JP6349793B2 - Commutator and motor with brush using commutator - Google Patents

Description

The present invention relates to a commutator used for a motor with a brush and a motor with a brush provided with the commutator.

Generally, a brushed motor has a coil and a copper commutator. In many cases, copper coils are used for the coils. However, in Japanese Patent No. 4553931, for example, a coil is formed by winding a conductive wire made of aluminum. As a method for joining the coil and the commutator, for example, fusing joining is used.

Japanese Patent No. 4553931

However, when the coil is joined to the commutator by resistance welding, it is difficult to stably perform fusing welding due to the difference in melting point between aluminum and copper. Moreover, since a commutator and a coil are dissimilar metals, electrolytic corrosion is generated at a joint location. In order to prevent the electric corrosion, in the mass production process of the brushed motor, it is necessary to apply resin to a portion where the commutator is joined to the coil. For this reason, there is a problem of an increase in cost and processes in mass production.

Therefore, an object of the present invention is to provide a copper commutator to which a coil made of an aluminum conductive wire is stably welded, and a brushed motor using the commutator.

The commutator in preferable one Embodiment concerning this invention has several segments and a holding body. The plurality of segments extend in the axial direction and are arranged in a ring around the central axis. The holding body is made of an insulating material that holds a plurality of segments. Each of the plurality of segments exposes the electrode surface, which is a section obtained by dividing the cylindrical surface in the circumferential direction, toward the radially outer side. The envelope surfaces of the electrode surfaces of the plurality of segments are the cylindrical surfaces. At least a part of the electrode surface is covered with a good conductor material having a melting point different from that of aluminum. The segment has an electrode surface member made of a good conductor material having an electrode surface and extending in the axial direction. The segment has a connection piece made of aluminum or aluminum alloy. The connecting piece has a rod shape or a bowl shape extending upward in the axial direction. The connecting piece is joined to the electrode surface member. The boundary between the electrode surface member and the connection piece on the surface of the segment is covered with a sealing material.

In a preferred embodiment according to the present invention, at least a part of the boundary is located on the inner surface of the electrode surface member. A portion of the boundary that is not located on the inner surface of the electrode surface member is covered with a sealing material . On the inner side surface of the electrode surface member, a step portion that is in axial contact with the axially lower end of the connection piece is disposed.

In a preferred embodiment according to the present invention, a convex portion extending radially inward is disposed on the inner surface of the electrode surface member. At least one concave portion corresponding to the convex portion is disposed on the outer surface of the holding body. A convex part is arrange | positioned in a recessed part. The dimension in the axial direction of the convex portion gradually increases toward the inner side in the radial direction. In the radial direction, the position of the end of the convex portion is substantially the same as the position of the inner surface of the connection piece.

In a preferred embodiment according to the present invention, the circumferential width of the electrode surface member is wider than the circumferential width of the connection piece.

In a preferred embodiment according to the present invention, the holding body functions as a sealing material , and the sealing material covers the boundary.

The motor has an armature and a rotor. The rotor is rotatably supported by the armature through a bearing mechanism. The rotor has an armature and the above commutator. The armature is composed of a plurality of coils. A shaft is fixed to the commutator. The end of the conducting wire that constitutes the coil is connected to the commutator. The conducting wire is made of aluminum or an aluminum alloy. Conductor wires are fused and fixed to the connection pieces of the plurality of segments.

In a preferred embodiment according to the present invention, a coil made of an aluminum conductor is stably electrically connected to the commutator.

It is sectional drawing of the motor with a brush concerning this invention. It is a top view of the armature concerning the invention in this application. It is a perspective view of the commutator concerning this invention. It is a top view of the commutator concerning this invention. It is sectional drawing of the commutator concerning this invention. It is a perspective view of the segment concerning this invention. It is a front view of the segment concerning this invention. It is the elements on larger scale of the connection piece concerning this invention.

In the present specification, the upper side of FIG. 1 in the direction of the central axis J1 of the motor is simply referred to as “upper side”, and the lower side is simply referred to as “lower side”. Note that the vertical direction does not indicate the positional relationship or direction when incorporated in an actual device. A direction parallel to or approximately parallel to the central axis J1 is referred to as an “axial direction”, a radial direction centered on the central axis J1 is simply referred to as a “radial direction”, and a circumferential direction centered on the central axis J1 is It is simply called “circumferential direction”.

FIG. 1 is a cross-sectional view of a motor with a brush according to a preferred embodiment of the present invention. FIG. 2 is a plan view of an armature in a preferred embodiment according to the present invention.

The brushed motor 1 (hereinafter referred to as motor 1) is a DC motor. The motor 1 has a rotor 11 and an armature 3. The motor 1 further has a housing 2. The rotor 11 is rotatably supported by the armature 3 through a bearing mechanism described later.

As shown in FIG. 1, the housing 2 includes a case 21 and a back cover 22. The case 21 has a substantially cylindrical shape with a lid. The case 21 has a disk part 211 and a cylindrical part 212. The disk part 211 has a substantially disk shape. An upper concave portion 213 that is concave toward the lower side in the axial direction is disposed substantially at the center of the disk portion 211. A through hole 214 penetrating in the axial direction is disposed in the upper recess 213. An upper bearing portion 23 is disposed in the upper recess 213.

The cylindrical portion 212 extends from the radially outer end of the disk portion 211 toward the lower side in the axial direction. In this preferred embodiment, the magnet 24 is substantially annular. The magnet 24 is disposed on the inner surface of the cylindrical portion 212. The magnet 24 is fixed to the inner surface of the cylindrical portion 212 by a method such as adhesive or press fitting.

The magnet 24 may be composed of a plurality of magnets. In this case, the plurality of magnets are disposed on the inner side surface of the cylindrical portion 212 in the circumferential direction.

The back cover 22 is substantially a disc and covers the opening of the case 21. The back cover 22 is fixed to the case 21 by, for example, caulking or welding. A lower recess 221 that protrudes downward in the axial direction is disposed at a substantially center of the back cover 22. A lower bearing portion 25 is disposed in the lower recess 221. In this preferred embodiment, the upper bearing portion 23 and the lower bearing portion 25 are each ball bearings. The upper bearing portion 23 and the lower bearing portion 25 rotatably support a shaft 4 described later. The bearing mechanism includes an upper bearing portion 23 and a lower bearing portion 25.

As the upper bearing portion 23 and the lower bearing portion 25, other types of bearings such as a slide bearing and a fluid dynamic bearing may be used instead of the ball bearing. Further, the upper bearing portion 23 may be a different type of bearing from the lower bearing portion 25.

Furthermore, in this preferred embodiment, the size of the upper bearing portion 23 is larger than the size of the lower bearing portion 25. However, the sizes of the upper bearing portion 23 and the lower bearing portion 25 may be substantially the same. The upper bearing portion 23 may be smaller than the lower bearing portion 25.

As shown in FIGS. 1 and 2, the armature 3 has a core 31 and a coil 32. The core 31 is configured by laminating a plurality of electromagnetic steel plates in the axial direction. The core 31 includes a core back 311 and a plurality of teeth 312. The core back 311 has a substantially annular shape. At least a part of the core back 311 faces the disk portion 211 in the axial direction.

Each tooth 312 has a winding portion 3121 and a tip portion 3122. Winding portion 3121 extends from the outer surface of core back 311 toward the radially outer side. The tip portion 3122 extends from the outer end portion of the winding portion 3121 toward both sides in the circumferential direction. The tip portion 3122 faces the inner surface of the magnet 24 in the radial direction.

A coil 32 is disposed in each winding part 3121 via an insulating member such as an insulator. The coil 32 is configured by winding a conducting wire. A plurality of lead wires 321 are drawn from each coil 32. In this preferred embodiment, the conductor material is made of aluminum or aluminum alloy.

A cylindrical shaft 4 is passed through the through hole 3111 of the core back 311. The shaft 4 is fixed to the inner side surface of the through hole 3111 by, for example, press fitting or adhesion. That is, the shaft 4 is fixed to the armature 3. The lower end of the shaft 4 is disposed in the lower recess 221. The lower end of the shaft 4 is rotatably supported by the lower bearing portion 25. The upper end of the shaft 4 passes through the through hole 214 of the disk portion 211 and protrudes upward in the axial direction from the disk portion 211. For example, an impeller having a plurality of blades is attached to the upper end portion of the shaft 4. At least a part of the shaft 4 on the upper side in the axial direction opposes the inner surface of the upper recess 213 in the radial direction. At least a part of the upper side of the shaft 4 in the axial direction is supported by the upper bearing portion 23. Thereby, the shaft 4 is supported so as to be rotatable relative to the magnet 24.

In this preferred embodiment, the shaft 4 has a solid cylindrical shape. However, the shaft 4 may be hollow.

As shown in FIG. 1, the commutator 5 is disposed between the armature 3 and the lower bearing portion 25. The commutator 5 is substantially cylindrical and has a through hole 55. The shaft 4 is passed through the through hole 55. At least a part of the shaft 4 is fixed to the commutator 5.

A circuit board 6 is disposed outside the commutator 5 in the radial direction. At least a part of the circuit board 6 faces the armature 3 in the axial direction. At least a part of the circuit board 6 is electrically connected to the commutator 5. The armature 3 has a connector 61 and a brush plate 62. The brush plate 62 has a substantially disk shape. The brush plate 62 is made of, for example, a resin material. At least a part of the lead wire 321 from the coil 32 is electrically connected to the circuit board 6. A connector 61 is electrically connected to the circuit board 6. It is supplied to the circuit board 6 from an external power source (not shown) via the connector 61.

The plurality of brushes 7 are arranged on the brush plate 62 and arranged on the radially outer side of the commutator 5. The brush 7 includes a plurality of positive brushes (not shown) and a plurality of negative brushes (not shown). An elastic member 8 is attached to the outside of the brush 7 in the radial direction. For example, a spring is used as the elastic member 8. The elastic member 8 presses the brush 7 against the commutator 5.

When electric power is supplied from the external power source (not shown) to the circuit board 6 via the connector 61, torque in the circumferential direction is generated between the armature 3 and the magnet 24 due to the interaction of electromagnetic force. . Thereby, the armature 3 including the shaft 4 can rotate in the circumferential direction with respect to the magnet 24. Further, as the shaft 4 rotates, the commutator 5 fixed to the shaft 4 also rotates at the same time. As the commutator 5 rotates, each brush 7 periodically contacts the commutator 5. As a result, current is periodically supplied from the circuit board 6 to the coil 32 in a predetermined order via the brush 7, the commutator 5, and the lead wire 321.

FIG. 3 is a perspective view of the commutator according to the present invention. FIG. 4 is a plan view of the commutator according to the present invention. FIG. 5 is a cross-sectional view of the commutator according to the present invention, and shows a cross section when the commutator shown in FIG. 4 is cut along the AA cross section. FIG. 6 is a perspective view of a segment according to the present invention. FIG. 7 is a front view of a segment according to the present invention. FIG. 8 is a partially enlarged view of a connection piece according to the present invention.

As shown in FIGS. 3, 4, and 5, the commutator 5 is substantially cylindrical and includes a holding body 51 and a plurality of segments 52. The plurality of segments 52 extend in the axial direction and are arranged in a ring around the central axis J1. The holding body 51 is made of an insulating material and holds a plurality of segments 52. In this preferred embodiment, the holding body 51 is made of an insulating resin material.

Each of the plurality of segments 52 includes an electrode surface member 53 and a connection piece 54. The electrode surface member 53 is made of a good conductor material. In this preferred embodiment, the electrode surface member 53 is made of copper or a copper alloy. The electrode surface member 53 extends in the axial direction. The electrode surface member 53 is a substantially plate-shaped member.

Each of the plurality of segments 52 has an electrode surface 531. More specifically, the electrode surface member 53 has an electrode surface 531. The electrode surface 531 is a slice obtained by dividing the cylindrical surface in the circumferential direction. The electrode surface 531 is exposed toward the radially outer side. The envelope surface of the electrode surface 531 of the plurality of segments 52 is the cylindrical surface. That is, the outer shape of the commutator 5 is substantially cylindrical.

At least a part of the electrode surface 531 is covered with a good conductor material having a melting point different from that of aluminum. In this preferred embodiment, at least a part of the electrode surface 531 is covered with a coating made of copper or a copper alloy (for example, cuprous oxide). The thickness of this coating is preferably a few micrometers. In this preferred embodiment, the entire electrode surface 531 is covered with a coating.

A step portion 532 is disposed on the radially inner surface (that is, the inner surface) of the electrode surface member 53. More specifically, the upper plate thickness of the electrode surface member 53 is thinner than the lower plate thickness of the electrode surface member 53. The step portion 532 connects the upper portion and the lower portion of the electrode surface member 53.

An inclined surface 533 that is inclined with respect to the central axis J <b> 1 is disposed at the axially upper end of the electrode surface member 53. The distance between the central axis J1 and the inclined surface 533 in the radial direction gradually increases toward the upper side in the axial direction.

Furthermore, a convex portion 534 extending toward the inside in the radial direction is disposed on the inner side surface of the electrode surface member 53. The dimension in the axial direction of the convex portion 534 gradually decreases as it goes outward in the radial direction. The end surface on the radially inner side of the convex portion 534 is a surface substantially parallel to the central axis J1. The upper surface and the lower surface of the convex portion 534 are inclined surfaces that are inclined with respect to the central axis J1. The circumferential width of the convex portion 534 is substantially the same as the circumferential width of the step portion 532.

The connection piece 54 is made of aluminum or an aluminum alloy. The connecting piece 54 is preferably a rod-like shape or a bowl shape extending upward in the axial direction. In this preferred embodiment, the connection piece 54 is substantially bowl-shaped. At least a part of the hook-shaped portion of the connection piece 54 faces the upper end portion of the electrode surface member 53 in the axial direction. The tip end portion on the upper side in the axial direction of the connection piece 54 is located on the radially outer side than the electrode surface member 53.

The axially lower end of the connecting piece 54 is in contact with the stepped portion 532 in the axial direction. Thereby, the connection piece 54 is positioned in the axial direction with respect to the electrode surface member 53. An end portion on the lower side in the axial direction of the connection piece 54 faces at least a part of the convex portion 534 in the axial direction. In this preferred embodiment, the upper surface of the convex portion 534 faces the lower end portion of the connection piece 54 in the axial direction.

In the radial direction, the position of the end of the convex portion 534 is substantially the same as the position of the inner surface of the connection piece 54. In other words, in the radial direction, the position of the radially inner surface of the connection piece 54 is substantially the same as the position of the radially inner surface of the convex portion 534.

The circumferential width of the connection piece 54 is narrower than the circumferential width of the electrode surface member 53. In other words, the circumferential width of the electrode surface member 53 is wider than the circumferential width of the connection piece 54.

The connection piece 54 is joined to the electrode surface member 53. More specifically, the radially outer surface (that is, the outer surface) of the bonding piece 54 is bonded to the inner surface of the electrode surface member 53 by ultrasonic bonding or the like. In other words, at least a part of the boundary between the electrode surface member 53 and the connection piece 54 on the surface of the segment 52 is located on the inner surface of the electrode surface member 53.

Conductive wires are fused and fixed to the connection pieces 54 of the plurality of segments 52. More specifically, as shown in FIG. 6, the lead wire 321 drawn out from the coil 32 surrounds and contacts the hook-like portion of the connection piece 54. The lead wire 321 is fixed to the connection piece 54 by welding or the like. That is, in each segment 52, the portion where the brush 7 contacts is made of copper, and the portion where the conductive wire contacts is made of aluminum.

Here, considering the case where the connection piece 54 is made of copper, when an aluminum conductive wire is joined to the connection piece 54, since it is a dissimilar metal, countermeasures against electrolytic corrosion are required. As a measure against electric corrosion, there is a method of blocking air by applying a resin or the like to the boundary between different metals. However, incorporating an electric corrosion countermeasure process further into the mass production process of the commutator 5 increases the number of processes and increases the production cost. Moreover, the melting point of copper is different from the melting point of aluminum. Therefore, it is difficult to weld when the connection piece 54 is made of copper and the conductive wire is made of aluminum.

However, in this preferred embodiment, as described above, the connection piece 54 and the conductive wire are both made of aluminum or an aluminum alloy. Therefore, no electrolytic corrosion occurs between the connection piece 54 and the conductive wire. In other words, it is not necessary to incorporate an electric corrosion countermeasure process in the mass production process of the commutator 5. Moreover, since the same kind of metals are joined together, the connection piece 54 and the conducting wire can be easily welded.

The holding body 51 is a substantially cylindrical member. The upper part of the holding body 51 is positioned on the upper side in the axial direction from the uppermost part of the connection piece 54. The lower end portion of the holding body 51 is substantially flush with the lower end portion of the electrode surface member 53.

The holding body 51 has a through hole 55 penetrating in the axial direction. The shaft 4 described above passes through the through hole 55 and extends to the lower recess 221. The through hole 55 is disposed at the approximate center of the holding body 51. The inner side surface constituting the through hole 55 includes a first inner side surface 511, a second inner side surface 512, and an inner stepped portion 519. The first inner surface 511 forms an edge serving as an opening of the through hole 55 on the upper surface of the holding body 51. In other words, the first inner surface 511 extends from the edge of the opening of the through hole 55 located on the upper side in the axial direction toward the lower side in the axial direction.

The second inner side surface 512 forms an edge serving as an opening of the through hole 55 on the lower surface of the holding body 51. In other words, the second inner side surface 512 extends from the edge of the opening of the through hole 55 on the lower side in the axial direction toward the upper side in the axial direction. An inner step 519 is disposed between the first inner surface 511 and the second inner surface 512. The inner step 519 connects the lower end of the first inner side surface 511 in the axial direction and the upper end of the second inner side surface 512 in the axial direction. The distance between the central axis J1 and the second inner side surface 512 in the radial direction gradually decreases toward the upper side in the axial direction. Thereby, for example, when the holding body 51 is molded in resin molding using a mold, it is easy to remove the mold for molding the second inner side surface 512 from the second side surface.

In the radial direction, the distance between the central axis J1 and the first inner side surface 511 is shorter than the distance between the central axis J1 and the second inner side surface 512. When viewed from the axial direction, the outer edge of the first inner surface 511 is surrounded by the outer edge of the second inner surface 512.

At least a part of the outer surface of the shaft 4 is in contact with the first inner surface 511. At least one groove extending in the axial direction is disposed on the outer surface of the shaft 4. The groove is disposed on a portion of the outer surface of the shaft 4 that is in contact with the first inner surface 511. In this preferred embodiment, a plurality of the grooves are arranged on the outer peripheral surface of the shaft 4 in the circumferential direction. Therefore, when at least a part of the shaft 4 is fixed to the holding body 51 by resin molding such as insert molding, the material forming the holding body 51 enters the groove. As a result, the shaft 4 is firmly fixed to the holding body 51. Here, in the portion of the outer surface of the shaft 4 that is in contact with the first inner surface 511, irregularities, knurled grooves, and the like may be provided in addition to the grooves. Furthermore, the surface roughness of the part may be roughened as compared with other parts of the outer surface of the shaft 4. Also by these, the shaft 4 is firmly fixed to the holding body 51.

The holding body 51 further includes a first outer surface 513, a second outer surface 514, and a first step portion 515. The first outer surface 513 is disposed on the upper portion of the holding body 51. The first outer surface 513 is disposed on the upper side in the axial direction than the end portion on the upper side in the axial direction of the connection piece 54. The distance between the central axis J1 and the first outer surface 513 gradually decreases as it goes upward in the axial direction.

The second outer surface 514 is disposed on the lower side in the axial direction of the first outer surface 513. A first step portion 515 is disposed between the second outer surface 514 and the first outer surface 513. The upper surface of the first step portion 515 is disposed on the upper side in the axial direction than the inclined surface 533 of the electrode surface member 53. In other words, at least a part of the inclined surface 533 of the electrode surface member 53 is covered with the holding body 51. The second outer surface 514 is connected to the first outer surface 513 via the first step portion 515. In the radial direction, the distance between the central axis J1 and the second outer surface 514 is longer than the distance between the central axis J1 and the first outer surface 513.

A plurality of extending portions 516 are disposed on the first outer surface 513. Each extending portion 516 extends from the first step portion 515 toward the upper side in the axial direction. In the circumferential direction, the position of each extending portion 516 is substantially equal to the position of the connection piece 54. The upper end portion of each extending portion 516 is disposed on the same or the upper side in the axial direction as the upper end portion of the connection piece 54. The outer surface of the extending portion 516 is in contact with the inner surface of the connection piece 54. Thereby, the holding body 51 can support the connection piece 54, and the connection piece 54 is prevented from falling inward in the radial direction.

A plurality of receiving groove portions 517 extending in the axial direction are arranged on the second outer side surface 514. On the second outer side surface 514, each receiving groove 517 is recessed toward the inside in the radial direction. The plurality of receiving grooves 517 are respectively arranged side by side in the circumferential direction on the second outer surface 514. In the circumferential direction, the position of each accommodation groove 517 is substantially equal to the position of each connection piece 54. At least a part of the connection piece 54 is disposed in each housing groove 517. At least a part of the second outer surface 514 is in contact with the connection piece 54. More specifically, at least a part of the inner side surface constituting the accommodation groove 517 is in contact with the inner side surface of the connection piece 54. The part located in the circumferential direction both sides of the accommodation groove part 517 among the 2nd outer side surfaces 514 is in contact with the inner surface of the electrode surface member 53. That is, the boundary between the electrode surface member 53 and the connection piece 54 on the surface of the segment 52 is covered with the sealing material. Here, the sealing material is a part of the holding body 51. The holding body 51 functions as a sealing material , and the sealing material covers the boundary. Since the boundary is covered with the holding body 51 (that is, a resin material), when manufacturing the commutator 5, there is no need to separately apply resin to the boundary and block the joint between the connection piece 54 and the electrode surface member 53 from the air. It becomes.

A second stepped portion 518 is disposed between the lower end portion of the housing groove portion 517 and the second outer side surface 514. The lower edge in the axial direction of the housing groove 517 is connected to the second step 518. The upper surface of the second step portion 518 is substantially flush with the upper surface of the step portion 532 of the electrode surface member 53. Further, the axially lower end portion of the connection piece 54 hits the second step portion 518. That is, the lower end of the connection piece 54 in the axial direction hits both the second step portion 518 and the step portion 532 of the electrode surface member 53. Thereby, the connection piece 54 is positioned with respect to the holding body 51 in the axial direction.

Note that the connection piece 54 may hit only one of the second step portion 518 and the step portion 532 of the electrode surface member 53. In this case, it is desirable to reduce the thickness of the electrode surface member 53 by the thickness of the connecting piece 54 in the radial direction.

Further, at least one concave portion 56 corresponding to the convex portion 534 is disposed on the outer surface of the holding body 51. The convex portion 534 is disposed in the concave portion 56. More specifically, a plurality of recesses 56 are arranged on the second outer surface 514 in the circumferential direction. The position of each concave portion 56 in the axial direction is substantially equal to the position of the convex portion 534 of the electrode surface member 53 in the axial direction. The circumferential position of each recess 56 is substantially equal to the circumferential position of the projection 534 of the electrode surface member 53. When the commutator 5 is formed, the convex portion 534 is accommodated in each concave portion 56. This prevents the electrode surface member 53 from coming out of the holder 51 radially outward. Furthermore, the electrode surface member 53 is prevented from moving in the circumferential direction with respect to the holding body 51.

It should be noted that a resin molding method such as insert molding is preferably used for manufacturing the commutator 5. As a manufacturing process of the commutator 5, first, an aluminum (or aluminum alloy) plate material is bonded to a copper plate material by ultrasonic bonding or the like. The joined plate material is pressed and molded. Next, the joined plate material is cut to form the electrode surface member 53 having a plurality of joined pieces. Further, a plurality of electrode surface members 53 are arranged in the mold. At this time, each electrode surface member 53 and each connection piece 54 are positioned on the mold by a jig or the like. Further, at least a part of the shaft 4 is disposed in the mold. Preferably, the outer surface of the shaft 4 is processed such as unevenness. When the processing is performed, the shaft 4 is arranged so that the portion is located in the mold. Next, the molten resin is poured into the mold. The poured resin is solidified in the mold. After the resin has solidified, the mold is removed. As a result, the holding body 51 is formed, and at the same time, the commutator 5 in which the shaft 4, the plurality of segments 52 (the plurality of electrode surface members 53 and the plurality of joining pieces), and the holding body 51 are integrated is formed. At the time of assembling the motor 1, a lead wire made of aluminum or aluminum alloy is hooked on the connection piece 54 and joined by welding or the like.

  As mentioned above, although preferred embodiment concerning this invention has been described, in addition to the above, this invention can be variously modified.

  For example, the electrode surface member 53 may be joined to the connecting piece 54 by ultrasonic welding, welding by an electron beam, or the like other than ultrasonic welding. The circumferential width of the electrode surface member 53 may be equal to the circumferential width of the connection piece 54. Even in this case, since a part of the holding body 51 (that is, the resin material) enters between the adjacent segments 52, the segments 52 are prevented from contacting each other. The shape of the convex portion 534 of the electrode surface member 53 may be changed to various shapes. An end surface on the radially inner side of the convex portion 534 may not be a surface substantially parallel to the central axis J1, but may be a curved surface. The upper and lower surfaces of the convex portion 534 may also be curved surfaces.

Moreover, the lead wire may be a clad wire of aluminum and copper other than those made of aluminum or aluminum alloy. Even in this case, the commutator 5 can use the above-described structure as it is.

  As described above, each extending portion 516 is disposed at a position corresponding to each joining piece. That is, the number of extending portions 516 is equal to the number of connection pieces 54. However, the number of connection pieces 54 may be smaller than the number of extending portions 516. That is, one extending portion 516 may be in contact with two or more connection pieces 54. In this case, it is desirable that the adjacent connection pieces 54 are arranged with a gap.

The present invention can be used for, for example, a motor with a brush or an engine cooling fan.

Center axis J1
Motor 1
Rotor 11
Housing 2
Case 21
Back cover 22
Disc part 211
Cylindrical part 212
Upper recess 213
Through hole 214
Upper bearing 23
Magnet 24
Lower recess 221
Lower bearing 25
Armature 3
Core 31
Coil 32
Core back 311
Teeth 312
Winding part 3121
Tip 3122
Leader 321
Through hole 3111
Shaft 4
Commutator 5
Holding body 51
Segment 52
Electrode surface member 53
Connection piece 54
Electrode surface 531
Step 532
Inclined surface 533
Convex part 534
Through hole 55
First inner surface 511
Second inner surface 512
First outer surface 513
Second outer surface 514
First step 515
Extension part 516
Housing groove 517
Second step 518
Recess 56
Circuit board 6
Connector 61
Brush plate 62
Brush 7
Elastic member 8

Claims (10)

A plurality of segments extending in the axial direction and arranged in a ring around the central axis;
A holding body made of an insulating material for holding the plurality of segments;
Consists of
Each of the plurality of segments exposes the electrode surface, which is a section obtained by dividing the cylindrical surface in the circumferential direction, toward the radially outer side,
The envelope surface of the electrode surface of the plurality of segments is the cylindrical surface,
At least a part of the electrode surface is covered with a good conductor material having a melting point different from that of aluminum,
The segment has an electrode surface member made of a good conductor material having the electrode surface and extending in the axial direction,
The segment has a connecting piece made of aluminum or aluminum alloy in a rod shape or a bowl shape extending in the axial direction upward,
The connection piece is joined to the electrode surface member,
The boundary between the electrode surface member and the connection piece on the surface of the segment is covered with a sealing material,
Commutator. A commutator according to claim 1,
A commutator, wherein at least a part of the boundary is located on an inner surface of the electrode surface member. A commutator according to claim 2,
A portion of the boundary that is not located on the inner surface of the electrode surface member is covered with the sealing material .
Commutator. A commutator according to claim 2 or claim 3, wherein
The commutator is provided with a stepped portion that is in axial contact with an end portion on the lower side in the axial direction of the connection piece on the inner side surface. A commutator according to any one of claims 2 to 4,
A convex portion extending radially inward is disposed on the inner side surface,
At least one concave portion corresponding to the convex portion is disposed on the outer surface of the holding body,
A commutator in which the convex portion is disposed in the concave portion. The commutator according to claim 5,
A commutator in which the axial dimension of the convex portion gradually increases toward the inside in the radial direction. A commutator according to any one of claims 5 and 6,
A commutator in which the position of the end of the convex portion is substantially the same as the position of the inner surface of the connection piece in the radial direction. A commutator according to any one of claims 5 to 7,
A commutator in which the circumferential width of the electrode surface member is wider than the circumferential width of the connection piece. The holding body functions as the sealing material , and the sealing material covers the boundary.
The commutator according to any one of claims 1 to 8. A motor,
Armature and
A rotor rotatably supported by a bearing mechanism with respect to the armature;
With
The rotor is
An armature consisting of multiple coils,
The commutator according to claim 1, wherein the commutator is fixed to a shaft and connected to an end of a conducting wire constituting the coil.
The conducting wire is made of aluminum or aluminum alloy,
The conducting wire is fused and fixed to the connection pieces of the plurality of segments.
motor.

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