JP2007016922A - Spindle motor and recording disk driving apparatus provided with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a spindle motor which can assure the fixation and the continuity between a sleeve 6 and a base 2 and can be manufactured at a low cost, and further to provide a recording disk driving apparatus provided with the spindle motor. <P>SOLUTION: The spindle motor comprises the base 2 having a circular through-hole, the sleeve 6 to be fitted and adhered in the circular through-hole, a shaft 10, a dynamic pressure bearing for supporting the shaft 10 so as to rotate with respect to the sleeve 6, and an electrically conductive member 34 for electrically connecting the base 2 and the sleeve 6 by coming into contact with them, wherein the electrically conductive member 34 is brought into contact with one of the base 2 and the sleeve 6 in the elastically deformed state, and an adhesive storing portion is provided in the neighborhood of at least one of the contact portions of the sleeve 6 and the base 2 with the electrically conductive member 34. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a spindle motor and a recording disk driving device including the spindle motor.

  A spindle motor for rotationally driving a recording disk such as a magnetic disk mainly includes a rotating part having a shaft and a stationary part to which a sleeve is fixed. The shaft is disposed on the inner peripheral side of the sleeve, and a rotor hub on which the recording disk is mounted is fixed to the upper end portion of the shaft. The sleeve rotatably supports the shaft via the fluid dynamic pressure bearing portion, and is fixed to the base or the like by means such as an adhesive.

  A recording disk drive using a spindle motor is provided with a magnetic head for reading data on the recording disk or writing data on the recording disk.

  In the spindle motor used in the recording disk drive apparatus described above, it is necessary to consider the static electricity generated by the friction between the recording disk surface and the air when the motor rotates as the rotational speed of the motor increases. That is, when the spindle motor is driven and the recording disk rotates at a high speed, friction is generated between the recording disk and air, and as a result, the recording disk is charged by static electricity. At this time, electrostatic discharge is generated in the rotating part of the motor including the recording disk between the recording surface of the recording disk and the magnetic head that reads and writes data in the vicinity of the recording surface, and the magnetic head is destroyed. There is a risk.

  In order to prevent such a problem, it is necessary to provide a conduction structure in which both members are electrically connected, such as between the rotating part and the stationary part. Conventionally, the following structure has been proposed as a conductive structure.

  For example, in a structure in which the rotating part is held by the stationary part via the fluid dynamic pressure bearing part, it is possible to achieve conduction between the rotating part and the stationary part by making the lubricating fluid conductive. Further, when an adhesive having conductivity is used as an adhesive for fixing the sleeve, which is a stationary part, and the base, conduction between the sleeve and the base can be obtained (see, for example, Patent Document 1). Furthermore, conduction can also be achieved by plastically deforming a part of the bonding portion between the sleeve and the base and performing metal bonding (see, for example, Patent Document 2).

Japanese Patent Laid-Open No. 11-167765 JP 09-126240 A

  Conventionally, the sleeve and the base are often made of different materials. For this reason, the thermal expansion coefficients of the sleeve and the base are often different. Also, the thermal expansion coefficient of the conductive adhesive is often different from that of the sleeve and the base.

  In such a case, when the rotor assembly of the spindle motor rotates, vibration or the like due to the rotation of the rotor assembly is transmitted to the sleeve via the fluid dynamic pressure bearing portion, and is further added to the conductive adhesive that fixes the sleeve and the base. For this reason, if a sufficient amount of the conductive adhesive is not applied between the sleeve and the base, the conductive adhesive may be cracked or peeled off due to vibration or the like. When it occurs in the agent, conduction between the sleeve and the base is hindered.

  On the other hand, many of the conductive adhesives are expensive because they are mainly composed of silver. For this reason, cost reduction is often achieved by reducing the amount of conductive adhesive used as much as possible. However, if the amount of conductive adhesive is too small, conduction between the sleeve and the base is hindered.

  In addition, even when a part of the bonded portion of the sleeve and the base is plastically deformed and metal-bonded, when the adhesive layer between the sleeve and the base is partially dried and the pinnacle pin is press-fitted and bonded to the metal, There is also a possibility that the pinnacle pin does not penetrate the adhesive. If the pinnacle pin does not penetrate the non-conductive adhesive, conduction between the sleeve and the base will be hindered. Further, if the pinnacle pin is pressed firmly to penetrate the dried adhesive layer, each member may be distorted, and the accuracy of the spindle motor may be reduced.

  Further, as shown in FIG. 10, even when a portion different from the bonding portion C between the sleeve A and the base B is fixed with the conductive member D, and the conduction between the sleeve A and the base B is achieved, the bonding portion C having no conductivity is provided. If the adhesive used for the flow-out flows and the adhesive adheres to the conductive portion between the conductive member D and the sleeve A and the base B, there is a possibility that the conduction is hindered.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a spindle motor capable of reliably fixing the sleeve and the base and ensuring the electrical connection, and a recording disk drive apparatus including the spindle motor. Is to provide.

  In order to achieve the above object, a spindle motor according to a first aspect of the present invention is a motor including a rotating portion and a stationary portion that rotatably supports the rotating portion, and the rotating portion includes: A shaft provided on the rotation center axis, and a rotor magnet disposed concentrically around the shaft, wherein the stationary portion includes a sleeve portion into which the shaft is inserted, and the rotor magnet. An armature that generates a rotational torque around the central axis, a conductive base portion to which the sleeve portion and the armature are attached, and an adhesive portion that fixes the sleeve portion and the base portion; A conductive member that contacts and electrically connects the sleeve portion and the base portion, and at least one of the sleeve portion and the base portion contacting the conductive member The wear in the vicinity, reservoir is provided adhesive.

  In the spindle motor according to a second aspect of the present invention, the adhesive reservoir portion is formed by chamfering the sleeve portion or the base portion.

  In the spindle motor according to a third aspect of the present invention, the adhesive reservoir portion is provided in a recessed shape in the sleeve portion or the base portion.

  In the spindle motor according to a fourth aspect of the present invention, the adhesive reservoir portion is provided in a convex shape on the sleeve portion or the base portion.

  In the spindle motor according to claim 5 of the present invention, at least a part of the adhesive reservoir has a surface roughness Ra of 5.0 μm or more.

  In a spindle motor according to a sixth aspect of the present invention, the base portion is made of aluminum.

  In the spindle motor according to claim 7 of the present invention, an oil-repellent film is formed in the vicinity of the conductive member of the adhesive reservoir.

  8. The recording disk drive device according to claim 8, wherein the spindle motor according to claim 1 is fixed to a housing, a top surface side or a bottom surface side of the housing, and an outer periphery of a rotating portion of the spindle motor. And a recording disk that can read and write information, and an information access unit for writing or reading information at a required position of the recording disk.

  In the spindle motor of the present invention, since the adhesive reservoir is provided in the vicinity of at least one of the sleeve portion and the base portion that contact the conductive member, the adhesive portion does not reach the vicinity of the conductive member. Absent. Therefore, the conductive member can be reliably connected to the sleeve portion and the base portion, and the sleeve portion and the base portion can be reliably fixed.

  The adhesive reservoir portion is provided in the sleeve portion or the base portion in a chamfered shape, a concave shape, or a convex shape. Therefore, even if the adhesive for adhering and fixing the sleeve portion and the base portion flows before solidifying, it stays in the adhesive reservoir portion and does not form an adhesive portion in the vicinity of the conductive member. Therefore, electrical conduction between the conductive member, the sleeve portion, and the base portion can be ensured.

  At least a part of the adhesive reservoir has a surface roughness Ra of 5.0 μm or more. Therefore, even if the adhesive for bonding and fixing the sleeve part and the base part flows before solidifying, the surface roughness of the part of the sleeve part or the base part in the vicinity where the adhesive flows is higher than that of other parts. Since it is set high, the fluidity of the adhesive can be deteriorated and it becomes difficult to flow. Therefore, the adhesive stays at a portion (adhesive reservoir) where the surface roughness of the sleeve portion or the base portion is set high. Therefore, electrical conduction between the conductive member, the sleeve portion, and the base portion can be ensured.

  An oil repellent film is formed in the vicinity of the conductive member in the adhesive reservoir. Therefore, even if the adhesive for bonding and fixing the sleeve portion and the base portion flows before solidifying, an adhesive reservoir portion is provided in the sleeve portion or the base portion in the vicinity where the adhesive flows, and Since the oil repellent film is formed, the flow of adhesion is hindered by the oil repellent film. Therefore, since the adhesive is held in the vicinity of the oil-repellent film in the sleeve portion or the base portion, conduction between the conductive member, the sleeve portion and the base portion can be ensured.

  In the recording disk drive device of the present invention, by using the spindle motor according to any one of claims 1 to 7, static electricity is generated outside the spindle motor regardless of the temperature environment in which the recording disk drive device is used. It can always escape stably. Therefore, it is possible to provide a recording disk drive device excellent in reliability and durability.

  A spindle motor according to an embodiment of the present invention and a recording disk driving apparatus including the spindle motor will be described below with reference to FIGS. In the description of the embodiment of the present invention, the vertical direction of each drawing is referred to as “vertical direction” for convenience, but the direction in the actual mounting state is not limited.

<First Embodiment>
<Structure of spindle motor>
A first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a longitudinal sectional view showing a spindle motor used in a hard disk drive, for example. The spindle motor includes a substantially cup-shaped base 2, and a bush 4 and a sleeve 6 that are fixed to a circular through hole 2 a at a substantially central portion of the base 2. The bush 4 has a circular opening 4a penetrating in the axial direction in the central portion, an adhesive reservoir portion 4b that is provided with a chamfer larger than the upper end portion at the lower end portion and can hold the adhesive, and has a sleeve 6 Is fixed between the sleeve 6 and the base 2 in order to buffer the vibration from the base 2 to the base 2.

  The sleeve 6 is a member formed in a hollow cylindrical shape. The lower end portion of the sleeve 6 is closed by a seal member 11, the inner peripheral surface of the sleeve 6 is opposed to the rotor 10 in the radial direction via a minute gap, and the upper end surface of the sleeve 6 is axially aligned with the lower surface of the rotor 10 (see FIG. 1 corresponding to the vertical direction of 1) through a minute gap. The base 2 is formed integrally with the housing (reference numeral 51 in FIG. 9) of the recording disk drive device of the present invention. However, the present invention is not limited to this, and the base 2 and the housing 51 are formed as separate members. Also good.

  The rotor 10 includes a rotor hub 12 and a shaft 14 fixed to the rotor hub 12. The shaft 14 rotates about the rotation center axis X with respect to the sleeve 6. The rotor hub 12 includes a substantially disk-shaped upper wall portion 12a and a peripheral wall portion 12b that hangs down from the outer peripheral portion of the upper wall portion 12a.

  A rotor magnet 16 is fixed to the inner peripheral surface of the peripheral wall portion 12b with an adhesive, and the rotor magnet 16 is opposed to the stator 8 via a gap in the radial direction. A disk plate (reference numeral 53 in FIG. 9) is disposed on the outer peripheral side surface of the peripheral wall portion 12b.

  In the structure described above, the gap between the lower surface of the upper wall portion 12a of the rotor hub 12 and the upper end surface of the sleeve 6, the gap between the inner peripheral surface of the sleeve 6 and the outer peripheral surface of the shaft 14, and the shaft 14 All the gaps between the lower end surface and the upper surface of the seal member 10 are continuous. In the continuous gap, oil as a lubricating fluid is held without interruption.

  The upper outer peripheral surface of the sleeve 6 is provided with an inclined surface in which the outer diameter of the sleeve 6 is reduced in the axial direction downward from the upper end surface, and the circumferential protrusion of the upper wall portion 12a of the rotor hub 12 facing the inclined surface. The size of the gap in the radial direction with respect to 12c increases toward the lower side in the axial direction (base 2 side). That is, the upper outer peripheral surface of the sleeve 6 and the circumferential protrusion 12 c of the upper wall portion 12 a of the rotor hub 12 cooperate to constitute the capillary seal portion 18. In the capillary seal portion 18, the oil held in each of the gaps described above balances the surface tension of the oil and the external air pressure, and the interface between the oil and air is formed in a meniscus shape.

<Fluid dynamic pressure bearing>
In the radial gap between the inner peripheral surface of the sleeve 6 and the outer peripheral surface of the shaft 14, an upper radial dynamic pressure bearing portion 20 and a lower radial dynamic pressure bearing portion 22 are provided so as to be separated in the axial direction. The upper radial dynamic pressure bearing portion 20 and the lower radial dynamic pressure bearing portion 22 are formed from an inner peripheral surface of the sleeve 6, an outer peripheral surface of the shaft 14, and oil held in a gap between both members facing in the radial direction. It is configured.

  Further, the upper end surface of the sleeve 6 and the lower surface of the upper wall portion 12a of the rotor hub 12 face each other through a minute gap in the axial direction, and a thrust dynamic pressure bearing portion 24 is provided in the gap. The thrust dynamic pressure bearing portion 24 includes an upper end surface of the sleeve 6, a lower surface of the upper wall portion 12a of the rotor hub 12, and oil that is held in a gap between both members facing in the axial direction.

  In addition, since the pressure generated in the thrust dynamic pressure bearing portion 24 is slightly higher than the atmospheric pressure, it is difficult to sufficiently float the rotor 10 with only the thrust dynamic pressure bearing portion 24. However, since all of the oil held in the series of bearing gaps is continuous without interruption, the oil internal pressure held in the gap between the lower end surface of the shaft 14 and the upper surface of the seal member 10 is also a thrust dynamic pressure bearing. Since it becomes a pressure equivalent to the oil internal pressure raised by the fluid dynamic pressure induced in the portion 24, it functions as the hydrostatic bearing portion 26. Therefore, the rotor 10 can be sufficiently levitated by the cooperation of the thrust dynamic pressure bearing portion 24 and the hydrostatic bearing portion 26.

  In addition, an annular thrust yoke 28 formed of a ferromagnetic material is provided at a portion located on the base 2 and facing the rotor magnet 16 in the axial direction. As a result, a magnetic attractive force in the axial direction is generated between the rotor magnet 16 and the thrust yoke 28. When the rotor 10 rotates, the rotor 10 is stably supported at a position where the magnetic attraction force described above and the flying pressure of the rotor 10 generated by the thrust dynamic pressure bearing portion 24 and the static pressure bearing portion 26 are balanced. Is done. Note that such magnetic urging on the rotor 10 can also be effected, for example, by making the magnetic centers of the stator 8 and the rotor magnet 16 different in the axial direction.

<Conductive member 34>
FIG. 2 is an enlarged bottom view of a part of the lower surface of the spindle motor of FIG. Therefore, in FIG. 2, the vertical direction is reversed. As shown in FIG. 2, a pedestal 2 b is formed integrally with the base 2 at the bottom of the base 2. A gap 40 is formed between the pedestal portion inner surface 2d of the pedestal portion 2b, the sleeve protruding outer peripheral surface 6d at the lower portion of the sleeve 6, and the lower end surface (the upper end surface in FIG. 3) of the bush 4. On the inner surface 2d of the pedestal portion 2b, an arc groove 2e recessed outward in the radial direction is formed, and the arc groove 2e is open to the gap 40 and the side surface 2f of the pedestal portion 2b.

  In addition, an enlarged diameter portion 3 is formed in the lower portion of the base 2 (upper portion in FIG. 2) by notching a part of the pedestal portion 2b. The enlarged diameter portion 3 defines a flat surface 2c that is substantially parallel to the lower end surface of the bush 4 and a side surface 2f that is the periphery of the pedestal portion 2b. An FPC 30 that connects the lead wire of the stator 8 and an external electrode (not shown) is fixed to the flat surface 2c with an adhesive or the like. The end portions (four in this embodiment) of the winding coils of the stator 8 are soldered by the land portions 30 a of the FPC 30. As a result, the power source current is applied from the external electrode to the stator 8 via the FPC 30, and the spindle motor is driven by the rotating magnetic field generated thereby.

  In the gap 40, a conductive member 34 that secures conduction between the sleeve 6 and the base 2 is disposed. As shown in FIG. 3, the conductive member 34 is an annular member formed by pressing, for example, stainless steel (SUS304, SUS303, SUS420, SUS430, etc.), phosphor bronze, beryllium steel, or the like. The conductive member 34 includes a through hole 34 a at the center, a held portion 34 b cut out from the outer peripheral surface of the conductive member 34 to the inner peripheral surface, and an elastic piece 34 c protruding from the outer peripheral surface of the conductive member 34. , And an elastic piece 34c and a thin width portion 34d opposed to each other in the radial direction.

<Assembly of spindle motor>
Next, a method for attaching the conductive member 34 to the base 2 and the sleeve 6 will be described. First, the rotor hub 12 to which the sleeve 6, the shaft 14, and the rotor magnet 16 are fixed is assembled, and oil is injected to constitute a fluid dynamic pressure bearing. On the other hand, after fixing the thrust yoke 28 and the stator 8 to the base 2 and electrically connecting them, as shown in FIG. 4A, an adhesive (not having conductivity) is formed on the cylindrical outer peripheral surface. The bush 4 to which a is attached is fixed to the circular through hole 2a of the base 2 using a jig (not shown). Thereafter, as shown in FIG. 4 (b), the upper wall portion 12a of the rotor hub 12 is set to the bottom (in the form that the spindle motor is turned upside down), the bottom surface of the base 2 is also directed upward, and the adhesive a is applied to the outer peripheral surface. The bush 4 is inserted into the sleeve 6 to which is attached, and fixed by adhesion. Finally, as shown in FIG. 4C, a tool (not shown) is engaged with the held portion 34 b of the conductive member 34 to hold the conductive member 34. Then, the conductive member 34 is inserted into the gap 40, and as shown in FIG. 2, the tool is turned in the direction indicated by the arrow 38 (counterclockwise in this embodiment), and the elastic piece 34c is inserted into the arc groove 2e. Fit. As a result, as shown in FIG. 4D, the conductive member 34 is firmly engaged with the sleeve 6 and the base 2 to prevent the spindle motor from being charged with static electricity.

  Next, the bonding location of the base 2, the bush 4, the sleeve 6 and the conductive member 34 will be described in detail. FIG. 5 is an enlarged view of a relevant portion of FIG. Here, the bush 4 is chamfered at the corner of the cylindrical bottom surface portion corresponding to the lower portion of the figure compared to the corner of the cylindrical upper surface portion corresponding to the upper portion of the drawing. Therefore, when the bush 4 and the base 2 are inserted with the adhesive a applied as shown in FIG. 4, even if the excess adhesive a protrudes from the adhesive fixing portion or leaks, as shown in FIG. The adhesive is not held by the adhesive reservoir 4b and spreads. This is because surface tension acts on the adhesive and remains in the adhesive reservoir 4b. Further, the surface of the base 2 and the sleeve 6 facing the portion where the chamfering of the bush 4 is provided may be formed with a surface roughness Ra of 5.0 μm or more (the illustrated mesh portion). This is to reduce the fluidity of the excess adhesive a and to make it easier to hold the adhesive in the adhesive reservoir 4b. Therefore, the adhesive does not flow into the engagement portion between the conductive member 34 and the sleeve 6 and the base 2.

  Therefore, when the rotor 10 rotates, static electricity generated on the recording disk is transmitted from the rotor 10 to the sleeve 6 via the fluid dynamic pressure bearing portion formed between the sleeve 6 and the rotor 10. Then, the static electricity is transmitted to the conductive member 34 through a portion where the sleeve protruding outer peripheral surface 6d and the thin width portion 34d of the conductive member 34 are engaged, and the radial outward convex portion 34c2 of the conductive member 34 and The base 2 is transmitted to the base 2 through a portion where the end of the base 2 in the arc groove 2e is engaged. Therefore, the conduction between the sleeve 6 and the base 2 can be ensured satisfactorily without hindering the adhesive, and a conduction failure such as static electricity staying in the spindle motor can be reliably prevented.

  In recent years, the hard disk drive has been started to be installed in in-vehicle devices represented by a car navigation system. However, in-vehicle devices are expected to be used in various environments, and therefore, devices used for these devices are required to operate stably in a very wide temperature range. For example, the hard disk drive device is required to be used in an unprecedented severe temperature environment that can be used even in an environment where the temperature difference is 100 ° C. or more.

  Under such a temperature environment, when a conductive adhesive is used between the sleeve and the bracket as in the conventional case, the conductive adhesive is cracked or peeled as described above, and the conduction between the sleeve and the bracket is prevented. Easy to be disturbed. However, in the present embodiment, since the metal conductive member 34 is provided between the sleeve and the bracket, the conduction between the sleeve and the bracket can be reliably ensured even under the temperature environment as described above.

Second Embodiment
Next, a second embodiment of the present invention will be described with reference to FIG. Since the motor of this embodiment has the same basic structure as that of the first embodiment described above, the correspondence is clearly indicated with reference numerals of the corresponding members being in the 100s, and only different parts will be described.

  FIG. 6 shows a spindle motor in which the shapes of the base 102, bush 104 and sleeve 106 in FIG. 5 are different. Specifically, the cylindrical upper bottom surface of the bush 104 is chamfered with substantially the same size, and the adhesive reservoir 104b forms a recess in the sleeve 106 and a protrusion and a recess in the base 102. A water / oil repellent film (shaded portion in the figure) is formed on a part of the convex part and the concave part so as not to reach the conductive member engaging part. As a result, even if the adhesive a protrudes, the adhesive a is stopped by the water / oil repellent film and held in the recess. Therefore, the adhesive does not flow into the engagement portion between the conductive member 34 and the sleeve 6 and the base 2.

  Further, the adhesive reservoir 104b can be formed with almost no change in the shape of the member by forming recesses in the sleeve 106 and the base 102 by machining and applying a water / oil repellent.

<Third Embodiment>
Next, a third embodiment of the present invention will be described with reference to FIG. In addition, since the motor of this embodiment is the same in basic structure as that of the above-described first embodiment, the correspondence is clearly indicated with the reference numerals of the corresponding members being in the 200s, and only different portions will be described.

  FIG. 7 shows a spindle motor in which the shapes of the base 202, bush 204 and sleeve 206 in FIG. 5 are different. Specifically, the chamfering of the cylindrical upper bottom surface of the bush 204 is approximately the same size, and the adhesive reservoir portion 204b is provided with a water / oil repellent film (shaded portion in the figure) on the sleeve 206 and an axial direction on the base 102. It is configured by forming extending protrusions and a water / oil repellent film.

  As a result, even when the bush 204 and the sleeve 206 are inserted, even if a surplus amount of the adhesive a hangs down, it is held in the adhesive reservoir 204b by the water / oil repellent film, and the flow of the adhesive a is prevented by the convex portion. . As a result, even if the adhesive a protrudes, the adhesive a is stopped by the water / oil repellent film and held in the recess. Therefore, the adhesive does not flow into the engagement portion between the conductive member 234, the sleeve 206, and the base 202.

  Further, when the spindle motor is assembled, the bushing 204 can be accurately positioned by bringing the bushing 204 into contact with the convex portion of the base 202.

<Fourth embodiment>
A fourth embodiment of the present invention will be described with reference to FIG. Since the motor of this embodiment has the same basic structure as that of the first embodiment described above, the corresponding members are designated by the reference numerals in the 300s, and only the differences will be described.

  In the fourth embodiment, a flat surface 302g extending in the radial direction is provided at a lower portion of the base 302, and a sleeve holding surface 302a to which the sleeve 306 is bonded and fixed. Further, there is a gap 340 between the flat surface 302g, the inner surface 302d of the pedestal portion 302b that protrudes downward in the axial direction from the flat surface 302g, and the lower outer peripheral surface of the sleeve 306 that also protrudes downward in the axial direction from the flat surface 302g. Is formed.

  An arc groove 302e is formed on the inner surface 302d of the pedestal portion 302b, and the conductive member 334 is fitted into the gap 340 in the same manner as in the first embodiment.

  Further, the lower end portion of the sleeve holding surface 302a of the base 302 is chamfered larger than the upper end surface shown in the figure, and opens widely toward the fixing portion of the conductive member 334 to form an adhesive holding portion 304b. Yes. Further, the surface (the mesh portion shown in the figure) facing the adhesive holding portion 304 of the sleeve 306 has a higher surface roughness than other surfaces and is formed with Ra of 5.0 μm or more.

  Also in the fourth embodiment, the base 302 and the sleeve 306 can be changed to the same structure as in the first to third embodiments, and the same action as in the first to third embodiments described above. An effect can be obtained.

<Recording disk drive>
Next, the internal configuration of the recording disk drive device 50 will be described with reference to FIG. The housings 51 and 58 form a clean space with extremely little dust and the like, and a spindle motor 52 on which a disk-like disk plate 53 such as a hard disk for storing information is installed is installed inside the housings 51 and 58. Has been. In addition, a head moving mechanism 57 for reading and writing information with respect to the disk plate 53 is disposed inside the housings 51 and 58. The head moving mechanism 57 includes a head unit 56 for reading and writing information on the disk plate 53, and The arm 55 that supports the head, the head 56, and the actuator unit 54 that moves the arm 55 to a required position on the disk plate 53 are configured.

  By using any one of the spindle motors shown in FIGS. 1 to 8 as the spindle motor 52 of the recording disk drive device 50, the spindle motor can be moved outside the spindle motor regardless of the temperature environment in which the recording disk drive device is used. Static electricity can always be released stably. Therefore, it is possible to provide a recording disk drive device excellent in reliability and durability.

  As mentioned above, although one embodiment of the spindle motor according to the present invention and the recording disk driving device provided with the spindle motor has been described, the present invention is not limited to the embodiment and does not depart from the scope of the present invention. Various variations or modifications are possible.

  For example, in this embodiment, oil is used as the fluid of the fluid dynamic pressure bearing. However, even if a motor using a so-called air dynamic pressure bearing using air as a fluid is used, the same operation and effect as the present invention can be obtained. It is done.

  In the present embodiment, the fluid dynamic pressure bearing has a structure including two radial dynamic pressure bearing portions and one thrust dynamic pressure bearing portion. However, the structure of the fluid dynamic pressure bearing is not limited to this, and The material of the fluid dynamic pressure bearing may be a sintered member using stainless steel, iron or copper.

  Further, the elastic member is not limited to the shape shown in FIG. 3, and may be any shape that can contact the base and the sleeve and can be electrically connected to each other.

  Also, the method of assembling the spindle motor is not limited to the method shown in FIG. 4, and any method can be applied as long as it can be assembled, such as the location where the adhesive a is applied and the drying method.

  Also, various combinations of the adhesive reservoir are possible. For example, an oil repellent film may be formed in the vicinity of the conductive member of the member facing the member provided with the chamfer.

  Further, although the outer rotor type motor provided with the stator in the radial direction of the rotor magnet is used, the present invention is not limited to this, and the present invention is applied to a so-called inner rotor type motor in which the stator is provided in the radial direction outward of the rotor magnet. Can be applied.

It is a longitudinal cross-sectional view which shows the spindle motor of 1st Embodiment of this invention. FIG. 2 is an enlarged view of a part of the lower surface of the spindle motor of FIG. It is a top view of the electroconductive member of FIG. It is the figure which showed the assembly method of the spindle motor of 1st Embodiment of this invention. FIG. 2 is an enlarged view around a conductive member in FIG. 1. It is an enlarged view of the electroconductive member periphery of 2nd Embodiment of this invention. It is an enlarged view of the conductive member periphery of 3rd Embodiment of this invention. It is a longitudinal cross-sectional view which shows the spindle motor of 4th Embodiment of this invention. It is a longitudinal cross-sectional view which shows the recording disk drive device of this invention. It is the figure which showed the periphery of the conventional electroconductive member.

Explanation of symbols

2 Base 4 Bush 4 b Adhesive reservoir 6 Sleeve 10 Rotor 34 Conductive member a Adhesive

Claims (8)

A rotating part;
A stationary part that rotatably supports the rotating part;
A motor consisting of
The rotating part is
A shaft provided on the rotation center axis;
A rotor magnet disposed concentrically around the shaft;
With
The stationary part is
A sleeve portion into which the shaft is inserted;
An armature that generates rotational torque about the central axis with the rotor magnet;
A conductive base portion to which the sleeve portion and the armature are attached;
An adhesive portion for fixing the sleeve portion and the base portion;
A conductive member that contacts the sleeve portion and the base portion to electrically connect the sleeve portion and the base portion;
A spindle motor, wherein an adhesive reservoir portion is provided in the vicinity of at least one of the sleeve portion and the base portion that contact the conductive member.   The spindle motor according to claim 1, wherein the adhesive reservoir portion is formed by providing a chamfer on the sleeve portion or the base portion.   The spindle motor according to claim 1, wherein the adhesive reservoir portion is provided in a recessed shape in the sleeve portion or the base portion.   The spindle motor according to claim 1, wherein the adhesive reservoir portion is provided in a convex shape on the sleeve portion or the base portion.   2. The spindle motor according to claim 1, wherein at least a part of the adhesive reservoir has a surface roughness Ra of 5.0 [mu] m or more.   6. The spindle motor according to claim 1, wherein the base portion is made of aluminum.   The spindle motor according to claim 1, wherein an oil-repellent film is formed in the vicinity of the conductive member of the adhesive reservoir. A housing;
The spindle motor according to any one of claims 1 to 7, which is fixed to a top surface side or a bottom surface side of the housing;
A recording disk fixed to the outer periphery of the rotating part of the spindle motor and capable of reading and writing information;
A recording disk drive device comprising: an information access unit for writing or reading information at a required position of the recording disk.

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