concerning one embodiment of the present invention.
  • FIG. 3 It is sectional drawing of the fluid hydrodynamic bearing apparatus shown in FIG. 3 is a cross-sectional view of the bearing sleeve shown in FIG. It is a principal part expanded sectional view of a fluid hydrodynamic bearing apparatus shown in FIG.
  • FIG. 2 shows the assembly process of the fluid hydrodynamic bearing apparatus shown in FIG. 2 and is a figure which shows the middle stage (at the time of insertion of a shaft member) of this assembly process.
  • FIG. 5 is a view for conceptually explaining the operation of the oil buffer space shown in FIG. 4, and is a main part enlarged cross-sectional view showing a state in which the lubricating oil is held in the oil buffer space.
  • FIG. 5 is a view for conceptually explaining the operation of the oil buffer space shown in FIG. 4, and is an enlarged sectional view of an essential part when the drawing of the lubricating oil occurs.
  • FIG. 1 conceptually shows one configuration example of a fan motor according to the present embodiment.
  • the fan motor includes a fluid dynamic pressure bearing device 1, a shaft member 2 serving as a rotating portion of the fluid dynamic pressure bearing device 1, a rotor 3 to which the shaft member 2 is attached and has blades not shown, and a rotor 3 And a stator coil 5 opposed to the rotor magnet 4 via a radial gap, and a motor base 6 as a holding member to which the stator coil 5 is attached and which constitutes the stationary side of the fan motor.
  • the housing 7 of the fluid dynamic bearing 1 is fixed to the inner periphery of the motor base 6, and the rotor 3 is fixed to one end of the shaft member 2 of the fluid dynamic bearing 1.
  • a magnetic force (repulsive force) in the direction to cancel this thrust acts, and the thrust load generated by the difference between the thrust and the magnetic force is the fluid dynamic bearing device 1 Acting on the thrust bearing T of the
  • the magnetic force in the direction to cancel the thrust can be generated, for example, by displacing the stator coil 5 and the rotor magnet 4 in the axial direction (detailed illustration is omitted).
  • a radial load acts on the shaft member 2 of the fluid dynamic bearing device 1.
  • the radial load acts on the radial bearings R1, R2 of the fluid dynamic bearing device 1.
  • FIG. 2 is a cross-sectional view of the fluid dynamic bearing device 1 according to the present embodiment.
  • the fluid dynamic bearing device 1 includes a housing 7, a bearing sleeve 8 disposed on the inner periphery of the housing 7, a shaft member 2 inserted on the inner periphery of the bearing sleeve 8, and the bearing sleeve 8 in the axial direction
  • it mainly includes a pressing member 9 for pressing in a direction along the central axis X of the bearing sleeve 8 (the same applies hereinafter) and holding the same with the housing 7.
  • the inner space of the housing 7 is filled with a predetermined amount of lubricating oil L (indicated by dense hatching in FIG.
  • the radial bearing gap Gr (see FIG. 4) and the bottom gap Gb accommodating the thrust bearing portion T supporting the lower end of the shaft member 2 in the thrust direction are filled with the lubricating oil L.
  • one side in the axial direction in which the housing 7 is open is referred to as the upper side, and the opposite side in the axial direction is the lower side.
  • the posture of the fluid dynamic bearing device 1 in use is limited. It is not a thing.
  • the housing 7 has a shape (a so-called bottomed cylindrical shape) having a cylindrical portion 7a and a bottom portion 7b closing the lower end side of the cylindrical portion 7a, and in the present embodiment, the cylindrical portion as shown in FIG. 7a and the bottom 7b are integrally formed of metal.
  • a stepped portion 7c is formed integrally with the cylindrical portion 7a and the bottom portion 7b on the inner periphery of the boundary portion between the cylindrical portion 7a and the bottom portion 7b, and the lower end surface 8b of the bearing sleeve 8 abuts on the upper end surface 7c1 of the stepped portion 7c.
  • the thrust plate 10 made of resin is disposed on the upper end surface 7b1 of the bottom 7b of the housing 7.
  • the upper end surface 10a of the thrust plate 10 is made lower than the upper end surface 7c1 of the step 7c by a predetermined height.
  • the upper end surface 10 a of the thrust plate 10 is a thrust bearing surface.
  • the thrust plate 10 is not necessarily provided, and may be omitted.
  • the upper end surface 7b1 of the bottom 7b is a thrust bearing surface.
  • the housing 7 can also be an injection-molded product of resin.
  • the shaft member 2 has a shaft portion 2 a inserted into the inner periphery of the bearing sleeve 8.
  • the shaft portion 2a of the shaft member 2 is formed of a highly rigid metal material including a steel material such as stainless steel.
  • the outer peripheral surface 2a1 of the shaft portion 2a is formed to be a smooth cylindrical surface, and is formed so that the outer diameter dimension is constant over the entire length of the shaft portion 2a except for the convex spherical tip 2a2.
  • the outer diameter of the shaft member 2 is smaller than the inner diameter of the bearing sleeve 8 (the diameter of the inner circumferential surface 8 a).
  • the shaft member 2 is insertable into and removable from the bearing sleeve 8.
  • the tip 2 a 2 of the shaft 2 a is in contact with the upper end surface 10 a of the thrust plate 10 disposed at the bottom of the housing 7.
  • the bearing sleeve 8 is either a porous body, in this case copper-based powder (including not only pure copper powder but also copper alloy powder) and / or iron-based powder (including not only pure iron powder but also iron alloy powder) It is formed in a cylindrical shape by a porous body of sintered metal which is a main component. In this case, the lubricating oil L may be impregnated in the internal holes of the bearing sleeve 8.
  • the bearing sleeve 8 may be formed of a porous body other than sintered metal, for example, a porous resin, or may be formed of a solid body of metal without internal pores (copper, stainless steel, etc.).
  • Cylindrical radial bearing surfaces forming radial bearing gaps Gr (see FIG. 4) between the inner peripheral surface 8a of the bearing sleeve 8 and the outer peripheral surface 2a1 of the opposing shaft portion 2a are provided at two axial positions.
  • dynamic pressure generating portions (radial dynamic pressure generating portions) A1 and A2 for generating dynamic pressure action on the lubricating oil L in the radial bearing gap Gr are formed on the respective radial bearing surfaces. ing.
  • the radial dynamic pressure generating portions A1 and A2 of the present embodiment are respectively inclined in opposite directions and axially spaced from each other, and are provided with a plurality of upper dynamic pressure grooves Aa1 and lower dynamic pressure grooves Aa2, It has a convex-shaped hill part which divides dynamic-dynamic-pressure groove Aa1 and Aa2, and has a herringbone shape as a whole.
  • the hill portion of the present embodiment is an annular portion provided between the inclined hill portion Ab provided between adjacent dynamic pressure grooves in the circumferential direction and the upper and lower dynamic pressure grooves Aa1 and Aa2 and having substantially the same diameter as the inclined hill portion Ab. It consists of hill part Ac.
  • the axial dimension of the upper dynamic pressure groove Aa1 is larger than the axial dimension of the lower dynamic pressure groove Aa2.
  • the axial dimension of the lower dynamic pressure groove Aa2 is larger than the axial dimension of the upper dynamic pressure groove Aa1.
  • the axial dimension of the upper dynamic pressure groove Aa1 constituting the radial dynamic pressure generating portion A1 is equal to the axial dimension of the lower dynamic pressure groove Aa2 constituting the radial dynamic pressure generating portion A2, and
  • the axial dimension of the lower dynamic pressure groove Aa2 constituting the pressure generating portion A1 is equal to the axial dimension of the upper dynamic pressure groove Aa1 constituting the radial dynamic pressure generating portion A2. Therefore, when the shaft member 2 rotates, the lubricating oil L in the radial bearing gap Gr on the upper side (radial bearing portion R1) and the lower side (radial bearing portion R2) respectively corresponds to the lower side (radial bearing portion R2) and the upper side (radial bearing portion R2). It is pushed into the radial bearing gap of the radial bearing portion R1).
  • the radial dynamic pressure generating portions A1 and A2 simultaneously perform the forming of the bearing sleeve 8 (more specifically, the sintered body formed by compacting the metal powder and then sintering is subjected to a sizing process Therefore, the bearing sleeve 8 may be formed by molding at the same time as molding the bearing sleeve 8 of finished dimensions, and in view of the good workability of the sintered metal, the inner peripheral surface is rolled to a smooth bearing surface. You may form by giving plastic processing, such as construction. Further, the form of the radial dynamic pressure generating portions A1, A2 (each dynamic pressure groove) is not limited to this.
  • any one or both of the radial dynamic pressure generating portions A1 and A2 may have a plurality of spiral dynamic pressure grooves arranged in the circumferential direction. Further, either or both of the radial dynamic pressure generating portions A1 and A2 may be formed on the outer peripheral surface 2a1 of the opposing shaft portion 2a.
  • the radial dynamic pressure bearing portions A1 and A2 do not necessarily have to be separated in the axial direction. For example, although not shown, they may be provided adjacent to each other in the axial direction.
  • the bearing sleeve 8 is located on the outer peripheral side of the upper end surface 8c and on the center side of the central axis X of the bearing sleeve 8 than the upper end surface 8c (in FIG. It has a receding surface 8g which is retracted to the side closer to the axial middle position).
  • the receding surface portion 8g has, for example, a flat shape, and is formed parallel to the lower end surface 8b and the upper end surface 8c.
  • the first outer peripheral surface 8d1 having a relatively small outer diameter is provided between the upper end surface 8c and the receding surface portion 8g, and the outer diameter is relatively provided between the lower end surface 8b and the receding surface portion 8g.
  • a large second outer circumferential surface 8d2 is provided.
  • both the lower end surface 8 b and the upper end surface 8 c have a flat shape without irregularities such as dynamic pressure grooves. However, this does not deny the existence of surface openings resulting from the porous structure (in particular, the sealing treatment such as coating may not be performed).
  • an inclined surface portion 11 forming an oil buffer space 12 with the outer peripheral surface 2a1 of the shaft portion 2a is provided between the inner peripheral surface 8a and the upper end surface 8c.
  • the inclined surface portion 11 is continuous with the inner peripheral surface 8a and the chamfered portion 8e continuous on the upper end side, and the chamfered portion 8e and the upper end side, and the inclined surface portion 11 with respect to the central axis X of the bearing sleeve 8 than the chamfered portion 8e
  • the inclination angle ⁇ 2 is composed of a large large inclined surface 8f.
  • the large inclined surface 8f is continuous with the upper end surface 8c.
  • the inclination angle ⁇ 1 of the chamfered portion 8e with respect to the central axis X is usually 45 °, but it is of course possible to increase or decrease it by adjusting the molding conditions or the like.
  • the inclination angle ⁇ 2 of the large inclined surface 8f with respect to the central axis X is arbitrary as long as the above conditions are satisfied, and is set, for example, in a range larger than 45 ° and smaller than 90 °. It is set in the range of ° or less. Further, in this case, the radial dimension of the large inclined surface 8 f can be arbitrarily set within the range of the upper end surface 8 c.
  • the bearing sleeve 8 having the above-mentioned shape is accommodated in the housing 7 in a state where the lower end surface 8 b is in contact with the upper end surface 7 c 1 of the step 7 c of the housing 7.
  • a predetermined volume of space between the lower end surface 8 b of the bearing sleeve 8 and the upper end surface 10 a of the thrust plate 10 provided at the bottom of the housing 7 is Bottom clearance Gb is formed.
  • the bearing sleeve 8 can be fixed to the housing 7 by an appropriate means such as press-fitting (press-fitting with a large interference), bonding, press-bonding (combination of press-fitting and bonding), but in the present embodiment
  • the bearing sleeve 8 is held between the pressing member 9 and the housing 7 by axially pressing the receding surface portion 8g provided radially outward with the pressing member 9, thereby fixing the bearing sleeve 8 to the housing 7 (see FIG. See Figure 2).
  • the outer peripheral surface (here, the second outer peripheral surface 8d2) of the bearing sleeve 8 does not have to be fixed directly to the inner peripheral surface 7a1 of the housing 7 Because the bearing sleeve 8 may be assembled, the operation of assembling the bearing sleeve 8 to the housing 7 is simplified.
  • the means for fixing the pressing member 9 to the housing 7 is optional.
  • the outer peripheral surface 9 b of the pressing member 9 is moved to a position where the lower end surface 9 a of the pressing member 9 abuts on the receding surface 8 g of the bearing sleeve 8.
  • the means etc. which press-fit to inner skin 7a1 of 5 are employable. In this case, a slight gap may exist between the inner circumferential surface 9 c of the pressing member 9 and the first outer circumferential surface 8 d 1 of the bearing sleeve 8.
  • the upper end surface 8c is open to the atmosphere, and in the present embodiment, The upper end surface 9 d of the pressing member 9 is at the same height position (the same position in the central axis X direction) as the upper end surface 8 c of the bearing sleeve 8.
  • the area of the remaining part of the internal space of the housing 7 (the area excluding the above-described part of the area) is not filled with the lubricating oil L at normal time (for example, at room temperature in terms of temperature).
  • the annular space (the remaining portion of the oil buffer space 12) between the large inclined surface 8f of the bearing sleeve 8 and the outer peripheral surface 2a1 of the shaft portion 2a is not usually filled with the lubricating oil L.
  • the amount (volume) of the lubricating oil L filled in the internal space of the housing 7 is smaller than the volume of the internal space of the housing 7.
  • the internal space of the pressure bearing device 1 (housing 7) is provided with a gap where the lubricating oil L does not exist.
  • lubricating oil L an ester-based, PAO-based or fluorine-based lubricating oil is suitably used in consideration of temperature change and the like during use and transportation of the fluid dynamic pressure bearing device 1.
  • the fluid dynamic bearing device 1 having the above configuration is assembled, for example, in the procedure shown in FIGS. 5A and 5B.
  • the bearing sleeve 8 in which the inner hole is impregnated with the lubricating oil L is prepared. Then, until the lower end surface 8b of the bearing sleeve 8 abuts on the upper end surface 7c1 of the step portion 7c of the housing 7, the bearing sleeve 8 is lightly press-fit onto the inner periphery of the housing 7 or fitted with a predetermined gap therebetween. . Subsequently, the lower end surface 9a of the pressing member 9 is fixed to the upper end portion of the inner peripheral surface 7a1 of the housing 7 in a state where the lower end surface 9a is in contact with the receding surface 8g of the bearing sleeve 8.
  • step 7c It clamps from the axial direction both sides with bottom 7b (step 7c), and fixes to housing 7.
  • a predetermined amount of lubricating oil L is filled in the internal space of the housing 7 (for example, the inner periphery of the bearing sleeve 8) (see FIG. See 5A).
  • the shaft 2a is inserted into the inner periphery of the bearing sleeve 8, and the tip 2a2 of the shaft 2a is brought into contact with the upper end surface 10a of the thrust plate 10 (see FIG.
  • a thrust bearing portion T is formed which contacts and supports the shaft member 2 in the thrust direction on the upper end surface 10 a of the thrust plate 10 disposed at the bottom of the housing 7.
  • the shaft member 2 exerts a magnetic force as an external force that presses the shaft member 2 downward (to the bottom 7 b of the housing 7). Therefore, excessive rotation of the shaft member 2 as the shaft member 2 rotates can be prevented as much as possible from being pulled out of the inner periphery of the bearing sleeve 8.
  • an inclined surface portion provided between the inner peripheral surface 8a and the upper end surface 8c of the bearing sleeve 8.
  • An oil buffer space 12 is formed between the shaft portion 2a and the outer peripheral surface 2a1 of the shaft portion 2a (see FIG. 4). Therefore, when the internal space of the housing 7 changes to a high temperature state, for example, the environment in which the fluid dynamic bearing device 1 is placed becomes a high temperature environment, the lubricating oil L filling the internal space of the housing 7 expands.
  • the lubricant oil L can be held by the amount of expansion in the above-mentioned oil buffer space 12 to prevent the lubricant oil L from leaking out (see FIG. 6A).
  • the inclination angle ⁇ 2 with respect to the central axis X of the large inclined surface 8f located on the bearing outer side is made relatively large, and the central axis X of the chamfered portion 8e located on the inner side of the bearing from the large inclined surface 8f.
  • the lubricating oil L in the state of being held in the oil buffer space 12 returns to the inside of the bearing (a radial bearing gap or the like) via the annular space between the chamfered portion 8e and the outer peripheral surface 2a1 of the shaft portion 2a See Figure 6B).
  • the fluid dynamic pressure bearing device 1 when the radial bearing gap Gr and the bottom gap Gb are filled with the lubricating oil L (see FIG. 2), A void is provided. This means that the amount of lubricating oil L filled in the inner space is smaller than the total volume of the inner space.
  • the shaft member 2 since the shaft member 2 is attachable to and detachable from the bearing sleeve 8, as described above, after the bearing sleeve 8 is fixed to the inner periphery of the housing 7.
  • a necessary amount of lubrication can be provided to the internal space of the housing 7 simply by filling the internal space of the housing 7 with the lubricating oil L using an appropriate oil supply tool before inserting the shaft member 2 into the inner periphery of the bearing sleeve 8.
  • Oil L can be supplied. Therefore, a large-scale equipment for oil supply such as vacuum impregnation or a highly precise adjustment or management operation of the oil surface is not necessary, and the manufacturing cost of the fluid dynamic bearing 1 can be reduced.
  • the bearing is adopted while filling a part of the internal space of the housing 7 with the lubricating oil L, so-called oil-filled structure in the form of a partial fill.
  • the upper end surface 8c of the sleeve 8 is open to the atmosphere, and an oil buffer space 12 is formed between the inner peripheral surface 8a and the upper end surface 8c of the bearing sleeve 8 and the outer peripheral surface 2a1 of the shaft portion 2a.
  • the inclined surface portion 11 was provided (see FIGS. 2 and 4).
  • the seal member which is essential in the fluid dynamic pressure bearing device having an oil-impregnated structure in the form of a conventional partial fill, can be eliminated, so the entire fluid dynamic pressure bearing device 1 can be obtained without changing the axial dimension of the bearing sleeve 8
  • the axial dimension of can be shortened.
  • the oil buffer space 12 having a sufficient volume can be obtained only by utilizing a part of the upper end side of the bearing sleeve 8 as the inclined surface portion 11 to form the oil buffer space 12.
  • the inclined surface portion 11 is continuous with the chamfered portion 8e continuous with the inner peripheral surface 8a of the bearing sleeve 8 and the chamfered portion 8e, and the inclination angle ⁇ 1 of the chamfered portion 8e with respect to the central axis X of the bearing sleeve 8
  • the inclination angle ⁇ 2 with respect to the central axis X of the bearing sleeve 8 is larger than that of the large inclination surface 8f.
  • the shaft portion 2a is smoothly inserted by the chamfered portion 8e having a relatively small inclination angle ⁇ 1 with respect to the central axis X .
  • the volume of the oil buffer space 12 can be increased by setting the inclination angle ⁇ 2 of the large inclined surface 8f relatively large.
  • the bearing sleeve 8 since the bearing sleeve 8 is axially pressed by the pressing member 9 and the bearing sleeve 8 is held between the pressing member 9 and the housing 7, the pressing member 9 is fixed to the housing 7.
  • the bearing sleeve 8 can be fixed to the housing 7 only by doing this. Therefore, the effort required for the assembly of members (especially the assembly of bearing sleeve 8 and housing 7) can be reduced.
  • the bearing sleeve 8 is provided with a receding surface portion 8g receding from the upper end surface 8c to the axial center side of the bearing sleeve 8, and the bearing surface 8 is held by pressing the receding surface portion 8g with the pressing member 9.
  • the fluid hydrodynamic bearing apparatus 1 which concerns on this invention, and its manufacturing method take any form in the range of this invention, without being limited to the form of the said illustration. obtain.
  • the inclined surface portion 11 is exemplified by the chamfered portion 8e both having a tapered shape and the large inclined surface 8f having a larger inclination angle ⁇ 2 with respect to the central axis X than the chamfered portion 8e.
  • the inclined surface portion 11 may be configured of one or more curved surfaces (for example, a shape in which the inclination angle with respect to the central axis X increases outward in the axial direction), or a tapered inclined surface
  • the inclined surface portion 11 may be configured by the curved surface described above.
  • the receding surface portion 8g has a flat shape and is parallel to the upper end surface 8c (see FIG. 2), but other shapes may of course be adopted.
  • the receding surface portion 8g can have any shape as long as the bearing sleeve 8 can be axially pressed by the pressing member 9, such as an inclined surface or a concave surface.
  • the shape of the pressing member 9 is arbitrary as long as the bearing sleeve 8 can be pressed in the axial direction, and may have a shape other than illustrated.
  • the housing 7 provided separately from the motor base 6 is fixed to the inner periphery of the motor base 6, but the part corresponding to the motor base 6 is integrally fixed to the housing 7 It can also be provided.
  • either or both of the radial bearing portions R1 and R2 may be configured by other known dynamic pressure bearings such as so-called multi-arc bearings, step bearings, and wave-shaped bearings.
  • the dynamic pressure bearing can also be configured by another known dynamic pressure bearing such as a so-called step bearing or a wave type bearing.
  • the means for making such an external force act on shaft member 2 is not restricted to the above-mentioned.
  • the magnetic force can be applied to the rotor 3 by arranging a magnetic member capable of attracting the rotor magnet 4 so as to face the rotor magnet 4 in the axial direction.
  • the present invention uses the rotating member as:
  • the present invention can be preferably applied to the fluid dynamic bearing device 1 in which a disk hub having a disk mounting surface or a polygon mirror is fixed to the shaft member 2. That is, according to the present invention, not only the fan motor as shown in FIG. 1, but also a fluid dynamic pressure bearing incorporated in other electric devices such as a spindle motor for a disk drive and a polygon scanner motor for a laser beam printer (LBP). It can be preferably applied to the device 1 as well.
  • LBP laser beam printer

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Sliding-Contact Bearings (AREA)
  • Mounting Of Bearings Or Others (AREA)

Abstract

L'invention concerne un dispositif de palier fluide dynamique (1), lequel dispositif comporte un boîtier tubulaire à fond (7), un manchon de palier (8) disposé sur la périphérie interne du boîtier (7), et un élément d'arbre (2) ayant une partie d'arbre (2a) insérée de façon amovible à travers la périphérie interne du manchon de palier (8). Une partie de l'espace interne du boîtier (7) est remplie d'huile de lubrification (L), le reste de l'espace interne étant une partie d'espace non remplie par l'huile de lubrification (L), une surface d'extrémité axiale (8c) du manchon de palier (8) constituant un côté ouvert du boîtier (7) étant ouverte vers l'atmosphère, et, entre une surface périphérique interne (8a) et la surface d'extrémité axiale (8c) du manchon de palier (8), étant disposée une partie de surface inclinée (11) constituant un espace tampon d'huile (12) avec une surface périphérique externe (2a1) de la partie d'arbre (2a).
PCT/JP2019/000242 2018-01-11 2019-01-08 Dispositif de palier fluide dynamique et moteur le comportant WO2019139007A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2018-002522 2018-01-11
JP2018002522A JP2019120389A (ja) 2018-01-11 2018-01-11 流体動圧軸受装置及びこれを備えたモータ

Publications (1)

Publication Number Publication Date
WO2019139007A1 true WO2019139007A1 (fr) 2019-07-18

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP7213329B1 (ja) 2021-11-29 2023-01-26 シチズンファインデバイス株式会社 軸受け部材

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001065554A (ja) * 1999-08-26 2001-03-16 Matsushita Electric Ind Co Ltd 流体軸受装置
JP2007091860A (ja) * 2005-09-28 2007-04-12 Ntn Corp ハブベアリング用グリースおよびハブベアリング
JP2009228873A (ja) * 2008-03-25 2009-10-08 Ntn Corp 流体軸受装置
JP2011021649A (ja) * 2009-07-14 2011-02-03 Ntn Corp 流体軸受装置
JP2011033103A (ja) * 2009-07-31 2011-02-17 Ntn Corp 流体軸受装置

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001065554A (ja) * 1999-08-26 2001-03-16 Matsushita Electric Ind Co Ltd 流体軸受装置
JP2007091860A (ja) * 2005-09-28 2007-04-12 Ntn Corp ハブベアリング用グリースおよびハブベアリング
JP2009228873A (ja) * 2008-03-25 2009-10-08 Ntn Corp 流体軸受装置
JP2011021649A (ja) * 2009-07-14 2011-02-03 Ntn Corp 流体軸受装置
JP2011033103A (ja) * 2009-07-31 2011-02-17 Ntn Corp 流体軸受装置

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP7213329B1 (ja) 2021-11-29 2023-01-26 シチズンファインデバイス株式会社 軸受け部材
JP2023079465A (ja) * 2021-11-29 2023-06-08 シチズンファインデバイス株式会社 軸受け部材

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