JP2007089254A - Dynamo-electric machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a starter for easily correcting a dynamic balance in a commutator 28 and suppressing a degradation in a performance due to a balance adjustment. <P>SOLUTION: A connection 28b is integrally provided in a commutator piece 28a for forming the commutator 28, and radially and outwardly raised at an end on the iron core side in the axial direction. A commutator coil 26 is connected to the connection 28b. The balance adjustment of an armature 11 is implemented by partially removing the connection 28b provided in the predetermined commutator piece 28a. An end face of the connection 28b on the opposite iron core side in the axial direction is cut by a cutter. The dynamic balance is corrected by reducing the mass of the predetermined connection 28b by the quantity of the previous measured balance. Since it is unnecessary to cut an armature iron core 25 for forming a magnetic path of the armature 11, the performance of the starter is prevented from being degraded. Since the connection 28b with a large outside diameter is partially removed, the dynamic balance can be corrected by a small quantity of cutting. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a rotating electrical machine having a commutator on one end side of an armature shaft.

Conventionally, for example, Patent Document 1 is known as a known technique related to armature balance adjustment. This Patent Document 1 discloses a method of adjusting the balance by applying an appropriate amount of cutting to the outer periphery of the tooth portion of the armature core with a drill or the like.
JP 54-119601 A

As an unbalance factor generated in the armature, the unbalance of the commutator itself has a great influence as well as the weight deviation due to the eccentricity of the armature shaft and the uneven distribution of the armature winding. In particular, since the commutator is disposed at the end of the armature shaft, the commutator unbalance appears as a deterioration in dynamic balance that represents an unbalance of the position biased with respect to the position of the center of gravity of the armature longitudinal section.
However, it is difficult to correct the dynamic balance on the commutator side by the known technique disclosed in Patent Document 1, that is, the method of adjusting the balance by cutting the outer periphery of the tooth portion of the armature core. This is because the armature core is arranged at the center of the armature shaft, so even if a part of the armature core close to the center of gravity of the armature is removed, the motion on the commutator side far from the center of gravity of the armature is removed. This is because the effect of correcting the balance is small.

Further, if a part of the armature core is cut for balance adjustment, the magnetic path cross-sectional area is reduced by that amount, which may affect the motor performance and cause a decrease in performance.
The present invention has been made based on the above circumstances, and an object of the present invention is to provide a rotating electrical machine that can easily correct the dynamic balance on the commutator side and suppress performance degradation due to balance adjustment.

(Invention of Claim 1)
A rotating electrical machine having a commutator on one end side of an armature shaft, the commutator having a plurality of commutator pieces arranged at equal intervals around the armature shaft via a mold resin. A connection portion to which an armature coil is connected is provided at one end portion, and a part of the connection portion is removed in the axial direction in order to correct the dynamic balance of the armature.
According to the present invention, since the balance adjustment is performed by removing a part of the connecting portion provided at the end of the commutator piece, it is easy to correct the dynamic balance on the commutator side. Moreover, since a part (connection part) of the commutator piece formed of a metal material (for example, copper) having a large specific gravity is removed, the balance can be adjusted with a small removal amount.

Furthermore, since the commutator piece itself is not cut and a part of the connecting portion provided at the end of the commutator piece is removed, the dynamic balance can be corrected without affecting the commutation performance.
Moreover, since it is not necessary to cut off the armature core that forms the magnetic path of the armature as in the known technique disclosed in Patent Document 1, the magnetic path cross-sectional area of the armature core does not decrease. The performance of the rotating electrical machine is not degraded.

(Invention of Claim 2)
In the rotating electrical machine according to claim 1, when the outer diameter of the armature core around which the armature coil is wound is D1, and the outer diameter of the connecting portion is D2,
D1-D2 ≦ 10mm ……………… (1)
The relationship (1) is established.
In this case, since a part of the connection portion having an outer diameter substantially the same as the outer diameter of the armature core is removed, the dynamic balance can be corrected with a small amount of cutting.

(Invention of Claim 3)
The rotating electric machine according to claim 2, wherein the plurality of commutator pieces are arranged in a cylindrical shape around the armature shaft, and are formed on a cylindrical outer peripheral surface (referred to as a commutator surface) formed by each commutator piece. The brush is disposed in contact, the connecting portion is provided at an end portion on the axial iron core side of the commutator piece, provided to protrude radially outward from the outer diameter of the commutator surface on which the brush is disposed, and A part of the end surface on the side opposite to the axial direction is removed.
The present invention can be applied to a cylindrical commutator configured by arranging a plurality of commutator pieces in a cylindrical shape around an armature shaft. In this cylindrical commutator, since the connecting part provided at the end of the commutator piece on the axial core side protrudes radially outward from the outer diameter of the commutator surface, it is connected at a location having a larger diameter than the commutator surface. A part of the portion can be removed, and the balance can be adjusted with a small amount of cutting.

(Invention of Claim 4)
The rotating electrical machine according to claim 2, wherein the plurality of commutator pieces are arranged in a disc shape orthogonal to the armature axis, and are formed as disc-shaped end faces (referred to as commutator surfaces). ) Is disposed in contact with the brush from the axial direction, and the connection portion is provided at an end portion on the radially outer side of the contact portion where the brush contacts the commutator surface, and the end surface on the side opposite to the axial direction is partially provided. It has been removed.
The present invention can be applied to a surface type commutator configured by arranging a plurality of commutator pieces in a disc shape orthogonal to the armature axis. In this surface-type commutator, each commutator piece is arranged orthogonal to the armature shaft, and therefore a connecting portion can be provided at the radially outer end of the commutator piece. Accordingly, since a part of the connecting portion can be removed at a portion having a large diameter, the balance can be adjusted with a small amount of cutting.

(Invention of Claim 5)
The rotating electrical machine according to any one of claims 1 to 4, wherein the connection portion is removed by a processing machine.
Since a part of the connecting portion is removed by the processing machine, it can be removed easily and easily.

(Invention of Claim 6)
The rotating electric machine according to any one of claims 1 to 5, wherein the armature is a rotor of a planetary reduction starter.
Since the planetary reduction starter has a higher rotational speed of the rotor than a starter having no internal speed reducer, a rotor suitable for high speed rotation can be provided by performing the balance adjustment of the present invention.

  The best mode for carrying out the present invention will be described in detail with reference to the following examples.

FIG. 1 is a half sectional view of an armature, and FIG. 3 is a half sectional view of a starter to which a rotating electrical machine of the present invention is applied.
The rotating electrical machine of the present invention is applied to, for example, a starter 1 that starts an automobile engine. First, the configuration of the starter 1 will be briefly described with reference to FIG.
The starter 1 includes a motor 2 that generates a rotational force, a speed reducer 3 that decelerates the rotation of the motor 2, an output shaft 4 that is driven by the motor 2 via the speed reducer 3, and an outer periphery of the output shaft 4. And a pinion gear 6 disposed integrally with the clutch 5 and a function of pushing the clutch 5 and the pinion gear 6 in the counter-motor direction (left direction in FIG. 3) via the shift lever 7 and a main circuit connected to the motor circuit. It comprises an electromagnetic switch 8 and the like for opening and closing a contact (described later).

The motor 2 includes a field configured by arranging a plurality of permanent magnets 10 on the inner periphery of the yoke 9 and an armature 11 rotatably disposed on the inner periphery of the field. This is a known DC motor that generates a rotational force on the armature 11 by an electromagnetic force acting between the armature 11 and the armature 11. The balance adjustment (dynamic balance correction) of the armature 11 according to the present invention will be described later.
The reduction gear 3 includes a sun gear 3a formed on a rotating shaft (referred to as an armature shaft 12) of the armature 11, an internal gear 3b whose rotation is restricted via an impact absorbing device (described below), This is a well-known planetary gear reduction device constituted by a planetary gear 3c meshing with both gears 3a and 3b.

The impact absorbing device is configured by disposing an elastic body (not shown) such as rubber between the center case 13 and the internal gear 3b. When an excessive torque is applied to the internal gear 3b at the time of starting the engine, the center case When the elastic body bends (compresses) in the circumferential direction between the internal gear 13b and the internal gear 3b, the internal gear 3b is allowed to rotate and absorbs excessive torque applied to the internal gear 3b.
The center case 13 is inserted into the inner periphery of the opening of the front housing 14 to which the motor 2 and the electromagnetic switch 8 are fixed, and the rotation of the center case 13 is restricted with respect to the front housing 14.
The output shaft 4 is arranged coaxially with the armature shaft 12, one end side is connected to the speed reduction device 3, and the other end portion is rotatably supported by the front housing 14 via a bearing 15.

The clutch 5 is fitted to a helical spline 4a formed on the output shaft 4 so as to be movable on the output shaft 4. The clutch 5 transmits the rotation of the output shaft 4 to the pinion gear 6 when the engine is started, and the pinion gear 6 is connected to the engine. As a one-way clutch that cuts off the power transmission between the two so that the rotation of the pinion gear 6 is not transmitted to the output shaft 4 when the rotation speed of the pinion gear 6 exceeds the rotation speed of the output shaft 4. It is configured.
The pinion gear 6 is disposed on the non-motor side of the clutch 5, moves in the anti-motor direction on the output shaft 4 together with the clutch 5, meshes with the ring gear 16 of the engine, and then is transmitted through the clutch 5. The force is transmitted to the ring gear 16.

The electromagnetic switch 8 includes an exciting coil 17 energized from a battery and a plunger 18 that moves inside the exciting coil 17. When an electromagnet is formed by energizing the exciting coil 17, the plunger 18 is moved to the electromagnet. The main contact is closed by suction. When the energization of the exciting coil 17 is stopped and the attractive force of the electromagnet disappears, the plunger 18 is pushed back by the reaction force of the return spring 19 to open the main contact.
The main contact includes a set of fixed contacts 22 connected to the motor circuit via the two external terminals 20 and 21 and a movable contact 23 movable in conjunction with the movement of the plunger 18 (or integrally with the plunger 18). The movable contact 23 comes into contact with a set of fixed contacts 22 and is brought into a closed state when the fixed contacts 22 are brought into conduction. The movable contact 23 is opened when the set of fixed contacts 22 is separated. It becomes a state.

  The shift lever 7 has a lever fulcrum portion 7a that is rotatably supported by the lever holder 24. A lever end 7b on one end side of the lever fulcrum portion 7a is connected to the plunger 18 of the electromagnetic switch 8, and the lever fulcrum The lever end 7 c on the other end side from the portion 7 a is engaged with the clutch 5, and the movement of the plunger 18 is transmitted to the clutch 5. That is, when the plunger 18 is attracted by the electromagnet and moves to the right in FIG. 3, the lever end 7 b connected to the plunger 18 is pulled and moved by the plunger 18, thereby engaging the clutch 5. 7c swings around the lever fulcrum portion 7a to push the clutch 5 in the direction opposite to the motor.

Subsequently, the operation of the starter 1 will be described.
When an electromagnet is formed by energizing the excitation coil 17 of the electromagnetic switch 8 by closing the start switch (not shown), the plunger 18 is attracted to the electromagnet and moves to the right in FIG. When the movement of the plunger 18 is transmitted to the clutch 5 via the shift lever 7, the clutch 5 moves integrally with the pinion gear 6 on the output shaft 4 in the counter-motor direction, and the end surface of the pinion gear 6 becomes the end surface of the ring gear 16. Stops in contact with.

  On the other hand, when the main contact of the motor 2 is closed by the movement of the plunger 18, power is supplied from the battery to the motor 2, and a rotational force is generated in the armature 11 by receiving an electromagnetic force generated in the field. When the rotation of the armature 11 is decelerated by the reduction gear 3 and transmitted to the output shaft 4 and further transmitted from the output shaft 4 to the pinion gear 6 via the clutch 5, the position where the pinion gear 6 can mesh with the ring gear 16. Rotational force is transmitted to the ring gear 16 from the pinion gear 6 and the engine is cranked.

When the engine is completely exploded from the cranking and the start switch is opened, the attraction force of the electromagnet disappears due to the stop of energization to the exciting coil 17, so that the plunger 18 is pushed back by the reaction force of the return spring 19. As a result, when the movable contact 23 is separated from the set of fixed contacts 22 and the main contact of the motor 2 is opened, energization from the battery to the motor 2 is stopped, and the rotation of the armature 11 is stopped.
Further, when the plunger 18 is pushed back, the shift lever 7 swings in the direction opposite to that at the start of the engine. Therefore, the clutch 5 and the pinion gear 6 are moved backward on the output shaft 4 (moved toward the motor 2), and FIG. It moves to the stop position shown in 3.

Next, the balance adjustment of the armature 11 will be described in detail.
First, the configuration of the armature 11 will be described.
As shown in FIG. 1, the armature 11 includes an armature shaft 12, an armature core 25 that is serrated and fitted to the outer periphery of the armature shaft 12, and an electric machine wound around the armature core 25. A commutator 28 is provided on one end side (the right side in FIG. 1) of the armature shaft 12 via a mold resin 27.

The commutator 28 is formed in a cylindrical shape by arranging a plurality of commutator pieces 28 a supported by the mold resin 27 around the armature shaft 12 at equal intervals. A plurality of carbon brushes 29 are arranged on a cylindrical outer peripheral surface (commutator surface) formed by each commutator piece 28a and pressed against the commutator surface by a brush spring (not shown).
The commutator piece 28 a is made of, for example, copper, which is a good conductor, and is insulated from the other commutator pieces 28 a adjacent in the circumferential direction by the mold resin 27. The commutator piece 28a is integrally provided with a connecting portion 28b that rises radially outward at the end on the axial iron core side (left side in FIG. 1), and the armature coil 26 is electrically and mechanically connected to the connecting portion 28b. It is connected to the.

When the outer diameter of the armature core 25 is D1, and the outer diameter of the connecting portion 28b is D2,
D1-D2 ≦ 10mm ……………… (1)
The above relationship (1) is established. In other words, the outer diameter D2 of the connecting portion 28b is substantially the same as the outer diameter D1 of the armature core 25, and the dimensional difference between them is 10 mm or less.
For example, as shown in FIG. 2, the balance adjustment of the armature 11 is performed by removing a part of the connection portion 28b provided in a predetermined commutator piece 28a (see FIG. 1). Specifically, the axially opposite iron core side end face of the connecting portion 28b is scraped off with a cutter 30 (see FIG. 2), etc., and the mass of the predetermined connecting portion 28b is reduced by a previously measured balance amount, thereby achieving dynamic balance. Correct it.

(Effect of Example 1)
The balance adjustment described above is performed by removing a part of the connecting portion 28b provided on the commutator piece 28a. Therefore, when compared with the conventional balance adjustment method of removing a part of the armature core 25, the commutator. The 28 side dynamic balance can be easily corrected. The commutator piece 28 a having the connection portion 28 b is formed of a metal material (for example, copper) having a large specific gravity, and a part of the connection portion 28 b having an outer diameter D 2 that is substantially the same as the outer diameter D 1 of the armature core 25. Since it is removed, the dynamic balance can be corrected with a small amount of cutting.

Furthermore, since the commutator piece 28a itself is not shaved but a part of the connecting portion 28b provided at the end of the commutator piece 28a is removed, the commutator 28 side operation is not affected without affecting the commutation performance. The balance can be corrected.
Further, since it is not necessary to cut the armature core 25 that forms the magnetic path of the armature 11, the magnetic path cross-sectional area of the armature core 25 is not reduced, and the performance of the starter 1 is not deteriorated.

(Modification)
The armature 11 described in the first embodiment includes a cylindrical commutator 28 configured by arranging a plurality of commutator pieces 28 a in a cylindrical shape around the armature shaft 12. The present invention can also be applied to a surface-type commutator configured by arranging the commutator pieces 28a in a disk shape orthogonal to the armature shaft 12. In this surface type commutator, the individual commutator pieces 28a are arranged orthogonal to the armature shaft 12, and therefore the connecting portion 28b can be provided at the radially outer end of the commutator piece 28a. Accordingly, since a part of the connection portion 28b can be removed at a location having a large diameter, the balance can be adjusted with a small amount of cutting.

It is a half sectional view of an armature. It is the axial front view which looked at the armature from the commutator side. It is a half sectional view of a planetary deceleration type starter.

Explanation of symbols

1 Planetary reduction starter (rotary electric machine)
11 Armature (rotor)
DESCRIPTION OF SYMBOLS 12 Armature shaft 25 Armature core 26 Armature coil 27 Mold resin 28 Commutator 28a Commutator piece 28b Connection part 29 Brush 30 Cutter (processing machine)

Claims (6)

A rotating electric machine including a commutator on one end side of an armature shaft,
The commutator has a plurality of commutator pieces arranged at equal intervals around the armature shaft via a mold resin, and a connecting portion to which an armature coil is connected to an end of the commutator piece. A rotating electric machine characterized in that a part of the connecting portion is removed in the axial direction in order to correct the dynamic balance of the armature. In the rotating electrical machine according to claim 1,
When the outer diameter of the armature core around which the armature coil is wound is D1, and the outer diameter of the connecting portion is D2,
D1-D2 ≦ 10mm ……………… (1)
A rotating electrical machine characterized in that the relationship of (1) above is established. In the rotating electrical machine according to claim 2,
The plurality of commutator pieces are arranged in a cylindrical shape around the armature shaft, and a brush is arranged in contact with a cylindrical outer peripheral surface (referred to as a commutator surface) formed by each commutator piece,
The connecting portion is provided at an end portion on the axial core side of the commutator piece, provided to protrude radially outward from an outer diameter of the commutator surface on which the brush is disposed, and an axial anti-iron core. A rotating electric machine characterized in that a part of the side end face is removed. In the rotating electrical machine according to claim 2,
The plurality of commutator pieces are arranged in a disc shape orthogonal to the armature shaft, and a brush is applied to a disc-shaped end surface (referred to as a commutator surface) formed by each commutator piece from the axial direction. The connecting portion is provided at an end portion on a radially outer side than a contact portion where the brush contacts the commutator surface, and a portion of the end surface on the axial antiferromagnetic core side is partially removed. Rotating electric machine. In any one of the rotating electrical machines according to claims 1 to 4,
The rotating electrical machine is characterized in that the removal of the connecting portion is removal processing by a processing machine. In any one of the rotating electrical machines according to claims 1 to 5,
The rotary electric machine is characterized in that the armature is a rotor of a planetary reduction starter.

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