JP2007166824A - Stepping motor and actuator unit using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stepping motor that is excellent in cost reduction and productivity while reducing the number of components and highly precisely executing assembling by saving labor after adopting a flat-shaped configuration desirable for thickness reduction and miniaturization. <P>SOLUTION: The stepping motor is composed so that two stators S1, S2 of a stator in an A phase and a stator in a B phase are arranged on both sides of a rotor 1 so as to be symmetrically protruded, and pole teeth 5 are vertically engaged with one another by clamping an upper yoke plate 3 and a lower yoke plate 4 by comb-shaped inductors (the pole teeth 5) thereon in face to face with the rotor 1 are provided between both ends of each magnetic core 20. The upper yoke plate 3 and the lower yoke plate 4 are assembled to upper and lower faces of a block member 8 with a prescribed thickness, respectively. Consequently, it is possible to adopt a configuration that allows the assembling of the motor by assembling each component to the block member 8. The diameter of the lower side of an opening 81 is made small into which the rotor 1 is fitted. A lower-side shaft 10 of the rotor 1 is freely rotatably supported by integrally providing a lower-side shaft receiver 9 to the lower side of the opening 81. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a flat stepping motor arranged so as to project a stator on both sides of a rotor, and more specifically, an upper yoke plate and a lower yoke plate are assembled to be sandwiched with respect to a central rotor, The present invention relates to an improvement in assemblability in a motor structure in which both comb-shaped pole teeth are engaged with each other vertically.

  One well known type of stepping motor is the claw pole type. This employs a configuration in which the stator side has comb-like inductors (pole teeth) and the A-phase and B-phase pole teeth are engaged with each other to face the rotor. The stepping motor having this configuration has an advantage that the resolution is relatively good and the manufacturing cost can be reduced.

As this claw pole type stepping motor, as can be seen in Patent Document 1 and the like, a stepping motor having a configuration in which a stator is projected in a flat shape is known. In the stepping motor of Patent Document 1, stators are arranged on both sides of a rotor for thinning, and each phase stator has a coil in a direction along the rotor axis, and a magnetic core is arranged at the center of the coil. In addition, the upper yoke plate and the lower yoke plate are sandwiched between both ends of the magnetic core so that the comb-shaped pole teeth of the yoke plates are engaged with each other vertically.
Japanese Patent Laid-Open No. 10-94237

  This type of stepping motor has a use as a drive source of an actuator unit (lens drive unit) for moving an optical lens, for example, and a miniaturized lens drive unit is incorporated into a mobile phone or the like to constitute a micro camera. Has been done. Portable devices such as mobile phones are particularly demanded to be thinner and smaller, and the demand for development to reduce the thickness and size of the stepping motor that is the driving source of the lens driving unit is also increasing. For this reason, there is a need for a review of the mechanism that enables further reduction in thickness and size. Therefore, although the thing of patent document 1 is made to reduce a number of parts, it is inadequate when it sees from the recent request | requirement.

  In addition, when thinning and downsizing, it is necessary to ensure that the machining accuracy (error) of each part that constitutes the motor exceeds a predetermined level, but errors such as misalignment do not occur when each part is assembled. It is necessary to pay attention to. In that respect, in the case of Patent Document 1, it is necessary to perform alignment adjustment in the process of sandwiching the upper and lower yoke plates, and if there is a positional deviation in the meshing relationship between the pole teeth, the design performance cannot be obtained. It becomes important, and it takes time and labor to assemble.

  The present invention solves the above-mentioned problems, and its object is to adopt a flat configuration preferable for thinning and miniaturization, enabling assembly with high accuracy without trouble, and reducing the number of parts. An object of the present invention is to provide a stepping motor that is cost effective and has high productivity.

  In order to achieve the above-described object, a stepping motor according to the present invention has a rotor with permanent magnets magnetized in multiple poles, two stators of A phase and B phase are arranged on both sides of the rotor, The stator has a coil in a direction along the rotor axis, and a magnetic core is arranged at the center of the coil, and an upper yoke plate and a lower yoke plate having comb-shaped pole teeth facing the rotor are arranged on the magnetic core. The stepping motor is arranged at both ends of the stepping motor so that the pole teeth are engaged with each other in the vertical direction. The stepping motor is made of a non-magnetic member and has openings for fitting the rotor, the coil, and the pole teeth. A block member for assembling the yoke plate and the lower yoke plate is provided, and the block member is integrally provided with a bearing portion that rotatably supports the rotor shaft.

  Further, the block member is formed from a resin material, and the bearing portion is configured to be formed by integrally molding at least one side of the rotor by resin material, or the bearing portion is formed from a metal material, On the other hand, at least one side of the rotor is integrated by insert molding, or at least one side of the upper yoke plate and the lower yoke plate is integrated by insert molding with respect to the block member. Or can be configured.

Further, one of the rotor shafts has a larger diameter than the other, and the outer diameter r2 of the large-diameter shaft and the outer diameter r1 of the small-diameter shaft with respect to the outer diameter r0 of the permanent magnet,
r1 ≦ r0 <r2
The block member has two parts, a small-diameter bearing portion that rotatably supports the small-diameter shaft (r1) and a large-diameter bearing portion that rotatably supports the large-diameter shaft (r2). It is preferable to provide a configuration.

  The actuator unit according to the present invention includes a movable body on which an optical lens or the like is mounted, a movable mechanism for moving the movable body, a drive source for the movable mechanism, and a support body for fixing them. In the actuator unit, the driving source is the stepping motor according to any one of claims 1 to 5, and the function of the support is provided integrally with the block member.

  With this configuration, in the present invention, the block member has an opening in which the rotor, the coil, and the pole teeth are fitted, and the upper yoke plate and the lower yoke plate are assembled to the upper and lower surface portions, respectively. Therefore, the motor can be assembled by assembling each component to the block member. At this time, since the mounting positions of the respective constituent elements are determined with respect to the block member, the assembly can be completed with a predetermined accuracy simply by assembling the respective constituent elements to the block member. And since the bearing part which supports a rotor axis | shaft rotatably is integrally provided in a block member, a rotor can be assembled | attached to a proper positional relationship and a number of parts can be reduced. As a result, when assembling, the alignment adjustment process is not required, and high-accuracy assembly can be easily performed without trouble.

  In the present invention, the motor can be assembled by adopting a flat configuration preferable for thinning and miniaturization and assembling each component to the block member. At this time, the mounting positions of the respective constituent elements are determined with respect to the block member, so that the assembling can be completed with a predetermined accuracy simply by assembling the respective constituent elements to the block member, and the assembling can be performed with high accuracy without trouble.

  Since the bearing member for rotatably supporting the rotor shaft is provided integrally with the block member, the rotor can be assembled in an appropriate positional relationship, and the number of parts can be reduced. That is, in assembling the motor, the block member serves as a base, and the positional relationship between the components can be determined appropriately simply by assembling, and assembling can be performed with high accuracy, thereby greatly reducing the assembly process. As a result, the cost is excellent and the productivity is good.

  1 and 2 show a first embodiment of the present invention. In this embodiment, the stepping motor has a rotor 1 made of permanent magnets magnetized in multiple poles, and two stators S1 and S2 of A phase and B phase are arranged symmetrically projecting on both sides of the rotor 1. The structure to do is taken. Each stator S1, S2 has a coil 2 in a direction along the axis of the rotor 1, a magnetic core 20 is arranged at the center of the coil 2, and a comb-shaped inductor (pole tooth 5) facing the rotor 1 is provided. The upper yoke plate 3 and the lower yoke plate 4 provided with a) are sandwiched between both ends of the magnetic core 20 so that the pole teeth 5 are engaged with each other in the vertical direction, thereby forming a so-called claw pole type stepping motor.

  The upper yoke plate 3 and the lower yoke plate 4 are made of an elongated band plate material, and a circular opening 6 is provided in the center, and the peripheral edge of the opening 6 is partially raised so that comb-like pole teeth 5 are arranged side by side. Is formed. Fitting holes 7 are provided on both sides of the opening 6, and the magnetic core 20 is fitted.

  The upper yoke plate 3 and the lower yoke plate 4 are assembled to a block member 8 having a predetermined thickness, and the components can be assembled to the block member 8 so that the motor can be assembled. That is, the block member 8 is made of a non-magnetic member and has openings 81, 82 and 85 into which the rotor 1, the coil 2 and the pole teeth 5 are fitted, and the upper yoke plate 3 and the lower yoke plate 4 on the upper and lower surfaces, respectively. Is to be assembled. The opening 81 to which the rotor 1 is fitted has a small diameter on the lower side, and the lower bearing portion 9 is integrally provided on the lower side. A lower shaft 10 of the rotor 1 is fitted to the lower bearing portion 9, and is configured to support it rotatably. A flange plate 11 is fixed on the upper yoke plate 3, and the flange plate 11 is provided with an upper bearing portion 12. The upper bearing portion 12 has a configuration in which the upper shaft 13 of the rotor 1 is fitted and rotatably supported.

  For the assembly, for example, the end of the magnetic core 20 is fitted and fixed in advance in the fitting hole 7 of the lower yoke plate 4, the coil 2 is assembled to each magnetic core 20, and the block member 8 is fitted to these. Assemble. Next, the upper yoke plate 3 is fitted with the pole teeth 5 facing each other from above, and the rotor 1 is inserted with the lower shaft 10 facing each other. Finally, the flange plate 11 is put on and the rotor 1 is put on the upper shaft 13 of the rotor 1. The upper bearing 12 is fitted together to complete the assembly. As a result, comb-shaped pole teeth 5 are engaged with each other on the outer periphery of the rotor 1, and the A phase and the B phase are alternately arranged to form an array of inductors, and the two stators S 1 and S 2 are arranged on both sides of the rotor shaft 10. It becomes a flat stepping motor that protrudes from the surface.

  The block member 8 can be formed from a resin material, for example. The bearing portion that rotatably supports the rotor shaft is preferably formed on the block member 8 at least one side of the rotor 1 by integral molding of a resin material. The bearing portion may be formed from a metal material. That is, as shown in FIG. 3, the bearing portion 14 is formed from a metal material as a single body, and the block member 8 is integrated by insert molding. Further, the upper yoke plate 3 and the lower yoke plate 4 may be configured such that at least one side is integrated with the block member 8 by insert molding.

  As described above, the block member 8 has the openings 81, 82, 85 in which the rotor 1, the coil 2, and the pole teeth 5 are fitted, and the upper yoke plate 3 and the lower yoke plate 4 are assembled to the upper and lower surface portions, respectively. ing. Therefore, the motor can be assembled by assembling each component to the block member 8. At this time, the mounting positions of the respective constituent elements are determined with respect to the block member 8, so that the assembly can be completed with a predetermined accuracy simply by assembling the respective constituent elements to the block member 8. Therefore, when assembling, the alignment adjustment process is not required, and high-precision assembly can be easily performed without trouble.

  Since the block member 8 is integrally provided with a bearing portion 9 that rotatably supports the rotor shaft, the rotor 1 can be assembled in an appropriate positional relationship, and the number of parts can be reduced. That is, in assembling the motor, the block member 8 serves as a base, and the positional relationship of each component can be appropriately determined simply by assembling, and assembly can be performed with high accuracy, thereby greatly reducing the assembly process. As a result, the cost is excellent and the productivity is good.

  4 to 6 show a second embodiment of the present invention. In the present embodiment, in the stepping motor, the upper bearing portion 15 is integrally provided on the block member 8 without providing the flange plate on the upper side of the rotor 1. Other configurations are the same as those in the first embodiment, and the same components are denoted by the same reference numerals and the description thereof is omitted.

One of the rotor shafts has a larger diameter than the other, the outer diameter r2 of the large-diameter shaft 13 and the outer diameter r1 of the small-diameter shaft 10 with respect to the outer diameter r0 of the permanent magnet (rotor 1),
r1 ≦ r0 <r2
The relationship is set. The block member 8 is provided with a small-diameter bearing portion 9 that rotatably supports the small-diameter shaft 10 (r1) and a large-diameter bearing portion 15 that rotatably supports the large-diameter shaft 13 (r2). Yes.

  The small diameter bearing portion 9 is provided on the lower side of the block member 8 and the large diameter bearing portion 15 is provided on the upper side of the block member 8. Therefore, the rotor 1 faces the block member 8 with the small diameter side facing from above. Will be inserted. Therefore, the rotor shaft can be seated on both the small diameter bearing portion 9 and the large diameter bearing portion 15 simply by fitting the rotor 1 from above, and can be easily assembled.

  FIG. 7 is a sectional view of an actuator unit using the stepping motor shown in FIGS. This actuator unit is an application example in which the stepping motor according to the present invention is used as a drive source, and the movable body 16 is moved in the axial direction of the rotor 1.

  The movable body 16 has a mounting portion for mounting an optical lens or the like, and a nut plate 17 is fitted in a recess formed at a predetermined position. The shaft portion of the rotor 1 is provided with a thread, and the nut plate 17 is engaged with the thread. The block member 8 is integrally provided with a support frame 18, and the movable body 16 moves in the axial direction as the rotor shaft rotates. At this time, the movable body 16 is provided in the support frame 18. It moves along the guide means, and it is a movement that prevents co-rotation.

1 is an exploded perspective view showing a preferred embodiment of a stepping motor according to the present invention. It is sectional drawing of the stepping motor shown in FIG. It is sectional drawing which shows the other example of a bearing part. It is a perspective view which decomposes | disassembles and shows 2nd Embodiment of the stepping motor which concerns on this invention. It is the perspective view which assembled the stepping motor shown in FIG. It is sectional drawing of the stepping motor shown in FIG. It is sectional drawing of the actuator unit using the stepping motor shown in FIGS.

Explanation of symbols

Reference Signs List 1 rotor 2 coil 3 upper yoke plate 4 lower yoke plate 5 pole teeth 6, 81, 82, 85 opening 7 fitting hole 8 block member 9 lower bearing portion 10 lower shaft 11 flange plate 12, 15 upper bearing portion 13 Upper shaft 14 Bearing portion 16 Movable body 17 Nut plate 18 Guide frame body 20 Magnetic cores S1, S2 Stator

Claims (6)

It has a rotor with permanent magnets magnetized in multiple poles, two stators of A phase and B phase are arranged on both sides of the rotor, the stator has a coil along the rotor axis, Is a stepping in which a magnetic core is disposed at the center, and an upper yoke plate and a lower yoke plate having comb-shaped pole teeth facing the rotor are disposed at both ends of the magnetic core so that the pole teeth mesh with each other vertically. In the motor
The rotor, the coil, and the pole teeth are made of nonmagnetic members, and the upper yoke plate and the lower yoke plate are respectively assembled to the upper and lower surface portions.
A stepping motor characterized in that the block member is integrally provided with a bearing portion for rotatably supporting the rotor shaft.   2. The stepping motor according to claim 1, wherein the block member is made of a resin material, and the bearing portion is formed by integrally molding the resin material on at least one side of the rotor.   The stepping motor according to claim 1, wherein the bearing portion is formed of a metal material, and at least one side of the rotor is integrated with the block member by insert molding.   4. The stepping motor according to claim 1, wherein at least one of the upper yoke plate and the lower yoke plate is integrated with the block member by insert molding. 5. One of the rotor shafts has a larger diameter than the other, and the outer diameter r2 of the large-diameter shaft and the outer diameter r1 of the small-diameter shaft with respect to the outer diameter r0 of the permanent magnet,
r1 ≦ r0 <r2
The block member has two parts, a small-diameter bearing portion that rotatably supports the small-diameter shaft (r1) and a large-diameter bearing portion that rotatably supports the large-diameter shaft (r2). The stepping motor according to claim 1, wherein the stepping motor is provided. In an actuator unit composed of a movable body to which an optical lens or the like is mounted, a movable mechanism for moving the movable body, a drive source of the movable mechanism, and a support body for fixing them.
6. The actuator unit according to claim 1, wherein the driving source is the stepping motor according to claim 1, and the function of the support is provided integrally with the block member.

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