JP4568075B2 - Small motor with brush - Google Patents

Description

  The present invention relates to a small motor with a brush provided with an overvoltage suppressing element such as a varistor, and more particularly to an improvement in the mounting structure of the overvoltage suppressing element and the commutator.

  As shown in FIG. 5, for example, a conventional small three-phase motor with a brush is supported by a motor shaft 1 and has an armature core 3 having a three-phase winding coil 2 at a salient pole portion, and is supported by the motor shaft 1. A commutator 4 adjacent to one side of the armature core 3 in the axial direction and electrically connected to the winding coil 2; a brush piece 6 supported on the motor case 5 side and in sliding contact with the commutator 4; A permanent magnet 7 fixed to the inner peripheral surface of the motor case 5 is provided. This small three-phase motor has a two-pole / three salient pole structure. The armature core 3 includes a first insulating bush (insulating core) 8a that covers an end face on one side in the axial direction, and a second insulating bush (insulating core) 8b that covers an end face on the other side in the axial direction. The commutator 4 is formed by assembling three commutator pieces (segments) into a commutator holder 17 press-fitted into the motor shaft 1 and fastening and fixing with a retaining ring 8 such as a washer. Each commutator piece has a radial terminal portion 4b as a riser standing upright from the brush sliding contact portion 4a and integrally oriented in the radial direction. An annular varistor 9 with three electrode portions is fitted on the outer peripheral side of the retaining ring 8 on the radial terminal portion 4b, and each electrode portion is fixed to the radial terminal portion 4b itself by soldering and conductively connected. A part of the winding coil 2 is tangled to the distal end side of the radial terminal portion 4b and soldered. Reference numeral 10 denotes a brush terminal for supplying power to the brush piece 6.

  As described above, in the brushed motor having the commutator 4 having the radial terminal portion 4b as the riser, the annular varistor 9 is mounted on the outer peripheral side of the retaining ring 8 on the radial terminal portion 4b. In this structure, a part of the winding coil 2 is connected to the tip side of the portion 4b.

  (1) Since the winding coil 2 is wound around the salient pole part of the armature core 3, the outer peripheral side of the annular varistor 9 or the radial terminal part 4b becomes an obstacle, and the winding part swells greatly in the axial direction. By the time, it is difficult to wind the winding, and there is a problem that the wire product of the winding coil 2 cannot be sufficiently secured by being restricted by the annular varistor 9 or the radial terminal portion 4b itself. For this reason, high torque or flattening (miniaturization) of the motor cannot be achieved.

  (2) Usually, the commutator holder 17 is a glass-containing heat-resistant resin molded product for the purpose of suppressing thermal deformation of the commutator holder 17 due to heat generated during the above-described fixed connection such as soldering. For this reason, since the commutator holder 17 is made of a resin molded product integrated with the first insulating bush 8a and glass-containing heat-resistant resin is used for the purpose of reducing the number of parts, it is hard, so that the winding coil There was also a risk of damaging and peeling off the insulating film 2 and its integration was difficult.

  As a technique for solving such a problem, there is, for example, Japanese Patent Application Laid-Open No. 2004-229438.

  In a motor with a brush according to Japanese Patent Application Laid-Open No. 2004-229438, an armature core 3 supported by a motor shaft 1 and having a winding coil 2 at a salient pole as shown in FIG. A commutator which is adjacent to one side of the armature core 3 in the axial direction and is electrically connected to the winding coil 2; and a brush 6 which is supported on the stator side and slidably contacts the commutator; In such a configuration, in order to limit the mounting position of the annular varistor 19 as close to the motor shaft as possible, an annular varistor 19 supported on the motor shaft 1 and disposed on the other side in the axial direction of the armature core 3; The armature core 3 has a current-carrying body for conducting and connecting the commutator and the annular varistor 19 through the thickness direction of the armature core 3 while being electrically insulated.

  Since the annular varistor 19 is disposed not on one side of the armature core 3 that is the same as the commutator, but on the other side of the armature core 3, the annular varistor 19 is independent of the size of the retaining ring 8 of the commutator. The mounting position of 19 can be limited to the vicinity of the motor shaft. For this reason, since the annular varistor 19 and the terminal portion of the commutator do not interfere with the winding coil 2 and can be wound around the salient pole portion so that the winding portion bulges in the axial direction as compared with the conventional case, A sufficient wire product of the winding coil 2 can be secured. Therefore, the motor can be increased in torque or flattened (downsized). Further, since the mounting position of the annular varistor 19 can be limited to the vicinity of the motor shaft, the surface area of the annular varistor 19 itself can be increased, leading to an improvement in the life of the annular varistor 19. In addition to this, since the other side of the armature away from the commutator position of the current-carrying member can be connected to the annular varistor 19 or a part of the winding coil 2, the heat generated during heat fixation such as soldering is generated by the commutator. Therefore, the commutator holder 15 does not need to use a glass-containing resin. Therefore, the commutator holder 15 and the insulating bush 18a are not required to be used. And the number of parts and assembly man-hours can be reduced. Further, since the solder connection of the annular varistor 19 is performed at a position away from the commutator, there is no possibility of the solder adhering to the commutator, and there is no possibility of a commutator short circuit due to the adhesion of the solder. No cleaning is required.

Here, as the above-mentioned electric conductor, the commutator piece constituting the commutator is integrally formed as an axial terminal portion S _3, and this axial terminal portion S ₃ is a step (flight) for the commutator piece. ) Corresponds to a step (stepping portion), not a riser (lifting portion).

In order to pass the axial terminal portion S ₃ in the thickness direction of the armature core 3, a first through hole H ₁ is formed in the non-salient pole portion (near the inner periphery) of the armature core 3, and this first penetration It is inserted through the axial terminal part S ₃ in the hole H _1. In this way, the energizing body protruding to the other side in the axial direction of the armature core 3 is connected to the annular varistor 19.

  Since there is no retaining ring for fixing the commutator on the other side of the armature core 3, the annular varistor 19 can be arranged on the inner peripheral side of the portion projecting to the other side of the current-carrying member, The increase and the diameter reduction of the annular varistor 19 are realized at the same time. The annular varistor 19 is conductively connected to the protruding portion on the outer peripheral surface.

  However, also in this prior art, the projecting portion of the energizing body projecting from the other side in the axial direction of the armature core 3 projects in a direction substantially perpendicular to the projecting direction of the armature core 3. In addition to the possibility that the length of the motor is reduced, the length of the electric coil for connection to a part of the winding coil 2 is difficult to be entangled. Furthermore, there is a problem that an adhesion process is required to securely fix the current-carrying member.

  Therefore, in view of the above-mentioned problems, the object of the present invention is to achieve a further miniaturization, and to improve the tangling of the winding coil to the commutator (electrical conductor) and the fixing to the commutator. Is to provide.

JP 2004-229438 A (Detailed description of the invention)

  In order to solve the above-described problem, in the brushed small motor according to the present invention, a portion extending to the other side of the current conductor for conductively connecting the commutator and the overvoltage suppressing element is bent in a direction away from the motor shaft. It is characterized by that. In addition, a portion of the energizing body that extends to the other side in the axial direction of the armature core is bent in a direction substantially perpendicular to the motor shaft, and its tip protrudes outward from the non-salient pole portion. Good. Further, a radial connecting portion bent in a direction substantially perpendicular to the motor shaft on one side of the armature core in the axial direction of the current-carrying member, and substantially on the motor shaft on the other side of the armature core in the axial direction. A configuration in which the commutator and the armature core are relatively fixed by the portions bent in the vertical direction (radially extending portions) pressing the armature core in opposite directions via the insulating member. You may take it.

  In the small motor with brush according to the present invention, the overvoltage suppressing element is arranged not on one side of the armature core as the commutator, but on the other side of the armature core. In addition, it is possible to limit the mounting position of the overvoltage suppression element closer to the motor shaft, and further promote the flattening (miniaturization) of the motor by bending the current-carrying body on the other side of the armature core. Since the current-carrying body (radially extending portion) extends in substantially the same direction as the protruding direction of the salient pole portion of the armature core, the winding coil can be easily entangled. Further, in the configuration in which the radial coupling portion and the radial extension portion press the armature core in the opposite directions via the insulating member, the commutator and the armature core are relatively fixed. The bonding process that has been necessary in the past to secure the fixing becomes unnecessary.

  Next, embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a longitudinal sectional view showing an embodiment of a small motor with a brush according to the present invention, FIG. 2 is a perspective view showing a state of assembly of the rotor from above, and FIG. 3 is a view of the assembly from below. FIG.

  The small motor with a brush of this example has a two-pole / three salient pole structure, and is supported by the motor shaft 1 and the armature core 3 supported by the motor shaft 1 and having the three-phase winding coil 2 on the salient pole portion 3a. A commutator 14 adjacent to one side of the armature core 3 in the axial direction and electrically connected to the winding coil 2, and a brush piece 6 supported on the motor case 5 side and slidably in contact with the commutator 14. And a permanent magnet 7 fixed to the inner peripheral surface of the motor case 5. The motor shaft 1 is rotatably supported by radial bearings 11 and 12 and a thrust bearing 13.

Commutator 14 consists of three commutator segments (segments) S, each commutator segment S has a brush sliding portion S _1, and the radial connecting portion S ₂ that is cut and raised to, the radial connecting portion S ₂ to consist of axial terminal portion S ₃ Metropolitan bent in a direction opposite to the brush sliding portion S _1. The armature core 3 includes a first insulating bush (insulating core) 18a that covers an end face on one side in the axial direction, and a second insulating bush (insulating core) 18b that covers an end face on the other side in the axial direction.

The first insulating bush 18a integrally has a holder receiving portion R for fitting the resin commutator holder 15. Commutator holder 15 holder receptacle put a cylindrical portion 15a for receiving against the brush sliding portion S ₁ of each commutator segment S in the plane manner, the lower end radial connecting portion S ₂ of the brush sliding portion S ₁ A substantially triangular base 15b for fitting to the portion R is integrally provided. And a positioning portion 15c in the axial direction a terminal portion S ₃ in three corners aspect of the base 15b. The first insulating bush 18a, as shown in FIG. 3, integrally has an insulating sheath A having a second through-hole of H ₂ for inserting the axial terminal portion S _3. The armature core 3 has a first through hole H ₁ for inserting the axial terminal portion S ₃ into a non-salient pole portion (inner peripheral side) outside the shaft through hole H. The second insulating bush 18b integrally has a hook portion F for carrying a relatively small-diameter annular varistor 19. The second insulating bush 18b, as shown in FIG. 2 integrally has an insulating sheath part B having a second through-hole of H ₂ for inserting the axial terminal portion S _3.

Commutator 14 assembled brush sliding portion S ₁ of the three commutator segments S in the cylindrical portion 15a of the commutator holder 15 press-fitted to the motor shaft 1, formed by fastening with fastening ring 8 of the washer, such as those However, each axial terminal portion S ₃ passes through the first through hole H ₁ of the armature core 3 and protrudes to the other side of the armature core 3. The projecting portion is bent in a direction substantially perpendicular to the motor shaft 1 (radially extending portion S ₃ ′), and the tip portion thereof is more than the non-saliency pole portion (inner peripheral side) of the armature core 3. Projects outward. Radial extending section S _{3 'located} toric varistor 19 on the inner circumferential side of the radial extending section S _3' electrode portion of the annular varistor 19 at the root portion of the tip portion of the winding coil 2 one The parts are entangled and conductively connected by soldering or the like (not shown). Reference numeral 10 denotes a brush terminal for supplying power to the brush piece 6.

In this example, since the annular varistor 19 is not adjacent to the brush sliding contact portion S ₁ of the commutator 14 and is disposed on the other side of the armature core 3, the size of the retaining ring 8 of the commutator 14 is large. Nevertheless, the mounting position of the annular varistor 19 can be limited to the vicinity of the motor shaft as the diameter of the annular varistor 19 is reduced. For this reason, the terminal portions of the annular varistor 19 and the commutator 14 do not interfere with the winding coil 2, and the salient pole portion so that the winding portion bulges in the axial direction as compared with the conventional motor shown in FIG. Therefore, the wire product of the winding coil 2 can be sufficiently secured. Therefore, the motor can be increased in torque or flattened (downsized).

Since the bent radial extension portion S ₃ ′ is also bent between the non-salient pole portions, that is, between the salient pole portions 3 a, the radial extension portion S ₃ ′ does not disturb the winding coil 2. The flattening (miniaturization) of the motor can be further promoted by the amount of bending.

Further, since the radially extending portion S ₃ ′ extends in substantially the same direction as the protruding direction of the salient pole portion 3a, the winding coil 2 can be easily entangled.

Furthermore, if the radial connecting portion S ₂ and the radially extending portion S ₃ ′ press the armature core 3 in the opposite directions via the first and second insulating bushes 18 a and 18 b, the commutator 14. Since the armature core 3 and the armature core 3 are relatively fixed, it is not necessary to fix the commutator 14 by adhesion, which is conventionally required.

Since the radially extending portion S ₃ ′ can be connected to the outer peripheral surface electrode of the annular varistor 19 and a part of the winding coil 2, heat generated during heat fixing such as soldering is conducted to the brush sliding portion S ₁ . It becomes difficult to suppress the thermal influence on the resin commutator holder 15. For this reason, since it is not necessary to use the glass-containing resin for the commutator holder 15, the commutator holder 15 and the insulating bush 18a can be integrated, although not shown in the present example. Accordingly, it is possible to reduce the number of parts and the number of assembly steps.

The axial terminal portion S ₃ (radially extending portion S ₃ ′) is integrally formed with the brush sliding contact portion S ₁ with a short radial connecting portion S _{2 on} which the retaining ring 8 can be mounted. For this reason, it is possible to avoid an increase in the number of parts, an increase in the number of connection points, and labor of assembly work.

To ensure the electrical insulation between the axial terminal portion S ₃ and the armature core 3, there is a method to increase the first diameter of the through-hole H ₁ achieve air insulation, correspondingly, the armature This is not preferable because the effective magnetic path cross-sectional area of the core 3 is reduced. The first and second insulating bush 18a, the insulating sheath portion A formed integrally with the 18b, by inserting a B to a first through hole H _1, the axial terminal portion to the second through hole H ₂ to become inserted through the S _3, need not be so large the first diameter of the through hole H _1. Further, since the insulating sheath portions A and B can be formed integrally with the bushes 18a and 18b, the number of parts can be reduced and the ease of assembly can be ensured. As shown in FIG. 1, the insulating sheath portions A and B do not need to be long enough to be in contact with each other.

  Furthermore, since the second insulating bush 18b has the hook portion F for supporting the annular varistor 19, the number of parts does not increase.

  Although the above embodiment shows a brushed motor having a two-pole / three-salient pole structure, the present invention can be applied to a brushed motor having a four-pole / six-salient pole structure, for example.

It is a longitudinal cross-sectional view which shows one Example of the small motor with a brush which concerns on this invention. It is a perspective view which shows the state which looked at the assembly aspect of the rotor of the Example from the top. It is a perspective view which shows the state which looked at the same assembly aspect from the bottom. It is a longitudinal cross-sectional view which shows an example of the conventional small motor with a brush. It is sectional drawing which shows the state which cut through the left half of an example of the other conventional small motor with a brush.

Explanation of symbols

1 ... motor shaft 2 ... winding coils 3 ... armature core 3a ... salient pole portions 4 and 14 ... commutator 4a, S 1 _... brush sliding portion 4b ... radial terminal portion 5 ... motor casing 6 ... brush piece 7 ... permanent Magnet 8 ... retaining ring 8a, 18a ... first insulating bush (insulating core)
8b, 18b ... second insulating bush (insulating core)
9, 19 ... annular varistor 10 ... brush terminals 11, 12 ... radial bearing 13 ... thrust bearings 15, 17 ... commutator holder 15a ... cylindrical portion 15b ... base 15c ... positioning portion A, B ... insulating sheath F ... Hook part H ... Shaft through hole H ₁ ... First through hole H ₂ ... Second through hole R ... Holder receiving part S ... Commutator piece (segment)
S ₂ ... Radial connection part S ₃ ... Axial terminal part S ₃ '... Radial extension part (axial terminal part)

Claims (2)

An armature core supported by the motor shaft, having a winding coil in the salient pole part, and having a through hole in the non-salient pole part;
A commutator that is supported by the motor shaft and adjacent to one side in the axial direction of the armature core, and is electrically connected to the winding coil;
A brush supported on the stator side and in sliding contact with the commutator;
An overvoltage suppression element supported on the motor shaft and disposed on the other side in the axial direction of the armature core;
In the small motor with a brush provided with an energizing body for conductively connecting the commutator and the overvoltage suppressing element, passing through the through hole in an electrically insulated state from the armature core,
The current-carrying body is an axial terminal portion integrally provided with commutator pieces constituting the commutator, and is bent in a direction substantially perpendicular to the motor shaft on one side of the armature core in the axial direction. And having a radially extending portion bent in a direction substantially perpendicular to the motor shaft on the other side in the axial direction of the armature core,
The commutator and the armature core are relatively fixed by the radial connecting portion and the radial extension portion pressing the armature core in opposite directions via an insulating member. A small motor with a brush. 2. The small motor with a brush according to claim 1 , wherein a distal end portion of the radially extending portion protrudes outward from a non-salient pole portion of the armature core.