JP2005295710A - motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor in which a coil winding shape of a stator is stabilized and there is little risk of coil collapse.
A motor M according to the present invention is wound around a rotor 1 magnetized with a plurality of magnetic poles, and a yoke 4 and a yoke 4 in which magnetic pole portions 4a1 and 4a2 are located close to the outer peripheral surface of the rotor 1. And a stator 3 having a coil 5. The yoke 4 has an H-shape composed of a pair of opposing leg portions 4a, 4a and a connecting portion 4b that connects them, and a coil 5 is wound around the connecting portion 4b of the yoke. It is preferable that the outer peripheral part of the coil 5 is in a position substantially equal to the outer end part of the leg part 4a. In addition, the motor M according to the present invention is incorporated in, for example, a driving unit that moves the lens system of the optical module.
[Selection] Figure 1

Description

  The present invention relates to a motor that prevents coil collapse.

2. Description of the Related Art In recent years, portable electronic devices such as mobile phones equipped with minute cameras, notebook computers, and portable videophones have become widespread. These portable electronic devices incorporate a small motor that accurately positions the optical system. The motor is generally composed of a rotor and a stator having a yoke and a coil. As such a motor, many proposals have been conventionally made (for example, Patent Document 1).
In the motor of Patent Document 1, a coil frame is inserted into the outer leg portion of the U-shaped or U-shaped yoke, and the coil is wound in the coil frame. This Patent Document 1 has a difficulty in that the number of parts increases because a coil frame is provided. Therefore, a stator structure in which a coil is directly wound around the outer leg or center of the U-shaped yoke is conceivable.

For example, a motor employing the latter stator structure is shown in FIG.
This motor is close to the outer peripheral surface of a rotor a magnetized with a plurality of magnetic poles, and a pair of stators d comprising a coil c and a yoke b in which a conducting wire is wound directly around the central portion of a U-shaped yoke b. , D are disposed, and an auxiliary yoke e is disposed in the opening of the yoke b in the vicinity of the outer peripheral surface of the rotor a. The motor includes a rotor shaft f and a boss portion g thereof.
JP 2001-61268 A

  In the motor shown in FIG. 6, a stator is formed by winding a conducting wire directly around the central portion of the U-shaped yoke. Therefore, both end faces of the coil wound in the opening of the yoke are supported between the pair of leg portions of the yoke, so that the winding shape is stabilized. However, in the stator structure shown in FIG. 6, there is no coil frame that is a constituent member of Patent Document 1, and therefore the coil portion wound around the outside of the yoke is simply supported on the previously wound conducting wire. Therefore, the winding shape is likely to be uneven, and in some cases, there is a risk of collapse. Therefore, as indicated by a broken line A in FIG. This also applies to the case where the conducting wire is directly wound around the leg portion of the U-shaped yoke.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-mentioned problems of the prior art, and provide a motor that stabilizes the winding shape of a coil wound around a yoke and reduces the risk of coil collapse. There is to do.

  A motor according to the present invention includes a rotor having a plurality of magnetic poles magnetized, a yoke having a magnetic pole portion positioned close to the outer peripheral surface of the rotor, and a coil formed by a conductive wire wound around the yoke; The yoke has an H-shape composed of a pair of opposed leg portions and a connecting portion that connects the yoke, and the coil is wound on the connecting portion and between the pair of leg portions. Yes.

The coil is configured, for example, by winding a conducting wire directly around a connecting portion of a yoke.
Moreover, it is preferable that the outer peripheral part of the coil wound by the said yoke exists in the position substantially equal to the outer end part of a leg part.

The optical module according to the present invention is incorporated in a driving unit in which the above-described motor moves the lens system.
A pair of stators are arranged on the outer peripheral portion of the optical unit including the lens system, the pair of stators are combined to form a square shape, and each stator is arranged in a direction along the outer periphery of the optical unit. ing.

  In the motor according to the present invention, the stator coil is wound between the pair of leg portions of the H-shaped yoke because the stator coil is wound around the connecting portion that connects the pair of opposed leg portions of the H-shaped yoke.・ Supported. Therefore, the winding shape of the coil is stabilized and the coil wound around the yoke is prevented from being collapsed.

Hereinafter, a motor according to an embodiment of the present invention will be specifically described with reference to a plan view and a side view of FIG.
In FIG. 1, the distributed PM motor M includes a rotor 1 and a pair of stators 3 and 3 that face each other with the rotor 1 interposed therebetween. The rotor 1 is composed of a permanent magnet structure magnetized with 10 magnetic poles, and includes a rotor shaft 2 having a boss portion 2a on its central axis.
The stator 3 includes a yoke 4 and a coil 5. The yoke 4 is formed of an H-shaped soft magnetic material including a pair of opposing leg portions 4a and 4a and a connecting portion 4b that connects the leg portions 4a and 4a. The coil 5 is formed by winding a conducting wire directly on the connecting portion 4b of the yoke, and the wound coil 5 is located between the pair of leg portions 4a and 4a. Such a stator 3 is arranged around the rotor 1 so that the magnetic pole portions 4a1 and 4a2 formed in the circular arc surface of the inner end portion of each leg portion 4a are located close to each other along the outer peripheral surface of the rotor 1. The
Further, arc-shaped auxiliary yokes 6 are arranged along the outer peripheral surface of the rotor 1 between the magnetic pole portions 4 a 1 and 4 a 2 at both ends of the yoke 4 in each stator 3.

  The pair of stators 3, 3 are arranged in a letter C shape with an intersecting angle of 198 ° with respect to the rotor shaft 2. Each coil 5 is connected to a drive circuit (not shown), and the magnetic pole portions 4a1 and 4a2 can be excited by a pulse current. Therefore, by applying an arbitrary pulse current to each coil 5, the rotor 1 can be rotated by a desired amount in a desired direction.

In the present embodiment, the rotor 1 is not particularly limited as long as the rotor 1 is set to an appropriate size according to the device to which the motor M is applied and two or more magnetic poles are magnetized. For example, when the motor M is a small stepping motor incorporated in a portable electronic device, the diameter of the rotor 1 is preferably in the range of 2 to 4 mm.
The H-shaped yoke 4 includes a pair of leg portions 4a and 4a and a connecting portion 4b that connects intermediate regions other than these end portions. The pair of leg portions 4a and 4a may not be in a completely parallel relationship, and both ends of the connecting portion 4b are portions of the length direction 1/2 to 3/4 from the inner end to the outer end of each leg portion 4a. It is preferable to connect to. FIG. 1 shows a preferred example of a yoke 4 in which a connecting portion 4b is connected to approximately 2/3 of the length direction.
When the torque of the motor M is made the same using the yoke of the same size, the outer peripheral part of the coil 5 may be in a position substantially equal to the outer end part of the pair of leg parts 4a, 4a from the viewpoint of space efficiency. preferable. However, the coil 5 may be slightly exposed from between the leg portions 4a and 4a, or the outer peripheral surface of the coil may not reach the outer end portion of the leg portions 4a and 4a.

In general, in the case of a small motor, it is difficult to stabilize the coil winding shape as compared with a large motor. However, according to the present invention, the coil winding shape is stabilized for the reasons described above. Coil collapse is prevented. As a result, the coil winding process is simplified, and the stator can be easily fixed to the motor. In addition, it is possible to improve the space efficiency of the stator described above.
Thus, in the embodiment of the present invention, the motor M is preferably used as a small motor.

Next, as an example, an optical module having an AF mechanism in which a stepping motor is incorporated as a motor according to the present invention will be described below with reference to FIGS. For easy understanding, FIG. 4 shows a plan view showing the positional relationship between the drive unit and the lower part of the lens holder in the optical module, and FIG. 5 shows the drive unit.
As shown in FIGS. 2 and 3A, the optical module 10 includes a base 11, a protective cover 20, an optical system unit 30, and a drive unit 40 including a stepping motor. The lower part of the optical system unit 30 is constituted by the base 11.

The base 11 includes a bottom portion 11 a, a lens barrel 12 that is a constituent member of the optical system unit 30, and a wall portion 13 that is adjacent to the lens barrel 12 and forms a lower portion of the drive unit 40. The lens barrel 12 is formed of a cylindrical body partially replaced with a partition wall 11b. The wall 13 is formed of a rectangular vertical wall that shares the partition wall 11b of the lens barrel 12 and has an upper surface opened.
The lens barrel 12 includes a substantially annular large-diameter portion 12a and an annular small-diameter portion 12b. A substrate 15 on which a predetermined wiring pattern is formed is fitted into the bottom 11a opening of the base 11 where the bottom surface of the small diameter portion 12b faces. A CCD (Charge Coupled Device; not shown), which is an image sensor, is fixed on the substrate 15.

  The protective cover 20 includes a cylindrical first cover portion 21 that covers the upper surfaces of the lens barrel 12 and the wall portion 13, and a second cover portion 22 that has a bottomless substantially rectangular parallelepiped shape. A bearing hole 23 that pivotally supports the upper end portion of the rotor shaft 2 is formed at the center of the upper surface of the second cover portion 22.

The optical system unit 30 includes a cylindrical lens holder 31 that holds one lens L, a cylindrical cam 33, the lens barrel 12, and an annular coil spring 34. In FIGS. 2 and 3A, a filter, a diaphragm, and the like are omitted.
The cylindrical cam 33 moves the lens holder 31 so as to advance and retreat in the optical axis direction LD by its rotation. That is, the cam surface 33a is formed on the upper surface (light incident side surface) of the cylindrical cam 33, and the rack portion 33b is formed on the lower outer peripheral surface. The rack portion 33 b meshes with a gear 42 b that is fixed to a shaft 17 described later provided on the base 11. The cylindrical cam 33 is disposed between the bottom 11a of the base 11 and a cam follower 31b described later of the lens holder 31. Such a cylindrical cam 33 can cause the lens L to be spelled out (AF).

A flange portion 31 a is formed on the outer peripheral surface of the lower portion of the lens holder 31. A pair of cam followers 31b protruding in the radial direction and facing each other are formed on the upper portion of the flange portion 31a. In the lens holder 31, the lower portion of the flange portion 31 a is fitted between the outer peripheral surface of the small diameter portion 12 b of the lens barrel 12 and the inner peripheral surface of the cylindrical cam 33, and the cam follower 31 b is formed in the large diameter portion 12 a of the lens barrel 12. By being fitted in the groove of the projecting portion 14, the lens barrel 12 is slidably guided.
The coil spring 34 urges the lens holder 31 toward the cylindrical cam 33, and is placed in a groove formed in the cam follower 31 b, and is placed in a space between the outer periphery of the lens holder 31 and the protective cover 20. Be placed. Due to the biasing force of the coil spring 34, the lower surface of the cam follower 31 b comes into contact with the cam surface 33 a of the cylindrical cam 33.

The drive unit 40 rotates the cylindrical cam 33, and includes a motor according to the present invention, a gear 41 provided on the rotor shaft 2, two gears 42 shown in FIG. 4 and an electromagnetic actuator fixing member 43 shown in FIG.
In the rotor shaft 2, an upper boss portion 2a, a large-diameter lower boss portion 2b, and a gear mounting portion 2c are integrally formed, and both end portions of the rotor shaft 2 are the bearing holes of the second cover portion 22, respectively. 23 and a bearing portion (not shown) formed on the bottom plate of the electromagnetic actuator fixing member 43. Each stator 3 is sandwiched between positioning members protruding from the bottom plate of the electromagnetic actuator fixing member 43 so that the magnetic pole portions 4a1 and 4a2 at both ends of the yoke are located close to the outer peripheral surface of the rotor 1. The auxiliary yoke 6 is also supported by positioning members 44 a and 44 b provided on the fixing member 43 on the back surface and both side surfaces thereof.

The gear 42 is fixed in two stages to a rotatable shaft 17 that extends upward from the bottom 11 a of the base 11. One gear 42 a meshes with a gear 41 provided on the rotor shaft 2, and the other gear 42 b meshes with the rack portion 33 b of the cylindrical cam 33.
The electromagnetic actuator fixing member 43 is formed with a side wall 43 a perpendicular to the side opposite to the lens holder 31. Further, a step portion 43b is formed in the actuator fixing member 43 on the lens holder 31 side. The step portion 43 b is a positioning portion for the stators 3 and 3, and also serves for positioning the lens holder 31.
In addition to protecting the optical system unit 30 and the drive unit 40, the protective cover 20 acts as a pressing spring for the coil spring 34 by being fixed to the base 11 by appropriate means.

  As shown in FIG. 4, a pair of stators 3 and 3 are arranged on the outer peripheral portion of the optical unit 30 including the lens L. The pair of stators 3, 3 are combined to form a square shape, and each stator 3 is arranged in a direction along the outer periphery of the optical unit 30. With this arrangement configuration, the stators 3 and 3 can be efficiently arranged in the lower space of the optical system unit 30 and the drive unit 40, and the optical module 10 can be made more compact.

  In the optical module 10 described above, in order to spell out (AF) one lens L, the current flowing through the stator coil 5 is controlled to change the magnetic poles of the magnetic pole portions 4a1 and 4a2 at both ends of the yoke to change the rotor 1. Rotate. As the rotor 1 rotates, the rotor shaft 2 rotates, and the shaft 17 to which the gear 42a meshing with the gear 41 fixed to the rotor shaft 2 is also rotated. As the shaft 17 rotates, the other gear 42b meshes with the rack portion 33b of the cylindrical cam 33, so that the cylindrical cam 33 also rotates. As the cylindrical cam 33 rotates, the cam follower 31b slides on the cam surface 33a of the cylindrical cam 33, so that the lens holder 31 moves in the optical axis direction LD corresponding to the sliding locus of the cam follower 31b. Thereby, the lens L attached to the lens holder 31 is spelled out (AF). That is, the back focus that is the distance between the lens L and the CCD can be changed.

  To assemble the drive unit 40 of the optical module 10, first, the gear 42 b is fixed to the shaft 17 provided on the base 11 so as to be engaged with the rack portion 33 b of the cylindrical cam 33. Next, the stepping motor is fixed to the electromagnetic actuator fixing member 43 so that the gear 41 provided on the rotor shaft 2 meshes with the gear 42a fixed to the shaft 17 of the base 11. By attaching to the base 11, the drive unit 40 is assembled.

The motor according to the present invention can be applied to mobile phones equipped with cameras, office computers such as notebook computers, copiers, facsimiles, and portable videophones.
The motor according to the present invention as described above is preferably used as a small motor having a risk of coil collapse.

(A) is a top view of the motor which concerns on embodiment of this invention, (B) is the side view. It is a perspective view of an optical module in which a motor according to the present invention is incorporated. FIG. 3A is a cross-sectional view taken along line III-III in FIG. 2, and FIG. 3B is a cross-sectional view of a drive unit in the optical module. FIG. 4 is a view taken along the line IV-IV in FIG. 3A showing the arrangement of the drive unit and the lens holder in the optical module shown in FIG. 2. It is a side view of the drive part shown in FIG. (A) is a top view which shows an example of the motor of the stator structure which wound the coil around the U-shaped yoke, (B) is the side view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rotor 3 Stator 4 Yoke 4a Leg part 4b Connection part 4a1, 4a2 Magnetic pole part 5 Coil M Motor

Claims (5)

  A rotor having a plurality of magnetic poles magnetized, a yoke having a magnetic pole portion located close to the outer peripheral surface of the rotor, and a stator having a coil formed by a conductive wire wound around the yoke, A motor having an H-shape composed of a pair of opposing leg portions and a connecting portion connecting the leg portions, wherein the coil is wound on the connecting portion and between the pair of leg portions. .   The motor according to claim 1, wherein the conductive wire of the coil is wound directly around the connecting portion of the yoke.   3. The motor according to claim 1, wherein an outer peripheral portion of a coil wound around the yoke is at a position substantially equal to an outer end portion of the leg portion.   An optical module in which the motor according to any one of claims 1 to 3 is incorporated in a drive unit that moves a lens system. A pair of the stators are disposed on the outer periphery of the optical unit including the lens system,
The optical module according to claim 4, wherein the pair of stators are combined to form a square shape, and each stator is disposed in a direction along an outer periphery of the optical unit.

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