JP2010035254A - Electric motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric motor that is enhanced in productivity and efficiency and yet reduced in size and thickness. <P>SOLUTION: The electric motor includes a single-phase stator 3 obtained by: compressing and molding magnetic powder into molded bodies 2 each having an annular base portion 2' and multiple claw-shaped magnetic poles 2a so formed that they are protruded from the base portion 2' in the circumferential direction; and arranging these molded bodies opposite to each other. The molded bodies are so arranged that the claw-shaped magnetic poles of one molded body are positioned between the claw-shaped magnetic poles of the other molded body 2. A bobbin 1 on which a coil is wound is provided between the molded bodies arranged opposite to each other, on the outer radius side of the claw-shaped magnetic poles 2a. This bobbin 1 has on its both sides multiple protrusions 1a protruded toward the molded bodies 2. Single-phase stators 3 are laminated in three phases and a first single-phase stator and a second single-phase stator adjacent thereto are positioned by the protrusions 1a and corrugated portions 1b, 1c provided in the bobbin 1. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electric motor.

  An electric motor is used as a drive source in various applications, and is often used by being incorporated in various products. For example, it is also used for blowers, compressors for refrigeration and air conditioning, and so-called auxiliary machines such as automobile power windows and wipers. As described above, regarding an electric motor incorporated in a product, not only high efficiency but also miniaturization (thinning) or improvement in assemblability is required. And the shape of the rotor or stator for improving efficiency, downsizing, and improving assemblability has been studied.

  Patent Document 1 discloses a configuration of a stepping motor for reducing the size and improving the productivity, and Patent Document 2 discloses positioning for the outer periphery of the core flat portion in order to position the core in the rotational direction. A configuration having a V-shaped groove is disclosed. Further, Patent Document 3 discloses a multiphase claw pole type motor, and it is possible to obtain a claw type magnetic pole having a complicated shape while facilitating manufacture by compressing magnetic powder, thereby achieving high efficiency of the motor. Is going on.

  Patent Documents 4 to 7 disclose a configuration using a bobbin with respect to positioning of the core.

JP 2005-287288 A Japanese Patent Laid-Open No. 4-17538 JP 2006-296188 JP JP-A-8-116659 JP 2005-304164 A JP-A-10-295070 JP 5-219705 A

  In order to reduce the size and increase the efficiency of the motor while improving the manufacturability, the positioning of the core is important. In particular, in a configuration in which cores having magnetic poles are arranged to face each other, positional deviation between both cores affects magnetic field formation, so that it is necessary to facilitate positioning.

  In Patent Document 1, a metal plate formed in the same shape is used as a pair of stators, and positioning is performed by forming positioning holes and through holes in the stators. Moreover, in patent document 2, it has a V-shaped groove | channel on the outer periphery of a core flat part, and performs the positioning of the rotation direction of a core using the slider for positioning. Furthermore, in patent document 3, a convex part and a ditch | groove are provided in a core, or a fitting protrusion and a fitting hole are provided (refer FIGS. 15-18), and positioning is aimed at by this.

  As shown in these patent documents 1 to 3, when a positioning structure is provided on the core, sufficient core strength is required. In Patent Document 1, it is considered that a positioning hole can be easily formed because a core obtained by molding a metal plate with a mold is used. However, when the core strength is low, the strength is further reduced by providing a through hole. As a result, the handling and reliability in the subsequent manufacturing process are reduced.

  In particular, Patent Document 3 uses a core formed by compression molding of magnetic powder to facilitate the formation of magnetic poles, but the core itself is only a compression of magnetic powder and it is easy to ensure sufficient strength. is not. Therefore, although positioning by a concavo-convex shape is employed without providing a through hole, the shape becomes complicated. One of the merits of compression molding is that a claw-shaped magnetic pole with a complicated shape is obtained, but unlike the claw-shaped magnetic pole, the positioning structure does not contribute to high efficiency as an electric motor after positioning is performed. A simple shape is desirable in terms of strength.

  In Patent Documents 4 to 6, positioning is performed using a bobbin. However, in Patent Document 4, a fitting between a bobbin positioning projection and a notch provided in the outer periphery of the core is used (paragraph 0037 and the like). Reference) and the same problem as in Patent Documents 1 to 3 may occur in that the core has a positioning structure.

  Patent Documents 5 to 6 disclose examples in which a positioning portion that protrudes toward the inner peripheral side of the bobbin is disclosed, and thereby the core is positioned, but these all protrude toward the inner peripheral side where the rotor is disposed. Therefore, the presence of the positioning portion has an influence on the shape of the magnetic pole and the distance between the magnetic poles, and the efficiency is restricted.

  Patent Document 7 discloses a configuration in which positioning coils and magnetic pole plates stacked by positioning pieces and positioning holes provided on a bobbin are positioned, but the magnetic pole plates also require a positioning hole. Therefore, in order to provide the positioning hole at a position that does not affect the magnetic characteristics, the annular width of the annular magnetic pole plate must be increased. Further, in order to provide an opening in the magnetic pole plate, it is necessary to use a material excellent in workability for the magnetic pole plate itself.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a small and thin electric motor while improving productivity and increasing efficiency.

In order to achieve the above object, a molded body having an annular base and a plurality of claw-shaped magnetic poles protruding from the base and formed in the circumferential direction is molded by compressing magnetic powder, and the molded body is opposed to the molded body. The present invention is arranged so as to face each other in an electric motor having a single-phase stator arranged in such a manner that a claw-shaped magnetic pole of another molded body is positioned between claw-shaped magnetic poles of one molded body. A bobbin around which a coil is wound is provided between the molded bodies and on the outer peripheral side of the claw-shaped magnetic pole,
The bobbin includes a plurality of protrusions protruding toward the molded body on both sides,
The single-phase stator is laminated in three phases, and a first single-phase stator and a second single-phase stator adjacent thereto are positioned by protrusions provided on the bobbin.

In the above-described configuration of the present invention, more preferable specific embodiments are as follows.
(1) The molded body has an inner peripheral side of the base portion and has a plurality of concave shapes between the claw-shaped magnetic poles, and the protrusions are located in the concave shapes.
(2) The protrusion has a convex portion and a concave portion, and is positioned by engaging the convex portion of the first single-phase stator and the concave portion of the second single-phase stator.
(3) The protrusion protrudes alternately on both sides of the bobbin by engaging the convex part and the concave part.
(4) The distance L1 between the claw-shaped magnetic poles in one molded body is larger than the width L2 of the claw-shaped magnetic poles, and the concave width and the width of the protrusions in the state where the molded body and the bobbin are combined. Equality.
(5) The protrusion is located between the concave bottom and the tip of the claw-shaped magnetic pole, and between the one claw-shaped magnetic pole and the claw-shaped magnetic pole adjacent to the claw-shaped magnetic pole. The distance L4 is smaller than the distance L5 between the tip of the claw-type magnetic pole and the concave bottom.
(6) A rotating shaft supported and supported by a bearing provided on the bracket, a stator assembled by laminating the single-phase stator, the bobbin and the coil for three phases, a bracket attached so as to sandwich the stator. And a rotor that rotates around the axis.

  According to the present invention, it is possible to provide a small and thin electric motor while improving productivity and increasing efficiency.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In this section, a configuration will be described in which a molded body formed by compressing magnetic powder is disposed opposite to a stator core, and the molded body formed of the powder magnetic core is positioned without any special unevenness. First, the structure of the electric motor of this embodiment is demonstrated using FIGS. 1-5.

  FIG. 1 is an exploded perspective view of one phase (reference numeral 3: single-phase stator) of a stator used in the electric motor of the present embodiment. As shown in FIG. 1, the upper and lower cores are opposed to a dust core 2 formed by compressing magnetic powder, thereby constituting a single-phase stator. That is, in this embodiment, the upper and lower cores for one phase are constituted by opposingly arranging the dust cores 2 having the same shape.

  A plurality of claw-type magnetic poles 2a are formed on the dust core 2, and the claw-type magnetic poles 2a of one dust core 2 and the claw-type magnetic poles 2a of the other dust core 2 do not interfere with each other. Are combined. Therefore, in the example shown in the present embodiment, there are 12 claw-type magnetic poles 2a in the core 2 on one side, and therefore 24 claw-type magnetic poles including the upper and lower cores are arranged adjacent to the inner peripheral surface of the stator. become.

  The bobbin 1 is sandwiched between the powder cores 2 arranged to face each other. A coil is wound around the bobbin 1, and the electric motor is rotated by passing a current through the coil. The bobbin 1 is provided with a core positioning protrusion 1a. Moreover, the convex part 1b and the recessed part 1c are provided in the surface of the protrusion 1a. The effects of the protrusion 1a, the convex portion 1b, and the concave portion 1c will be described later.

  FIG. 2 is an exploded view of the three-phase crotice motor. The stator 10 is obtained by laminating the upper and lower cores 2, the bobbin 1 and the coil shown in FIG. 1 in three phases, and a rotor 11 configured by combining a shaft, a rotor core, and a magnet is inserted into the center of the stator 10. Brackets are arranged on both sides of the stator 10, and in FIG. 2, both end surfaces of the stator 10 are sandwiched between the load side bracket 12a and the anti-load side bracket 12b. The rotor 11 is supported by a bearing 13, and each component is fixed by a through screw 14 in order to form a laminated structure thereof.

  3 is a view showing a cross section of the stator 10 shown in FIG. 2, and FIG. 4 is an external perspective view showing a stator shape for three phases inside the stator 10. As shown in FIG. FIG. 5 is an exploded view of the single-phase stator 3 for one phase of the three-phase stator 10 of FIG. 4. The insulating bobbin 1 is interposed between two opposing dust cores 2. It shows that the coil 4 manufactured by winding a copper wire around is sandwiched.

  Further, a winding lead-out recess 2c is provided on the outer peripheral side surface of the dust core 2. By combining the upper and lower cores, the drawer recess 2c becomes an opening, from which the winding is drawn. In the case of three-phase lamination, there are also three winding lead portions, but by arranging them close to each other, an electric motor can be configured with a simple configuration. Specifically, in this embodiment, the protrusion 1b and the recess 1c are provided on the protrusion 1a of the bobbin 1, and the recess 1c and the protrusion 1b of the bobbin provided in the adjacent single-phase stator 3 are engaged with each other. Therefore, the positions of the recesses 2c for drawing provided in the three-phase cores can be arranged close to each other.

  Further, a winding lead portion 1d is located from the bobbin 1 in the opening formed by the lead recess 2c, and energization is enabled by drawing the coil from the lead portion 1d.

  As is clear from these configurations, the drawing recess 2c and the drawing portion 1d also contribute to the positioning of the upper and lower cores and the interphase core.

  As shown in FIGS. 1 to 5, the claw-shaped magnetic pole 2 a provided on the dust core 2 is disposed adjacent to the inner peripheral surface of the stator 10, that is, the portion facing the rotor 11, and current is supplied to the coil 4. By flowing, magnetic flux is generated between the magnetic poles adjacent to each other. As a result, a rotational force is generated in the rotor 11 to function as an electric motor.

  As shown in FIG. 1, the upper and lower cores are opposed to a dust core 2 made of a magnetic powder compact, and claw-shaped magnetic poles 2a provided on the dust core 2 are arranged adjacent to each other. The bobbin 1 includes a plurality of core positioning protrusions 1a. The protrusion 1a protrudes on both the upper and lower sides toward the dust core 2 that sandwiches the bobbin 1, and the protrusion 1a is inserted between the claw-type magnetic poles 2a of the dust core 2. As shown in FIGS. 1 and 5, the protrusions 1 a protruding on both the upper and lower sides protrude in a staggered manner in the upper and lower sides, and can be easily inserted into a concave shape 2 b described later.

  Further, the projection 1a has a convex portion 1b and a concave portion 1c, which enables positioning between phases.

  The dust core 2 and the bobbin 1 are of an annular shape, and the claw-shaped magnetic pole 2a of one dust core 2 and the claw-shaped magnetic pole 2a of the other dust core 2 are alternately arranged as shown in FIG. Both cores are combined so that they line up. At this time, the distance between the claw-shaped magnetic poles 2a adjacent to each other in a state where the upper and lower cores are combined is defined as L4.

  Since the upper and lower cores are combined in this way, the claw-type magnetic pole 2a constituting the inner peripheral surface of the stator 10 has a circumferential width L2 smaller than the distance L1 between the claw-type magnetic poles 2a.

  Further, the annular dust core 2 is provided with a recess 2b between the claw-shaped magnetic poles 2a in the planar base 2 '. As shown in the figure, the concave shape 2b has a concave shape in the annular surface of the base portion 2 ′ between the claw-shaped magnetic poles 2a, and is notched in the annular surface of the base portion 2 ′. It is formed without providing a special uneven shape.

  In the state where the upper and lower cores are combined, the tip of the claw-shaped magnetic pole 2a of the other dust core 2 is located in the recess 2b, so the width of the recess 2b in the inner peripheral portion of the dust core 2 is larger than L2. It has become big. Further, the protrusion 1a of the bobbin 1 is inserted into the root portion of the concave shape 2b. That is, the protrusion 1a of the bobbin 1 is positioned between the bottom of the concave 2b and the tip of the claw-type magnetic pole 2a. Therefore, the circumferential width L3 of the concave shape 2b is the same as the width L3 of the protrusion 1a provided on the bobbin 1 in a state where the dust core 2 and the bobbin 1 are combined.

  By providing the above configuration, the protrusion 1a of the bobbin 1 is inserted into the concave shape 2b of the dust core 2 so that the upper and lower cores are positioned, and the dust core 2 is not displaced in the rotational direction. Moreover, since the protrusion 1a protrudes not on the inner peripheral side but on each dust core 2 side, it does not affect the arrangement of the adjacent claw-type magnetic poles 2a on the rotor 11 side, and between adjacent claw-type magnetic poles 2a. The distance L4 can be set to a desired value.

  Further, by placing the tip of the claw-shaped magnetic pole 2a in the concave shape 2b, the claw-shaped magnetic pole 2a can be arranged on the inner peripheral portion facing the rotor 11 without interfering with the base 2 ′ of the opposing dust core. it can. That is, the claw-shaped magnetic pole 2a has a configuration in which the tip end portion can be extended to the annular surface of the base portion 2 'of the opposing dust core 2, and an effective magnetic path can be formed.

  Further, in the upper and lower cores facing each other, a magnetic path is formed between the adjacent claw-shaped magnetic poles 2a, but the distance L5 between the tip portion of the claw-shaped magnetic pole 2a and the base 2 'is set to the adjacent claw-shaped magnetic pole 2a. Since the protrusion 1a of the bobbin 1 made of an insulating material is positioned between the distal end portion of the claw-type magnetic pole 2a and the base portion 2 ', the magnetic flux leakage is suppressed and the configuration is highly efficient. It can be. That is, since the distance L4 between the claw-type magnetic poles adjacent to each other is smaller than the distance L5 between the tip portion of the claw-type magnetic pole 2a and the bottom portion (base portion 2 ′) of the concave shape 2b, the influence on the magnetic flux formed during energization is affected. Can be reduced. In addition, since the radial width L6 of the protrusion 1a is substantially the same as L5, it contributes to magnetic flux leakage reduction.

  As described above, when a bobbin is used, the bobbin 1 is provided with protrusions 1a to be fitted with the core 2 on both sides, and the bobbin 1 and the core 2 are combined to combine the cores 2 to form a single-phase stator. In doing so, they can be positioned at the required angle. Further, the leakage of magnetic flux can be suppressed from the positional relationship of the concave shape 2b, the protrusion 1a, and the claw-shaped magnetic pole 2a, and high efficiency can be achieved.

  The electric motor of this embodiment can be obtained by laminating three-phase single-phase stators (first single-phase stator) for one phase formed as described above. Next, positioning between phases will be described in more detail. explain.

  The protrusion 1a of the bobbin 1 protrudes toward the surface of the base 2 'of the powder core 2, and as described above, the protrusion 1b is provided. This convex part 1b protrudes further from the surface of the base part 2 'of the dust core 2, and when the single-phase stator for one phase is formed as shown in FIG. 4, the convex part 1b is formed from the annular core surface. It becomes a protruding shape. On the other hand, since the recess 1c is provided on the surface of the protrusion 1a, the recess 1c exists on the surface of the single-phase stator for one phase.

  Similarly, a single-phase stator (second single-phase stator) disposed adjacent to the first single-phase stator has a convex portion and a concave portion on the surface. Therefore, positioning between the phases becomes possible by engaging the convex portions and concave portions of the adjacent cores.

  The positions where the convex portions and the concave portions are formed are determined so that each phase is shifted by 120 degrees in electrical angle in consideration of the flow of a three-phase current. In the present embodiment, the mechanical angle is shifted by a predetermined angle, but the predetermined angle is at least the protrusion surface of the first single-phase stator and the protrusion surface of the second single-phase stator opposite to the protrusion surface. Therefore, the range is such that the convex portion and the concave portion can be engaged with each other.

  In this embodiment, as shown in FIG. 5, the protrusions 1a on which the bobbin 1 is provided are alternately provided on both sides. Further, the protrusion 1a has a width L3 as described above, and the convex portion 1b and the concave portion 1c are provided within the range of this width. Therefore, the degree of freedom of the installation location of the convex part 1b and the concave part 1c for shifting the electrical angle of 120 degrees is high. In addition, positioning of the interphase core and the upper and lower cores can be performed entirely with the bobbin 1 instead of the dust core 2, variation among individuals is reduced, and productivity is improved.

  FIG. 6 is a diagram showing an example using the electric motor shown in the above-described embodiment, and in this example, FFU is shown. A fan 21 is attached to a rotating shaft of the electric motor 20 and is housed in a housing 22 together with a filter 23 to constitute a fan filter unit (FFU). The housing 22 has an opening on the upper side, and air is taken in from the opening as the fan 21 rotates. That is, air is sucked from the upper part in the drawing by the rotation of the fan 21 and passes through the filter 23 attached below the fan 21.

  Therefore, when passing through the filter 23, the air is filtered and discharged to the downstream side (lower part in the figure) of the filter 23 as clean air. During operation of the FFU, it is possible to keep supplying clean air in the clean room by continuously supplying air from which dust or the like has been removed.

  Since the FFU of this embodiment is attached to the ceiling of a clean room, there is a strong demand for thinning. Since the filter 23, the electric motor 20, and the fan 21 are attached to the housing 22, the FFU can be reduced in thickness as the FFU by reducing the size of the electric motor 20.

The disassembled perspective view of one phase (single phase stator) of a stator. The exploded view of a three-phase Crotice motor. The figure which shows the cross section of a stator. The external appearance perspective view which shows the stator shape for three phases inside a stator. The figure which decomposed | disassembled and showed one phase part among the stators which consist of three phases. The figure which shows the structure of FFU of this embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Bobbin, 1a ... Protrusion, 1b ... Convex part, 1c ... Concave part, 1d ... Drawer part, 2 ... Compaction core, 2 '... Base, 2a ... Claw-shaped magnetic pole, 2b ... Concave shape, 2c ... Concave part for drawer, 3 ... Single-phase stator, 4 ... Coil, 5 ... Mold, 5a ... Protrusion, 10 ... Stator, 11 ... Rotor, 12 ... Bracket, 13 ... Bearing, 14 ... Through screw, 20 ... Electric motor, 21 ... Fan, 22 ... FFU Housing, 23 ... filter.

Claims (7)

A molded body having an annular base and a plurality of claw-shaped magnetic poles protruding from the base and formed in the circumferential direction is molded by compressing magnetic powder, and a single-phase stator in which the molded body is arranged to face each other is formed. An electric motor configured such that the claw-shaped magnetic pole of another molded body is located between the claw-shaped magnetic poles of one molded body,
A bobbin around which a coil is wound is provided between the molded bodies arranged to face each other and on the outer peripheral side of the claw-shaped magnetic pole,
The bobbin includes a plurality of protrusions on both sides,
The electric motor according to claim 1, wherein the single-phase stator is laminated in three phases, and a first single-phase stator and a second single-phase stator adjacent thereto are positioned by a protrusion provided on the bobbin.   The electric motor according to claim 1, wherein the molded body has a plurality of concave shapes between the claw-shaped magnetic poles on an inner peripheral side of the base portion, and the protrusions are located in the concave shapes.   The protrusion has a convex portion and a concave portion, and is positioned by engaging the convex portion of the first single-phase stator and the concave portion of the second single-phase stator. 2. The electric motor according to 2.   The electric motor according to claim 3, wherein the protrusions protrude alternately on both sides of the bobbin.   The distance L1 between the claw-shaped magnetic poles in one molded body is larger than the width L2 of the claw-shaped magnetic pole, and the concave width is equal to the width of the protrusion in a state where the molded body and the bobbin are combined. The electric motor according to any one of claims 2 to 4, characterized in that: The protrusion is located in the concave shape between the concave bottom portion and the tip of the claw-shaped magnetic pole,
The distance L4 between one claw-shaped magnetic pole and the claw-shaped magnetic pole adjacent to the claw-shaped magnetic pole is smaller than the distance L5 between the tip portion of the claw-shaped magnetic pole and the concave bottom portion. The electric motor in any one of 2-4.   A stator assembled by laminating the single-phase stator, the bobbin, and the coil for three phases, a bracket attached so as to sandwich the stator, and a bearing provided on the bracket and supported by a bearing. The electric motor according to claim 1, further comprising a rotor that rotates.

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