JP4940022B2 - motor - Google Patents

Description

  The present invention relates to a brushed DC motor.

2. Description of the Related Art Conventionally, as shown in Patent Document 1, for example, a DC motor with a brush is fixed to a rotating shaft with a magnet fixed to the inner peripheral surface of a bottomed cylindrical yoke housing to constitute a stator side. An armature (armature) as a rotor formed by winding a winding around a core is housed inside the magnet. The armature is a bearing in which a predetermined portion of the rotation shaft is rotatably supported by a bearing disposed in the motor, and among them, a bearing in which a base end portion of the rotation shaft is held by a bearing holding portion at the bottom of the yoke housing. The configuration supported in this manner is a conventional one.
JP 2001-103702 A

  However, in the motor with the above configuration, considering the influence on the magnetic circuit in the core, the fixing strength between the core and the rotating shaft, and the structure when using a core in which a plurality of core materials are laminated, The portion supported by the bearing is set to a portion protruding in the axial direction from the core of the rotating shaft. Therefore, in order to dispose the bearing on the axially outer side corresponding to the protruding portion, it is necessary to configure a cylindrical bearing holding portion for holding the bearing so as to protrude from the bottom portion of the yoke housing. This is one of the harmful effects of downsizing by increasing the size in the axial direction.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a motor that can be configured in a small size.

In order to solve the above-described problem, the invention according to claim 1 is configured such that an armature having a commutator with which a power supply brush is slidably contacted is disposed opposite to a magnet fixed to a yoke, and the armature is separated from the power supply brush. A DC motor with a brush that is driven to rotate based on power supply, wherein the magnet is disposed on the outer surface of the yoke, and a winding is wound around the magnet in the radial direction to form the armature. A core is disposed, and includes a housing member that accommodates at least the armature, the yoke, and the magnet. The housing member is formed with a bearing holding member that extends inward in the axial direction from the bottom thereof, and the bearing holding the members, supports the with yoke is fitted supported by the radially outward, a base end portion of the rotating shaft of the armature radially inwardly of the bearing holding member 該回That thrust bearing which receives the thrust load of the shaft is retained as its gist.

In this invention, the armature having the commutator is disposed on the radially outer side of the magnet in which the armature core around which the winding is wound is disposed on the outer surface of the yoke, and the yoke is fitted and supported. A thrust bearing that supports the base end portion of the rotary shaft of the armature and receives the thrust load of the rotary shaft is held inside the holding member in the radial direction. That is, in such a yoke, it is easy to secure a space on the radially inner side while preferably forming a magnetic circuit. For this reason, a thrust bearing can be disposed radially inside the yoke (the bearing holding member on which the yoke is fitted and supported) , thereby preventing the bearing portion from protruding in the axial direction and miniaturizing the motor. .
Further, the yoke is fitted and supported on the outer side of the bearing holding member in the radial direction. Thereby, it is not necessary to consider the configuration in which the thrust bearing is held by the yoke. That is, since the yoke is made of magnetic metal, it is desirable that the shape be simple. If the bearing holding member is separately provided and the yoke is externally supported, the yoke shape can be simplified.
Further, since the thrust bearing is held by the bearing holding member, the thrust bearing, which tends to have a complicated configuration, can be easily held by the bearing holding member other than the yoke.
Further, since the yoke is externally fitted and supported on the bearing holding member, it is not necessary to separately provide a means for supporting the yoke, and the number of parts of the motor can be reduced.
Moreover, since the bearing holding member extended inward along the axial direction from the bottom part is formed in a housing member, the number of parts of a motor can be reduced.

According to a second aspect of the present invention, in the motor according to the first aspect, a radial bearing that rotatably supports a base end portion of the rotating shaft of the armature is accommodated and disposed inside the yoke in the radial direction . This is the gist.

In the present invention, the radial bearing and the thrust bearing that support the rotating shaft of the armature are accommodated inside the yoke in the radial direction, thereby further reducing the size of the motor .

  ADVANTAGE OF THE INVENTION According to this invention, the motor which can be comprised small can be provided.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention will be described with reference to the drawings.
FIG. 1 shows a motor of this embodiment. The motor 10 of this embodiment is used as a drive source of a power window device that automatically opens and closes a window glass of an automobile. The motor 10 is configured by integrally assembling a motor unit 11 constituted by a DC motor and a reduction unit 12 that decelerates and outputs the rotation generated in the motor unit 11.

  As shown in FIGS. 2 and 4, the motor unit 11 has a motor housing 13 that is formed of a resin material in a bottomed cylindrical shape, and the center of the bottom 13 a of the housing 13 extends from the inner surface of the bottom 13 a. A support cylinder 13b extending along the axial direction is provided. The support cylinder part 13b is formed in a hexagonal cylinder shape with a length of about one third of the axial length of the motor housing 13 (see FIG. 4). A yoke 14 formed of a magnetic metal in a hexagonal cylinder shape is externally fitted and supported on the support cylinder portion 13b.

  The yoke 14 is formed with a length that is approximately one-half of the axial length of the motor housing 13 and protrudes from the tip of the support cylinder portion 13b. Further, the yoke 14 has six outer surfaces 14 a each formed of a plane, and each of the six magnets 15 is fixed to each outer surface 14 a of the yoke 14. Each magnet 15 has a flat surface corresponding to the outer surface 14a of the yoke 14 and the outer surface of each magnet 15 is formed into a concentric circle or a curved surface conforming to the concentric circle. . Incidentally, the magnet 15 of the present embodiment is composed of a small-sized rare earth magnet that can obtain a strong magnetic force, and in particular, the armature 20 side (rotor side) is more radially outward than the magnet 15 side as in the present embodiment. It is suitable for use in an outer rotor type motor to be arranged.

  A radial bearing 16 that contacts the outer peripheral surface of the base end of the rotating shaft 21 of the armature 20 and supports the base end in the radial direction is fixed to the inner peripheral surface of the portion of the yoke 14 that protrudes from the support cylinder 13b. Has been. In addition, a ball 17 serving as a thrust bearing that contacts the proximal end surface of the rotating shaft 21 of the armature 20 and supports the proximal end portion in the thrust direction is accommodated inside the support cylinder portion 13b. That is, the base end portion of the rotating shaft 21 is rotatably supported by the bearing 16 and is subjected to a thrust load by point contact with the ball 17. Further, a metal plate 18 is accommodated in the back side of the ball 17, and a thrust adjusting member 19 made of an elastic member is accommodated in the back side of the plate 18, and the thrust adjusting member 19 is interposed via the plate 18. Thus, an elastic force is applied to the ball 17 to prevent the rotating shaft 21 from rattling in the thrust direction.

  A fixing collar 22 for fixing the armature core 23 is fixed to the central portion of the rotating shaft 21. The fixing collar 22 is made of a nonmagnetic material such as stainless steel and has a bottomed cylindrical shape, and the opening side of the collar 22 is arranged facing the bottom 13 a of the motor housing 13. At the center of the bottom portion 22a of the fixing collar 22, a fixing portion 22b extending in a cylindrical shape in the axial direction toward the opening side of the collar 22 is provided. The fixing collar 22 is attached so that the fixing portion 22b is press-fitted into the rotating shaft 21, and can rotate integrally with the rotating shaft 21.

  An armature core 23 is fixed to the inner peripheral surface of the cylindrical portion 22 c of the fixing collar 22. The armature core 23 is configured by laminating a plurality of core materials made of magnetic metal plates, and has an annular outer ring portion 23a and teeth 23b extending radially inward from the inner peripheral edge of the outer ring portion 23a. (See FIG. 4), and eight teeth 23b are provided at equal intervals in the circumferential direction. A winding 24 is wound around each tooth 23b.

  The armature core 23 of the present embodiment is configured as a split core 23x in which the outer ring portion 23a is split at an intermediate portion between the teeth 23b, and a connecting portion of adjacent split cores 23x is configured to be rotatable. Yes. When the windings 24 are mounted on the teeth 23b, the divided cores 23x are linear or the teeth 23b face outward so that the tips of the teeth 23b are widened with the adjacent teeth 23b. It is arranged in a ring shape so that the windings 24 can be easily wound around the teeth 23b. When the mounting of the winding 24 to each tooth 23b is completed, the outer ring portion 23a is formed in an annular shape so that each tooth 23b is inside, and the outer ring portion 23a of the armature core 23 is a cylindrical portion 22c of the fixing collar 22. It is fixed to the inner peripheral surface.

  A plurality (eight) positioning recesses 23 c are provided at equal intervals on the outer peripheral edge of the outer ring portion 23 a of the armature core 23, and are equally spaced on the inner peripheral surface of the cylindrical portion 22 c of the fixing collar 22. A plurality (eight) of positioning protrusions 22d are fitted into the recesses 23c, and the armature core 23 is positioned in the circumferential direction (preventing misalignment) with respect to the fixing collar 22. The armature core 23 thus fixed to the rotating shaft 21 with the fixing collar 22 is disposed so as to face the magnet 15 in the radial direction.

  A commutator 25 is fixed to the front end side of the center portion of the rotating shaft 21 with respect to the fixing collar 22. The commutator 25 has a disk shape, and is configured by arranging a plurality of segments (not shown) in the circumferential direction on a slidable contact surface 25 a formed by an axis orthogonal to the tip of the rotating shaft 21. Each segment is connected to a terminal 24 a of a winding 24 led out through a plurality of through holes (not shown) provided in the bottom 22 a of the fixing collar 22.

  A brush holder 30 as shown in FIG. 5 is fitted into the opening 13 c of the motor housing 13. The brush holder 30 shown in FIG. 5 is a plan view seen from the motor unit 11 side. A bearing 31 that supports the distal end portion of the rotating shaft 21 in the radial direction is attached to the central portion of the brush holder 30, and a pair of power supply brushes 32 are concentrically arranged at positions offset radially outward from the central portion. It is held at a predetermined interval. Each power supply brush 32 is held so as to be slidable along the axial direction of the rotary shaft 21, and a biasing force of a spring 33 is applied to the rear end surface of the brush 32 (see FIG. 2). The slidable contact surface 25a of the commutator 25 is pressed and contacted.

  Each power supply brush 32 has a two-stage shape in which a rear end side is a rectangular parallelepiped shape and a contact portion 32a on a front end side is a trapezoidal column shape. That is, each segment in contact with the power supply brush 32 has a fan shape so that the intervals between adjacent segments are equal in the radial direction, so that the contact portion at the tip of the power supply brush 32 corresponds to the fan shape. 32a is trapezoidal in cross section, and the remaining part is a rectangular parallelepiped shape that is easily supported by the brush holder 30. The power supply brush 32 is electrically connected to a connector portion 34 attached to a gear housing 40 described later, and supplies driving power supplied from the outside via the connector portion 34 to the armature 20 via the commutator 25. To do. The armature 20 rotates based on power feeding through the commutator 25.

  In the opening 13c of the motor housing 13, mounting portions 13d are formed to extend outward in the radial direction at respective positions facing the axis. The motor housing 13 is fixed to the gear housing 40 by screwing screws 35 into the gear housing 40 with the respective attachment portions 13d interposed therebetween. Further, since the motor housing 13 is made of resin, as shown in FIGS. 2 and 3, reinforcing ribs 13e are erected on the outer surface. Four reinforcing ribs 13e extend radially from the center of the bottom portion 13a toward the mounting portions 13d provided on the opening portion 13c side through the cylindrical portion, respectively, at substantially equal angular intervals. The vibration and noise generated from the motor unit 11 during driving are suppressed.

  As shown in FIG. 1, the speed reduction unit 12 includes a gear housing 40 made of a resin material, and the gear housing 40 is formed in a predetermined shape that can accommodate a worm shaft 41, a worm wheel 42, and a clutch 43. . In the gear housing 40, a worm shaft 41 is disposed coaxially with the rotating shaft 21 of the motor unit 11 via a clutch 43, and both shafts 41 and 21 are drivingly connected by the clutch 43. A worm 41 a is formed at the center of the worm shaft 41, and both ends of the worm 41 a are rotatably supported by a pair of bearings 44 and 45 provided in the gear housing 40 in the radial direction. A ball 46 that receives the thrust load of the shaft 41 is disposed at the tip of the worm shaft 41. In this case, the elastic force of the thrust adjusting member 19 provided in the motor unit 11 is transmitted to the worm shaft 41 via the rotary shaft 21 and the clutch 43, and the worm shaft 41 is rattled in the thrust direction together with the rotary shaft 21. It also prevents.

  The worm wheel 42 is rotatably supported in the gear housing 40, and is connected to rotate integrally with the output shaft 47 at the center of the wheel 42. The worm wheel 42 meshes with a worm 41 a provided on the worm shaft 41, and the rotational force from the worm shaft 41 side driven by the motor unit 11 is decelerated by the worm wheel 42 and output from the output shaft 47. The window glass opens and closes based on the drive of the shaft 47.

  The clutch 43 provided between the worm shaft 41 and the rotary shaft 21 transmits the rotation of the rotary shaft 21 based on the driving of the motor unit 11 to the worm shaft 41, while being input from the output shaft 47 side. It is comprised so that rotation of may be prevented. As a result, idling of the output shaft 47 from the load side is prevented, thereby preventing an unexpected drop caused by the weight of the window glass and preventing manual opening from the outside (theft prevention).

Next, characteristic effects of the present embodiment will be described.
(1) In this embodiment, the armature 20 having the commutator 25 is disposed on the radially outer side of the magnet 15 in which the armature core 23 around which the winding 24 is wound is disposed on the outer surface 14 a of the yoke 14. In addition, a radial bearing 16 that supports the base end portion of the rotating shaft 21 of the armature 20 and a ball 17 as a thrust bearing are accommodated and disposed inside the yoke 14 in the radial direction. That is, in such a yoke 14, it is easy to secure a space on the radially inner side while suitably forming a magnetic circuit. Therefore, a bearing (bearing 16, ball) is disposed on the radially inner side of the yoke 14 as in the present embodiment. 17) can be arranged. Thereby, the protrusion to the axial direction of the bearing part of the motor housing 13 can be suppressed, and the motor 10 can be reduced in size.

  Incidentally, by adopting a configuration in which the yoke 14 is disposed inside the armature 20 as in the present embodiment, the material of the motor housing 13 does not need to be a magnetic metal, and the shape can be changed as appropriate, so that the design is free. The degree is improved. For example, the frequency of noise generated when the motor unit 11 is driven can be easily adjusted by the material and shape of the motor housing 13.

  (2) In this embodiment, since the radial bearing 16 and the thrust bearing (ball 17) that support the rotating shaft 21 of the armature 20 are housed inside the yoke 14 in the radial direction, either one is housed. The motor 10 is further downsized as compared with the above.

  (3) In the present embodiment, a support cylinder portion 13b (bearing holding member) that holds the thrust bearing (ball 17) is inserted and arranged inside the yoke 14 in the radial direction. Thereby, it is not necessary to consider the configuration in which the bearing (ball 17) is held by the yoke 14. That is, since the yoke 14 is formed of magnetic metal, it is desirable that the shape thereof be simple. In the configuration of the present embodiment in which the separately provided support cylinder portion 13b is inserted into the yoke 14, the shape of the yoke 14 is simple. Can be achieved.

  (4) In this embodiment, since the thrust bearing (ball 17) is held by the support cylinder portion 13b, the ball 17 which is a thrust bearing that tends to have a complicated configuration using the plate 18 or the thrust adjusting member 19 is used. Further, it can be easily held by the support cylinder portion 13b which is not the yoke 14.

  (5) In this embodiment, since the yoke 14 is externally fitted and supported on the support cylinder portion 13b, it is not necessary to separately provide a means for supporting the yoke 14, and the number of parts of the motor 10 is reduced. Can do.

(6) In this embodiment, since the support cylinder part 13b is integrally provided in the motor housing 13, the number of parts of the motor 10 can be reduced.
In addition, you may change embodiment of this invention as follows.

  In the above embodiment, the radial bearing 16 is held by the yoke 14 and the thrust bearing (ball 17) is held by the support cylinder portion 13b of the motor housing 13, but the radial bearing 16 and the thrust bearing are held by the yoke 14. It is good also as a structure which hold | maintains (the ball | bowl 17) together, and the structure which hold | maintains both the bearings in the support cylinder part 13b. Further, although the bearing is held by the support cylinder portion 13b provided integrally with the motor housing 13, the support cylinder portion 13b may be configured as a bearing holding member by a member different from the motor housing. If it does in this way, the freedom degree of the shape of a motor housing will improve.

  In the above embodiment, the radial bearing 16 and the thrust bearing (ball 17) are both accommodated and arranged inside the yoke 14 in the radial direction. For example, only one of the bearings such as the radial bearing 16 is used. It is good also as a structure to accommodate and arrange.

  In the above embodiment, the support cylinder portion 13b that accommodates the ball 17 that is a thrust bearing has a hexagonal cylinder shape, but may have another polygonal cylinder shape or a cylindrical shape. In this case, the shape of the yoke 14 is changed according to the shape of the support cylinder part 13b. Moreover, it is good also as a structure which makes this yoke 14 the shape recessed in the axial direction instead of the cylinder shape, and accommodates a bearing in the recessed part.

  In the above embodiment, the armature core 23 is fixed on the inner peripheral surface of the cylindrical portion 22c of the fixing collar 22, but the outer periphery of the cylindrical portion 22c of the fixing collar 22 is shown in FIG. The armature core 23 may be fixed on the surface. In this way, since the winding 24 is exposed to the commutator 25 side, the connection between the terminal 24a of the winding 24 and the commutator 25 is facilitated.

  In the above embodiment, the slidable contact surface 25a of the commutator 25 is an axial orthogonal plane, and the power supply brush 32 is in axial contact with the slidable contact surface 25a. However, as shown in FIG. It is good also as a structure which makes the outer peripheral surface of this contact the sliding contact surface 25a, and makes the electric power supply brush 32 contact the radial direction with the sliding contact surface 25a.

  In the above embodiment, the reinforcing rib 13e is continuously provided from the bottom 13a of the motor housing 13 to the mounting portion 13d on the opening 13c side. However, for example, as shown in FIG. The reinforcing ribs 13e may be individually provided on the bottom 13a portion and the opening 13c portion (near the mounting portion 13) of the motor housing 13, as shown in FIG. 8B. May be. That is, the shape of the reinforcing rib 13e can be changed as appropriate to adjust not only the rigidity of the motor unit 11 but also the frequency of noise generated during driving.

  In addition, four reinforcing ribs 13e are provided at substantially equal angular intervals from the center of the bottom 13a of the motor housing 13 toward the mounting portions 13d on the opening 13c side, but the number and shape thereof may be changed as appropriate. . For example, as shown in FIG. 9A, a plurality of reinforcing ribs 13e may be provided radially at equal intervals from the center of the bottom 13a of the motor housing 13 to the entire circumference. Further, as shown in FIG. 9B, four reinforcing ribs 13e may be provided in parallel to each other. Further, as shown in FIG. 9C, four reinforcing ribs 13e may be provided so as to surround the bottom portion 13a of the motor housing 13. In this way, it is possible to improve the rigidity of the motor unit 11 and to adjust the frequency of noise generated when the motor unit 11 is driven. Moreover, although the motor housing 13 was formed in the bottomed cylindrical shape, it is not restricted to this, For example, you may form the hole for motor cooling.

  In the above embodiment, the present invention is applied to the motor 10 with the speed reduction mechanism in which the motor unit 11 and the speed reduction unit 12 are integrally assembled. For example, the present invention is applied to a motor with a built-in link mechanism or a motor without a speed reduction unit. May be.

It is a block diagram of the motor in this embodiment. It is sectional drawing of a motor part. It is the top view seen from the bottom part side of a motor part. It is sectional drawing of the axis part direction of a motor part. It is the top view seen from the motor part side of the brush holder. It is sectional drawing of the motor part in another example. It is sectional drawing of the motor part in another example. (A) (b) is sectional drawing of the motor part in each another example. (A)-(c) is the top view seen from the bottom part side of the motor part in each example.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Motor, 13 ... Motor housing (housing member), 13b ... Supporting cylinder part (bearing holding member), 14 ... Yoke, 14a ... Outer surface, 15 ... Magnet, 16 ... Radial bearing, 17 ... Ball (thrust bearing), DESCRIPTION OF SYMBOLS 20 ... Armature, 21 ... Rotary shaft, 23 ... Armature core, 24 ... Winding | winding, 25 ... Commutator, 32 ... Feed brush.

Claims (2)

A brushed DC motor in which an armature having a commutator that is in sliding contact with a power supply brush is disposed opposite to a magnet fixed to a yoke, and the armature is rotationally driven based on power supplied from the power supply brush,
The magnet is disposed on the outer surface of the yoke, and an armature core around which a winding is wound to configure the armature is disposed on the radially outer side of the magnet ,
A housing member that houses at least the armature, the yoke, and the magnet;
A bearing holding member extending inward along the axial direction from the bottom of the housing member is formed,
The bearing holding member has the yoke fitted and supported on the outer side in the radial direction, and the base end portion of the rotary shaft of the armature is supported on the inner side in the radial direction of the bearing holding member, and the thrust load of the rotary shaft motor, wherein a thrust bearing for receiving the is held. The motor according to claim 1,
A motor characterized in that a radial bearing for rotatably supporting a base end portion of a rotating shaft of the armature is accommodated and disposed inside the yoke in the radial direction .

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