JP6838838B2 - Rotating machine - Google Patents

Description

The present invention relates to a rotary electric machine.

As a rotary electric machine, for example, there is an electric motor with a brush. In this type of electric motor, a plurality of magnets are arranged on the inner peripheral surface of the tubular yoke. In addition, an armature is arranged inside the magnet on the yoke. The armature has an end bracket (front bracket, rear bracket) that covers both ends of the yoke, a rotating shaft that is rotatably supported, an armature core that is externally fitted to the rotating shaft and wound with a coil, and a rotating shaft. It is equipped with a commutator that is externally fitted and fixed so as to be adjacent to the armature core and to which the end portion of the coil is connected.

Further, the end bracket is provided with a plurality of brushes that are in sliding contact with the commutator, a brush holder that holds these brushes, and a terminal for electrically connecting an external power supply and the brush. The plurality of brushes are held by an insulating brush holder. The brush holder is often fastened and fixed to the end bracket by bolts.
Then, when the power of the external power source is supplied to the coil via the terminal, the brush, and the commutator, a predetermined magnetic field is generated in the armature core. A magnetic attractive force or repulsive force is generated between this magnetic field and the magnet of the yoke, and the armature rotates.

Japanese Unexamined Patent Publication No. 2004-260892

By the way, when the brush holder is fastened and fixed to the end bracket with a bolt, the bolt and the brush holder may rotate together as the bolt is tightened. Therefore, it may be difficult to position the brush holder on the end bracket with high accuracy. If the position accuracy of the brush holder deteriorates, the position of the brush will vary and the motor performance will deteriorate.

Therefore, the present invention has been made in view of the above circumstances, and provides a high-performance rotary electric machine by improving the position accuracy of the brush holder.

In order to solve the above problems, the rotary electric machine according to the present invention has a tubular yoke portion, and the motor case provided with a magnet in the yoke portion and the opening of the motor case are closed. An end case having a first positioning convex portion, an armature rotatably supported by the motor case and the end case and having a commutator, a plurality of brushes slidably contacted with the commutator, and the plurality of brushes. The brush holder is provided with a brush holder having a second positioning convex portion while holding the brush freely toward the commutator, and the brush holder is fastened and fixed to the end case by one bolt. positioning projection is characterized in that it is arranged to abut with said first positioning projection toward the rotational direction of the Rutoki tightening the bolt.

With this configuration, when the bolts are tightened to fasten and fix the brush holder to the end case with bolts, the second positioning convex part of the brush holder that rotates together with this bolt becomes the first positioning convex part of the end case. Contact the part. As a result, the brush holder is positioned with high accuracy with respect to the end case. Therefore, the position of the brush with respect to the end case is stable, and the performance of the rotary electric machine can be stably improved.

In the rotary electric machine according to the present invention, the end case has a third convex portion, while the brush holder has a fourth convex portion, and the fourth convex portion loosens the bolt. It is characterized in that it is arranged so as to come into contact with the third convex portion in the direction of rotation.

With this configuration, when the bolt is loosened, the fourth convex portion of the brush holder that rotates together with the bolt comes into contact with the third convex portion of the end case. Therefore, when loosening the bolt, it is possible to prevent the brush holder from swinging around together with the bolt. Therefore, rattling at the time of assembling and removing the brush holder can be suppressed as much as possible.

In the rotary electric machine according to the present invention, the first positioning convex portion has the function of the third convex portion.

With such a configuration, it is possible to reduce the material cost for suppressing rattling at the time of assembling and removing the brush holder. In addition, the end case and brush holder can be miniaturized.

In the rotary electric machine according to the present invention, the first positioning convex portion is a rib provided on the end case, and the contact surface of the rib with the second positioning convex portion passes through the rotation axis of the armature. It is formed so as to face a straight line in the radial direction and the axial direction, and the contact surface of the second positioning convex portion with the first positioning convex portion is the circumference of the brush that is along the axial direction and is held. It is characterized in that it is formed so as to face a straight line passing through the center of the direction.

With this configuration, the center of the brush in the circumferential direction can be aligned with the radial straight line passing through the rotation axis in a state where the second positioning convex portion is in contact with the first positioning convex portion. As a result, the end face of the brush can be brought into contact with the outer peripheral surface of the commutator with high accuracy, and the life of the brush can be extended.

According to the present invention, when the bolts are tightened so as to fasten and fix the brush holder to the end case with bolts, the second positioning convex portion of the brush holder that rotates together with the bolt becomes the first positioning convex portion of the end case. Contact. As a result, the brush holder is positioned with high accuracy with respect to the end case. Therefore, the position of the brush with respect to the end case is stable, and the performance of the rotary electric machine can be stably improved.

It is a perspective view of the starter motor in embodiment of this invention. It is sectional drawing of the starter motor in embodiment of this invention. It is a perspective view which looked at the front case in embodiment of this invention from the motor case side. It is an exploded perspective view of the part provided in the front case in embodiment of this invention. It is a top view of the front case in the embodiment of the present invention seen from the motor case side, and shows the state in which the brush holder unit is removed. It is sectional drawing which follows the AA line of FIG. It is sectional drawing which follows the line BB of FIG. It is a perspective view which looked at the brush holder unit in embodiment of this invention from the bottom side of the front case. It is a perspective view which shows the positional relationship between the motor case and the brush holder unit in embodiment of this invention. It is a side view which looked at the 1st holder main body in the embodiment of this invention from the inside in the radial direction. It is explanatory drawing which shows the behavior of the head head of the terminal bolt at the time of tightening a nut in embodiment of this invention. It is a top view of the mounting state of the brush holder unit to the front case in the embodiment of the present invention as viewed from the motor case side.

Next, an embodiment of the present invention will be described with reference to the drawings.

(Starter motor)
FIG. 1 is a perspective view of the starter motor 1, and FIG. 2 is a cross-sectional view of the starter motor 1.
As shown in FIGS. 1 and 2, the starter motor 1 is used as, for example, a starter motor for two wheels. The starter motor 1 includes a substantially bottomed cylindrical motor case 2, a substantially bottomed cylindrical front case 3 that closes an opening 2a of the motor case 2, and a space closed by the motor case 2 and the front case 3. The main configuration is an armature 4 rotatably stored in the motor case 3, a terminal 64 and a brush holder unit 70 provided in the front case 3 for supplying power to the armature 4, and a bracket 5 attached to the motor case 2. .. In the following description, the rotation axis L1 direction of the armature 4 is simply referred to as an axial direction, the rotation direction of the armature 4 is referred to as a circumferential direction, the axial direction, and the radial direction of the armature 4 orthogonal to the circumferential direction is simply referred to as a radial direction. ..

(Motor case)
The motor case 2 is formed by, for example, deep drawing an iron plate. That is, the motor case 2 is composed of a substantially cylindrical yoke portion 6 and a bottom portion 7 integrally molded at the end of the yoke portion 6 opposite to the front case 3. An in-row portion 2c having an outer diameter reduced by a step is formed on the peripheral edge of the opening 2a of the motor case 2. The front case 3 is fitted with the inro to the inro portion 2c. Further, the in-row portion 2c is formed with a notch portion 2b (see FIG. 9) for determining the relative position between the motor case 2 and the brush holder unit 70. The details of the notch portion 2b will be described later.

A plurality of magnets 8 are provided on the inner peripheral surface of the yoke portion 6 at equal intervals in the circumferential direction, and the magnetic poles are provided in order in the circumferential direction. Here, in the present embodiment, the number of magnets 8 is set to four (see FIG. 12). That is, the starter motor 1 is a 4-pole motor.
Further, on the bottom portion 7, a bearing portion 9 for rotatably supporting the rotating shaft 14 of the armature 4 is formed in the center in the radial direction so as to project toward the side opposite to the front case 3. The bearing portion 9 is formed in a substantially bottomed cylindrical shape so that the bottom portion 10 faces outward in the axial direction by deep drawing. A slide bearing 12 is press-fitted into the inner peripheral surface of the peripheral wall 11 of the bearing portion 9. One end of the rotating shaft 14 is rotatably supported by the slide bearing 12.

On the bottom portion 10 of the bearing portion 9, a bearing side boss 13 is formed so as to project in the axial direction (front case 3 side) in the center in the radial direction, that is, on the same straight line as the rotation axis L1. The bearing side boss 13 is formed by pressing the motor case 2 (bearing portion 9). That is, the bearing side boss 13 is recessed on the outer surface side (axially outer side) of the bottom portion 10.

(bracket)
The bracket 5 is attached to the bottom 7 of the motor case 2. The bracket 5 is formed by pressing a metal plate such as iron by pressing or the like to form a substantially L-shaped cross section. More specifically, the bracket 5 has a motor-side bracket portion 34 that abuts on the bottom portion 7 of the motor case 2.
The motor-side bracket portion 34 is formed so as to pass on the rotation axis L1 and be elongated in the radial direction. In the following description, the extending direction of the motor-side bracket portion 34 is referred to as the longitudinal direction of the motor-side bracket portion 34.

Further, the motor side bracket portion 34 is formed in a substantially hat shape that is long along the radial direction. That is, the motor-side bracket portion 34 is arranged at substantially the center in the longitudinal direction and is bent and extended from both ends of the bulging portion 36 in the longitudinal direction and bent so as to avoid the bearing portion 9 of the motor case 2. It is composed of two flange portions 37 that come into contact with the bottom portion 7 of the motor case 2. A bolt 100 is inserted into each of the flange portion 37 and the bottom portion 7 of the motor case 2 where the flange portion 37 abuts. The bolt 100 is screwed into the front case 3. As a result, the motor case 2 and the bracket 5 are fastened together with the front case 3.

The bulging portion 36 of the motor-side bracket portion 34 is composed of a pair of rising portions 41 rising from the flange portion 37 and a flat upper wall portion 42 extending so as to straddle the tips of the rising portions 41. Then, the upper wall portion 42 is in contact with the bottom portion 10 of the bearing portion 9 formed in the motor case 2.
On the upper wall portion 42, a bracket-side boss 43 is formed so as to project toward the bearing portion 9 side at a position corresponding to the bearing-side boss 13 formed on the bearing portion 9. The bracket-side boss 43 is formed by pressing the bracket 5 (motor-side bracket portion 34).

Here, the shape of the bracket side boss 43 is the same as the shape of the bearing side boss 13 formed in the bearing portion 9. Therefore, when the upper wall portion 42 of the motor-side bracket portion 34 is in contact with the bearing portion 9, the bracket-side boss 43 is fitted into the recess of the bearing-side boss 13. As a result, the bracket 5 is positioned with respect to the motor case 2.

On one side of the motor-side bracket portion 34 formed in this manner in the lateral direction, the bracketed portion 35 is located in the surface direction of the motor-side bracket portion 34 (the surface direction of the flange portion 37 and the surface direction of the upper wall portion 42). It is bent and extended along the direction orthogonal to. Further, the bracketed portion 35 extends from the motor side bracket portion 34 toward the side opposite to the motor case 2.
The bracketed portion 35 is attached to, for example, an engine case or a vehicle body (not shown), and is for fixing the starter motor 1 to the engine case or the vehicle body. The bracketed portion 35 is flat and extends in a substantially quadrangular shape in a plan view. Bolt insertion holes (not shown) for fastening and fixing the bracketed portion 35 to the engine case or the vehicle body are formed at the corners of the bracketed portion 35 opposite to the motor side bracket portion 34, respectively.

(Armature)
The armature 4 mainly includes a rotating shaft 14 whose one end is rotatably supported by a slide bearing 12, an armature core 15 and a commutator 16 which are externally fitted and fixed to the rotating shaft 14. The other end of the rotating shaft 14 projects from the front case 3 via a connecting portion 24 described later of the front case 3. A pinion gear 17 (see FIG. 1), which is connected to a ring gear of an engine (not shown) via a one-way clutch or the like, is externally fitted and fixed to the other end of the protruding rotating shaft 14. Further, on both end faces of the rotating shaft 14, center recesses 98 are formed coaxially with the rotating axis L1. The center recess 98 is formed in a substantially circular shape when viewed from the axial direction.

Here, the center recess 98 has two functions. As the first role, the center recess 98 has a role of fitting a chuck claw of a tool (not shown) into the rotary shaft 14 and causing the tool to hold the rotary shaft 14 when cutting. The second role is to avoid interference with the bearing-side boss 13 formed in the bearing portion 9 of the motor case 2.

The armature core 15 is arranged at a position corresponding to the magnet 8 of the rotating shaft 14. The armature core 15 is formed by laminating electromagnetic steel plates, and has a plurality of teeth 18 extending radially around a rotation shaft 14. A dovetail groove-shaped slot (not shown) long in the axial direction is formed between the teeth 18, and the coil 19 is wound around the teeth 18 through the slot (not shown).

The commutator 16 is arranged at a position corresponding to the front case 3 of the rotating shaft 14. The commutator 16 is for supplying an electric current to the coil 19. The commutator 16 is composed of a substantially cylindrical commutator main body 20 having an insulating property that is fitted and fixed to the rotating shaft 14, and a plurality of conductive segments 21 provided on the outer peripheral surface of the commutator main body 20. .. The segments 21 are arranged side by side at predetermined intervals in the circumferential direction. The terminal portion of the coil 19 is connected to such a segment 21.

(Front case)
FIG. 3 is a perspective view of the front case 3 as viewed from the motor case 2 side. FIG. 4 is an exploded perspective view of FIG. 3, that is, an exploded perspective view of a component provided in the front case 3.
As shown in FIGS. 2 to 4, the front case 3 is formed by, for example, aluminum die casting. An in-row portion 3d having an inner diameter expanded by a step is formed on the peripheral edge of the opening 3c of the front case 3. The front case 3 is attached to the motor case 2 by fitting the inro portion 3d into the opening 2a of the motor case 2.

On the bottom portion 3a of the front case 3, a substantially bottomed cylindrical bearing portion 22 is formed so as to project toward the side opposite to the motor case 2 in most of the radial center. The bottom portion 22a of the bearing portion 22 faces outward in the axial direction. A rolling bearing 23 is internally fitted and fixed to the inner peripheral surface 22b of the bearing portion 22. The other end side of the rotating shaft 14 is rotatably supported by the rolling bearing 23.

Further, on the bottom portion 22a of the bearing portion 22, a substantially cylindrical connecting portion 24 is formed in the center in the radial direction so as to project toward the side opposite to the motor case 2. The connecting portion 24 is a portion where the starter motor 1 (front case 3) is connected to an engine case (not shown). The inner surface side of the connecting portion 24 is communicated with the bearing portion 22. As a result, the other end of the rotating shaft 14 projects outward in the axial direction via the connecting portion 24.

A seal ring 25 is provided on the inner peripheral surface side of the connecting portion between the connecting portion 24 and the bearing portion 22. The seal ring 25 is for ensuring the sealing property between the front case 3 and the rotating shaft 14.
Further, an O-ring groove 26 is formed on the outer peripheral surface of the connecting portion 24 at substantially the center in the axial direction. An O-ring 27 is mounted in the O-ring groove 26. The O-ring 27 is for ensuring a sealing property between the engine case (not shown) and the front case 3.

FIG. 5 is a plan view of the front case 3 as viewed from the motor case 2 side, and shows a state in which the brush holder unit 70 is removed.
As shown in FIGS. 4 and 5, recesses 28 are formed in the bottom portion 3a of the front case 3 over the entire outer peripheral portion on the inner surface side. Further, the recess 28 is formed so that the wall thickness t1 between the bearing portion 22 and the inner peripheral surface 22b is constant. The terminal 64 and the brush holder unit 70 are arranged in the recess 28 formed in this way.

Further, on the peripheral wall 3b of the front case 3, two bolt seats 29 are integrally molded on the inner peripheral surface side and on the recess 28. The two bolt seats 29 are arranged so as to face each other with respect to the rotation axis L1. Each bolt seat 29 is engraved with a female screw portion 29a into which the bolt 100 is screwed.

Further, in the recess 28 of the front case 3, a plurality of ribs 30 for improving the strength of the front case 3 are formed so as to straddle between the bearing portion 22 and the peripheral wall 3b. Specifically, the plurality of ribs 30 have a total of four side ribs 30a arranged on both sides of one bolt seat 29 with the bolt seat 29 interposed therebetween and arranged in parallel with each other. Further, it has one center rib 30b arranged on the straight line L3 passing through the rotation axis L1 and orthogonal to the center of the two female screw portions 29a and the straight line L2 passing through the rotation axis L1. Further, with respect to the first contact convex portion 30c1 and the second contact convex portion 30c2 arranged between the center rib 30b and the side rib 30a, and the first contact convex portion 30c1 and the second contact convex portion 30c2. It has an intermediate rib 30d arranged point-symmetrically about the rotation axis L1.

Further, the first contact convex portion 30c1, the second contact convex portion 30c2, and the intermediate rib 30d are arranged along the radial direction, respectively. Further, the first contact convex portion 30c1 and the first contact side surface 30e on the side rib 30a side of the second contact convex portion 30c2 face the linear straight line L4 in the radial direction passing through the rotation axis L1 and the axial direction.

Further, in one of the four side ribs 30a, a bolt seat 31 having a substantially circular shape when viewed from the axial direction is formed at the connection portion with the bearing portion 22. The bolt seat 31 is for grounding one of the two brushes 72 constituting the brush holder unit 70. An in-row convex portion 32 is formed so as to project from most of the radial center of the bolt seat 31. The in-row convex portion 32 temporarily positions the front case 3 and the brush holder unit 70. A female screw portion 33 is engraved at the center of the in-row convex portion 32 in the radial direction. The details of the grounding method of the brush 72 and the temporary positioning method of the brush holder unit 70 with respect to the front case 3 will be described later.

Further, on the peripheral wall 3b of the front case 3, a terminal seat 50 having a flat side surface 50a formed on the inner peripheral surface is integrally molded. The terminal seat 50 is arranged so as to face the center rib 30b with the rotation axis L1 as the center, and is integrally molded with the peripheral wall 3b of the front case 3. The terminal seat 50 is for attaching the terminal 64 to the front case 3.

The terminal seat 50 is formed over the entire axial direction of the peripheral wall 3b of the front case 3, and is formed in a substantially rectangular shape when viewed from the inside in the radial direction so that the length in the circumferential direction is slightly longer than the length in the axial direction. ing. A terminal insertion hole 51 is formed so as to penetrate the peripheral wall 3b in most of the centers of the terminal seat 50 in the axial direction and the circumferential direction. A terminal bolt 52 constituting the terminal 64 is inserted into the terminal insertion hole 51 from the side surface 50a side of the terminal seat 50.

The terminal bolt 52 is formed of a conductive metal member. For example, the terminal bolt 52 is formed of SCM45 or the like. The terminal bolt 52 is integrally formed with a shaft portion 53 that is inserted through the terminal insertion hole 51 and projects radially outward from the peripheral wall 3b of the front case 3 and an end portion of the shaft portion 53 on the terminal seat 50 side. It is composed of 54 and. An O-ring 47 is mounted on the terminal insertion hole 51 on the peripheral wall 3b of the front case 3, so that the insulation between the terminal insertion hole 51 and the shaft portion 53 of the terminal bolt 52 is ensured.

A nut 59 is screwed onto the tip end side of the shaft portion 53 opposite to the head portion 54. The nut 59 is used to fasten and fix a terminal (not shown) extending from an external power source to the terminal bolt 52. A ring insulator 49 and a washer 48 are attached to the terminal bolt 52.
These ring insulators 49 and washers 48 are arranged between the nut 59 and the peripheral wall 3b of the front case 3. The washer 48 cooperates with the nut 59 to fasten and fix a terminal (not shown) extending from an external power source to the terminal bolt 52. The ring insulator 49 is made of resin and secures insulation between the nut 59 and the front case 3.

On the other hand, the head 54 of the terminal bolt 52 is formed by a plate-shaped metal member in a substantially square shape so as to be about one size smaller than the side surface 50a of the terminal seat 50 and one side along the axial direction. There is. The head 54 of the terminal bolt 52 thus formed is held by the terminal insulator 55 provided on the side surface 50a of the terminal seat 50 via the intermediate member 60.

6 is a cross-sectional view taken along the line AA of FIG. 3, and FIG. 7 is a cross-sectional view taken along the line BB of FIG.
As shown in FIGS. 4, 6 and 7, the terminal insulator 55 is formed of a resin such as phenol resin in a box shape having an opening 55a on one surface. That is, the terminal insulator 55 is formed in a substantially square shape on one side along the axial direction so as to correspond to the side surface 50a of the terminal seat 50. The terminal insulator 55 is formed by integrally molding a flat bottom wall 56 that abuts on the side surface 50a and a frame portion 57 that is erected along the outer peripheral edge of the bottom wall 56. The terminal insulator 55 is arranged in the recess 28 of the front case 3, and the frame portion 57 is in contact with the recess 28.

The head 54 of the terminal bolt 52 is housed inside the frame portion 57. That is, the frame portion 57 is formed in a substantially square shape with one side along the axial direction so as to surround the outer peripheral portion of the head 54 of the terminal bolt 52. One side 57a of the frame portion 57 that is in contact with the recess 28 (bottom portion 3a) of the front case 3 is in contact with the bottom portion 3a of the front case 3. An insertion hole 58 through which the shaft portion 53 of the terminal bolt 52 can be inserted is formed in the center of the bottom wall 56 in the axial direction and the circumferential direction. The hole diameter of the insertion hole 58 is set to be slightly larger than that of the shaft portion 53.
In the following description, one side 57a on the bottom 3a side of the front case 3 in the frame portion 57 is the bottom 57a, the side facing the bottom 57a in the axial direction is the upper side 57b, and the bottom side 57a and the upper side 57b are connected in the circumferential direction. Both sides are referred to as side sides 57c.

The intermediate member 60 is formed by pressing a plate material having conductivity that is harder than the terminal insulator 55 and softer than the terminal bolt 52. For example, the intermediate member 60 is formed by pressing a brass plate material. The intermediate member 60 is formed in a substantially U-shaped cross section so that it can be housed in the terminal insulator 55. That is, the intermediate member 60 is arranged so as to abut on the bottom wall 56 of the terminal insulator 55, and has a base portion 61 whose side is formed in a substantially square shape along the axial direction so as to correspond to the shape of the bottom wall 56. , Two side wall portions 62a, 62b (upper side wall portion 62a, lower side wall portion 62b) that bend and extend along the inner side surface of the frame portion 57 from both ends in the lateral direction (both ends in the axial direction) of the base portion 61. Has been done.

The base portion 61 is formed with an insertion hole 61a at a position corresponding to the insertion hole 58 of the terminal insulator 55, which is communicated with the insertion hole 58 and allows the shaft portion 53 of the terminal bolt 52 to be inserted. As a result, the terminal bolt 52 is inserted from above the base portion 61 of the intermediate member 60, and the shaft portion 53 of the terminal bolt 52 is projected from the radial outside of the peripheral wall 3b of the front case 3 via the terminal insulator 55. Can be done.

Further, the distance between the two side wall portions 62a and 62b is set to be substantially equal to or slightly longer than the length of one side of the head 54 of the terminal bolt 52. Therefore, when the head 54 of the terminal bolt 52 and the intermediate member 60 are housed in the terminal insulator 55, the head 54 and the base portion 61 of the intermediate member 60 are in contact with each other, and further, the two sides of the head 54 and the middle member 60 are in contact with each other. The two side wall portions 62a and 62b of the member 60 are brought into contact with each other.
Further, of the two side wall portions 62a and 62b, a pigtail connection is made to the upper side wall portion 62a located on the side opposite to the bottom portion 3a of the front case 3 (on the opening 3c side of the front case 3) with the base portion 61 interposed therebetween. The portion 63 is bent and extended along the axial direction. The pigtail 77 of the brush 72, which will be described later, is connected to the pigtail connection portion 63.

Here, the size of the head 54 of the terminal bolt 52, the size of the base portion 61 of the intermediate member 60, and the sizes of the side wall portions 62a and 62b are formed so as to satisfy the following conditions. That is,
(A) Of the two side wall portions 62a and 62b, the lower side wall portion 62b on the bottom side 57a side of the frame portion 57 is in contact with the bottom side 57a of the frame portion 57.
(B) A minute clearance C1 is formed between the upper side wall portion 62a and the upper side 57b of the frame portion 57.
(C) A minute clearance C2 is formed between both ends of the head portion 54 of the terminal bolt 52 in the circumferential direction and the side sides 57c of the corresponding frame portions 57, and the circumference of the base portion 61 of the intermediate member 60 is formed. A minute clearance C3 is formed between both ends in the direction and the side sides 57c of the corresponding frame portions 57.
In the following description, the condition (A) above is referred to as a condition (A), the condition (B) above is referred to as a condition (B), and the condition (C) above is referred to as a condition (C). Refer to.

Further, the front case 3 straddles the two side ribs 30a on the side on which the bolt seat 31 is formed, the first contact convex portion 30c1 adjacent to the side ribs 30a in the circumferential direction, and the intermediate rib 30d. , The brush holder unit 70 is arranged.

FIG. 8 is a perspective view of the brush holder unit 70 as viewed from the bottom 3a side of the front case 3.
As shown in FIGS. 3, 4, and 8, the brush holder unit 70 is arranged at a position that faces the armature 4 commutator 16 in the radial direction in a state where the starter motor 1 is assembled. The brush holder unit 70 mainly includes a resin brush holder 71 and two brushes 72 housed in the brush holder 71. The brush holder 71 is a connecting portion 74 that connects two holder bodies 81, 82 (first holder body 81, second holder body 82) and two holder bodies 81, 82 straddling these two holder bodies 81, 82. And are integrally molded.

The two holder bodies 81 and 82 are arranged at intervals of 90 ° in the circumferential direction. More mimicically, of the two holder bodies 81 and 82, the first holder body 81 is arranged on the first contact convex portion 30c1. Further, of the two holder main bodies 81 and 82, the second holder main body 82 is arranged on the intermediate rib 30d.
The holder bodies 81 and 82 are formed in a rectangular parallelepiped shape so as to be slightly longer in the radial direction when viewed from the axial direction. Further, each of the holder bodies 81 and 82 is formed in a box shape having first openings 81a and 82a on the bottom 3a side of the front case 3 and having second openings 81b and 82b on the inner side in the radial direction. ..

Brushes 72 are housed in such holder bodies 81 and 82, respectively. Further, the tip of the brush 72 is free to appear and disappear inward in the radial direction (toward the commutator 16) via the second openings 81b and 82b of the holder bodies 81 and 82. Further, the spring 78 is stored in the holder main bodies 81 and 82 in a compressed state on the base end side of the brush 72, respectively. As a result, the brush 72 is constantly urged inward in the radial direction (toward the commutator 16), and the tip of the brush 72 is slidably contacted with the segment 21 of the commutator 16.

Further, a slit 76 is formed in the center in the circumferential direction on the upper wall 75 of each holder body 81, 82 on the side opposite to the first openings 81a, 82a. The slit 76 is formed so as to communicate with the second openings 81b and 82b, respectively. The slit 76 is used to pull out the pigtail 77 made of a copper wire connected to the brush 72 to the outside of the holder body 73.

The terminal portion of the pigtail 77 pulled out from the first holder main body 81 is grounded (details will be described later). On the other hand, the terminal portion of the pigtail 77 pulled out from the second holder main body 82 is connected to the pigtail connecting portion 63 provided in the intermediate member 60 of the terminal 64 by, for example, brazing welding. Since the pigtail connection portion 63 is formed of brass, it has almost the same specific heat as the pigtail 77, and the pigtail 77 can be easily brazed and welded to the pigtail connection portion 63.

Here, the first holder main body 81 is formed with a positioning protrusion 83 protruding from the radial outer end of the upper wall 75. Further, the first holder main body 81 is formed with a positioning convex portion 84 and a position restricting convex portion 85 protruding in a bifurcated shape at the edge portion of the radial outer end of the first opening 81a.
The positioning protrusion 83 is for determining the relative position between the brush holder 71 and the motor case 2. The positioning protrusion 83 is formed in a plate shape. The positioning protrusion 83 is composed of a rising portion 83a that rises from the upper wall 75 along the axial direction, and a tongue piece portion 83b that bends and extends outward in the radial direction from the tip of the rising portion 83a. The rising portion 83a is arranged flush with the radial outer radial end wall 81c of the first holder main body 81. Further, the positioning protrusion 83, that is, the center L6 in the circumferential direction of the rising portion 83a and the tongue piece portion 83b, is a straight line L5 that runs along the axial direction and passes through the center in the circumferential direction of the first holder main body 81 (second opening 81b). (See FIG. 10) It is located above.

FIG. 9 is a perspective view showing the positional relationship between the motor case 2 and the brush holder unit 70.
As shown in the figure, when the starter motor 1 is assembled, the tongue piece portion 83b of the positioning protrusion 83 of the brush holder 71 is located on the peripheral edge of the opening 2a of the motor case 2. The notch 2b formed on the peripheral edge of the opening 2a of the motor case 2 is arranged at a position corresponding to the tongue piece 83b of the brush holder 71.

The notch portion 2b is formed in a substantially rectangular shape so as to correspond to the shape of the tongue piece portion 83b. The width of the notch portion 2b in the circumferential direction is set to be substantially the same as or slightly larger than the width of the tongue piece portion 83b of the positioning protrusion 83 in the circumferential direction. As a result, the tongue piece portion 83b is fitted into the notch portion 2b, and the relative positions of the motor case 2 and the brush holder 71 (brush holder unit 70) are accurately determined.

FIG. 10 is a side view of the first holder main body 81 of the brush holder 71 as viewed from the radial inside (commitator 16) side.
As shown in FIGS. 8 and 10, the positioning convex portion 84 and the position restricting convex portion 85 projecting from the brush holder 71 are flush with the radial end wall 81c of the first holder main body 81, respectively. It has been postponed. Further, the positioning convex portion 84 is formed so as to have a substantially triangular shape in a radial plan view so as to taper toward the tip end. Further, the positioning convex portion 84 is formed so that one side 84a faces a straight line L5 that passes along the axial direction and passes through the center of the brush 72 (first holder main body 81, second opening 81b) in the circumferential direction. ..

On the other hand, the position-regulating convex portion 85 is formed in a substantially rectangular shape in a radial plan view. The position regulation convex portion 85 is extended so that one side 85a is flush with the side wall 81d on the side opposite to the second holder main body 82 of the first holder main body 81.
Here, the distance K1 between the positioning convex portion 84 and the position restricting convex portion 85 is set to be slightly larger than the wall thickness t2 of the first contact convex portion 30c1 (see also FIG. 5). There is. Then, the first contact convex portion 30c1 is interposed between the positioning convex portion 84 and the position restricting convex portion 85. That is, the position-regulating convex portion 85 is located on the opposite side of the positioning convex portion 84 with the first contact convex portion 30c1 interposed therebetween.

As shown in FIGS. 3, 4, and 8, the connecting portion 74 connecting the two holder bodies 81 and 82 extends in an arc shape along the outer peripheral surface of the bearing portion 22 (commitator 16). In other words, the connecting portion 74 extends in a substantially arc shape so as to correspond to the shape of the peripheral wall 3b of the front case 3.
Further, the connecting portion 74 is formed so that the cross-sectional shape along the axial direction is L-shaped. That is, the connecting portion 74 is a base portion 86 straddling between the ends of the two holder bodies 81 and 82 on the front case 3 side and an inner peripheral wall portion 87 straddling between the radial inner ends of the two holder bodies 81 and 82. It is composed of and.

A pedestal 88 is formed in the base portion 86 near the second holder main body 82. In other words, the pedestal 88 is formed at a position corresponding to the in-row convex portion 32 of the front case 3 in the base portion 86. The pedestal 88 is formed with a through hole 88a that can be fitted into the inlay convex portion 32. The pedestal 88 is fitted onto the in-row convex portion 32, and the bolt 101 is screwed into the female screw portion 33 of the in-row convex portion 32 from above. As a result, the brush holder 71 is fastened and fixed to the front case 3. The details of the method of fastening and fixing the brush holder 71 to the front case 3 will be described later.

Here, the terminal 89 is attached to the terminal portion of the pigtail 77 pulled out from the first holder main body 81. Then, when the brush holder 71 is fastened and fixed to the front case 3 by the bolt 101, the brush holder 71 and the terminal 89 are fastened together.
Further, when the pedestal 88 is fitted onto the inlay convex portion 32, the tip surface of the pedestal 88 and one surface of the base portion 86 are substantially flush with each other. Therefore, when the brush holder 71 is fastened and fixed to the front case 3, the terminal 89 comes into contact with the in-row convex portion 32 of the front case 3. As a result, the terminal portion of the pigtail 77 pulled out from the first holder main body 81 is grounded (body ground).

Further, the brush holder unit 70 has a base portion 90 arranged on the bottom portion 3a side of the front case 3 in the brush holder 71.
The base portion 90 closes the first opening 81a of the first holder main body 81 and the first opening 82a of the second holder main body 82. That is, the base portion 90 is composed of two base portion main bodies 91 that close the openings 81a and 82a, and a connecting portion 92 that straddles the two base portion main bodies 91 and connects the two base portion main bodies 91. Has been done.

The base portion main body 91 is formed in a substantially rectangular shape when viewed from the axial direction so as to correspond to the openings 81a and 82a of the holder main bodies 81 and 82. In each base portion main body 91, a claw portion 91a is formed so as to protrude on the side wall 81d, 82d side of each holder main body 81, 82. The claw portion 91a snap-fits the base portion 90 to the brush holder 71.
The connecting portion 92 is formed with an opening 92a that exposes the through hole 88a at a position corresponding to the through hole 88a of the pedestal 88 formed in the brush holder 71. As a result, even when the base portion 90 is attached to the brush holder 71, the inlay convex portion 32 of the front case 3 can be fitted to the pedestal 88.

(Assembly of terminal and brush holder unit to front case)
Next, assembling the terminal 64 and the brush holder unit 70 to the front case 3 will be described.
First, the assembly of the terminal 64 to the front case 3 will be described.
When assembling the terminal 64 to the front case 3, the intermediate member 60 and the terminal insulator 55 are previously inserted into the terminal bolt 52 through the shaft portion 53 in this order. At this time, the intermediate member 60 and the head 54 of the terminal 64 are housed in the frame portion 57 of the terminal insulator 55.

After that, the shaft portion 53 of the terminal bolt 52 is inserted from the terminal seat 50 side of the front case 3. At this time, the pigtail connection portion 63 of the intermediate member 60 is directed toward the opening 3c side of the front case 3. Then, the bottom wall 56 of the terminal insulator 55 is brought into contact with the side surface 50a of the terminal seat 50.
The terminal insulator 55 and the intermediate member 60 may be arranged on the side surface 50a of the terminal seat 50 of the front case 3 without inserting the intermediate member 60 and the terminal insulator 55 into the shaft portion 53 of the terminal bolt 52 in advance. In this case, after that, the shaft portion 53 of the terminal bolt 52 is inserted into the terminal insulator 55, the intermediate member 60, and the front case 3.

Subsequently, the O-ring 47, the ring insulator 49, the washer 48, and the nut 59 are inserted in this order into the shaft portion 53 of the terminal bolt 52 protruding radially outward from the peripheral wall 3b of the front case 3, and tightened by the nut 59. To go.

FIG. 11 is an explanatory view showing the behavior of the head 54 of the terminal bolt 52 when tightening the nut 59, and corresponds to the view taken along the arrow C in FIG.
As shown in the figure, when the nut 59 is tightened, the terminal bolt 52 tries to rotate together with the nut 59 (see the arrow Y1 in FIG. 11).

Here, in a state where the head 54 of the terminal bolt 52 and the intermediate member 60 are housed in the terminal insulator 55, the head 54 and the base portion 61 of the intermediate member 60 are in contact with each other. Further, the two sides of the head 54 facing each other in the direction of the rotation axis L1 and the two side wall portions 62a and 62b of the intermediate member 60 are brought into contact with each other. The head 54 of the terminal bolt 52 housed in the terminal insulator 55 satisfies the above conditions (A), (B), and (C). That is, the lower side wall portion 62b, which is in contact with one side of the head 54, is in contact with the frame portion 57 only on the bottom side 57a.

Therefore, when the head 54 tries to rotate, the head 54 presses the bottom 57a of the frame portion 57 via the lower side wall portion 62b of the intermediate member 60 (see arrow Y2 in FIG. 11), and the bottom 57a is pressed. Try to transform. At this time, the pressing force is positively applied to the bottom side 57a of the frame portion 57, whereas the pressing force of the head 54 is hardly applied to the other sides (upper side 57b and side side 57c) of the frame portion 57.
Further, the bottom side 57a of the frame portion 57 is in contact with the recess 28 (bottom portion 3a) of the front case 3. Therefore, the front case 3 receives the pressing force of the head 54, and the deformation of the bottom 57a is suppressed by the front case 3. As a result, the rotation of the head 54 is prevented, and the nut 59 can be firmly tightened to the shaft portion 53 of the terminal bolt 52.

Further, the intermediate member 60 is made of, for example, a brass plate which is harder than the terminal insulator 55 and softer than the terminal bolt 52. Therefore, the lower side wall portion 62b of the intermediate member 60 is compressively deformed by the pressing force caused by the rotation of the head 54. As a result, the lower side wall portion 62b absorbs the pressing force of the head portion 54, and the load applied to the bottom side 57a of the frame portion 57 is relaxed.

Subsequently, assembling the brush holder unit 70 to the front case 3 will be described.
Before assembling the brush holder unit 70 to the front case 3, the brush 72 and the spring 78 are stored in the first holder main body 81 and the second holder main body 82 of the brush holder 71, respectively. At this time, one end of the pigtail 77 is connected to the brush 72 by, for example, brazing welding. Further, a terminal 89 is attached to the other end of the pigtail 77 of the brush 72 housed in the first holder main body 81. The other end of the pigtail 77 of the brush 72 stored in the second holder body 82 may be connected to the pigtail connection portion 63 of the intermediate member 60 in advance, or the brush holder unit 70 may be assembled to the front case 3. After that, it may be connected to the pigtail connection portion 63.

Then, after storing the brush 72 and the spring 78 in the first holder main body 81 and the second holder main body 82, respectively, the base portion 90 is assembled to the brush holder 71 to complete the assembly of the brush holder unit 70.
After that, with the base portion 90 facing the bottom portion 3a of the front case 3, the side ribs 30a on the recess 28 of the front case 3, that is, the side rib 30a on the side where the bolt seat 31 is formed, the first contact convex portion 30c1, and The brush holder unit 70 is placed on the intermediate rib 30d.

At this time, the brush holder unit 70 is placed so that the inlay convex portion 32 formed in the bolt seat 31 of the front case 3 is fitted into the through hole 88a of the pedestal 88 of the brush holder 71. Further, the brush holder unit 70 is placed so that the first contact convex portion 30c1 is inserted between the positioning convex portion 84 and the position restricting convex portion 85 of the brush holder 71. As a result, the position of the brush holder unit 70 with respect to the front case 3 is tentatively determined.
Here, when the brush holder unit 70 is placed on the bottom 3a of the front case 3, the base 90 faces the bottom 3a of the front case 3, so that the brush holder 71 is the first when viewed from the opening 3c side of the front case 3. 1 The positioning convex portion 84 and the third convex portion 85 enter the blind spot of the operator.

By the way, the circumferential center L6 of the positioning protrusion 83 formed on the upper wall 75 of the first holder main body 81 passes along the axial direction and passes through the circumferential center of the first holder main body 81 (second opening 81b). It is located on the straight line L5 (see FIG. 10). Further, the positioning convex portion 84 formed on the edge of the first opening 81a of the first holder main body 81 is formed so that one side 84a faces the straight line L5. Therefore, by visually recognizing the position of the positioning protrusion 83, the approximate position of the positioning convex portion 84 and the third convex portion 85, which are blind spots, can be recognized. Therefore, the operator can easily place the brush holder unit 70 so that the first contact convex portion 30c1 is inserted between the positioning convex portion 84 and the position restricting convex portion 85 of the brush holder 71. Can be done.

After the position of the brush holder unit 70 with respect to the front case 3 is tentatively determined, the bolt 101 is screwed from above the pedestal 88 of the brush holder 71 to the female screw portion 33 of the inlay convex portion 32 of the front case 3. At this time, the terminal 89 attached to the pigtail 77 of the brush 72 housed in the first holder main body 81 is also tightened together.

FIG. 12 is a plan view of the state in which the brush holder unit 70 is attached to the front case 3 as viewed from the motor case 2 side.
As shown in the figure, as the bolt 101 is tightened (see the arrow Y3 in FIG. 12), the brush holder unit 70 tries to rotate together with the bolt 101. That is, the brush holder unit 70 tries to rotate around the bolt 101 in the tightening direction of the bolt 101 (see arrow Y4 in FIG. 12).

Then, one side 84a of the positioning convex portion 84 of the brush holder 71 comes into contact with the first contact side surface 30e on the side rib 30a side of the first contact convex portion 30c1 in the front case 3. Then, when the bolt 101 is further tightened, the brush holder unit 70 is in contact with the front case 3 with one side 84a of the positioning convex portion 84 still in contact with the first contact side surface 30e of the first contact convex portion 30c1. Is fastened and fixed. As a result, the brush holder unit 70 is positioned with respect to the front case 3. That is, among the plurality of ribs 30 formed in the concave portions 28 of the front case 3, the first contact convex portion 30c1 has a role of improving the strength of the front case 3 and a brush for the front case 3. It has a role of positioning the holder unit 70.

Here, the first contact side surface 30e of the first contact convex portion 30c1 of the front case 3 faces the radial straight line L4 passing through the rotation axis L1 and the axial direction. Further, the positioning convex portion 84 of the brush holder 71 is formed so that one side 84a faces a straight line L5 that passes along the axial direction and passes through the circumferential center of the brush 72 (second opening 81b). Therefore, when the brush holder unit 70 is fastened and fixed to the front case 3 while one side 84a of the positioning convex portion 84 is still in contact with the first contact side surface 30e of the first contact convex portion 30c1, the first contact convex portion 30c1 is fixed. 1 The center of the brush 72 housed in the holder body 81 in the circumferential direction coincides with the linear straight line L4 in the radial direction passing through the rotation axis L1. That is, the direction of the brush 72 is along the radial direction, and the brush 72 is positioned with high accuracy.

Further, when the bolt 101 is tightened while the one side 84a of the positioning convex portion 84 of the brush holder 71 is in contact with the first contact side surface 30e on the side rib 30a side of the first contact convex portion 30c1. The pressing force of the positioning convex portion 84 acts on the first contact convex portion 30c1. Then, this pressing force becomes a reaction force, and a force acts on the brush holder 71.

Here, in the brush holder 71, the inner peripheral wall portion 87 of the connecting portion 74 connecting the two holder bodies 81 and 82 is formed so as to straddle between the radial inner ends of the two holder bodies 81 and 82. .. Therefore, since the peripheral length of the inner peripheral wall portion 87 can be set as short as possible, the strength of the inner peripheral wall portion 87 is ensured and the force acting on the brush holder 71 prevents the inner peripheral wall portion 87 from being deformed. To.

That is, for example, when the inner peripheral wall portion 87 is formed so as to straddle between the radial outer ends of the two holder bodies 81 and 82, the inner peripheral wall portion 87 is the radial inner end of the two holder bodies 81 and 82. The circumference is longer than when straddling the space. When the inner peripheral wall portion 87 becomes long, the strength is weakened by this amount, and it becomes easy to be affected by the force acting on the brush holder 71. Therefore, the strength of the inner peripheral wall portion 87 can be increased by setting the peripheral length of the inner peripheral wall portion 87 as short as possible.

On the other hand, when the bolt 101 is loosened in order to remove the brush holder unit 70 from the front case 3, the brush holder unit 70 tries to rotate together. That is, the brush holder unit 70 tries to rotate around the bolt 101 in the loosening direction of the bolt 101 (see arrow Y5 in FIG. 12).
Then, the position-regulating convex portion 85 of the brush holder 71 comes into contact with the second contact side surface 30f (see FIG. 5) on the side opposite to the side rib 30a of the first contact convex portion 30c1 in the front case 3. Therefore, when the bolt 101 is loosened to remove the brush holder unit 70 from the front case 3, the brush holder unit 70 is prevented from swinging around.

(Assembly of motor case and front case)
Next, the assembly of the motor case 2 and the front case 3 will be described.
Here, as described above, the terminal 64 and the brush holder unit 70 are assembled in advance on the motor case 2. On the other hand, in the motor case 2, the slide bearing 12 is attached to the bearing portion 9 in advance, and the armature 4 is further attached.
In this state, the in-row portion 2c of the motor case 2 and the in-row portion 3d of the front case 3 face each other. Further, the notch portion 2b formed in the in-row portion 2c of the motor case 2 and the positioning protrusion 83 of the brush holder unit 70 attached to the front case 3 are aligned with each other.

Then, when the motor case 2 and the front case 3 are overlapped with each other, the in-row portion 3d of the front case 3 is fitted with the in-row portion 2c of the motor case 2. At the same time, the positioning protrusion 83 of the brush holder unit 70 attached to the front case 3 is fitted into the notch 2b formed in the in-row portion 2c of the motor case 2. As a result, the front case 3 is positioned in the circumferential direction with respect to the motor case 2. That is, the brush holder unit 70 (brush holder 71) is positioned with reference to the motor case 2.

Here, the motor case 2 is provided with a plurality of magnets 8 (for example, four in the present embodiment), and these magnets 8 are also positioned with reference to the motor case 2. Therefore, the brush holder unit 70 (brush holder 71) is positioned with respect to the magnet 8 with high accuracy. As a result, the brush 72 is positioned with respect to the magnet 8 with high accuracy (see FIG. 12).

(Operation of starter motor)
Next, the operation of the starter motor 1 will be described.
The terminal bolt 52 is electrically connected to the pigtail 77 via an intermediate member 60. Therefore, when a voltage is applied to the terminal bolt 52, a current is supplied to the segment 21 of the commutator 16 to which the brush 72 is in sliding contact. Here, since the position of the brush 72 is positioned with high accuracy along the radial direction, the brush 72 is in good sliding contact with the segment 21.

The current supplied to the segment 21 is further supplied to the coil 19. Then, a predetermined magnetic field is formed in the teeth 18 of the armature core 15, and a magnetic attraction force or a repulsive force is generated between this magnetic field and the magnet 8 provided in the motor case 2. This causes the armature 4 to rotate.
Here, since the position of the brush 72 is positioned with high accuracy with respect to the magnet 8, the relationship between the position of the magnetic field formed on the armature core 15 and the position of the magnet 8 becomes good. Therefore, the armature 4 is efficiently rotated.
The rotation of the armature 4 is transmitted to the ring gear of the engine via a pinion gear 17, a one-way clutch (not shown), or the like. This starts the engine.

As described above, in the above-described embodiment, the brush holder 71 is fastened and fixed to the front case 3 by the bolt 101 by using the pedestal 88 formed in the connecting portion 74. Further, the brush holder 71 has a protruding positioning convex portion 84, and when the bolt 101 is tightened, the positioning convex portion 84 is formed on the first contact side surface 30e of the first contact convex portion 30c1 of the front case 3. One side 84a comes into contact with each other. That is, when the brush holder 71 is fastened and fixed to the front case 3, the positioning convex portion 84 of the brush holder 71 always comes into contact with the first contact convex portion 30c1. Therefore, the position of the brush holder 71 with respect to the front case 3 can be stably determined with high accuracy, and the performance of the starter motor 1 can be stably improved.

Further, the brush holder 71 is formed with a position-regulating convex portion 85 projecting on the side opposite to the positioning convex portion 84 with the first contact convex portion 30c1 interposed therebetween. Therefore, when the bolt 101 is loosened to remove the brush holder unit 70 from the front case 3, the position-regulating convex portion 85 comes into contact with the first contact convex portion 30c1 to prevent the brush holder unit 70 from swinging. Therefore, rattling at the time of assembling and removing the brush holder unit 70 (brush holder 71) can be suppressed as much as possible.

Further, one of the first contact convex portions 30c1 has a plurality of functions of reinforcing the front case 3, positioning the brush holder unit 70, and preventing swinging when the brush holder unit 70 is removed. .. Therefore, the number of parts to be arranged in the front case 3 can be reduced. Therefore, the material cost of the front case 3 can be reduced, and the front case 3 and the brush holder unit 70 (brush holder 71) can be miniaturized.

Further, the first contact side surface 30e of the first contact convex portion 30c1 of the front case 3 faces the linear straight line L4 in the radial direction passing through the rotation axis L1 and the axial direction. Further, the positioning convex portion 84 of the brush holder 71 is formed so that one side 84a faces a straight line L5 that passes along the axial direction and passes through the circumferential center of the brush 72 (second opening 81b). Therefore, when the brush holder unit 70 is fastened and fixed to the front case 3 while one side 84a of the positioning convex portion 84 is still in contact with the first contact side surface 30e of the first contact convex portion 30c1, the first contact convex portion 30c1 is fixed. 1 The center of the brush 72 housed in the holder body 81 in the circumferential direction coincides with the linear straight line L4 in the radial direction passing through the rotation axis L1. That is, the direction of the brush 72 is along the radial direction, and the brush 72 can be positioned with high accuracy. As a result, the contact state of the brush 72 with the segment 21 of the commutator 16 is improved, and the life of the brush 72 can be extended.

Further, the brush holder 71 is formed with the positioning protrusion 83 protruding, while the in-row portion 2c of the motor case 2 is formed with the notch portion 2b. Then, when the motor case 2 and the front case 3 are assembled, the tongue piece portion 83b of the positioning protrusion 83 is fitted into the notch portion 2b of the motor case 2, so that the motor case 2 and the front case 3 are in the circumferential direction. Not only the positioning is performed, but also the positioning of the motor case 2 and the brush holder 71 (brush holder unit 70) in the circumferential direction is performed.

Therefore, the position of the brush holder 71 with respect to the motor case 2 can be determined with high accuracy. That is, the brush holder 71 can be positioned and the magnet 8 can be positioned with reference to the motor case 2. Therefore, it becomes easy to determine the relative position between the brush 72 and the magnet 8 held in the brush holder 71 with high accuracy, and the performance of the starter motor 1 can be improved.
Further, when the brush holder 71 and the motor case 2 are unevenly fitted, the brush holder 71 is made convex (positioning protrusion 83). Therefore, the convex shape can be easily formed as compared with the case where the convex shape is formed on the motor case 2 side. By this amount, the manufacturing cost of the starter motor 1 can be reduced.

Further, the brush holder 71 includes two holder bodies 81, 82 (first holder body 81, second holder body 82) for holding the brush 72, and two holder bodies 81, straddling these two holder bodies 81, 82. It is said that the connecting portion 74 connecting the 82 and the connecting portion 74 are integrally molded. The connecting portion 74 extends in an arc shape along the outer peripheral surface of the bearing portion 22 (commitator 16). In other words, the connecting portion 74 extends in an arc shape along the inner peripheral surface of the peripheral wall 3b of the front case 3. In this way, the connecting portion 74 can be arranged in the minimum space without creating a dead space. Therefore, while integrating the two brushes 72 by the brush holder 71, the space occupied by the brush holder 71 can be minimized to improve the layout of each component. As a result, the starter motor 1 can also be miniaturized.

Further, in the brush holder 71, the inner peripheral wall portion 87 of the connecting portion 74 connecting the two holder bodies 81 and 82 is formed so as to straddle between the radial inner ends of the two holder bodies 81 and 82. Therefore, the peripheral length of the inner peripheral wall portion 87 can be set as short as possible. Therefore, the material cost of the brush holder 71 can be reduced.
Further, the strength of the inner peripheral wall portion 87 is ensured, and the force acting on the brush holder 71 can prevent the inner peripheral wall portion 87 from being deformed. That is, for example, when the inner peripheral wall portion 87 is formed so as to straddle between the radial outer ends of the two holder bodies 81 and 82, the inner peripheral wall portion 87 is the radial inner end of the two holder bodies 81 and 82. The circumference is longer than when straddling the space. When the inner peripheral wall portion 87 becomes long, the strength is weakened by this amount, and it becomes easy to be affected by the force acting on the brush holder 71. Therefore, the strength of the inner peripheral wall portion 87 can be increased by setting the peripheral length of the inner peripheral wall portion 87 as short as possible.

Further, when positioning the motor case 2 and the brush holder 71 (brush holder unit 70) in the circumferential direction, the first positioning protrusion 83 fitted into the notch 2b of the motor case 2 is placed on the first holder main body 81. It is formed at the radial outer end of the wall 75.
Here, the distance between the radial outer end of the first holder main body 81 and the peripheral wall 3b of the front case 3 is shorter than the distance between the connecting portion 74 and the peripheral wall 3b of the front case 3. Therefore, by providing the positioning protrusion 83 at the radial outer end of the first holder main body 81, the extending length of the positioning protrusion 83 in the radial direction is increased as compared with the case where the first positioning protrusion 83 is provided on the connecting portion 74. The extending length of the tongue piece 83b) can be set short. Therefore, the material cost of the brush holder 71 can be reduced.

Further, the circumferential center L6 of the positioning protrusion 83 formed on the upper wall 75 of the first holder main body 81 passes along the axial direction and passes through the circumferential center of the first holder main body 81 (second opening 81b). It is located on the straight line L5 (see FIG. 10). Further, the positioning convex portion 84 formed on the edge of the first opening 81a of the first holder main body 81 is formed so that one side 84a faces the straight line L5. Therefore, by visually recognizing the position of the positioning protrusion 83, the operator can recognize the approximate positions of the positioning convex portion 84 and the position restricting convex portion 85, which are blind spots. Therefore, the operator can easily place the brush holder unit 70 so that the first contact convex portion 30c1 is inserted between the positioning convex portion 84 and the position restricting convex portion 85 of the brush holder 71. Can be done.

Further, the terminal 64 includes a terminal insulator 55 for holding the substantially square head 54 of the terminal bolt 52 at a position corresponding to the terminal seat 50 formed on the peripheral wall 3b of the front case 3, and the terminal insulator 55. An intermediate member 60 interposed between the head 54 and the head 54 is provided. Further, the bottom side 57a of the substantially square frame portion 57 is brought into contact with the recess 28 of the front case 3, and the lower side wall portion 62b of the intermediate member 60 is interposed between the bottom side 57a and the head 54. I'm dressed up.

Therefore, when the nut 59 is tightened to the shaft portion 53 of the terminal bolt 52, the front case 3 receives the load that the terminal bolt 52 (head 54) tries to rotate together with the bottom 57a of the frame portion 57, and the terminal. It is possible to prevent the bolt 52 from rotating together with the nut 59. At this time, the load from the head 54 of the terminal bolt 52 is positively applied to the bottom 57a of the frame portion 57. However, this load can be absorbed by the intermediate member 60, which is harder than the terminal insulator 55 and softer than the terminal bolt 52. Therefore, it is possible to prevent the terminal insulator 55 from being deformed or damaged, and it is possible to ensure the insulation between the front case 3 and the terminal bolt 52 (head 54).

The head 54 of the terminal bolt 52 housed in the terminal insulator 55 satisfies the above conditions (A), (B), and (C). That is, the head 54 is in contact with the frame portion 57 only at the bottom 57a. Therefore, when the head 54 tries to rotate, the pressing force of the head 54 can be positively applied to the bottom 57a of the frame portion 57. On the other hand, it is possible to prevent the pressing force of the head 54 from being applied to the other sides (upper side 57b and side 57c) of the frame portion 57.

That is, the load from the head 54 can be reliably applied to the bottom 57a of the frame portion 57 in contact with the recess 28 of the front case 3, and this load can be reliably received by the front case 3. As a result, the front case 3 can surely suppress the deformation of the base 57a of the frame portion 57, and can prevent the terminal insulator 55 from being damaged. Further, it is possible to surely prevent the head 54 from rotating, and the nut 59 can be firmly tightened to the shaft portion 53 of the terminal bolt 52.

Instead of receiving the load applied to the terminal insulator 55 in the recess 28 of the front case 3, it is also possible to provide a separate receiving plate in the front case 3 and receive the load applied to the terminal insulator 55 by this receiving plate. In this case, the receiving plate and the frame portion 57 of the terminal insulator 55 are positively brought into contact with each other.
However, as in the above-described embodiment, by bringing the bottom side 57a of the terminal insulator 55 into contact with the recess 28 of the front case 3, it is not necessary to separately provide a receiving plate on the front case 3. Therefore, the number of parts of the starter motor 1 can be reduced, or the material cost of the front case 3 can be reduced. Further, since it is not necessary to separately provide a receiving plate, the front case 3 can be miniaturized.

Further, a pigtail connecting portion 63 for connecting the pigtail 77 is bent and extended along the axial direction on the upper side wall portion 62a of the two side wall portions 62a and 62b of the intermediate member 60. Therefore, it is not necessary to directly connect the pigtail 77 to the head 54 of the terminal bolt 52. That is, the pigtail 77 and the head 54 of the terminal bolt 52 can be electrically connected via the pigtail connecting portion 63 and the intermediate member 60. As a result, the degree of freedom in the wiring layout of the pigtail 77 can be increased. For example, the distance between the brush 72 and the pigtail connecting portion 63 can be set as short as possible, and the length of the pigtail 77 can also be set short. In such a case, the wire rod cost of the pigtail 77 can be reduced.

Further, the pigtail connecting portion 63 (intermediate member 60) is made of a brass plate material. Further, the pigtail 77 is also made of copper wire. That is, the specific heat of the pigtail connecting portion 63 and the specific heat of the pigtail 77 can be set to be substantially the same. Therefore, when the pigtail 77 is connected to the pigtail connecting portion 63 by, for example, brazing welding, the welding operation can be easily performed.

The present invention is not limited to the above-described embodiment, and includes various modifications of the above-described embodiment without departing from the spirit of the present invention.
For example, a case where a structure like the above-described embodiment is adopted for the starter motor 1 for two wheels has been described. However, the present invention is not limited to this, and a configuration as in the above-described embodiment can be adopted for motors and generators having various specifications.

Further, the case where the motor case 2 is formed by, for example, deep drawing an iron plate has been described. Further, the case where the front case 3 is formed by, for example, aluminum die casting has been described. Further, the case where the bracket 5 is formed of a metal plate such as iron has been described. However, the material of the motor case 2, the front case 3, and the bracket 5 is not limited to these, and various materials can be selected.

Further, in the above-described embodiment, the case where the positioning protrusion 83 is projected from the brush holder 71, the notch portion 2b is formed in the motor case 2, and the positioning protrusion 83 is fitted into the notch portion 2b has been described. However, the present invention is not limited to this, and the motor case 2 may be provided with a protrusion, while the brush holder 71 may be formed with a recess so that the protrusion of the motor case 2 is fitted into the recess.

Further, in the above-described embodiment, the brush holder 71 straddles the two holder main bodies 81, 82 (first holder main body 81, second holder main body 82) and these two holder main bodies 81, 82, and the two holder main bodies 81. A case where the connecting portion 74 connecting the, 82 and the connecting portion 74 are integrally molded has been described. However, the present invention is not limited to this, and two or more holder bodies 81 and 82 for holding the brush 72 may be provided according to the motor specifications.
Further, in the above-described embodiment, the case where the connecting portion 74 of the brush holder 71 extends in an arc shape along the inner peripheral surface of the peripheral wall 3b of the front case 3 has been described. However, the present invention is not limited to this, and various shapes can be adopted depending on the layout of the brush holder 71, the arrangement of other parts, and the like.

Further, in the above-described embodiment, one of the first contact convex portions 30c1 of the front case 3 is used to reinforce the front case 3, position the brush holder unit 70, and prevent runout when the brush holder unit 70 is removed. I explained the case where it has multiple functions such as. However, the present invention is not limited to this, and the front case 3 has a convex portion that abuts on one side 84a of the positioning convex portion 84 when tightening the bolt 101 and a convex portion that abuts on the position regulating convex portion 85 when loosening the bolt 101. The unit and the unit may be provided separately. Further, only the function of any one of these convex portions may be provided to the first contact convex portion 30c1.
When the front case 3 is provided with a convex portion that comes into contact with one side 84a of the positioning convex portion 84 when the bolt 101 is tightened separately from the first contact convex portion 30c1, it is desirable to configure the front case 3 as follows. That is, it is desirable that the contact surface of the convex portion with one side 84a of the positioning convex portion 84 faces the linear straight line L4 in the radial direction passing through the rotation axis L1 and the axial direction.

Further, in the above-described embodiment, the case where the intermediate member 60 of the terminal 64 is formed by pressing a brass plate material has been described. However, the present invention is not limited to this, and the intermediate member 60 may be formed of a conductive material. As a result, the intermediate member 60 is deformed by receiving the load of the head 54 of the terminal bolt 52, so that the load of the head 54 can be absorbed by the intermediate member 60.

Further, in the above-described embodiment, the intermediate member 60 bends and extends from the base portion 61 and both ends in the lateral direction (both ends in the axial direction) of the base portion 61 along the inner side surface of the frame portion 57. , 62b (upper side wall portion 62a, lower side wall portion 62b) and the case where the cross section is formed in a substantially U-shape have been described. However, the present invention is not limited to this, and an intermediate member 60 is provided between at least the bottom 57a of the frame portion 57, that is, the bottom 57a that is in contact with the recess 28 of the front case 3 and the head 54 of the terminal bolt 52. It suffices if it is intervened. Further, the intermediate member 60 may have side wall portions 62a and 62b formed on the entire circumference of the outer peripheral edge of the base portion 61.

Further, in the above-described embodiment, the case where the frame portion 57 of the terminal insulator 55 is brought into contact with the recess 28 of the front case 3 has been described. Then, the case where the load applied to the terminal insulator 55 is received by the recess 28 of the front case 3 has been described. However, the present invention is not limited to this, and the front case 3 may be separately provided with a receiving plate that receives the load applied to the terminal insulator 55. In this case, the receiving plate and the frame portion 57 of the terminal insulator 55 are positively brought into contact with each other.

Further, in the above-described embodiment, the case where the head 54 of the terminal bolt 52 and the frame portion 57 of the terminal insulator 55 holding the head 54 are formed in a substantially square shape has been described. However, the present invention is not limited to this, and the head 54 and the frame portion 57 may be formed in a polygonal shape. For example, it may be formed in a rectangular shape long in the circumferential direction.
Further, in the above-described embodiment, the case where the pigtail connecting portion 63 is bent and extended along the axial direction on the upper side wall portion 62a of the two side wall portions 62a and 62b of the intermediate member 60 has been described. However, as long as the pigtail connecting portion 63 is formed on the intermediate member 60, its shape and forming portion are not particularly limited.

Further, in the above-described embodiment, the connecting portion 74 constituting the brush holder 71 is a base portion 86 straddling between the ends of the two holder bodies 81 and 82 on the front case 3 side and the two holder bodies 81 and 82. The case where it is composed of the inner peripheral wall portion 87 straddling between the inner ends in the radial direction has been described. However, the present invention is not limited to this, and the connecting portion 74 may have at least an inner peripheral wall portion 87. In this case, the pedestal 88 may be formed so as to protrude from the connecting portion 74.

1 ... Starter motor (rotary machine)
2 ... Motor case 2a ... Opening 3 ... Front case (end case)
4 ... Armature 6 ... Yoke part 8 ... Magnet 16 ... Commitator 30 ... Rib 30c 1 ... First contact convex part (first positioning convex part, third convex part)
30e ... First contact surface (contact surface)
70 ... Brush holder unit 71 ... Brush holder 72 ... Brush 84 ... Positioning convex portion (second positioning convex portion)
84a ... One side (contact surface)
85 ... Position regulation convex part (fourth convex part)
101 ... Bolt L1 ... Rotation axis L4 ... Straight line (straight line in the radial direction)
L5 ... Straight line

Claims (4)

A motor case having a tubular yoke portion and a magnet provided in the yoke portion,
An end case provided so as to close the opening of the motor case and having a first positioning protrusion, and an end case.
An armature rotatably supported by the motor case and the end case and having a commutator,
A plurality of brushes that are slidably contacted with the commutator,
A brush holder that holds the plurality of brushes freely toward the commutator and has a second positioning protrusion.
With
The brush holder is fastened and fixed to the end case by one bolt.
The second positioning projections, the rotary electric machine, characterized in that it is arranged to abut with said first positioning projection toward the rotational direction of the Rutoki tightening the bolt. The end case has a third convex portion, while the brush holder has a fourth convex portion.
The fourth convex portions, the rotating electric machine according to claim 1, characterized in that it is arranged to abut with the third convex portion toward the direction of rotation of Rutoki loosening the bolts. The rotary electric machine according to claim 2, wherein the first positioning convex portion has a function of the third convex portion. The first positioning convex portion is a rib provided on the end case, and the contact surface of the rib with the second positioning convex portion is a radial straight line passing through the rotation axis of the armature and an axial direction. It is formed to face the
The contact surface of the second positioning convex portion with the first positioning convex portion is formed so as to face a straight line passing along the axial direction and the center of the circumferential direction of the brush to be held. The rotary electric machine according to any one of claims 1 to 3.

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