JP2009124921A - Electric motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric motor which can efficiently generate a magnetic field while ensuring mechanical strength and can suppress production cost, and can easily correspond to a change in models. <P>SOLUTION: The electric motor with a brush has an armature core 6 in which a plurality of teeth 31 extending in a diameter direction are provided equally spaced along a circumferential direction on an annularly formed core body 30, and a permanent magnet allowed to interact with the magnetic field generated by the armature core 6. In the motor, the core body 30 and the teeth 31 can be split, the core body 30 is formed by stacking a plurality of magnetic steel plates 35 and the teeth 31 are formed by compression-molding a soft magnetic powder. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an electric motor that drives a rotating shaft using a magnetic field generated by an armature core.

  2. Description of the Related Art Conventionally, there is known an electric motor with a brush in which a permanent magnet is provided on an inner peripheral surface of a cylindrical yoke and an armature (armature) is rotatably disposed inside the yoke. An armature (armature core) of this type of electric motor has an armature core that is externally fixed to a rotating shaft. The armature core has an annular core body that is externally fitted and fixed to a rotating shaft, and a plurality of teeth portions that project radially from the core body. A winding is wound around the tooth portion, and when a current is supplied to the winding, a magnetic field is generated. The rotating shaft is driven by a magnetic attractive force or a repulsive force generated between the magnetic field and a permanent magnet provided on the yoke.

By the way, as an armature core, there are a laminated core formed by laminating a plurality of magnetic steel plates and a dust core formed by press-molding soft magnetic powder. The laminated core has high mechanical strength and low production cost, but it has a limit in reducing iron loss, and it is difficult to make the cross-sectional shape of the teeth part elliptical. For this reason, there is a limit in efficiently generating a magnetic field by increasing the winding resistance. On the other hand, the dust core is easy to reduce iron loss, and the cross-sectional shape of the tooth part can be easily made elliptical, so that the winding resistance can be reduced and a magnetic field can be generated efficiently. It becomes possible. However, not only the production cost is increased, but also the mechanical strength is weaker than that of the laminated core, so that there is a possibility that the powder core will be cracked when it is externally fixed to the rotating shaft, that is, press-fitted. Therefore, a technique has been proposed in which an outer core formed by press-molding soft magnetic powder is integrally cast into an inner core formed by laminating a plurality of magnetic steel plates to form an armature core, and a tooth portion is provided on the outer core. Yes. By doing in this way, since a magnetic steel plate can be used only for the part for which mechanical strength is required, it can be easily press-fitted into the rotating shaft. Moreover, since the teeth part can be made by press-molding soft magnetic powder, a magnetic field can be generated efficiently (see, for example, Patent Document 1).
JP 2006-296162 A

However, in the above-described prior art, since an outer core is cast in the inner core, not only a large-scale production facility but also an expensive metal mold is required for forming the armature core. There is a problem that becomes higher.
Also, for example, when changing the number of armature core teeth by changing the model of the electric motor or changing the outer diameter of the armature core, a new mold is required each time, such as changing the model. There is a problem that it is difficult to deal with.

Accordingly, the present invention has been made in view of the above-described circumstances, and provides an electric motor capable of efficiently generating a magnetic field while ensuring mechanical strength and suppressing production costs. is there.
It is another object of the present invention to provide an electric motor that can easily cope with model changes.

  In order to solve the above-described problem, the invention described in claim 1 is an armature in which a plurality of teeth portions extending in the radial direction are provided at equal intervals in the circumferential direction on an annular core body. In an electric motor comprising a core and a permanent magnet for interacting with a magnetic field generated by the armature core, the core body of the armature core and the plurality of tooth portions are configured to be separable, The core body is formed by laminating a plurality of magnetic steel plates, and the plurality of teeth are formed by press-molding soft magnetic powder.

  The invention described in claim 2 is characterized in that the core body of the armature core is fitted and fixed to a rotating shaft, and the teeth portions are provided radially on the core body.

  According to a third aspect of the present invention, a pair of locking projections are provided on both ends in the circumferential direction on the base end side of the teeth portion, and one of the pair of locking projections is disposed on one axial end side. And the other is arranged on the other end side in the axial direction, the core body is divided into two in the axial direction to form a first core body piece and a second core body piece, the first core body piece, and the second core A groove portion for receiving a proximal end side of the teeth portion is formed in a portion corresponding to the tooth portion of the core body piece, and a groove portion of the first core body piece corresponds to one end side in the axial direction of the teeth portion. One recess is formed, and a second recess corresponding to the other axial end of the tooth portion is formed in the groove of the second core body piece.

  According to a fourth aspect of the present invention, the core body and the teeth portion of the armature core are configured to be detachable from each other in the axial direction, and the omission that restricts the teeth portion from being removed from at least one side surface of the core body. A stop plate is provided.

  According to a fifth aspect of the present invention, a tooth holding portion extending along a radial direction is provided at a portion corresponding to the tooth portion of the core main body, and the tooth holding portion is wound from the core main body to the tooth portion. The tooth portion extends to a position corresponding to the winding body portion around which the wire is wound, and the tooth portion is formed to be detachable in the axial direction with respect to the tooth holding portion.

According to the present invention, it is possible to separately produce the core body and the tooth portion. For this reason, even if the core body is formed by laminating magnetic steel plates, the armature core can be easily formed (assembled) even if the teeth are pressure-molded with soft magnetic powder. In addition, large production facilities are not required, and the cost of the mold can be reduced. Therefore, it is possible to efficiently generate a magnetic field while keeping the mechanical strength and to suppress the production cost.
In addition, for example, when changing the number of teeth or changing the outer diameter of the armature core according to the model change of the electric motor, use the teeth as it is, This can be done by simply changing the shape. In addition, since the teeth portion is simply assembled to the core body, it is possible to easily cope with the model change of the electric motor.
Furthermore, for example, when the armature is disassembled, the teeth portion is formed by press-molding soft magnetic powder, and therefore the teeth portion can be easily broken. For this reason, the armature can be easily disassembled and the material can be easily separated.

Next, a first embodiment of the present invention will be described with reference to FIGS.
As shown in FIGS. 1 and 2, the brushed electric motor 1 serves as a drive source for an electrical component (for example, a radiator fan) mounted on the vehicle, and is freely rotatable in a bottomed cylindrical yoke 2. The armature (armature) 3 provided at the end of the yoke 2 is closed by an end bracket 17.
On the peripheral wall 2a of the yoke 2, a plurality of permanent magnets 4 are arranged in parallel along the circumferential direction on the inner surface side. Further, a boss portion 10 is formed in the end portion (bottom portion) 2b of the yoke 2 at a substantially radial center. The boss portion 10 is formed with an insertion hole 11 for inserting the rotation shaft 5 of the armature 3 and a bearing 12 for rotatably supporting one end side of the rotation shaft 5.

The armature 3 includes a commutator 13 disposed on the other end side of the rotating shaft 5 and formed in a cylindrical shape, and an armature core (armature core) 6 that is externally fitted and fixed slightly closer to one end than the axial center of the rotating shaft 5. And an armature coil 7 formed by winding a winding 16 around the armature core 6.
A plurality of segments 14 made of a conductive material are attached to the outer peripheral surface of the commutator 13. The segment 14 is made of a plate-like metal piece that is long in the axial direction, and is fixed in parallel at equal intervals along the circumferential direction while being insulated from each other. A riser 15 is integrally formed at the end of each segment 14 on the side of the armature core 6 so as to be folded back to the outer diameter side. A winding start end and a winding end end of the winding 16 drawn from the armature coil 7 are respectively wound around the riser 15 and fixed by fusing. Thereby, the segment 14 and the armature coil 7 corresponding to this are electrically connected.

The end bracket 17 is made of metal and is formed in a substantially disk shape, and a boss portion 18 is formed so as to protrude at a substantially radial center. A bearing 19 for rotatably supporting the other end side of the rotating shaft 5 is press-fitted and fixed to the boss portion 18. A holder stay 20 is attached to the inside of the end bracket 17 (the lower side in FIG. 1).
The holder stay 20 is made of resin and formed in a substantially disk shape, and a plurality of brush holders 21 are fixed thereto. Each brush holder 21 is provided with a brush 22 that can be moved in and out in a state where the brush 22 is urged through a spring 23. The tips of these brushes 22 are urged by springs 23 and are in sliding contact with the segments 14 of the commutator 13. Each brush 22 is electrically connected to an external power source (not shown), so that the external power source is supplied to the segment 14 of the commutator 13 via the brush 22.

Here, as shown in FIGS. 3 and 4, the armature core 6 includes an annular core body 30 that is externally fixed to the rotating shaft 5, and a plurality of teeth that detachably project from the core body 30. Part 31.
The core body 30 is obtained by superposing two core body pieces 32 and 32 that are divided into two substantially equally in the axial direction. The core body piece 32 is formed by laminating a plurality of substantially disk-shaped magnetic steel plates 35 in the axial direction, and a hole 36 into which the rotary shaft 5 can be press-fitted is formed at a substantially radial center. A plurality of groove portions 33 having a substantially U-shaped cross section for receiving the proximal end side of the teeth portion 31 are formed on the outer peripheral surface of the core body piece 32 and corresponding to the teeth portion 31. A concave portion 41 is formed on one side surface of each groove portion 33 in the circumferential direction, and the convex portion 43 formed between the groove portions 33 thereby has a bowl shape. The two core main body pieces 32, 32 formed in this way are overlapped so that the direction of the ridges of the concave portions 41, that is, the convex portions 43 are reversed, to form the core main body 30.

  Further, as shown in FIGS. 4 and 5, each core body piece 32 is formed with four caulking convex portions 34 having a substantially serrated cross section in the circumferential direction at equal intervals. The caulking convex portion 34 is for fixing the core main body pieces 32 to each other so that the core main body pieces 32 can be fixed and maintained in a state where they are overlapped. That is, as shown in FIG. 5, the two core body pieces so that the ridge line portion 34 a of the caulking convex portion 34 of one core body piece 32 is aligned with the valley 34 b of the caulking convex portion 34 of the other core body piece 32. The core body 30 is formed by overlapping 32 and caulking the caulking convex portions 34 and 34 with each other.

The teeth part 31 is formed by press-molding soft magnetic powder, and is formed in a substantially T shape in an axial plan view. That is, the tooth part 31 is integrally formed with a winding drum part 37 extending in the radial direction and an outer peripheral part 38 extending in the circumferential direction and the axial direction from the tip of the winding drum part 37.
The winding drum portion 37 is a portion around which the winding 16 is wound, and has a substantially elliptical cross section. On the base end side of the winding drum portion 37, locking projections 39, 39 respectively corresponding to the concave portions 41 of the two core body pieces 32 are formed on both sides in the circumferential direction. That is, the locking projection 39 is formed on one side in the circumferential direction (the right side in FIG. 6) on the proximal end side of the winding drum portion 37 near one end in the axial direction (the lower side in FIG. 6). On the other hand, a locking projection 39 is formed on the other side in the circumferential direction (left side in FIG. 6) on the proximal end side of the winding drum portion 37 on the other end in the axial direction (upward in FIG. 6). The thickness H1 of each locking projection 39 in the axial direction is set substantially equal to the thickness H3 of the core body piece 32. Further, the thickness H2 of the winding drum portion 37 in the axial direction is set to approximately twice the thickness H3 of the core body piece 32, that is, approximately equal to the thickness of the core body 30.

  The outer peripheral portion 38 is a portion constituting the outer peripheral surface of the armature core 6 and has a substantially bowl-shaped cross section. That is, the outer peripheral portion 38 includes an arcuate surface 38a formed in an arc shape on the radially outer side, a flat surface 38b formed flat on the radially inner side, side surfaces 38c and 38c disposed opposite to each other in the axial direction, and a circumferential direction. And end faces 38d, 38d arranged opposite to each other.

As shown in FIG. 3, dovetail-shaped slots 40 are formed between the radially arranged teeth portions 31. Note that the winding 16 wound around the winding drum portion 37 of the teeth portion 31 may be wound through the slot 40, or when the winding 16 is wound by the concentrated winding method. For example, the winding 16 may be wound around the tooth portion 31 in advance.
A plurality of armature coils 7 are formed on the outer periphery of the armature core 6 by winding the winding 16 around the winding drum portion 37. Here, the tooth portion 31 is covered with an insulating coating 42 on the side surfaces 38c and 38c and the end surfaces 38d and 38d of the winding drum portion 37 and the outer peripheral portion 38 (see FIG. 1).

Next, based on FIG. 3, FIG. 4, the assembly method of the armature core 6 of this 1st embodiment is demonstrated.
First, the teeth portion 31 is assembled to one core body piece 32 (the lower core body piece 32 in FIG. 4) of the two core body pieces 32 and 32. Specifically, one locking projection 39 of the two locking projections 39, 39 formed on the base end side of the tooth portion 31 corresponds to the recess 41 formed in one core body piece 32. The direction of the teeth part 31 is matched so that it may. And the base end part of the teeth part 31 is inserted in the groove part 33 of one core main body piece 32 from an axial direction. At this time, the teeth portion 31 is in a state in which movement in the circumferential direction and the radial direction is restricted by the groove portion 33 and the concave portion 41 of the core body piece 32. Further, since the recess 33 is not formed in the groove portion 33 of the one core body piece 32 on the side of the other locking projection 39 of the teeth portion 31, the other locking projection 39 of the teeth portion 31 is connected to the core body piece 32. Abuts on one side.

  After the base end side of the teeth portion 31 is fitted into the groove portion 33 of the one core body piece 32, the other core body piece 32 (the upper core body piece 32 in FIG. 4) is set from above. At this time, the other core body piece 32 is superimposed on the one core body piece 32 so that the direction of the ridges of the recesses 41, that is, the protrusions 43, is opposite to the one core body piece 32. The position of the concave portion 41 of the other core body piece 32 and the position of the other locking projection 39 of the tooth portion 31 are matched, and the two core body pieces 32 are overlapped.

  Here, when the two core main body pieces 32 and 32 are overlapped and the base end side of the tooth portion 31 is fitted in the groove portion 33, the locking protrusions 39 and 39 formed on the tooth portion 31 are formed. Each is in contact with one side of the core body piece 32. For this reason, when the two core main body pieces 32 and 32 are overlapped, the movement of the teeth portion 31 in the axial direction is restricted, and the teeth portions 31 can be prevented from coming off from the core main body 30. Thereby, the assembly of the armature core 6 is completed.

Therefore, according to this first embodiment, it is possible to form the armature core 6 by separately producing the core main body 30 and the tooth portion 31 and then assembling them. For this reason, the mechanical strength can be increased by forming the core body 30 (core body piece 32) by laminating a plurality of magnetic steel plates 35. Moreover, by forming the teeth part 31 by pressing soft magnetic powder, the cross-sectional shape of the winding drum part 37 can be made substantially elliptical, so that the winding resistance can be reduced and the iron loss can be reduced.
Further, the cross-sectional shape of the tooth portion 31 can be easily optimized in the axial direction such as a skew shape (formed by twisting in the axial direction) in addition to an elliptical shape.

  And since the metal mold | die for forming the core main body piece 32 and the metal mold | die which forms the teeth part 31 can be prepared separately, and the assembly of the core main body 30 and the tooth part 31 is also easy, conventionally This eliminates the need for large production facilities. In addition to this, it is possible to manufacture a mold at a lower cost than a conventional mold for forming an inner core and a mold for casting an outer core on the inner core formed thereby. become. Therefore, production costs can be suppressed.

  Moreover, since the core main body 30 and the tooth part 31 can be produced separately, for example, when the number of the tooth parts 31 is changed or the outer diameter of the armature core 6 is changed due to the model change of the brushed electric motor 1 or the like. In this case, it is possible to cope with the model change by simply changing the number of the grooves 33 formed in the core body piece 32 or changing the outer diameter of the core body piece 32. For this reason, it becomes possible to divert the comparatively expensive teeth part 31 formed by press-molding soft magnetic powder as it is. Therefore, it is possible to provide the armature core 6 that can suppress the production cost caused by the model change and can easily cope with the model change.

  Furthermore, for example, when the armature 3 is disassembled, the tooth portion 31 around which the winding 16 is wound is formed by press-molding soft magnetic powder, so that the tooth portion 31 can be easily broken. Can do. For this reason, the armature 3 can be easily disassembled, and the material can be easily separated.

  In the first embodiment described above, the two core body pieces 32, 32 are each provided with a groove portion 33 on the outer peripheral surface thereof, and a concave portion 41 is formed on one side surface in the circumferential direction of the groove portion 33. The case where the images are superposed so as to be opposite to each other has been described. However, the present invention is not limited to this, and it is sufficient that the movement of the teeth portion 31 in the axial direction can be restricted using the two core body pieces 32, 32. For example, the groove portions 33 of the two core body pieces 32, 32 have different shapes. While providing a recessed part, you may provide the latching protrusion corresponding to each recessed part in the base end side of the teeth part 31. FIG.

Next, a second embodiment of the present invention will be described with reference to FIGS. In addition, the same code | symbol is attached | subjected and demonstrated to the same aspect part as 1st embodiment (same also in the following embodiment).
In the second embodiment, the brushed electric motor 1 includes an armature 3 rotatably provided in a bottomed cylindrical yoke 2, and the opening 2 c of the yoke 2 is closed by an end bracket 17. The armature 3 includes a commutator 13 disposed on the other end side of the rotary shaft 5 and formed in a cylindrical shape, an armature core 51 that is fitted and fixed slightly closer to one end than the axial center of the rotary shaft 5, and an armature core The basic configuration such as the configuration of the armature coil 7 formed by winding the winding 16 around 51 is the same as that of the first embodiment.

Here, the armature core 51 is provided on both sides of the core body 52, an annular core body 52 that is externally fitted and fixed to the rotary shaft 5, a tooth portion 53 that is detachably provided on the core body 52 in the axial direction. And a pair of retaining plates 54 and 54 for restricting the tooth portion 53 from coming off.
The core body 52 is formed by laminating a plurality of substantially disk-shaped magnetic steel plates 55 in the axial direction, and a hole 36 into which the rotary shaft 5 can be press-fitted is formed at a substantially radial center. A plurality of dovetail grooves 57 for receiving the proximal end side of the tooth portion 31 are formed on the outer peripheral surface of the core body 52 and corresponding to the tooth portion 53. The dovetail groove 57 is set such that the radially inner groove width H1 is larger than the radially outer groove width H2.

On the other hand, the teeth part 53 is formed by pressure-molding soft magnetic powder, and is formed in a substantially T shape in an axial plan view. The winding drum portion 37 of the teeth portion 53 is provided with a convex portion 58 formed on the proximal end side so as to correspond to the dovetail groove 57 of the core body 52 and fitted into the dovetail groove 57.
Further, on the base end side of the winding drum portion 37, step portions 59 and 59 formed by being cut flat at both ends in the axial direction are provided.
The retaining plate 54 is formed in a substantially disk shape, and a hole 60 into which the rotary shaft 5 can be press-fitted is formed in the substantially radial center. That is, the armature core 51 is externally fixed to the rotary shaft 5 by the hole 36 of the core body 52 and the hole 60 of the retaining plate 54. The hole 60 of the retaining plate 54 may be set to a size that can be inserted into the rotating shaft 5, and the armature core 51 may be externally fixed to the rotating shaft 5 only by the hole 36 of the core body 52.

The outer diameter E1 of the retaining plate 54 is set substantially equal to the outer diameter E2 of the core body 52. Here, the stepped portion 59 formed in the winding drum portion 37 of the teeth portion 53 functions as a relief portion when the retaining plate 54 is set on both side surfaces of the core body 52. That is, the stepped portion 59 of the tooth portion 53 is formed so as to correspond to the outer shape of the core body 52 in a state where the tooth portion 53 is set on the core body 52. Further, the step height of the step portion 59 is set to be substantially equal to the thickness of the retaining plate 54, and the axial thickness H2 ′ of the base end side of the winding drum portion 37 cut by the step portion 59 is The thickness is set substantially equal to the thickness of the core body 52.
Further, on the respective mating surfaces of the retaining plate 54 and the core body 52, there are four caulking convex portions 34 having a substantially serrated cross section in the circumferential direction at equal intervals. Can be maintained.

Next, based on FIG. 7, the assembly method of the armature core 51 of this second embodiment will be described.
First, the convex portion 58 formed on the base end side of the tooth portion 53 is aligned with the dovetail groove 57 of the core body 52, and the convex portion 58 is fitted into the dovetail groove 57 from the axial direction. At this time, the teeth part 53 is in a state in which movement in the circumferential direction and the radial direction is restricted by the dovetail groove 57 of the core body.
Subsequently, retaining plates 54, 54 are overlapped on both side surfaces of the core body 52. At this time, it sets so that the position of the convex part 34 for crimping formed in the core main body 52 and the retaining plates 54 and 54, respectively may match. On the base end side of the tooth portion 53, step portions 59, 59 for avoiding interference with the retaining plates 54, 54 are formed at both ends in the axial direction, so that the retaining plate 54 is securely attached to the core body 52. Fixed to. Thereby, the movement of the teeth part 53 in the axial direction is restricted, and the assembly of the armature core 51 is completed.

Therefore, according to this 2nd embodiment, there can exist an effect similar to the above-mentioned 1st embodiment.
In the second embodiment, the case where the retaining plates 54 and 54 are set on both side surfaces of the core main body 52 after the base end side of the tooth portion 53 is fitted to the core main body 52 has been described. However, the present invention is not limited to this, and the core body 52 is a core body 52 in which the retaining plate 54 is set in advance on one side surface of the core body 52. The retaining plate 54 may be set in

Next, a third embodiment of the present invention will be described with reference to FIGS. 9 and 10 are perspective views of the armature core 61 according to the third embodiment. FIG. 9 shows the front surface and FIG. 10 shows the back surface. FIG. 11 is an exploded perspective view partially enlarged.
In the third embodiment, the brushed electric motor 1 includes an armature 3 rotatably provided in a bottomed cylindrical yoke 2, and the opening 2 c of the yoke 2 is closed by an end bracket 17. The armature 3 includes a commutator 13 disposed on the other end side of the rotating shaft 5 and formed in a cylindrical shape, an armature core 61 that is fitted and fixed slightly closer to one end than the axial center of the rotating shaft 5, and an armature core The basic configuration is the same as that of the first embodiment, including the armature coil 7 formed by winding the winding 16 around 61.

Here, the armature core 61 includes an annular core body 62 that is externally fitted and fixed to the rotary shaft 5, and a teeth portion 63 that is detachably provided on the core body 62 in the axial direction.
The core body 62 is formed by laminating a plurality of substantially disk-shaped magnetic steel plates 64 in the axial direction, and a hole 65 into which the rotary shaft 5 can be press-fitted is formed at a substantially radial center. Around the hole 65, a plurality of through holes 66 penetrating in the axial direction are formed at equal intervals along the circumferential direction.

  The through-hole 66 is formed in a substantially fan shape when viewed in the axial direction plan view. In the armature core 61, by forming the through hole 66 in the core body 62, the heat dissipation effect can be improved and the weight can be reduced. In addition, you may apply this through-hole 66 to the core main body 30 of the above-mentioned first embodiment, and the core main body 52 and the retaining plate 54 of the second embodiment.

  A plurality of teeth holding portions 67 corresponding to the teeth portions 63 are radially projected at equal intervals along the circumferential direction on the outer peripheral portion of the core main body 62. The teeth holding portion 67 extends from the core body 62 to a position corresponding to the winding drum portion 37 of the teeth portion 63. Locking portions 68 and 68 having a sawtooth cross section are formed on both side surfaces in the circumferential direction on the tip side of the teeth holding portion 67 (see FIG. 11).

On the other hand, the teeth portion 63 is formed by pressure-molding soft magnetic powder, and the winding drum portion 37 is formed with a receiving recess 69 capable of receiving the teeth holding portion 67 of the core body 62 from the axial direction. ing. The receiving recess 69 opens one side surface in the axial direction of the winding drum portion 37 and opens the proximal end side of the winding drum portion 37. In the receiving recess 69, a locking groove 70 having a sawtooth cross section corresponding to the locking portion 68 is formed in a portion corresponding to the locking portions 68, 68 of the teeth holding portion 67. Thereby, the teeth part 63 is configured to be detachable in the axial direction with respect to the tooth holding part 67 of the core main body 62 and is not slidable in the radial direction.
An outer flange portion 71 is formed on the proximal end side of the winding drum portion 37. The outer flange portion 71 has a role of preventing the winding 16 wound around the winding drum portion 37 together with the outer peripheral portion 38 of the tooth portion 63 from being collapsed (see FIGS. 9 and 10).

Next, a method for assembling the armature core 61 according to the third embodiment will be described.
First, the receiving recess 69 of the teeth portion 63 is directed toward the teeth holding portion 67 side of the core body 62, and the teeth portion 63 is fitted to the teeth holding portion 67 from the axial direction. At this time, only the movement of the tooth portion 63 in the circumferential direction and the radial direction is restricted, and the tooth portion 63 is detachable in the axial direction.
Subsequently, an insulating coating (not shown) is applied to the winding drum portion 37 of the teeth portion 63 and the teeth holding portion 67 of the core body 62. This insulating film not only has a role of ensuring an insulation state between the winding drum portion 37 and the tooth holding portion 67 and the winding 16 wound around the winding drum portion 37, but also the teeth portion 63 and the teeth. It also has a role of fixing the holding part 67 to each other. For this reason, the movement of the axial direction with respect to the teeth holding | maintenance part 67 of the teeth part 63 is controlled by coat | covering an insulating film.

Subsequently, the winding 16 is wound around the winding drum portion 37 of the teeth portion 63 to form the armature coil 7. Then, since the armature coil 7 is formed so as to surround the periphery of the winding drum portion 37, the teeth holding portion 67 can be more reliably prevented from coming off from the receiving recess 69. Thereby, the assembly of the armature core 61 is completed.
Therefore, according to the third embodiment, the same effects as those of the first embodiment described above can be achieved.

The present invention is not limited to the above-described embodiment, and includes various modifications made to the above-described embodiment without departing from the spirit of the present invention.
Moreover, in the above-described embodiment, the case where the armature cores 6, 51, 61 are externally fixed to the rotating shaft 5 of the brushed electric motor 1 has been described. However, the present invention is not limited to this, and application to a brushless motor is also possible. In other words, as in the case of a brushless motor, when a permanent magnet is provided on the rotating shaft side and an armature is provided around this, a plurality of magnetic steel plates are laminated in the axial direction to form an annular core body serving as a yoke. Then, the teeth portion projecting radially inward from the core body may be configured by press-molding soft magnetic powder.

  In the third embodiment described above, a locking portion 68 having a sawtooth cross section is formed on the distal end side of the teeth holding portion 67 in order to restrict the sliding movement of the teeth portion 63 relative to the teeth holding portion 67 in the radial direction. The case where the locking groove 70 corresponding to the locking portion 68 is formed in the receiving recess 69 of the teeth portion 63 has been described. However, the shape is not limited to this, and any shape that can regulate the sliding movement of the teeth portion 63 in the radial direction with respect to the teeth holding portion 67 may be used.

  Furthermore, in above-mentioned 3rd embodiment, the teeth part 63 and the teeth holding | maintenance part 67 are made into fitting, and until the teeth part 63 and the teeth holding | maintenance part 67 are coat | covered with an insulating film, with respect to the teeth holding | maintenance part 67 of the teeth part 63 The case where movement in the axial direction is possible has been described. However, the present invention is not limited to this, and the teeth holding portion 67 may be set to be lightly press-fitted into the receiving concave portion 69 of the winding drum portion 37. By doing in this way, before the teeth part 63 and the teeth holding | maintenance part 67 are coat | covered with an insulating film, it becomes possible to control the movement to the axial direction of the teeth part 63. FIG. For this reason, it can prevent that the teeth part 63 rattles at the time of the coating | covering operation | work of an insulating film, and it becomes possible to aim at the efficiency of assembly work.

It is a longitudinal cross-sectional view which shows the structure of the electric motor with a brush in 1st embodiment of this invention. It is a cross-sectional view of the electric motor with a brush in the first embodiment of the present invention. It is a perspective view of the armature core in the first embodiment of the present invention. It is a disassembled perspective view of the armature core in 1st embodiment of this invention. It is sectional drawing which follows the AA line of FIG. It is a perspective view of the teeth part in a first embodiment of the present invention. It is a disassembled perspective view of the armature core in 2nd embodiment of this invention. It is a perspective view of the teeth part in a second embodiment of the present invention. It is a perspective view of the armature core in the third embodiment of the present invention. It is a perspective view of the armature core in the third embodiment of the present invention. It is a perspective view of the teeth part and teeth holding part in a third embodiment of the present invention.

Explanation of symbols

1 Brushed electric motor (electric motor)
3 Armature 4 Permanent magnet 5 Rotating shaft 6, 51, 61 Armature core (armature core)
30, 52, 62 Core body 31, 53, 63 Teeth portion 32 Core body piece (first core body piece, second core body piece)
33 Groove (first groove, second groove)
34 Caulking convex portions 35, 55, 64 Magnetic steel plate 37 Winding barrel portion 38 Outer peripheral portion 39 Locking protrusion 41 Recess 42 Insulating coating 54 Retaining plate 57 Dovetail groove 58 Protruding portion 59 Stepped portion 67 Teeth holding portion 68 Locking portion 69 Receiving recess 70 Locking groove 71 Outer flange

Claims (5)

An armature core provided with a plurality of teeth portions extending along the radial direction at equal intervals along the circumferential direction on the annularly formed core body,
In an electric motor comprising a permanent magnet for interacting with a magnetic field generated by the armature core,
The core body of the armature core and the plurality of teeth portions are configured to be splittable,
The core body is formed by laminating a plurality of magnetic steel plates,
The plurality of teeth are formed by press-molding soft magnetic powder. The core body of the armature core is fitted and fixed to the rotating shaft,
The electric motor according to claim 1, wherein the teeth are provided radially on the core body. Provided with a pair of locking projections on the both ends in the circumferential direction on the base end side of the teeth portion,
One of the pair of locking projections is disposed on one end side in the axial direction, and the other is disposed on the other end side in the axial direction.
The core body is divided into two in the axial direction to form a first core body piece and a second core body piece,
Forming a groove portion for receiving a base end side of the teeth portion in a portion corresponding to the teeth portion of the first core body piece and the second core body piece;
In the groove portion of the first core body piece, a first recess corresponding to one end side in the axial direction of the teeth portion is formed,
The electric motor according to claim 1, wherein a second recess corresponding to the other axial end of the tooth portion is formed in the groove portion of the second core body piece. The core body of the armature core and the teeth portion are configured to be detachable from each other in the axial direction,
3. The electric motor according to claim 1, wherein a retaining plate for restricting the tooth portion from slipping out is provided on at least one side surface of the core body. In a portion corresponding to the tooth portion of the core body, a tooth holding portion extending along the radial direction is provided,
The teeth holding portion extends from the core body to a position corresponding to a winding drum portion around which the winding of the teeth portion is wound,
The electric motor according to claim 1, wherein the teeth portion is formed to be detachable in the axial direction with respect to the teeth holding portion.

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