JPH1023691A - Direct-current motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily place magnets in specified positions in a casing, by forming in the casing a magnet fixing section that controls the position of the magnets relative to the casing. SOLUTION: A magnet-fixing section 33 is formed, and notches 35 are formed in the body 34 of the fixing section the notches which extend from a second bracket 50 along the axial line C. Magnets 32a-32d are inserted into the notches, and the fixing section fits into a casing 30. A first bracket 40, a brush holder 60, the magnet-fixing section 33 and the second bracket 50 are fastened together using bolts 80. This enables is possible easy placing of the magnets 32a-32d in specified positions in the casing 30 and to facilitate the alignment of the magnets with brushes 61a-61d.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a DC motor in which a magnet is fixed to an inner surface of a casing, and more particularly to a DC motor which facilitates positioning of a magnet when assembling the DC motor and prevents the magnet from falling off.

[0002]

2. Description of the Related Art In a general DC motor, a plurality of magnets are arranged in a cylindrical casing so as to be separated in a circumferential direction. In such a DC motor, there are several fixing methods for preventing the magnet from falling off. For example, FIG. 6A shows four magnets M
Is fixed. That is, the hole 1 is formed in the casing 1.
Then, a rivet male 2 is inserted into the hole 1a from the outside, passed through the fixing bracket 3, and fixed to the rivet female 4. The fixture 3 is formed so as to sandwich the magnet M with the inner wall of the casing 1. FIG. 6B shows a method of assembling the DC motor. After the magnet M is attached as described above, the brackets 5 and 6 that support the rotor (not shown) are connected to the opening of the casing 1. Respectively. In the bracket 5, a brush (not shown) for supplying electric power to a current collector provided on the rotor is provided.

On the other hand, in a DC motor, a magnet M
It is necessary to match the center of the magnet M and the brush position with the magnet M. Therefore, as shown in FIG. 6B, in order to align the casing 1 with the brackets 5 and 6, the casing 1 and the brackets 5 and 6 are provided with matching marks G or are structurally engaged with each other. The notch was made so that it might be done.

[0004] In addition to the above-described fixing method, there is a method in which a concave portion 8 is provided from the outside of the casing 7 and a magnet M is inserted into the concave portion 8 as shown in FIG. Further, as shown in FIG. 7B, there is a method in which a projection 11 is provided in the casing 10 and the magnet M is fixed by a spring 12 or the like.

[0005]

However, the conventional method of fixing a magnet to a casing in a DC motor has the following problems. That is, in the method shown in FIG. 6A, it is necessary to form a hole in the casing 1, and the manufacturing efficiency is reduced, and the waterproof property is reduced by the hole 1a. Further, when the magnet M has four magnets, four rivet males 2, four rivet females 4, and four fixing brackets 3 are required, and the number of parts increases. Further, the work involved is complicated.

In the method shown in FIGS. 7A and 7B, the casing 7 and the casing 10 are provided with
Therefore, there is a problem that the number of processing steps is increased and the manufacturing efficiency is reduced.

On the other hand, as shown in FIG. 6B, when a matching mark G is provided or a notch is provided for positioning the casing 1 with the brackets 5 and 6, the number of processing steps is increased, and work efficiency is increased. However, there was a problem that was reduced.

Accordingly, an object of the present invention is to provide a DC motor which can easily position a magnet at a predetermined position of a casing, and which can increase manufacturing efficiency by reducing the number of parts and processing steps. .

[0009]

Means for Solving the Problems To solve the above problems and achieve the object, the invention described in claim 1 is provided with a cylindrical casing and an inner surface of the casing which is circumferentially separated from each other. A plurality of magnets, a first bracket covering one opening of the casing, a second bracket covering the other opening of the casing, and a first bracket coaxially arranged in the casing. A rotor pivotally supported by the bracket and the second bracket, a brush holder for holding a brush for supplying power to a current collector provided on the rotor, and a relative position of the magnet with respect to the casing, the magnet being disposed in the casing. A magnet fixing part for regulating the position and the first bracket, the magnet fixing part, the brush holder and the second bracket are fastened together. And to include a plurality of bolts.

According to a second aspect of the present invention, in the first aspect of the invention, the magnet fixing portion is coaxially arranged with the casing and fitted into the casing. And a plurality of cutouts formed along the axis from the second bracket side of the fixed body and supporting the magnet movably only in the axis direction. Is preferred.

According to a third aspect of the present invention, in the second aspect, the inner peripheral surface of the fixing portion is substantially flush with the inner peripheral surface of the magnet disposed in the casing. Preferably, it is formed.

According to a fourth aspect of the present invention, in the second aspect, an end of the fixing portion main body on the first bracket side contacts the first bracket,
It is preferable that an end of the fixing portion main body on the second bracket side is in contact with the second bracket.

According to a fifth aspect of the present invention, in the invention described in the fourth aspect, the length of the notch is the same as the length of the magnet in the direction along the axis. preferable.

As a result of taking the above measures, the following operation occurs. That is, in the invention described in claim 1, the relative positions of the plurality of magnets with respect to the casing can be regulated by the magnet fixing portion that regulates the relative position with respect to the casing by the magnet fixing portion disposed in the casing. In addition, the first bracket, the magnet fixing part, the brush holder, and the plurality of bolts for fastening the second bracket together are provided.
The bracket, the magnet fixing portion, the brush holder, and the second bracket can be determined in a predetermined positional relationship, and in particular, the position of the brush held by the brush holder and the position of the magnet can be determined.

According to the second aspect of the present invention, since the fixing portion main body of the magnet fixing portion is arranged coaxially with the casing and is fitted in the casing, the fixing portion main body is aligned with the casing along the axis. It can be positioned at a predetermined position in a direction perpendicular to the direction.

Further, the fixing portion main body is formed along the axis from the second bracket side of the fixing portion main body, and supports the magnet movably only in the axis direction. The magnet can be easily positioned in the notch, and the magnet can be positioned with respect to the casing.

According to the third aspect of the present invention, since the inner peripheral surface of the fixed portion main body is formed substantially flush with the inner peripheral surface of the magnet disposed in the casing, the inner peripheral surface is generated by rotation of the rotor. Since the air flow is not obstructed by the magnet, no wind noise is generated. Further, since the air resistance that hinders the rotation of the rotor can be reduced, the torque loss can be reduced.

According to the fourth aspect of the present invention, the end of the fixing portion main body on the first bracket side is in contact with the first bracket, and the end portion of the fixing portion main body on the second bracket side is the second bracket. Since it is in contact with the bracket, the position of the fixing portion main body in the axial direction can be determined.

According to the fifth aspect of the present invention, the length of the cutout portion is the same as the length in the direction along the axis of the magnet, thereby restricting the movement of the magnet in the direction of the axis. Thus, the magnet can be positioned at a predetermined position.

[0020]

FIG. 1 is a longitudinal sectional view of a DC motor according to an embodiment of the present invention, taken along line BB in FIG. 2 and viewed in a direction indicated by an arrow. FIG. 2 is a cross-sectional view of the DC motor taken along line AA in FIG.
FIG. 3 is an exploded perspective view of the DC motor, and FIG. 4 is a diagram showing a main part.

The DC motor 20 has a cylindrical casing 3
0, a first bracket 40 disposed on the opening 31a side of the casing 30, and a second bracket 50 disposed on the opening 31b side of the casing 30.

Four magnets 32a to 32d are arranged on the inner peripheral surface of the casing 30 so as to be separated in the circumferential direction.
It is fixed by a magnet fixing part 33. The magnet fixing part 33 is coaxially arranged on the casing 30,
Further, it has a cylindrical fixing portion main body 34 fitted to the casing 30. In FIG. 1, reference numerals 34a and 34b denote end portions of the fixing portion main body 34. In the fixing part main body 34,
Notch 3 along the axis C from the second bracket 50 side
5 are formed. The notch 35 is a magnet 32a
~ 32d is movable only in the direction of the axis C,
A groove 35a is formed. Due to the groove 35a, β is longer than α in FIG. Further, the fixing portion main body 33 is provided with bolt holes 36 a to 36 d parallel to the axis C. The position of the fixing portion main body 33 in the direction of the axis C is determined by being sandwiched between a small diameter portion 45 and an annular portion 53 described later.

The first bracket 40 is connected to the casing 30.
And a bracket main body 41 arranged coaxially with the bottom and formed in a cylindrical shape with a bottom. At the center of the bottom portion 42 of the bracket body 41, a bearing 43 having an axis C as a rotation axis is attached. Further, a small diameter portion 45 is formed in the opening 44 so as to fit into the opening 31 a of the casing 30. Further, bolt holes 46a to 46d (46b and 46d are not shown) are formed at positions corresponding to the bolt holes 36a to 36d.

A brush holder 60 is mounted in the first bracket 40. The brush holder 60 is provided with brushes 61a to 61d (61b and 61d are not shown). The brushes 61a to 61d supply power to a current collector 73 of the rotor 70 described later. Also, bolt holes 3
Bolt holes 62a to 62d at positions corresponding to 6a to 36d.
(62b and 62d are not shown) are formed.

The second bracket 50 is connected to the casing 30.
And a disk-shaped bracket body 51 coaxially arranged. At the center of the bracket body 51, a bearing 52 having an axis C as a rotation axis is attached. The bracket body 41 has an opening 3 of the casing 30.
An annular portion 53 is formed so as to fit into 1b. Further, bolt holes 54a to 54d are formed at positions corresponding to the bolt holes 36a to 36d. A mounting hole 56 is formed in the outer peripheral portion 55 of the bracket body 51.

On the other hand, in the casing 30, the first bracket 40 and the second bracket 50, a rotor 70 whose axis of rotation is the axis C is rotatably arranged. The two ends 71 and 72 of the rotor are respectively connected to the first bracket 4.
0 and a bearing 52 of the second bracket 50. The brushes 61a to 61d are attached to the rotor 70.
A power collection unit 73 to which power is supplied from is provided.

Further, reference numeral 80 in FIG. 1 denotes a bolt, and the above-mentioned bolt holes 36a, 46a, 54a, 62
a, bolt holes 36b, 46b, 54b, 62b, bolt holes 36c, 46c, 54c, 62c, bolt holes 36d,
46d, 54d, and 62d are inserted and fastened together.

In the DC motor 20 described above, the magnets 32a to 32d are mounted at predetermined positions on the casing 30 as follows. That is, the magnets 32a to 32
When attaching d to the inner peripheral surface of the casing 30, it is inserted into the notch 35 of the magnet fixing part 33 as shown in FIG. Thus, the positions of the magnets 32a to 32d with respect to the magnet fixing part 33 are determined.

Next, the magnet fixing portion 33 is fitted into the casing 30 together with the magnets 32a to 32d.
Further, the small-diameter portion of the first bracket 40 and the annular portion 53 of the second bracket 50 are fitted into both the openings 31a and 31b of the casing 30, respectively. Thereby, the magnets 32a to 32d in the direction of the axis C of the casing 30 are formed.
Is determined.

Next, the four bolts 80 are respectively inserted into the bolt holes 36a, 46a, 54a, 62a and the bolt holes 36b, 4b.
6b, 54b, 62b, bolt holes 36c, 46c, 54
c, 62c, bolt holes 36d, 46d, 54d, 62d
And tighten them together. Thereby, the magnet fixing part 3
3 is determined with respect to the first bracket 40 and the second bracket 50, and accordingly, the magnet 32a
To 32d are positioned at predetermined positions of the casing 30. In particular, the brushes 61a to 61a held by the brush holder 60
The position of 61d and the position of the magnet M can be determined.

As described above, in the DC motor 20 according to one embodiment of the present invention, since the fixing bracket for stopping the magnets 32a to 32d is not used in the casing 30, the number of parts is reduced, and the manufacturing process is reduced. It can be simplified. In addition, since a screw hole is unnecessary, waterproofness can be improved. On the other hand, since there is no need to provide the casing 30 with a concave portion or a projecting portion, the manufacturing process can be simplified.

Further, since the inner peripheral surface of the fixed portion main body 34 is formed substantially flush with the inner peripheral surfaces of the magnets 32a to 32d, it does not obstruct the flow of air generated by the rotation of the rotor 70, and No noise is produced. Also, the rotor 70
Since the air resistance that hinders the rotation of the motor can be reduced, the torque loss can be reduced.

Further, an end 34a of the fixing portion main body 34 on the side of the first bracket 40 abuts on the small diameter portion 45, and an end 34b of the fixing portion main body 34 on the side of the second bracket 50 is an annular portion 53. , The position of the fixing portion main body 34 in the axial direction of the casing 30 can be easily determined. At this time, since the length of the notch 35 is the same as the length of the magnets 32a to 32d in the direction along the axis C, the movement of the magnets 32a to 32d in the direction of the axis C can be restricted. , Magnets 32a to 32
d can be positioned at a predetermined position.

FIG. 5 is a diagram showing a modification of the above-described embodiment. That is, in the above-described embodiment, the magnet fixing part 33 and the brush holder 60 are configured separately, but a magnet fixing part integrated with the brush holder as indicated by 100 in FIG. 5 may be used. . FIG.
The middle 101 indicates a brush holder. The magnet fixing portion 100 can be manufactured by molding using PPS (polyphenylene sulfide) resin or phenol resin as a material. It should be noted that the present invention is not limited to the above-described embodiment, and it goes without saying that various modifications can be made without departing from the spirit of the present invention.

[0035]

According to the first aspect of the present invention, the plurality of magnets are positioned relative to the casing by the magnet fixing portion which regulates the relative position with respect to the casing by the magnet fixing portion disposed coaxially within the casing. Can be regulated. In addition, since there are provided a plurality of bolts for fastening the first bracket, the magnet fixing part and the second bracket together, the first bracket, the magnet fixing part, the brush holder and the second bracket are mutually fixed. The positional relationship can be determined, and in particular, the position of the brush held by the brush holder and the position of the magnet can be determined.

According to the second aspect of the present invention, since the fixing portion main body of the magnet fixing portion is disposed coaxially with the casing and fitted in the casing, the fixing portion main body is axially aligned with the casing. It can be positioned at a predetermined position in a direction orthogonal to the line. Further, the fixing portion main body is formed along the axis from the second bracket side of the fixing portion main body, and supports the magnet movably only in the axis direction, so that the magnet can be easily cut out. And a magnet can be positioned with respect to the casing.

According to the third aspect of the present invention, since the inner peripheral surface of the fixed portion is formed substantially flush with the inner peripheral surface of the magnet arranged in the casing, the inner peripheral surface is generated by the rotation of the rotor. Since the air flow is not obstructed by the magnet, wind noise does not occur. Further, since the air resistance that hinders the rotation of the rotor can be reduced, the torque loss can be reduced.

According to the fourth aspect of the present invention, the end of the fixed portion main body on the first bracket side contacts the first bracket, and the end portion of the fixed portion main body on the second bracket side is the second bracket side. Since it is in contact with the second bracket, the position of the fixing portion main body in the axial direction can be determined.

According to the fifth aspect of the present invention, the length of the cutout portion is the same as the length along the axis of the magnet, thereby restricting the movement of the magnet in the direction of the axis. And the magnet can be positioned at a predetermined position.

[Brief description of the drawings]

FIG. 1 shows a DC motor according to an embodiment of the present invention in FIG.
FIG. 5 is a vertical cross-sectional view taken along a line BB in FIG.

FIG. 2 is a cross-sectional view of the DC motor taken along a line AA in FIG. 1 and viewed in a direction indicated by an arrow.

FIG. 3 is an exploded perspective view of the DC motor.

FIG. 4 is an exploded perspective view of a main part of the DC motor.

FIG. 5 is a diagram showing a modification of the DC motor.

FIG. 6 is a diagram showing an example of a conventional DC motor.

FIG. 7 is a diagram showing another example of a conventional DC motor.

[Explanation of symbols]

 Reference Signs List 20 DC motor 30 Casing 32a to 32d Magnet 33 Magnet fixing part 34 Fixed part main body 35 Notch 36a to 36d Bolt hole 40 First bracket 41 Bracket main body 43 Bearing 45 Small diameter part 50 ... Second bracket 51 ... Bracket body 52 ... Bearing 60 ... Brush holder 70 ... Rotor 80 ... Bolt C ... Axis wire

Claims (5)

[Claims] 1. A cylindrical casing, a plurality of magnets arranged in a circumferential direction on an inner surface of the casing, a first bracket covering one opening of the casing, and a second bracket of the casing. A second bracket covering the opening; a rotor coaxially disposed in the casing and supported by the first bracket and the second bracket; and a power collector provided in the rotor. A brush holder for holding a brush for supplying a brush; a magnet fixing portion disposed in the casing to regulate a relative position of the magnet with respect to the casing; a first bracket, the magnet fixing portion, the brush holder, and the first A plurality of bolts for fastening the two brackets together. 2. The magnet fixing portion is disposed coaxially with the casing, and has a cylindrical fixing portion main body fitted into the casing; and a second bracket side of the fixing portion main body. 2. The DC motor according to claim 1, further comprising a plurality of cutouts formed along the axis and supporting the magnet movably only in the axis direction. 3. The DC motor according to claim 2, wherein an inner peripheral surface of the fixed portion is formed substantially flush with an inner peripheral surface of the magnet disposed in the casing. 4. An end of the fixed portion main body on the first bracket side abuts on the first bracket, and an end of the fixed portion main body on the second bracket side is connected to the second bracket. The direct current motor according to claim 2, wherein the direct current motor is in contact with the direct current motor. 5. The DC motor according to claim 4, wherein the length of the notch is the same as the length of the magnet in the direction along the axis.