JP2009207277A - Compact motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor which allows a worker to easily mount a member for electrically connecting a circuit substrate with a mounting board. <P>SOLUTION: In the motor, a steel ball 36 is fixed in contact with an inner-peripheral surface, on the whole periphery forming the mounting board side through-hole 333 in the mounting board 33. On a top face of the mounting board 33, a circuit board 34 is mounted. At a position corresponding to the mounting board side through-hole 333 in the circuit board 34, a circuit board side through-hole 3416c is provided. The circuit board side through-hole 3416c is provided inside an annular portion 3416a. A solder 37 is applied so that the steel ball 36 and the annular portion 3416a of a ground portion 3416 of the circuit board 34 are electrically connected to each other. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a small motor, and more particularly to a motor having a mounting portion for mounting a disk-shaped disk such as an optical disk or a magnetic disk.

  Conventionally, in order to make the potential of the land portion serving as the reference potential of the circuit board of the motor coincide with the potential of the conductive mounting plate, the land portion and the mounting plate are connected by a conductive member such as a screw. There is a structure. With this structure, the mounting plate prevents electromagnetic waves from entering the circuit board from the outside of the motor (see, for example, Patent Document 1 as an example of a conventional structure for connecting the land portion of the circuit board and the mounting plate).

Japanese Patent No. 3344913

  With the recent miniaturization of motors associated with the portability of disk drive devices, the components that make up the motors are becoming smaller. Therefore, when manufacturing a motor, since each component is small, the motor may not be manufactured unless an operator uses a special jig and tool to handle the small component. In particular, in the case of a member having conductivity such as a screw for conducting the circuit board and the mounting plate, the component can be mounted on the circuit board and the mounting plate only in a predetermined direction for mounting the member. The efficiency of manufacturing motors has been reduced.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a motor in which an operator can easily attach a member for conducting a circuit board and a mounting plate.

  According to a first aspect of the present invention, there is provided a motor, which is a rotating body that rotates around a predetermined central axis, a bearing mechanism that rotatably supports the rotating body, and a stationary body that holds the bearing mechanism. The stationary body has a mounting plate made of a substantially flat metal plate, and a circuit board attached to the mounting plate, and the mounting plate has a mounting plate side through hole, A circuit board side through hole is formed at a position corresponding to the mounting plate side through hole of the circuit board, and a land portion of a ground pattern is provided on the periphery of the circuit board side through hole, and the mounting The plate-side through-hole and the circuit board-side through-hole have at least a part of a conductive member made of a conductive material that is used to establish conduction between the mounting plate and the land portion of the circuit board. The conductive member and the mounting plate side through hole are accommodated. It is in contact with an inner surface, said conductive member is a spherical shape or, it is a regular polyhedron shape, characterized by.

  According to claim 1 of the present invention, the conductive member is formed in a spherical shape or a regular polyhedral shape so that the conductive member is accommodated in the mounting plate side through hole and the circuit board side through hole in any orientation. However, since the workers are accommodated in substantially the same direction, the operator performs the operation of accommodating the conductive member in the mounting plate side through hole and the circuit board side through hole without considering the direction of the conductive member. be able to. Therefore, the working efficiency for manufacturing the motor can be improved. In addition, since the orientation of the conductive member is not taken into account, it is possible to easily realize the automation of the manufacture of the motor.

  According to a second aspect of the present invention, according to the first aspect, the conductive member and the land portion are connected by a conductive adhesive or solder.

  According to claim 2 of the present invention, the conductive wire member and the land portion can be easily connected to each other by connecting the conductive member and the land portion with a conductive adhesive and solder.

  According to a third aspect of the present invention, according to any one of the first and second aspects, the conductive member has a spherical shape, and the portion of the maximum diameter of the conductive member and the mounting plate side through-holes The inner side surface is characterized by contacting.

  According to the third aspect of the present invention, the conductive member is brought into contact with the inner surface of the mounting plate side through hole at the portion of the maximum diameter of the conductive member so that the conductive member is on the surface opposite to the mounting plate from the circuit board. The height of the protruding portion from the circuit board can be suppressed. Therefore, the possibility of contact with other members arranged near the conductive member can be suppressed.

  According to a fourth aspect of the present invention, according to the third aspect, the mounting plate side through hole is circular, and the inner side surface of the mounting plate side through hole covers the maximum diameter portion of the conducting member. It touches over the circumference.

  According to the fourth aspect of the present invention, the inner surface of the mounting plate side through hole is brought into contact with the inner surface of the mounting plate side through hole and the portion of the maximum diameter of the conducting member over the entire circumference, so that the inner surface of the mounting plate side through hole It can be held more reliably. Therefore, even if the motor vibrates due to an external impact or the like, it is possible to provide a highly reliable motor in which the conductive member does not come off the mounting plate.

  According to a fifth aspect of the present invention, according to any one of the first to fourth aspects, the land portion is an annular shape surrounding a periphery of the circuit board side through hole.

  According to claim 5 of the present invention, the land portion is formed in an annular shape surrounding the periphery of the through hole on the circuit board side, so that the land portion is more reliably applied when the conductive adhesive or solder is applied. be able to. Further, by providing the land portion around the entire circumference of the through hole on the circuit board side, the portion where the conductive adhesive or solder and the land portion are connected increases, so that the land of the mounting plate and the circuit board can be more reliably secured. Connection with the part can be achieved. Therefore, a highly reliable motor can be provided.

  According to a sixth aspect of the present invention, according to any one of the first to fifth aspects, the circuit board is a flexible circuit board.

  According to claim 6 of the present invention, the flexible circuit board is used as the circuit board, so that the thickness can be reduced as compared with the rigid circuit board. Therefore, even if the conductive member is reduced in size, the conductive adhesive protrudes from the circuit board, or the conductive member and the surface of the circuit board have substantially the same height, so that the conductive adhesive and the solder can be more reliably supplied. Can be applied.

  According to a seventh aspect of the present invention, according to any one of the first to sixth aspects, the conductive member is disposed on a radially outer side than the rotating body.

  According to claim 7 of the present invention, the conductive member is disposed on the radially outer side of the rotating body, thereby preventing the conductive member from coming into contact with the rotating body even if the conductive member protrudes from the circuit board to the rotating body side. Can do. Therefore, a highly reliable motor can be provided. In addition, if a conductive adhesive or solder is further applied to the conductive member, the possibility of contact between the conductive adhesive and the solder and the rotating body is increased, but the conductive member is disposed radially outside the rotating body. The possibility can be suppressed.

  ADVANTAGE OF THE INVENTION According to this invention, the motor which an operator can attach easily the member which aims at conduction | electrical_connection of a circuit board and an attachment board can be provided.

<Overall structure of motor>
The overall structure of the motor 10 of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a schematic cross-sectional view of the motor 10 according to the present invention cut along a plane along the axial direction including the central axis J1. FIG. 2 is a schematic plan view of the motor 10 of the present invention as viewed from above.

  The motor 10 of the present invention includes a rotating body 20 having a rotor magnet 22 that rotates around a central axis J1, a stationary body 30 having an armature 32 that faces the rotor magnet 22 via a gap in the radial direction, and a stationary body. 30 and a bearing mechanism 40 that supports the rotating body 20 so as to be rotatable about a central axis J1. Hereinafter, the rotating body 20 side is defined as the axial upper side and the stationary body 30 side is defined as the axial lower side along the central axis J1. However, the central axis J1 does not necessarily coincide with the direction of gravity.

  The rotating body 20 includes a shaft 21 arranged coaxially with the central axis J1, a hub 23 fixed to the upper portion of the shaft 21, a rotor magnet 22 and an annular clamp magnet 24 fixed to the hub 23, and a clamp magnet. And a mounting member 25 which is fixed to the upper surface of 24 and serves as a mounting portion on which a disk (not shown) is mounted.

  The hub 23 is composed of a magnetic metal material (in this embodiment, martensitic stainless steel is used). The hub 23 includes a substantially cylindrical base portion 231 having an inner peripheral surface for fixing the shaft 21, an annular outer lid portion 232 extending radially outward from a lower portion of the base portion 231, and an outer peripheral edge of the outer lid portion 232. And a cylindrical portion 233 extending along the lower side in the axial direction.

  The base 231 is provided on the radially inner side of the clamp magnet 24 with a tapered outer peripheral surface for guiding the disk to the mounting member 25, and an inner peripheral surface (not shown) of the center opening hole of the disk. A central cylindrical portion 2312 having an outer peripheral surface opposed in the radial direction. A clamp magnet 24 is fixed to the upper surface of the outer lid portion 232. An annular rotor magnet 22 is fixed to the inner peripheral surface of the cylindrical portion 233.

  The stationary body 30 includes an armature 32, a hollow cylindrical housing 31 that holds the armature 32, a mounting plate 33 that is fixed to the housing 31, a circuit board 34 that is mounted on the upper surface of the mounting plate 33, and a mounting plate And a cap 35 attached to the lower side in the axial direction of 33.

  The housing 31 has a hollow cylindrical shape having an outer surface that holds the armature 32. The outer surface of the housing 31 includes an armature holding portion 311 that holds the armature 32, and an attachment plate fixing portion 312 that is provided below the armature holding portion 311 in the axial direction and fixes the attachment plate 34. Composed.

  The armature 32 includes a core back portion 3211 having an inner surface that contacts the outer surface of the housing 31 and a core back portion 3211 (portion radially inward from the broken line along the central axis J1 of the armature 32 in FIG. 1). An armature core 321 having a teeth portion 3212 extending radially outward (a portion radially outside the broken line along the central axis J1 of the armature 32 in FIG. 1), and a conductive wire is wound around the teeth portion 3212 a plurality of times. The coil 322 is formed. A plurality of teeth portions 3212 are provided apart from each other in the circumferential direction (in this embodiment, six teeth portions 3212 are provided). The coil 322 is formed by concentrated winding in which one conductive wire is concentratedly wound around each tooth portion 3212. The coil 322 includes a U phase, a V phase, and a W phase. Moreover, a neutral point is comprised by star-connecting the end of U phase, V phase, and W phase. The other end of each of the U-phase, V-phase, and W-phase of coil 322 and the neutral point are electrically connected to circuit board 34.

  The bearing mechanism 40 is a circle 41 that is disposed on the upper surface of the mounting plate 33 and is in contact with the lower end surface of the shaft 21. The sleeve 41 is formed of an oil-impregnated sintered material that is fixed to the inner surface of the housing 31. And a plate-like thrust plate 42. The sleeve 41 holds the shaft 21 rotatably in the radial direction, and the thrust plate 42 supports the shaft 21 rotatably in the axial direction.

<Structure of circuit board>
Next, the structure of the circuit board 34 will be described with reference to FIG. FIG. 3 is a schematic plan view showing the circuit board 34 of the present invention.

  The circuit board 34 includes a wiring path 341 made of copper foil having a certain thickness, and an insulator 342 that covers the wiring path 341. The circuit board 34 of the present embodiment is a flexible circuit board in which the insulator 342 is made of a polyimide film. The circuit board 34 is provided with a through hole centered on the central axis J1.

  The wiring path 341 is electrically connected to the output-side land portions 3411 (three in the present embodiment) electrically connected to the U-phase, V-phase, and W-phase ends of the coil 322, and the neutral point. Connection-side land part 3412 to be connected, connection part 3413 connected to an external circuit board, output-side land part 3411 and output-side wiring part 3414 for electrically connecting the connection part 3413, and connection-side land part 3412 And a connection-side wiring part 3415 that electrically connects the connection part 3413 and a ground part 3416 that establishes electrical connection with the mounting plate 33.

  The connection-side land portion 3412 has a substantially arc shape along the through-hole centered on the central axis J1. In the present embodiment, three neutral points of the coil 322 are formed. Each of them is separated from each other and electrically connected to the connection side land portion 3412. Thereby, the neutral point of the coil 322 can be electrically connected to each other by the connection side land portion 3412.

  The connection portion 3413 includes a plurality of terminal portions 3413a (five in this embodiment) arranged in parallel. That is, it is composed of three terminal portions 3413a connected to the output side wiring portion 3414, one terminal portion 3413a connected to the connection side wiring portion 3415, and one terminal portion 3413a connected to the ground portion 3416. Is done.

  The ground portion 3416 includes an annular portion 3416a that is electrically connected to the mounting plate 33, and a ground-side wiring portion 3416b that electrically connects the annular portion 3416a and the connection portion 3413. A circuit board side through hole 3416c is provided inside the annular portion 3416a.

<Conductive structure between mounting plate and circuit board>
Next, a conduction structure between the mounting plate 33 and the circuit board 34 will be described with reference to FIGS. 4 and 5. FIG. 4 is a schematic plan view showing a state where the circuit board 34 is attached to the attachment plate 33. FIG. 5 is a schematic cross-sectional view showing a conduction structure between the mounting plate 33 and the circuit board 34.

  The mounting plate 33 is a flat plate made of a metal material such as a steel plate or aluminum. The mounting plate 33 is provided with a fixing hole 331 for fixing the housing 31 (see FIG. 1) and a plurality of mounting holes 332. Further, a mounting plate side through hole 333 is provided at a position corresponding to the circuit board side through hole 3416 c of the circuit board 34 in the mounting plate 33. Here, the diameter R1 of the inner peripheral surface of the mounting plate 33 constituting the mounting plate side through hole 333 is larger than the diameter R2 of the inner peripheral surface of the circuit board 34 constituting the circuit board side through hole 3416c. small. Here, the diameter R1 of the inner peripheral surface of the mounting plate 33 constituting the mounting plate side through hole 333 is substantially equal to the diameter R2 of the inner peripheral surface of the circuit board 34 constituting the circuit board side through hole 3416c. It may be the same.

  Referring to FIG. 5, the conductive structure between the mounting plate 33 and the circuit board 34 is a spherical metal steel ball 36 that contacts the mounting plate side through hole 3416 c of the mounting plate 33 (the conductive member in the claims). And solder 37 that contacts the steel ball 36 and the annular portion 3416a of the ground portion 3416 of the circuit board 34. More specifically, first, the steel ball 36 is fixed to the inner peripheral surface constituting the attachment plate side through hole 333 by press fitting. That is, the diameter R3 of the steel ball 36 is formed to be equal to or larger than the diameter R1 of the inner peripheral surface constituting the mounting plate side through hole 333. Thereby, the outer surface of the steel ball 36 can contact over the perimeter of the circumferential direction of the internal peripheral surface which comprises the attachment plate side through-hole 333. FIG.

  Further, it is desirable that the thickness T of the mounting plate 33 is equal to or larger than the radius (R3 / 2) of the steel ball 36. In the present embodiment, the plate thickness T is about 0.5 mm, and the radius of the steel ball 36 is about 0.35 mm (that is, the diameter R3 of the steel ball 36 is about 0.7 mm). Members other than the cap 35 (see FIG. 1) can be prevented from projecting downward in the axial direction from the axial position of the lower surface of the portion where the mounting hole 332 (see FIG. 4) of the mounting plate 33 is provided. Thereby, the motor 10 can be easily attached to a device mounted on the motor 10.

  Further, it is desirable that the steel ball 36 protrudes at substantially the same position as the upper surface of the circuit board 34 in the axial direction or more upward in the axial direction. In particular, when the maximum diameter of the steel ball 36 (that is, the diameter R3) and the inner peripheral surface constituting the mounting plate side through-hole 333 are in contact with each other, the height of the steel ball 36 protruding toward the circuit board 34 is reduced. can do. Thereby, while the plate | board thickness T of the attachment board 33 is made thin, the height which the steel ball 36 protrudes to the circuit board 34 side can be made low.

  The solder 37 is applied so as to connect the upper surface of the portion of the steel ball 36 projecting toward the circuit board 34 and the annular portion 3416a of the ground portion 3416. As a result, the mounting plate 33 and the circuit board 34 are electrically connected to the inner peripheral surface of the mounting plate side through-hole 333, the steel ball 36, the solder 37, and the annular portion 3416a of the ground portion 3416. Conduct.

  Here, the steel ball 36 can be mounted without considering the mounting direction of the steel ball 37 when mounting to the inner peripheral surface constituting the mounting plate side through hole 333. Therefore, the work efficiency of the worker can be improved. In addition, since it is possible to perform the mounting operation on the inner peripheral surface constituting the mounting plate side through-hole 333 without considering the mounting direction of the steel ball 36, the operation can be easily automated.

  In addition, referring to FIG. 2, it is desirable that the conduction structure using the steel ball 36 is disposed on the outer side in the radial direction from the rotating body 20. As a result, contact between the hub 23 (see FIG. 1) and the solder 37 can be avoided. In particular, the maximum height H (see FIG. 5) of the solder 37 from the circuit board 34 only needs to be radially outer than the outer peripheral surface of the hub 23. As a result, the ground side wiring portion 3416b of the ground portion 3416 of the circuit board 34 can be made small, and the circuit board 34 can be downsized.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims.

  For example, in the embodiment of the present invention, the solder 37 is used for electrical connection between the steel ball 36 and the annular portion 3416a of the ground portion 3416 of the circuit board 34, but the present invention is not limited to this. . Since it is only necessary that the steel ball 36 and the annular portion 3416a can be electrically connected, for example, a conductive adhesive may be applied. In addition, a conductive material may be used.

  For example, although the ground portion 3416 of the present invention has the annular portion 3416a, the present invention is not limited to this. Since the solder 37 (or a conductive material such as a conductive adhesive) and the ground portion 3416 may be electrically connected, the shape of the annular portion 3416a is not limited to the annular shape. For example, the annular portion 3416a may have an arc shape.

  For example, the mounting plate side through hole 333 and the circuit board side through hole 3416c of the present invention have a circular shape in a top view, but the present invention is not limited to this. Since the attachment plate side through-hole 333 only needs to have a shape in contact with the steel ball 36, the attachment plate side through hole 333 may have a polygonal shape or an elliptical shape in a top view. The same applies to the shape of the circuit board side through hole 3416c. Further, the annular portion 3416a has a shape other than the annular shape in accordance with the shape of the circuit board side through hole.

  For example, although the conduction member of the present invention is a steel ball 36, the present invention is not limited to this. The shape of the conducting member may be a regular polyhedral shape. If it is a regular polyhedron shape, the direction in the case of attachment of a conduction | electrical_connection member can be suppressed substantially.

It is the schematic cross section which cut the axial direction which showed the motor of this invention. It is the model top view seen from the axial direction upper side which showed the motor of this invention. It is the model top view seen from the axial direction upper side which showed the circuit board of this invention. It is the model top view seen from the axial direction upper side which showed the attachment state of the attachment board and circuit board of this invention. It is the schematic cross section cut in the axial direction which showed the conduction | electrical_connection state of the attachment board and circuit board of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Motor 20 Rotating body 22 Rotor magnet 23 Rotor hub 30 Stationary body 31 Housing 32 Armature 33 Mounting plate 332 Mounting hole 333 Mounting plate side through-hole 34 Circuit board (flexible circuit board)
3416 Ground part 3416a Annular part (land part)
3416c Circuit board side through hole 36 Steel ball (conductive member)
37 Solder (conductive member)
40 Bearing mechanism J1 Center axis R1 Diameter of mounting plate side through hole R2 Diameter of circuit board side through hole R3 Diameter of steel ball (maximum diameter)

Claims (7)

A motor,
A rotating body that rotates about a predetermined central axis;
A bearing mechanism for rotatably supporting the rotating body;
A stationary body holding the bearing mechanism;
With
The stationary body includes a mounting plate made of a substantially flat metal plate, and a circuit board attached to the mounting plate.
The mounting plate has a mounting plate side through hole,
A circuit board side through hole is formed at a position corresponding to the mounting plate side through hole of the circuit board, and a land portion of a ground pattern is provided on the periphery of the circuit board side through hole,
The mounting plate side through hole and the circuit board side through hole are at least one of conductive members made of a conductive material used for electrical connection between the mounting plate and the land portion of the circuit board. Part is housed,
The conducting member and the inner surface constituting the mounting plate side through hole are in contact with each other,
The conducting member is spherical or regular polyhedral;
A motor characterized by The motor according to claim 1,
The conductive member and the land portion are connected by a conductive adhesive or solder,
A motor characterized by A motor according to any one of claims 1 and 2,
The conducting member has a spherical shape,
The maximum diameter portion of the conducting member and the inner side surface of the mounting plate side through hole are in contact with each other;
A motor characterized by The motor according to claim 3,
The mounting plate side through hole is circular,
The inner side surface of the mounting plate side through hole is in contact with the maximum diameter portion of the conducting member over the entire circumference;
A motor characterized by The motor according to any one of claims 1 to 4,
The land portion is an annular shape surrounding the periphery of the circuit board side through hole;
A motor characterized by A motor according to any one of claims 1 to 5,
The circuit board is a flexible circuit board;
A motor characterized by The motor according to any one of claims 1 to 6,
The conductive member is disposed radially outside the rotating body;
A motor characterized by

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