JP5271046B2 - Electric motor - Google Patents

Description

  The present invention relates to an electric motor used for starting an engine of a two-wheeled vehicle, for example.

  For example, a starter motor as an electric motor used for starting an engine of a motorcycle includes a cylindrical yoke, a front bracket that closes both ends of the yoke, an end bracket, and an armature that is rotatably supported by these brackets. It has. The front bracket is fixed to the engine case, and the rotary shaft of the armature and the crankshaft of the engine are connected to each other. Under such a configuration, the engine starts when the rotating shaft rotates the crankshaft.

Here, the front bracket is manufactured from, for example, aluminum die-casting, and a hole for inserting the rotation shaft of the armature is formed substantially in the center in the radial direction. The front bracket is also provided with a thrust support and two washers. The thrust support is clamped between the front bracket and the C-type retaining ring attached to the rotating shaft, so that the thrust of the armature Receives the power of direction. As described above, the thrust support is provided on the front bracket to prevent the rotation shaft from moving in the removal direction (see, for example, Patent Document 1).
JP 2008-106632 A

  However, in the above-described prior art, the thrust support is only sandwiched between the front bracket and the C-type retaining ring attached to the rotating shaft. Therefore, the thrust support is desired when the thrust support is assembled. It may be out of position. In such a case, the worker has to manually correct the position of the thrust support each time, and there is a problem that it takes time to assemble the thrust support.

  Accordingly, the present invention has been made in view of the above-described circumstances, and provides an electric motor that can prevent a shift at the time of assembling a thrust support and improve assembly workability.

In order to solve the above-mentioned problem, the invention described in claim 1 includes a cylindrical yoke, a pair of brackets closing both ends of the yoke, and an armature rotatably supported by the pair of brackets. A restriction plate for restricting movement of the armature in the direction in which the armature is detached from the inner surface of one of the pair of brackets, and corresponding to the restriction plate of the rotation shaft. The part is provided with a restricting member that restricts movement of the rotating shaft in the pulling direction in cooperation with the restricting plate, and the restricting plate is formed by pressing a sheet metal member. A caulking projection is formed on the inner surface of the bracket, and a caulking hole capable of receiving the caulking projection is formed in the restriction plate. The caulking projection and the caulking hole are formed in the regulation. Symmetry plane that divides the outer shape of the plate to the plane of symmetry, characterized in that it is arranged in a non-planar symmetry.
In this way, by fixing the restricting plate to one bracket, it is possible to prevent the restricting plate from being displaced and dropped off during assembly.
Further, by setting the restricting plate to caulking, for example, even if one bracket is formed by pressing the sheet metal member, the restricting plate can be easily fixed to the bracket.
Furthermore, the restriction plate can be easily caulked and fixed to one bracket.
In addition, the assembly operator can easily determine the direction in which the restriction plate is assembled, and can prevent the restriction plate from being assembled incorrectly.

The invention described in claim 2 is characterized in that any one of the caulking protrusion and the caulking hole is formed on the regulating plate.
By comprising in this way, the incorrect assembly | attachment of a control board can be prevented cheaply.

The invention described in claim 3 is characterized in that the one bracket is formed by pressing a sheet metal member.
By comprising in this way, manufacturing cost can be reduced compared with the case where a bracket is manufactured from aluminum die-casting conventionally.

The invention described in claim 4 is characterized in that the one bracket and the yoke are integrally formed by pressing the sheet metal member.
By comprising in this way, a number of parts can be reduced and manufacturing cost can be reduced more.

According to the first aspect of the present invention, the restricting plate is caulked and fixed to one of the brackets, so that the restricting plate can be prevented from being displaced and dropped during assembly. For this reason, it becomes possible to improve the assembly workability | operativity of an electric motor.
Further, by setting the restricting plate to caulking, for example, even if one bracket is formed by pressing the sheet metal member, the restricting plate can be easily fixed to the bracket. For this reason, the manufacturing cost of the bracket can be reduced, the manufacturing variations of the bracket can be increased, and the electric motor according to the user's request can be provided.
Further, the restriction plate can be easily caulked and fixed to one bracket. For this reason, the assembly workability of the electric motor can be further improved, and the manufacturing cost can be suppressed.
Furthermore, the assembly operator can easily determine the direction in which the restricting plate is assembled, and can prevent erroneous assembling of the restricting plate. For this reason, it becomes possible to provide an electric motor with stable quality.

According to the invention described in claim 2 , it is possible to prevent erroneous assembly of the regulation plate at low cost. For this reason, it becomes possible to provide an inexpensive and stable electric motor.

According to the invention described in claim 3 , the manufacturing cost can be reduced as compared with the case where the bracket is manufactured from aluminum die casting as in the prior art.

According to the invention described in claim 4 , the number of parts can be reduced, and the manufacturing cost can be further reduced.

Next, embodiments of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the electric motor 1 is used as, for example, a two-wheel starter motor. The electric motor 1 is a cylindrically formed yoke 21 and is integrally formed with the yoke 21 and fixed to the case of the engine 60. A front bracket 2, a rear bracket 4 that closes one end of the yoke 21, a front bracket 2, and an armature 5 that is rotatably supported by the rear bracket 4. The rotating shaft 10 of the armature 5 is connected to the crankshaft of the engine 60.

  The armature 5 includes an armature core 11 that is externally fitted and fixed to the rotary shaft 10, and a commutator 12 that is disposed closer to the rear bracket 4 than the armature core 11. The armature core 11 is manufactured by laminating a plurality of plate materials made of a magnetic material, and has a plurality of teeth 50 extending radially about the rotation shaft 10. The teeth 50 are formed in a substantially T shape in a plan view in the axial direction, and a dovetail slot (not shown) long in the axial direction is formed between the teeth 50.

  A coil 13 is wound around the tooth 50 through a slot. The commutator 12 has a plurality of segments 14 in the circumferential direction. Each segment 14 is provided with a riser 51 formed to be folded outward at an end on the armature core 11 side. A terminal portion of the coil 13 is wound around the riser 51 and connected by fusing or the like.

  The rear bracket 4 is formed in a bottomed cylindrical shape by, for example, aluminum die casting. The end portion (bottom portion) 4a of the bracket 4 is formed with a bearing housing 42 protruding outward in the axial direction at a substantially radial center, and the bearing 41 is press-fitted and fixed thereto. The bearing 41 rotatably supports the end portion of the armature 5.

A plurality of brushes 43 are fixed inside the rear bracket 4 so as to surround the periphery of the commutator 12. The brush 43 is urged toward the center by a spring (not shown), and is in sliding contact with the commutator 12 of the armature 5.
In addition, a pigtail 45 is connected to the brush 43, and the brush 43 and the power supply terminal 46 are electrically connected via the pigtail 45. The power supply terminal 46 is inserted from the peripheral wall 4b of the rear bracket 4 via the insulator 47, and a portion exposed to the outside is connected to a power source (not shown).

  A male screw portion 48 is engraved in a portion exposed to the outside of the power supply terminal 46, and a nut 49 is screwed therein. The feed terminal 46 is fastened and fixed to the rear bracket 4 by screwing the nut 49. An O-ring 61 is mounted between the insulator 47 and the nut 49 on the outer peripheral surface of the power supply terminal 46. Thereby, the sealing property of the insertion part of the power feeding terminal 46 of the rear bracket 4 can be secured.

As shown in FIGS. 1 and 2, the yoke 21 and the front bracket 2 are integrally formed by deep drawing the sheet metal member 20 by pressing.
An inlay portion 22a for stamping and joining the rear bracket 4 is formed at the end of the yoke 21 on the rear bracket 4 side. The inlay portion 22a has a shape whose outer diameter is reduced by cutting.

  At the opening edge of the rear bracket 4, an inlay portion 22 b having an inner diameter increased by cutting is formed so as to correspond to the inlay portion 22 a of the yoke 21. The yoke 21 and the front bracket 2 are stamped and joined by fitting the both 22a and 22b. A plurality of field magnets 24 are arranged on the inner peripheral surface of the yoke 21. The magnet 24 is fixed to the yoke 21 with a known adhesive such as an epoxy resin.

The front bracket 2 includes a bracket main body 71 formed in a substantially disc shape so as to close the opening of the yoke 21, and a fitting portion 72 that protrudes outward in the axial direction from the radial center of the bracket main body 71. And have.
The fitting portion 72 is formed in a stepped shape so that the diameter gradually decreases by a step from the bracket body 71 toward the distal end side (engine side), and the fitting portion 72 is formed in order from the proximal end side, that is, the bracket body 71 side. It has one cylinder part 73, a second cylinder part 74, and a third cylinder part 75. The front bracket 2 is fixed by fitting the fitting portion 72 of the front bracket 2 to the case of the engine 60. The rotating shaft 10 of the armature 5 is inserted into the fitting portion 72, and the rotating shaft 10 projects to the engine side through the fitting portion 72.

The first cylindrical portion 73 is provided with an oil seal 76 that improves the sealing performance between the rotary shaft 10 and the fitting portion 72 on the inner peripheral surface side. Thereby, intrusion of dust from the fitting portion 72 into the electric motor 1 is prevented.
A bearing 77 is press-fitted and fixed to the inner peripheral surface of the second cylindrical portion 74 which is on the tip side of the first cylindrical portion 73 and is reduced in diameter by a step. This bearing 77 is for supporting the rotating shaft 10 rotatably.

  The third cylindrical portion 75 which is on the distal end side than the second cylindrical portion 74 and has a diameter reduced by a step, was partly peeled off from the distal end side over the entire circumference and raised toward the proximal end side, A rising portion 78 is formed. Since the rising portion 78 is formed by separating a part of the third cylindrical portion 75, the distal end side of the rising portion 78 is thinner than the proximal end side of the rising portion 78. By forming the rising portion 78, a groove-shaped mounting portion 79 is formed on the outer peripheral surface of the third cylindrical portion 75 by the rising portion 78 and the step surface 74 a of the second cylindrical portion 74. An O-ring 80 for improving the sealing performance between the fitting portion 72 and the case of the engine 60 is attached to the mounting portion 79.

  That is, the mounting portion 79 functions as an O-ring groove for mounting the O-ring 80. Further, the mounting portion 79 is formed on the outer peripheral surface of the third cylindrical portion 75 by the rising portion 78 and the stepped surface 74a of the second cylindrical portion 74, and the O-ring 80 is mounted on the mounting portion 79. The bearing 77 provided in the two cylinder part 74 exists in the position which mutually shifted | deviated to the axial direction. In other words, the O-ring 80 exists on the tip end side in the axial direction from the bearing 77.

  Further, the inner diameter D1 of the third cylinder portion 75 is set to be slightly larger than the shaft diameter D2 of the portion corresponding to the third cylinder portion 75 of the rotating shaft 10. As a result, a slight gap K is formed between the third cylindrical portion 75 and the rotary shaft 10. Further, a tapered portion 81 is formed on the distal end side of the third cylindrical portion 75 so as to gradually taper toward the distal end. The inner diameter of the tapered portion 81 is also set slightly larger than the shaft diameter D2 of the portion corresponding to the third cylindrical portion 75 of the rotating shaft 10, so that the third cylindrical portion 75 and the rotating shaft 10 do not interfere with each other. Yes.

  A plurality of bolt holes 82 are formed in the bracket main body 71 provided on the proximal end side of the fitting portion 72 along the circumferential direction closer to the outer periphery. The bolt hole 82 is used for fastening and fixing the yoke 21, the front bracket 2, and the rear bracket 4. That is, a bolt (not shown) is inserted into the bolt hole 82 and this bolt is screwed into a female screw portion (not shown) formed on the rear bracket 4, whereby the yoke 21, the front bracket 2, and the rear bracket are inserted. 4 is fastened and fixed.

  A pair of caulking projections 83, 83 are formed on both sides of the rotating shaft 10 on the inner surface of the bracket body 71. The caulking projection 83 is used for caulking and fixing the thrust supporter 84, and is buckled and deformed after the thrust supporter 84 is attached to the bracket body 71.

  As shown in FIGS. 1, 3A, and 3B, the thrust supporter 84 is formed by pressing a sheet metal member, and has four corners of the rectangular main body portion 85 in plan view. A chamfered portion 85a is formed on the surface. An insertion hole 86 through which the rotation shaft 10 of the armature 5 can be inserted is formed in the center of the main body 85. The diameter D3 of the insertion hole 86 is set to be slightly larger than the shaft diameter D2 of the rotary shaft 10.

A pair of caulking holes 87a and 87b for receiving a pair of caulking projections 83 and 83 formed on the inner surface of the bracket body 71 are formed on both sides in the longitudinal direction across the insertion hole 86.
Here, the pair of caulking holes 87a and 87b are arranged non-symmetrically with respect to the symmetry planes F1 and F2 that divide the outer shape of the thrust supporter 84 into plane symmetry. More specifically, in FIG. 3 (a), the caulking hole 87a formed on the left side of the paper surface is formed substantially at the center in the short direction of the main body portion 85, while the caulking hole formed on the right side of the paper surface. The hole 87b is formed slightly below the center of the main body 85 in the short direction.

The pair of caulking protrusions 83 and 83 of the bracket body 71 are formed so as to correspond to the caulking holes 87 a and 87 b of the thrust supporter 84.
With this configuration, the front / back direction and the circumferential direction of the thrust supporter 84 are determined, so that it is possible to prevent erroneous assembly of the thrust supporter 84 to the bracket body 71.

  Further, since the thrust supporter 84 is formed by pressing, burrs are easily formed on either the front surface or the back surface. For this reason, when the thrust supporter 84 is assembled to the bracket main body 71, the pair of caulking holes 87a, 87a, 87b and a pair of caulking projections 83, 83 are formed. By setting in this way, the thrust supporter 84 can be securely attached to the bracket body 71.

  The rotating shaft 10 of the armature 5 is formed with a retaining ring groove 16 on the armature core 11 side slightly from the mounting position of the thrust supporter 84, and a C-shaped retaining ring 15 is attached thereto. A thrust adjusting washer 17 is provided between the C-type retaining ring 15 and the thrust supporter 84. The thrust supporter 84, the C-type retaining ring 15, and the thrust adjusting washer 17 cooperate with each other to restrict movement of the rotary shaft 10 toward the engine 60, that is, movement of the rotary shaft 10 in the removal direction. To do.

  The washer 17 for adjusting the thrust is for preventing the armature 5 from rattling in the axial direction. In other words, the thickness of the washer 17 is set in accordance with the size of the gap between the thrust supporter 84 and the C-type retaining ring 15 caused by an assembly error when each component is assembled or a processing tolerance of each component.

Next, the assembly procedure of the electric motor 1 will be described.
First, the sheet metal member 20 is deep drawn by press working, and the front bracket 2 and the yoke 21 are integrally formed. At this time, the rising portion 78 is also formed in the fitting portion 72 of the front bracket 2 by pressing.
Next, the thrust supporter 84 is inserted from the opening at one end of the yoke 21 and set on the inner surface of the bracket body 71 of the front bracket 2. At this time, the thrust supporter 84 is set such that the pair of caulking holes 87 a and 87 b of the thrust supporter 84 are fitted to the pair of caulking projections 83 and 83 formed on the bracket body 71.

Since the pair of caulking projections 83 and 83 and the pair of caulking holes 87a and 87b are arranged non-symmetrically with respect to the symmetry planes F1 and F2 (see FIG. 3A), the thrust supporter 84 is It can be set only in a desired direction.
When the thrust supporter 84 is set, the tip of the caulking protrusion 83 of the front bracket 2 passes through the thrust supporter 84 and protrudes to one end side of the yoke 21. The protruding tip portion is buckled and deformed using a jig (not shown). As a result, the thrust supporter 84 is caulked and fixed to the front bracket 2.

  After the thrust supporter 84 is caulked and fixed to the front bracket 2, the armature 5 is inserted from the opening at one end of the yoke 21. At this time, the commutator 12 is inserted so as to face the rear bracket 4 side. Further, a C-type retaining ring 15 is mounted in advance in the retaining ring groove 16 of the rotating shaft 10. A thrust adjusting washer 17 is interposed between the thrust supporter 84 and the C-type retaining ring 15.

Here, since the front bracket 2 and the yoke 21 are integrally formed by deep drawing the sheet metal member 20 by pressing, the armature 5 and the yoke 21 become an obstacle when the armature 5 is inserted, and the front bracket 2 It becomes difficult for an operator to visually recognize the state of the inner surface side of the bracket body 71. That is, it is difficult for the operator to assemble the armature 5 while visually checking the thrust supporter 84. However, since the thrust supporter 84 is fixed by caulking to the front bracket 2, there is no possibility that the thrust supporter 84 is displaced from a desired position or dropped when the armature 5 is assembled. For this reason, the operator does not need to assemble the armature 5 while paying attention so that the thrust supporter 84 does not shift.
Thereafter, assembly of the electric motor 1 is completed by assembling the rear bracket 4 to which the power supply terminal 46 and the like are attached in advance so as to close one end of the yoke.

When the electric motor 1 assembled in this way is used, the rotary shaft 10 is connected to the crankshaft. When starting the engine, power is supplied to the brush 43 from the power supply terminal 46. A predetermined coil 13 is energized from the segment 14 in contact with the brush 43, and a magnetic attractive force or repulsive force is generated between the magnetic field formed in the armature 5 and the magnet 24 of the yoke 21. Thereby, a rotational force is generated and the rotating shaft 10 rotates the crankshaft.
At this time, the thrust supporter 84, the C-type retaining ring 15, and the thrust adjusting washer 17 cooperate with each other to restrict the movement of the rotary shaft 10 toward the engine 60, that is, the movement of the rotary shaft 10 in the removal direction. Therefore, the operation of the electric motor 1 can be stabilized.

  Therefore, according to the above-described embodiment, the thrust supporter 84 is caulked and fixed to the front bracket 2, so that the thrust supporter 84 can be prevented from being displaced and dropped when the electric motor 1 is assembled. For this reason, it becomes possible to improve the assembly workability of the electric motor 1.

Even if the front bracket 2 is formed by pressing the sheet metal member 20, the caulking protrusion 83 is formed on the bracket body 71 of the front bracket 2, and the caulking holes 87 a and 87 b are formed on the thrust supporter 84. In addition, the thrust supporter 84 can be easily caulked and fixed to the front bracket 2. For this reason, the manufacturing cost of the front bracket 2 can be reduced. Further, it is not necessary to manufacture the front bracket 2 from, for example, aluminum die casting, and the manufacturing variations of the front bracket 2 can be increased. Therefore, it is possible to provide the electric motor 1 that is inexpensive and meets the user's request.
Furthermore, the front bracket 2 and the yoke 21 can be deeply drawn and integrally formed, so that the manufacturing cost can be further reduced.

  And since the pair of caulking projections 83, 83 and the pair of caulking holes 87a, 87b are arranged non-plane symmetrically with respect to the symmetry planes F1, F2 that divide the outer shape of the thrust supporter 84 into plane symmetry, The thrust supporter 84 can be set only in a desired direction. For this reason, erroneous assembly of the thrust supporter 84 can be prevented. Therefore, it becomes possible to provide the electric motor 1 with stable quality.

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.
In the above-described embodiment, the case where the caulking projections 83 and 83 are formed on the front bracket 2 while the caulking holes 87a and 87b are formed on the thrust supporter 84 has been described. However, the present invention is not limited to this, and the caulking holes 87 a and 87 b may be formed in the front bracket 2, while the caulking protrusions 83 and 83 may be formed in the thrust supporter 84.
Further, one caulking projection 83 and one caulking hole 87 a are formed on the front bracket 2, and one caulking projection 83 and one caulking hole 87 b are formed on the thrust supporter 84. It may be fixed.

  In the above-described embodiment, the case where the pair of caulking projections 83 and 83 and the pair of caulking holes 87a and 87b are formed at asymmetric positions around the rotation shaft 10 has been described. However, the present invention is not limited to this, and three or more crimping projections 83 and three or more crimping holes 87a and 87b may be formed as long as they are formed at asymmetric positions around the rotation shaft 10.

  In the above-described embodiment, the yoke 21 and the front bracket 2 have been described as being integrally formed by deep drawing the sheet metal member 20 by pressing. However, the present invention is not limited to this, and the sheet metal member 20 may be separately formed by pressing. In this case, the yoke 21 and the front bracket 2 may be fixed by stamping or welding or the like.

Furthermore, the front bracket 2 and the thrust supporter 84 may be fixed by caulking, and the front bracket 2 may be molded by aluminum die casting or the like.
In the above-described embodiment, when the thrust supporter 84 is caulked and fixed to the front bracket 2, the tip of the caulking protrusion 83 formed on the bracket body 71 protrudes through the thrust supporter 84, and the caulking protrusion 83. The case where the protruding portion is buckled using a jig or the like has been described. However, the present invention is not limited to this, and the caulking projections 83 may be press-fitted into the caulking holes 87a and 87b, respectively, and the thrust supporter 84 may be caulked and fixed to the front bracket 2.

It is a partial cross section figure which shows the structure of the electric motor in embodiment of this invention. It is sectional drawing of the front bracket and yoke in embodiment of this invention. The thrust supporter in embodiment of this invention is shown, (a) is a top view, (b) is sectional drawing.

Explanation of symbols

1 Electric motor 2 Front bracket (one bracket)
4 Rear bracket (bracket)
5 Armature 10 Rotating shaft 15 C type retaining ring (Regulator)
20 Sheet metal member 21 Yoke 71 Bracket main body 83 Caulking protrusion 84 Thrust supporter (regulator plate)
87a, 87b Crimping holes F1, F2 Symmetry plane

Claims (4)

A cylindrical yoke,
A pair of brackets closing both ends of the yoke;
An armature rotatably supported by the pair of brackets,
On the inner surface of one of the pair of brackets, while fixing the restriction plate for restricting the movement of the rotation axis of the armature in the removal direction,
In a portion of the rotating shaft corresponding to the restricting plate, a restricting member that restricts movement of the rotating shaft in the pulling direction in cooperation with the restricting plate is provided .
The regulation plate is formed by pressing a sheet metal member,
A caulking protrusion is formed on the inner surface of the one bracket, and a caulking hole that can receive the caulking protrusion is formed in the restriction plate;
The electric motor , wherein the caulking protrusion and the caulking hole are arranged in a non-plane symmetry with respect to a symmetry plane that divides the outer shape of the restriction plate in a plane symmetry . Electric motor according to claim 1 wherein the regulating plate, wherein the caulking projections, and that one of the caulking holes are formed two. Said one bracket, the electric motor according to claim 1 or claim 2, characterized in that it is formed by pressing a sheet metal member. The electric motor according to claim 3 , wherein the one bracket and the yoke are integrally formed by pressing the sheet metal member.

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