JP5078328B2 - motor - Google Patents

Description

  The present invention relates to a motor, and more particularly to a motor with a brush.

Conventionally, a motor with a brush provided with a brush for passing a current through a commutator has been proposed. As such a motor with a brush, for example, those disclosed in Patent Documents 1 and 2 are known.
JP 2006-149019 A JP-A-10-136615

  In this motor with a brush, one of the important issues is how to achieve and maintain good contact between the brush and the commutator. However, solving this problem is not easy. First, during the motor assembly process, it is necessary to assemble the bracket including the brush and the rotor including the commutator. is there. In this case, there is also a possibility of damaging the rotor side. If permanent deformation occurs in the brush, good contact with the commutator cannot be achieved.

  Therefore, when assembling the bracket and the rotor, a space larger than the diameter of the commutator is secured by pushing the brush with a jig or the like (that is, letting the brush escape). Is called. In this way, interference between the commutator and the brush can be avoided.

However, this time, a new problem arises due to the brush being released in advance. That is, in order to secure the space, it is necessary to sufficiently deform the brush. For this reason, this deformation often occurs at a point where the elastic limit of the brush is exceeded or exceeded. It may be necessary to carry out up to (that is, the plastic region). In the end, there is a risk that permanent deformation of the brush may occur (although if the brush is not escaped, it may damage the rotor as described above, It can be said that it has improved.)
When such permanent deformation occurs in the brush, the contact pressure between the commutator and the brush varies, and as a result, the reliability of the operation of the entire motor may be reduced.
Note that, as the motor is reduced in size, the brush is naturally reduced in size, so the range in which the brush can be elastically deformed is reduced. Then, the problem becomes more serious.

In the above-mentioned Patent Document 1, a bracket having a magnet on the output shaft side and a bracket constituting a magnetic circuit on the counter-output side are provided, and the latter bracket is provided with a flat portion extending to the inner diameter portion of the magnet and the bracket. A technology of a coreless motor with a flat brush in which a resin-molded brush holder is fixed to a flat portion is disclosed.
However, in the motor disclosed in Patent Document 1, when assembling the motor, the brush is released to secure a space larger than the diameter of the commutator or the rotor is assembled while the brush is pushed away by the commutator. There is a need, and no particular consideration has been given to the above problems.

  Patent Document 2 discloses a technique of a DC motor including a brush body including a pair of elastic brush pieces in which a peripheral surface of a brush holding block and a commutator is elastically sandwiched. This patent document 2 points out the difficulty of “increasing the spacing between the brush pieces” when “introducing the brush pieces to the commutator”, and is aware of the above-mentioned problems or similar problems. Has been. The configuration disclosed in Patent Document 2 aims to solve the problem.

  However, this Patent Document 2 does not fully solve the above-described problem. According to Patent Document 2, when the brush holding block is inserted into the brush piece introduction hole, the pair of elastic brush pieces is initially pushed and spread along the circumferential surface of the commutator, and then the commutator is Since it is advanced along the longitudinal direction of the elastic brush piece while sandwiching, and finally the commutator is sandwiched and stopped by a predetermined elastic force, it is certainly between the elastic brush piece and the commutator. A certain degree of suitable contact can be realized and maintained.

  However, in this process, since it is assumed that contact between the elastic brush piece and the commutator occurs from the beginning of insertion of the brush holding block into the brush piece introduction hole, one of them may damage the other. That cannot be denied. Further, as the motor is further downsized, the range in which the elastic brush piece can be elastically deformed becomes smaller, so whether the process of moving forward with the elastic brush piece sandwiching the commutator can be performed smoothly. It cannot be said that there is no problem.

  This invention is made | formed in view of the said situation, and it aims at providing the motor which can implement | achieve and maintain the suitable contact between a commutator and a brush.

In order to achieve the above object, a motor according to the present invention is a motor that rotates a shaft by a force generated by an interaction between a fixed magnetic field and a magnetic field generated by a current flowing in the winding, and is electrically connected to the winding. A commutator fixedly attached to the shaft, a brush that contacts the commutator when the commutator rotates with the shaft, and an integrated structure that holds the brush so as to contact the commutator. A contour of the commutator facing the commutator from the axial direction is a circle, and the bracket is connected to the commutator in the axial direction to achieve contact between the commutator and the brush. a hole for passing along, have a commutator through hole having a larger contour than the contours of the started the commutator in the axial direction of the commutator, the commutator through hole, Having a contour shape surrounded by two overlapping circles and two tangent lines in contact with both of the two circles, and passing the commutator through the commutator through-hole without contacting the brush The commutator penetrated through the commutator through hole is moved in a direction perpendicular to the axis of the commutator so that the brush can be brought into contact with the brush .

The motor according to the present invention further includes a bearing that holds one end of the shaft, and oil leakage prevention means that prevents oil that can leak from the bearing from reaching the installation region of the commutator. You may comprise so that the outline shape of a child through-hole may have a magnitude | size which the said brush does not contact the said oil leak prevention means, even if the said oil leak prevention means is penetrated to the said commutator through-hole.

  The motor according to the present invention further includes a bottom plate portion that is connected to the bracket and holds one end of the shaft so that the shaft can rotate, and the bottom plate portion and the bracket are respectively You may comprise so that the positioning means which can determine the relative positional relationship between both may be provided.

The motor according to the present invention, prior Symbol commutator through hole, in the case where a circular contour and the same size of the commutator two aligned, and the two circles, between these two circles You may comprise so that it may have the outline shape enclosed by the common tangent.

According to the present invention, the contact between the brush and the commutator is realized with the commutator passing through the commutator through hole. In the present invention, the commutator through-hole has a second contour shape larger than the first contour shape facing the commutator from the axial direction. Therefore, when assembling the bracket including the brush and the rotor including the commutator. The commutator can be inserted (penetrated) into the commutator through-hole while avoiding the commutator from hitting the brush as much as possible (contact between the commutator and the brush is realized thereafter). Thereby, the possibility that the commutator hits the brush and permanently deforms the brush can be greatly reduced.
Therefore, according to this invention, the suitable contact between a commutator and a brush can be implement | achieved and maintained, and the reliability about the operation | movement of the whole motor can be improved by extension.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 and 2. The motor according to the present embodiment includes a brush holding portion 1, a bottom plate portion 2, an amateur portion 3, and a frame portion 4.

  As shown in FIGS. 1 and 2, the brush holding unit 1 includes a bracket 11, electrodes 12 and 12 (hereinafter simply referred to as “12”), brushes 131 and 132, and the like. Of these, the bracket 11 is made of a suitable resin material and has a substantially cylindrical shape. One end of the substantially cylindrical shape is an opening that substantially matches the diameter of the substantially cylindrical shape, and a bottom 11A is provided at the other end. The bottom 11A and the side wall surface of the bracket 11 are integral.

  As shown in FIG. 1, the electrode 12 has a certain length that exceeds the length of the bracket 11 in the longitudinal direction (left-right direction in the figure). One end (left end in the figure) of the electrode 12 is disposed so as to coincide with one end of the bracket 11 where the opening is formed. Thereby, the other end of the electrode 12 protrudes beyond the bottom 11A. A part of the protruding portion of the electrode 12 is covered with an electrode holding portion 11B formed integrally with the bottom 11A. As will be described later, the electrode holding portion 11B plays a certain role in positioning the bottom plate portion 2 with respect to the brush holding portion 1. A lead (not shown) is connected to a portion of the electrode 12 exposed from the electrode holding portion 11B.

  As shown in FIG. 2, the bottom 11A is provided with brush fasteners 141 and 142. These brush fasteners 141 and 142 are provided so as to be buried in a groove having a predetermined shape formed in the bottom 11A. Here, the predetermined shape means that the groove corresponding to the brush fastener 141 has a shape as if the upper and lower sides of the U-shape are opened opposite to each other, and the groove corresponding to the brush fastener 142 is as follows: It has a shape as if one side constituting the L-shape is open so as to conflict with the other piece. The brush fasteners 141 and 142 have substantially the same shape as these.

Brushes 131 and 132 are connected to brush fasteners 141 and 142, respectively. Both brushes 131 and 132 have substantially the same shape, and as shown in FIG. 2, the shape in plan view is substantially L-shaped. One side of the L shape is connected to the brush holding members 141 and 142. Thereby, the other side of the L-shape comes into contact with the peripheral surface of the commutator 31 as will be described later.
The brushes 131 and 132 and the brush fasteners 141 and 142 are electrically connected. Further, the brush fasteners 141 and 142 are electrically connected to the electrode 12.

  In this embodiment, a commutator through hole 110 is formed in the bottom 11A of the bracket 11 as shown by the hatched area in FIG. The outline shape of the commutator through-hole 110 is generally an oval shape (however, an ellipse is different from an ellipse, which will be described in detail later).

  Hereinafter, the shape of the commutator through hole 110 will be described in detail. First, the contour shapes C1 and C2 of the commutator 31 are included inside the contour shape of the commutator through-hole 110 in plan view, as shown in FIG. Here, the contour shapes C1 and C2 of the commutator 31 are contour shapes when the commutator 31 constituting the armature portion 3 described later is viewed from the axial direction. In FIG. 2, it is shown that these contour shapes C1 and C2 can be arranged to include portions that overlap each other.

  The circle which is the contour shape C2 is drawn so that the center thereof coincides with the center of the bracket 11 of the brush holding unit 1 as shown in FIG. That is, in FIG. 2, if the commutator 31 is actually arranged so that the center axis of the commutator 31 and the center of the bracket 11 coincide, the contour of the peripheral surface of the commutator 31 is as follows. It represents that it matches the contour shape C2. In this case, the brushes 131 and 132 are in contact with the circumferential surface of the commutator 31 while being bent by a predetermined amount of deflection (not shown in FIG. 2, see FIG. 4 to be referred to later). In FIG. 2, the symbol R represents the radius of the contour shape C2.

  The circle which is the contour shape C1 is drawn so that the brushes 131 and 132 are in contact with the circumference. A gap G having a predetermined size (for example, 0.15 mm) is provided around the contour shape C1. According to this, when the commutator 31 is passed through the commutator through-hole 110, the perimeter of the commutator 31 is a circle in which the gap G is added to the contour shape C1 (the contour shape of the circle in the figure). If it is carried out so as to be in contact with the circumference of the whole (not shown), it means that no interference occurs between the commutator 31 and the brushes 131 and 132. In FIG. 2, the symbol D represents the diameter of the contour shape C1.

Two common tangent lines T1 and T2 are drawn between the circle obtained by adding the gap G to the contour shape C1 and the circle that is the contour shape C2.
The contour shape of the commutator through-hole 110 is the shape described above, a part of the circumference of the circle obtained by adding the gap G to the contour shape C1, the part of the circumference of the contour shape C2, and the tangent lines T1 and T2. It has become. Thereby, the above-mentioned “oval shape” is configured.

Below, the remaining components (the bottom plate part 2, the amateur part 3, and the frame part 4) constituting the motor will be described.
The bottom plate portion 2 includes a bottom plate 21, a bearing 22, and a thrust plate 23. The bottom plate 21 has a substantially top hat shape. That is, the bottom plate 21 includes a bottomed cylindrical portion and a hook portion surrounding the bottomed cylindrical portion. Of these, a hole 21 </ b> A for penetrating the electrode holding portion 11 </ b> B protruding from the bottom 11 </ b> A of the brush holding portion 1 is formed in the flange portion. As will be described later, the hole 21A is used for positioning between the bracket 11 for holding the brush and the bottom plate portion 2 during assembly.

  The bearing 22 and the thrust plate 23 are provided so as to be housed in a bottomed cylindrical portion of the bottom plate 21. The thrust plate 23 has a circular shape substantially matching the bottomed cylindrical bottom shape. The central axis of the bearing 22, the axis passing through the center of the thrust plate 23, and the central axis of the bottomed cylindrical portion of the bottom plate 21 all coincide.

The amateur section 3 includes a commutator 31, an armature core 32, a winding 33, a shaft 34, and an oil drain washer 35 as an example of an oil leakage prevention means.
The commutator 31 according to the present embodiment suitably contacts the brushes 131 and 132 as will be described later when the motor is finally assembled. By this contact, the current passed through the brushes 131 and 132 through the electrode 12 electrically connected to the power source is passed through the commutator 31.

  The amateur core 32 is made of, for example, silicon steel. The winding 33 is wound around the amateur core 32. The shaft 34 is arranged so that its central axis coincides with the central axis of the winding 33. The shaft 34 and the commutator 31 are physically and fixedly connected to each other. If the former rotates, the latter rotates in exactly the same manner. In this case, both rotation axes are collinear and coincide. Further, the commutator 31 and the winding 33 are electrically connected.

  As will be described later, the oil drain washer 35 prevents oil leaking from the bearing 22 from leaching in the direction of the commutator 31 when the right end of the shaft 34 is fitted into the bearing 22 of the bottom plate portion 2. To prevent. In the present embodiment, in particular, the diameters of the commutator 31 and the oil draining washer 35 are substantially the same (however, refer to the modifications described later).

The frame portion 4 includes a frame 41, a permanent magnet 42, and a bearing 43. The frame 41 has a substantially cylindrical shape, and includes a bottom 41A at one end thereof. A bearing 43 is provided on the bottom 41A. The central axis of the bearing 43 coincides with the central axis of the frame 41. These central axes also coincide with the central axis of the shaft 34 after the motor is assembled. Further, the central axes of the bearing 43, the frame 41, and the shaft 34 coincide with the central axes of the bottom plate 21 and the like constituting the bottom plate portion 2 after the motor is assembled.
Thrust washers 51 and 52 are provided between the end face of the bearing 43 and the end face of the armature core 32 facing the bearing 43.

  The permanent magnet 42 is provided along the inner side surface of the substantially cylindrical shape of the frame 41. The shaft 34 rotates about its central axis by the force generated by the interaction between the magnetic field formed by the permanent magnet 42 and the magnetic field generated by the current flowing in the winding 33.

Next, the assembly process of the motor having the above-described configuration will be described with reference to FIGS. 3 and 4 in addition to FIGS. 1 and 2 referred to above.
First, the amateur part 3 and the brush holding part 1 are assembled. This assembly is performed so that the commutator 31 of the armature part 3 passes through the commutator through hole 110 formed in the bracket 11 of the brush holding part 1. And this penetration is performed so that the peripheral surface part of the commutator 31 may contact | connect the circumference of the circle | round | yen which added the gap G to outline shape C1. 2, the commutator 31 advances in a direction perpendicular to the drawing while the peripheral surface portion of the commutator 31 is separated from the brushes 131 and 132 by the gap G (see FIG. 2). (It may be assumed that the contour shape C2 drawn in 2 is slightly shifted in the upper left direction in the figure). Therefore, no interference occurs in principle between the commutator 31 and the brushes 131 and 132 during the assembly work.

  When the assembly of the armature portion 3 and the brush holding portion 1 is completed, the assembly is as shown in FIG. 3A (hereinafter, the assembly of the armature portion 3 and the brush holding portion 1 is referred to as “first assembly”. Sometimes called ")." At this time, thrust washers 51 and 52 are inserted from the left end side of the shaft 34 of the armature portion 3 in the figure.

  Subsequently, as shown in FIG. 3B, the first assembly is fitted into the frame 41 of the frame portion 4 to assemble them (hereinafter, the first assembly and the frame portion 4 are assembled together). The assembled product may be referred to as a “second assembly”.) In this case, the outer surface of the brush holding unit 1 is press-fitted and fixed along the inner surface of the frame 41. Further, a part of the shaft 34 on the left end side in the drawing is supported by the bearing 43. Accordingly, at least a part of the shaft 34 supported by the bearing 43 on the left end side in the drawing has a central axis thereof as a central axis of the final motor 100 (see FIG. 3C described later). A nearly matching state is realized.

  Subsequently, the bottom plate portion 2 is assembled to the second assembly. This assembly is performed so that the right end in the drawing of the shaft 34 of the second assembly is fitted into the bearing 22 of the bottom plate portion 2. In this assembly, the electrode holding portion 11B formed integrally with the bracket 11 is formed on the flange portion of the bottom plate 21 constituting the bottom plate portion 2 simultaneously with the fitting between the shaft 34 and the bearing 22. It is also performed so as to fit into the hole 21A.

  According to this, in the assembly of the second assembly and the bottom plate portion 2, the relative positional relationship between the brush holding portion 1 and the bottom plate portion 2 is determined almost uniquely. That is, both are positioned with each other by fitting the electrode holding portion 11B and the hole 21A and fitting the shaft 34 and the bearing 22.

  Further, along with such positioning, the commutator 31 is also positioned in the commutator through hole 110. This is because, since the shaft 34 and the commutator 31 are physically and fixedly connected, if the shaft 34 is centered by the bearing 22, the commutator 31 is also centered.

  In the present embodiment, the commutator 31 is initially arranged along the circumference of a circle obtained by adding the gap G to the contour shape C1 as described above, and thus the positioning is in such a state. This means that the central axis of the commutator 31 coincides with the center of the bracket 11, in other words, the contour shape facing the commutator 31 from the axial direction coincides with the contour shape C <b> 2 of FIG. 2.

  In such a positioning process, in FIG. 2, the commutator 31 initially located in the upper left direction in the drawing gradually moves in the lower right direction in the drawing. As the movement proceeds, the circumferential surface of the commutator 31 gradually spreads the other side of the L-shape of each of the brushes 131 and 132 (that is, the side not connected to the brush fasteners 141 and 142). Will go. Further, when the commutator 31 moves, the unnecessary movement of the commutator 31 is relatively restricted because the commutator through-hole 110 has the oval shape as described above. This aids quick positioning with respect to the commutator 31.

Finally, as described above, the contour shape facing the commutator 31 from the axial direction matches the contour shape C2 of FIG. This final state is shown in FIG. As shown in FIG. 4, the brushes 131 and 132 achieve a suitable contact state with the peripheral surface of the commutator 31 while being deflected by a suitable deflection amount. During the above process, the brush 131 and 132 are hardly deformed excessively.
In this way, the completion of the motor 100 as shown in FIG.

According to the motor assembled by the configuration and the assembly method described above, the following operational effects can be obtained.
First, according to the present embodiment, in the assembly process of the motor 100, the possibility that the commutator 31 and the brushes 131 and 132 interfere with each other and damage each other is extremely reduced. In particular, there is almost no risk of permanent deformation of the brushes 131 and 132. Therefore, in this embodiment, suitable contact between the commutator 31 and the brushes 131 and 132 can be realized, and it can be suitably maintained after the motor 100 is completed. Thereby, the reliability about the operation | movement of the motor 100 whole is improved.

In order to enjoy this effect better, setting R (the radius of the contour shape C2) shown in FIG. 2 within a range in which the brushes 131 and 132 are not deformed beyond the elastic limit, in other words, For example, it is preferable to set the diameter of the commutator 31 so as to meet the conditions described above.
Of course, in order to satisfy the above-mentioned conditions, the shape, material and size of the brush, the mode of holding the brush by the brush holding unit 1, and the overall size of the brush holding unit 1 are appropriately changed. Also good. Of course, the relationship between the amount of deflection of the brushes 131 and 132 and the diameter of the commutator 31 is mutually related.

This effect becomes clearer than the conventional example. 5 and 6, the specific forms of the brush, the brush fastener, and the like are slightly different from those of FIG. 2 and the like, but their functions are not different from those in the above-described embodiment (note that the deformation is performed later). (See FIGS. 9 and 10 and their descriptions as examples.)
First, in FIG. 5, when the commutator 39 is inserted between the brushes 133 and 134, brush spreading jigs 201 and 201 (hereinafter simply referred to as “201”) are used. The jig 201 has a substantially rectangular parallelepiped shape with a small thickness (length in the vertical direction in the figure).
When the commutator 39 is inserted between the brushes 133 and 134, the jig 201 is moved in the right direction in the figure, and the brushes 133 and 134 are pushed by the end face of the jig 201, whereby the commutator 39 Space for inserting is secured. However, at this time, the brushes 133 and 134 may be deformed outside the elastic deformation range, and as a result, there is a high possibility that the brushes 133 and 134 remain permanently deformed.

On the other hand, in FIG. 6, brush spreading jigs 203 and 203 (hereinafter simply referred to as “203”) fitted in arc grooves 204 and 204 (hereinafter simply referred to as “204”) formed in the bracket 91. Abbreviated). This jig 203 is a rod-shaped jig extending in a direction perpendicular to the paper surface of FIG. According to FIG. 6, there is an advantage that it is not necessary to use a relatively large jig as shown in FIG.
In FIG. 6, when the commutator 39 is inserted between the brushes 133 and 134, the jig 203 is moved along the arc groove 204 as indicated by the arrow in the figure, and the brushes 133 and 134 are moved at the end face of the jig 203. By pushing, a space for inserting the commutator 39 is secured. However, even in such a case, there is a possibility that permanent deformation may remain in the brushes 133 and 134 as in the case of FIG. 5 described above. In addition, in FIG. 6, since the arc groove 204 exists, there is a possibility that external foreign matter may enter the motor through the arc groove 204 after the motor is completed. That is, in FIG. 6, there is an advantage that it is not necessary to use a relatively large jig as in FIG. 5, but the inconvenience as described above must be accepted.

In turn, the motor 100 of the present embodiment is completely free from the above-described problems as shown in FIGS. As already described, the brushes 131 and 132 are not adapted to apply unnecessary force even when the commutator 31 is inserted (penetrated) into the commutator through-hole 110, and therefore the brushes are not affected. There is almost no possibility of leaving permanent deformation in 131 and 132.
Further, in the present embodiment, it is not necessary to prepare a brush spreading jig or to spread the brush in advance with the jig as compared with FIGS. 5 and 6. Furthermore, since the commutator through-hole 110 is finally closed by the bottom plate 21, in this embodiment, there is no need to worry about problems such as foreign matter contamination related to the arc groove 204.

  Secondly, according to the present embodiment, as described in detail with reference to FIGS. 2 to 4, the shape of the commutator through-hole 110 has a unique oval shape. 2 When assembling the assembly and the bottom plate 2, positioning between the two and the positioning with respect to the commutator 31 can be performed relatively easily. This is because the commutator through-hole 110 has the ellipse shape, so that the movement of the commutator 31 is restricted to a certain extent, and instead, the central axis of the commutator 31 is set to the center of the bracket 11. It is easy to guide.

  Third, in the present embodiment, since the gap G defined as described above is provided in the commutator through-hole 110, interference may occur between the brushes 131 and 132 and the commutator 31. There is also an advantage that is further reduced. Further, the presence of the gap G also provides an advantage that the commutator 31 can be inserted relatively easily.

Note that the present invention can be modified in various ways regardless of the above embodiment. Examples of such modifications include the following.
(1) In the above embodiment, the diameter of the oil draining washer 35 is the same as the diameter of the commutator 31, but in order to more effectively prevent the commutator 31 from entering the oil of the bearing 22, The diameter of the cutting washer is preferably larger than the diameter of the commutator 31. For example, it looks like the oil drain washer 351 shown in FIG. 7 (in this figure, the diameter of the oil drain washer 351 is drawn relatively large in order to emphasize this point).
However, in this case, it is necessary to give some consideration to the commutator through hole 110.
That is, when the oil drain washer 351 having a diameter larger than the diameter of the commutator 31 is used, the commutator through hole 110 needs to have a size that allows the oil drain washer 351 to pass therethrough. And in order to enjoy the above-mentioned effect effectively while realizing this, it is necessary to avoid interference between the oil drain washer 351 and the brushes 131 and 132.
Therefore, in this case, it is preferable to set D shown in FIG. 2 so as to match the diameter of the oil drain washer 351. Then, a part of the contour shape of the commutator through hole 110 is constituted by a part of a circle having a gap G having a predetermined size around a circle having a diameter D that matches the diameter of the oil draining washer 351. (In this case, the contour shape is close to a so-called saddle shape). Even in this case, no special consideration is required for R shown in FIG. 2 unless the diameter of the commutator 31 is changed. This is because, as is apparent from FIG. 7, the oil drain washer 351 passes through the commutator through-hole 110 in a moment, and the brushes 131 and 132 are finally in contact with each other only to the commutator 31. It is because of the circumference.

  (2) In the above embodiment, the positioning of the brush holder 1 and the bottom plate 2, and further the positioning of the commutator 31 in the commutator through-hole 110, the electrode holder 11 B of the bracket 11 and the bottom plate 2 Although the fitting with the hole 21A is used, the present invention is not limited to such a form. For example, a convex portion (or a concave portion) is provided on the brush holding portion 1, and a concave portion (or a convex portion) that corresponds to the convex portion (or the concave portion) is positioned corresponding to the convex portion (or the concave portion) on the bottom plate portion 2. In addition, it is possible to adopt a configuration such as forming each of them.

(3) In the above embodiment, the commutator through hole 110 having the oval shape as described above has been described, but various other specific forms of the commutator through hole can be considered. A specific example is as shown in FIG. In FIG. 8, the contour shape of the commutator through-hole 111 is irregular.
Even in such a commutator through-hole 111, the contour shapes C1 and C2 of the commutator 31 are included as in the commutator through-hole 110 as shown in FIG. Therefore, even in this case, an operation effect which is not substantially different from that in the above-described embodiment can be obtained. In this case, in particular, since the commutator through-hole 111 is relatively large, there is an advantage that the initial commutator 31 can be inserted easily.

Moreover, although the said embodiment demonstrated the brush 131 and 132 which has a substantially L shape, this invention is not limited to this form. For example, you may employ | adopt an aspect as shown in FIG.9 and FIG.10. 9 and 10, the brushes 133 and 134 have a linear shape in plan view. Accordingly, the shapes and arrangement of the brush fasteners 143 and 144 are also different from those in FIG.
More specifically, the brush fasteners 143 and 144 have a shape as if the upper side and the lower side of the substantially U-shape are open so as to oppose each other. The brush fasteners 143 and 144 are arranged so that the sides in the substantially U-shape are opposed to each other. The brushes 133 and 134 are connected to the brush fasteners 143 and 144 so that one end thereof is in contact with the upper side or the lower side. Accordingly, the other ends of the brushes 133 and 134 are positioned near the center of the bracket 91. As is apparent from the drawing, the set of the brush fastener 143 and the brush 133 and the set of the brush fastener 144 and the brush 134 have a symmetrical form with respect to the center line of the bracket 91 separating the upper and lower sides in the drawing. .
As described above, the brushes 133 and 134 and the brush fasteners 143 and 144 are different from the brushes 131 and 132 and the brush fasteners 141 and 142 in their shapes and arrangements, but their functions are different from each other. There is no.

And with the deformation | transformation of the form of such a brush, the form of a commutator through-hole is also different from FIG.2 etc. and FIG. That is, the commutator through-hole 112 in FIG. 9 has an oval-shaped longitudinal direction changed compared to the commutator through-hole 110 described above. This originates in the difference in the arrangement | positioning mode of the brush between both. However, there is no difference between the commutator through holes 112 and 110 with respect to the background circumstances in which this oval shape is formed. This point will not be repeated because it is clear from the figure.
On the other hand, the commutator through-hole 113 in FIG. 10 is different from the commutator through-hole 110 in the contour shape itself. That is, the contour shape is substantially rectangular as shown in FIG. However, even if so, the contour shapes C1 and C2 of the commutator 31 are included in the same manner as the commutator through-hole 110. Therefore, even in the case of the commutator through-hole 113, the above-described embodiment is used. The effect which is not substantially different from that in the case is obtained. In this case, in particular, since the commutator through hole 113 is relatively large, there is an advantage that the initial operation of inserting the commutator 31 can be performed easily.

  (4) In the above-described embodiment, the gap G is provided in the commutator through-hole 110. However, in some cases, the gap G may not be provided. In this case, the commutator through-hole has, for example, a contour shape surrounded by contour shapes C1 and C2 and a tangent line common to both. It can be said that this is the smallest contour shape for preventing interference between the commutator and the brushes 131 and 132. The bracket 11 is desired to have an appropriate physical strength. However, if the commutator through hole is too large, there is a high possibility that the strength will be impaired. Therefore, it can be said that the commutator through-hole having the minimum contour shape described above is the best form from this point of view.

(5) In the above-described embodiment, as the assembly process of the motor 100, first, the armature part 3 and the brush holding part 1 are assembled to form the first assembly, and secondly, the first assembly The order of assembling the frame part 4 to form the second assembly and thirdly assembling the second assembly and the bottom plate part 2 is described. I am not tied up.
For example, first, the armature portion 3 and the brush holding portion 1 are assembled to form a first assembly, and secondly, the bottom plate portion 2 is assembled to the first assembly, and thirdly, the first assembly is assembled. The order of assembling the frame part 4 with respect to the assembly according to the process 2 may be adopted.
Alternatively, the order may be as follows: first, the arm portion 3 and the frame portion 4 are assembled, second, the brush holding portion 1 is assembled to the assembly, and third, the bottom plate portion 2 is assembled.
In any case, insertion of the commutator 31 into the commutator through hole 110 avoiding excessive deformation of the brushes 131 and 132 (penetration), positioning between the brush holding portion 1 and the bottom plate portion 2, and accompanying it The main process elements in this embodiment such as positioning of the commutator 31 in the commutator through hole 110 are still performed.
However, in the above embodiment, the bottom plate portion 2 is assembled in a state where a part of the shaft 34 on the left end side in the drawing is supported by the bearing 43 and the center axis of the shaft 34 is centered to some extent. Therefore, it may be said that positioning with respect to the commutator 31 is slightly easier.

  (6) Although the above embodiment has been described by taking a cored motor as an example, the present invention is also applicable to a coreless motor.

It is a disassembled sectional view (a part is side view) of the motor of this embodiment. It is a top view (surface on the side which contacts an amateur part) of the brush holding | maintenance part of FIG. It is a figure which shows the assembly process of a motor later on from (a) to (c). FIG. 3 is a plan view of a state where a commutator is set in FIG. 2. It is a top view (the 1) of a brush holding | maintenance part provided with the jig | tool for the conventional brush spreading. It is a top view (the 2) of a brush holding part provided with the jig | tool for the conventional brush spreading. It is a side view of an amateur part provided with an oil draining washer different from FIG. It is a figure which shows the commutator through-hole which has a different outline shape from FIG. It is a figure which shows the commutator through-hole which has a brush etc. which have a shape etc. different from FIG. 2, and an outline shape. It is a figure which shows the commutator through-hole which has a different outline shape from FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Brush holding part 11 Bracket 11A Bottom 11B Electrode holding part 12 Electrode 131,132,133,134 Brush 141,142,143,144 Brush fastener 110,111,112,113 Commutator through-hole C1, C2 Contour shape T1, T2 tangent line G gap 2 bottom plate portion 21 bottom plate 21A hole 22 bearing 23 thrust plate 3 amateur portion 31, 39 commutator 32 amateur core 33 winding 34 shaft 35, 351 oil washer 4 frame portion 41 frame 42 permanent magnet 43 bearing 100 motor

Claims (4)

A motor that rotates a shaft by a force generated by an interaction between a fixed magnetic field and a magnetic field generated by a current flowing in a winding;
A commutator electrically connected to the winding and fixedly attached to the shaft;
A brush that contacts the commutator when the commutator rotates with the shaft;
A one-piece bracket that holds the brush in contact with the commutator, and
The contour shape of the commutator facing the commutator from the axial direction is a circle,
The bracket is a hole that penetrates the commutator along its axial direction in order to realize contact between the commutator and the brush, and has a contour shape of the commutator facing the commutator from the axial direction. have a commutator through holes with even larger contour,
The commutator through hole is
It has a contour shape surrounded by two overlapping circles and two tangents that touch both of these circles,
The commutator can be penetrated through the commutator through-hole without contacting the brush, and the commutator penetrated through the commutator through-hole is moved in a direction perpendicular to the axis of the brush. Has a size that can be in contact with
A motor characterized by that. A bearing for holding one end of the shaft;
Oil leakage preventing means for preventing oil that can leak from the bearing from reaching the installation region of the commutator;
The contour shape of the commutator through-hole has a size such that the brush does not contact the oil leakage preventing means even if the oil leakage preventing means passes through the commutator through-hole. The motor according to 1 . A bottom plate portion connected to the bracket and holding one end of the shaft so that the shaft is rotatable;
3. The motor according to claim 1, wherein each of the bottom plate portion and the bracket includes positioning means capable of determining a relative positional relationship between them. Before SL commutator through hole, in the case where the same size of the circle and the contour shape of the commutator two aligned, and the two circles, the common outline surrounded by the tangent between these two circles motor according to any one of claims 1 to 3, characterized in that with the shape.

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