JP3238098B2 - Small motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small motor used for rotating a portable CD player spindle, etc.
In particular, the present invention relates to a small motor having a rotor provided with a spark quenching element.

[0002]

2. Description of the Related Art A small motor to be incorporated in a portable CD player or the like must be made thinner.
Further, such a small motor requires a varistor to be attached to the rotor. In a small motor having a commutator, an arc is generated when the brush passes between the commutator pieces because the brush is in sliding contact with the commutator, and this arc may cause radio wave interference in communication equipment or shorten the life of the brush. It has been conventionally known that a varistor is attached to a rotor of a commutator motor as a spark quenching element in order to shorten the length.

FIG. 4 is a longitudinal sectional view of a commutator of a conventional small motor rotor and its vicinity, and shows how a varistor is attached to the rotor (Japanese Utility Model Laid-Open No. 63-7955). In FIG. 4, reference numeral 14 denotes a core of a rotor magnetic pole only partially illustrated, and reference numeral 13 denotes a rotor winding only partially illustrated. A commutator is mounted on the shaft 11 and includes a commutator piece 22, a commutator foot 26 extending therefrom, a commutator core 24, and a commutator washer 23 for fixing the commutator piece 22. It is configured. And
A flange 33 is integrally provided on the resin-made commutator core 24, and the varistor 21 is tightly fitted between the flange 33 and the commutator foot 26, and its electrode is connected to the winding 13 and the rectifier. It is soldered to the child leg 26. With such a configuration,
The varistor 21 is located on the end face of the commutator portion.
However, in such a configuration, the flange portion 33 is necessary to hold the varistor 21, and thus, in addition to the thickness of the varistor 21, the length in the thrust direction increases due to the thickness of the flange portion 33. There are drawbacks.

FIG. 5 shows another prior art. FIG.
In the figure, 22 is a commutator piece, 23 is a commutator washer for fixing the commutator piece 22, 24 is a commutator core, and 26 is a commutator foot. The varistor 21 is provided on the outer peripheral side of the commutator washer 23, and the outer periphery of the varistor 21 is connected to the commutator foot 26 by solder 25. In this way, by providing the varistor 21 on the outer peripheral side of the commutator washer 23, the varistor 21 is not added to the thickness of both the commutator washer 23 and the varistor 21 but to one of the (thicker) thicknesses. , The length in the thrust direction can be shortened. However, in order to further reduce the thickness, the varistor 21 and the commutator washer 23 are required.
Need to be formed thinly, but the varistor 21
Has a certain thickness (for example, at least 0.5mm
) Is required, and with such a configuration, there is a limit to further thinning the motor.

In order to reduce the thickness, a varistor may be attached to the space inside the winding.
However, this space is limited, and when the coil is wound around the magnetic pole core, the coil hits the outer periphery of the varistor, and the wound coil becomes slack and the winding resistance varies, or the wire breaks. Or The configuration shown in FIG. 6 (Japanese Utility Model Application Laid-Open No. 58-103576) solves this problem by adjusting the varistor 2 according to the winding configuration of the three-pole magnetic pole.
1 is a triangular shape. In FIG. 6, 1
1 is a shaft, 22 is a commutator piece, and 26 is a commutator foot. However, since the varistor 21 having such a special shape is non-uniform, an imbalance in strength is generated, cracks are easily generated, and the cost is increased.

[0006]

SUMMARY OF THE INVENTION Therefore, the present invention provides a small commutator motor having a varistor on a rotor without using a specially-shaped varistor and effectively using dead space. Thus, the object is to reduce the length in the rotor thrust direction and reduce the thickness of the motor.

[0007]

In order to solve the above-mentioned problems, the present invention provides a salient pole comprising a core 14 and a winding 13, a commutator, a rotor having a spark quenching element, and a fixed body comprising a magnet 2. The commutator is a resin-made commutator core 24, which is disposed on the outer periphery of the commutator core 24, and is provided with a brush 8 from outside.
A plurality of commutator segments 22, of a conductor through which current is conducted,
And a plurality of commutator feet 26, each of which is bent and extended integrally radially outward from the commutator piece 22, and the plurality of commutator feet 26 are integrally formed with the resin-made commutator core 24. A corresponding commutator foot receiving portion 31, a core insertion portion 30 disposed toward the core 14 on the outer periphery of the shaft 11 for positioning with respect to the core 14, and a wall portion 32 are formed. Core insertion part 3
It is configured to be separated from the winding 13 by being arranged close to the commutator foot 26 on the outer periphery of the zero and by locating the wall 32 on the outer peripheral side of the spark extinction element ( Claim 1). Further, in the small motor of the present invention, a plurality of space-like commutator foot insertion portions 34 are formed on the inner peripheral side of the commutator foot receiving portion 31 so that the commutator foot 26 is exposed, The side of the wall portion 32 facing the commutator foot insertion portion 34 is cut out, and the commutator foot 26 exposed at the commutator foot insertion portion 34 and the electrode of the arranged spark extinction element are soldered. (Claim 2).

FIG. 2 is a diagram showing details of the commutator portion and the varistor 21 attached thereto. Commutator part 20
Is composed of a commutator core 24 made of resin, a plurality of commutator pieces 22 of a conductor arranged on the outer periphery of the commutator core and through which a current is guided from the outside through a brush, and a commutator washer 23. A plurality of commutator feet 26 are formed integrally with the piece 22 and bent outward in the radial direction, and the windings 13 are connected to the commutator feet 26. The commutator core 24 is integrally formed with the core insertion portion 30, the commutator foot receiving portion 31, and the wall portion 32 from a synthetic resin. The core insertion portion has a tip portion inserted into a corresponding concave portion formed in the rotor magnetic pole core to position both the commutator portion and the rotor magnetic pole portion in the circumferential direction and the thrust direction. It is. A disk varistor whose center is cut out in a donut shape is fitted into a space formed between the inside of the wall 32 and the outer periphery of the core insertion portion 30.

A space-like commutator foot insertion portion 34 is formed on the inner peripheral side of the commutator foot receiving portion 31 corresponding to the plurality of commutator feet, and the back side of the commutator foot 26 is exposed here. are doing.
In this portion, the commutator foot insertion portion 34 is in a spatial state, and in this space portion, the commutator foot 26 and the varistor 21 fitted and in contact are in direct contact. And the back side of the commutator foot 26 are soldered.

The wall 32 formed integrally with the commutator core 24 prevents contact between the winding 13 and the varistor 21. The height of the wall 32 is at least equal to or greater than the thickness of the varistor. In the present invention, it becomes possible to arrange the varistor located on the inner peripheral side of the wall portion 32 without contacting the dead space inside the winding, thereby achieving a thin motor.

[0011]

FIG. 1 is a longitudinal sectional view showing the entire structure of a small motor according to the present invention. Although the number of magnetic poles of the present invention is not limited to the illustrated ones, in the following description, a description will be given taking a three-pole salient-pole rotor magnetic pole and a two-pole stator magnetic pole as examples. In FIG. 1, 1 is a case, and 6 is a case lid. Reference numeral 2 denotes a magnet constituting the stator magnetic pole. 3 and 7 are bearings for the rotor shaft 11, and 12 is a bush. Reference numeral 14 denotes a core on which the rotor magnetic poles are stacked, and reference numeral 13 denotes a winding wound on the core. The core 14 and the winding 13 constitute a three-pole salient pole. Reference numeral 20 denotes a commutator portion as a whole, and reference numeral 8 denotes a brush for supplying a current from the outside. Current is passed from this brush through the commutator, winding 13
Flows to Reference numeral 27 denotes an oil return washer, and reference numeral 21 denotes a varistor serving as a spark quenching element. As shown in FIG. 7, the varistor 21 has a disk shape in which the center is cut out in a donut shape, and three electrodes 40 are provided on the outer peripheral side of the disk.
It is soldered to the underside of the commutator foot 26, but is itself normal. The mounting configuration of the varistor 21 will be described later with reference to FIGS. 2 and 3, but FIG.
It is shown that the varistor 21 is located so as to enter the space inside the winding 13 in the radial direction.

FIG. 2 is a diagram showing the details of the commutator section and the varistor 21 attached thereto in a cross section of the left half. In FIG. 2, 11 is a shaft, and 8 is a brush. Reference numeral 22 denotes a commutator piece with which the brush 8 contacts. In this three-pole salient pole configuration, commutator feet 26 are integrally formed from the three commutator pieces 22 respectively. 23
Is a commutator washer, which fixes the commutator piece 22. 21 is a varistor. The configuration of the commutator foot receiving portion 31 and the wall portion 32 is shown in FIG. FIG. 3 shows the commutator core 24 and the core insertion part 30, the commutator foot receiving part 31, and the wall part 32 integrally formed with the commutator core 24 together with the space-like commutator foot insertion part.

The commutator section 20 includes a commutator core 24 made of resin,
It is composed of a plurality of commutator segments 22 and a commutator washer 23 of a conductor, which are arranged on the outer periphery of the commutator core and from which current is guided from the outside through a brush, and each of which is integrally formed with the commutator segment 22 in the radially outward direction. A plurality of commutator feet 26 are formed to be bent and extended, and the winding 13 is connected to the commutator feet 26. The commutator core 24 includes a core insertion portion 30,
Together with the commutator foot receiving portion 31 and the wall portion 32, they are integrally formed of synthetic resin. When the core insertion portion 30 is arranged on the outer periphery of the shaft, the core insertion portion 30 is oriented in the core direction,
It is inserted into the corresponding concave portion formed in the rotor magnetic pole core to position both the commutator portion and the rotor magnetic pole portion in the circumferential direction and the thrust direction. That is, in the circumferential direction, for example, the phase of the three-pole magnetic pole configuration and the phase of the commutator portion composed of three commutator pieces are adjusted, and in the thrust direction, the commutator portion and the varistor are aligned with the magnetic pole core. This is for positioning. A disk varistor whose center is cut out like a donut is inserted into a space formed between the inside of the wall portion 32 and the outer periphery of the core insertion portion 30,
It is arranged close to the commutator foot 26. After the varistor is inserted and positioned in the thrust direction on the shaft by the core insertion portion, as is clear from FIG. 1, the varistor 21 is positioned so as to enter the dead space inside the winding 13. To be. As described above, the varistor 21 is not provided on the outer periphery of the commutator piece or the commutator washer as in the related art.
Since there is only the core insertion portion 30 for positioning on the inner periphery of the varistor 21, the diameter of the varistor 21 can be reduced. This makes it possible to secure a space for soldering the electrodes of the varistor 21. Varistor 2
It has been confirmed that even if the diameter of 1 is reduced, it does not affect the spark elimination function, which is the function of the varistor 21.

A space-like commutator foot insertion portion 34 is formed on the inner peripheral side of the commutator foot receiving portion 31 corresponding to the plurality of commutator feet, and the back side of the commutator foot 26 is exposed here. are doing.
At this portion, the commutator foot insertion portion 34 is in a spatial state, and in this space portion, the commutator foot 26 and the fitted varistor 21 are in direct contact with each other. The electrode 32 located on the outer peripheral side of the varistor 21 and the back side of the commutator foot 26 are soldered.

The contact between the winding 13 and the varistor 21 is prevented by the wall 32 formed integrally with the commutator core 24. The height of the wall 32 is sufficient to prevent the winding 13 from contacting the varistor 21 and is at least equal to or greater than the thickness of the varistor. In small motors aimed at thinning, after winding a core around the core, "winding crushing" is performed to compress the winding in the thrust direction to reduce the winding thickness. The winding projecting in the direction comes into contact with the varistor. However, in the present invention, this is prevented by the wall portion 32, and the varistor located on the inner periphery of the wall portion 32 can be arranged in the dead space inside the winding without contacting the winding. As a result, the motor can be made thinner.

The assembly of the rotor of such a small motor is as follows.
First, the commutator foot receiving portion 31, the wall portion 32, and the core insertion portion 3
Commutator core 24 integrally formed with synthetic resin
Then, the commutator piece 22 is fixed using a commutator washer 23 to assemble the commutator portion 20. Next, the disk varistor 21 is inserted between the outer periphery of the integrally formed core insertion portion 30 and the inner periphery of the wall portion 32, and the electrodes located on the outer periphery of the varistor in the space-like commutator foot insertion portion 34. It is soldered to the commutator foot 26 exposed in the space. Then, it is assembled integrally with the rotor having the magnetic pole core positioned on the shaft 11. During this assembling, the core insertion portion 30 positions both of them in the thrust direction and the circumferential direction. Thereafter, winding is performed, the ends of the windings are connected to the commutator feet 26, and "winding crushing" is performed to complete the assembly of the rotor.

[0017]

According to the present invention, a commutator foot receiving portion, a core insertion portion, and a wall portion are formed integrally with a resin commutator core, and a disk-shaped varistor is provided on the outer periphery of the core insertion portion. The contact between the winding 13 and the varistor 21 can be prevented by arranging the wall near the foot and on the outer peripheral side of the varistor. Even if it protrudes inward in the circumferential direction, this is prevented by the wall portion 32, and the winding can be arranged in the dead space inside the winding without making contact with the varistor located on the inner periphery of the wall 32. .

By forming the diameter of the varistor to a predetermined size, such a varistor arrangement can be obtained. Since the commutator foot insertion portion 34 is formed in the inner periphery of the commutator foot receiving portion 31, the varistor 21 fitted with the exposed commutator foot 26 is inserted in this space.
Are directly in contact with each other, and the electrode located on the outer peripheral side of the varistor 21 and the back side of the commutator foot 26 can be soldered easily and without requiring any special space and connecting parts. .

As described above, according to the present invention, in a small commutator motor having a varistor on a rotor, it is not necessary to use a varistor having a special shape, and a dead space can be effectively used. It is possible to reduce the length in the rotor thrust direction and reduce the thickness of the motor without reducing the number of windings or the number of turns of the winding. Further, since the thickness can be reduced while securing the length of the brush sliding portion of the commutator, the sliding stability is not reduced.

Further, the core insertion portion integrally formed of resin is inserted into a corresponding recess formed in the rotor magnetic pole core so that the tip of the core insertion portion is formed in a circle of both the commutator portion and the rotor magnetic pole portion. Positioning in the circumferential direction and the thrust direction can be performed.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing the entire configuration of a small motor according to the present invention.

FIG. 2 is a view showing the details of a commutator portion shown in FIG. 1 and a varistor 21 attached thereto in a cross section of a left half.

FIG. 3 shows a commutator core of the present invention and a core insertion portion, a commutator foot receiving portion, and a wall portion formed integrally therewith, together with a spatial commutator foot insertion portion.

FIG. 4 is a longitudinal sectional view of a commutator of a conventional small motor rotor and a vicinity thereof, showing a mounting configuration of a varistor.

FIG. 5 is a diagram showing a mounting configuration of another conventional varistor.

FIG. 6 is a diagram showing a mounting configuration of still another conventional varistor.

FIG. 7 is a perspective view of a varistor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Case 2 Magnet 3 Bearing 6 Case lid 7 Bearing 8 Brush 11 Shaft 13 Winding 14 Core 20 Commutator part 21 Varistor 22 Commutator piece 23 Commutator washer 24 Commutator core 26 Commutator foot 30 Core insertion part 31 Commutator Foot support part 32 Wall part 34 Commutator foot insertion part 40 Electrode

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H02K 13/00 H02K 23/66

Claims (3)

(57) [Claims] 1. A salient magnetic pole comprising a core and a winding, a commutator,
And a rotor having a spark quenching element, and a stator magnetic pole made of a magnet, wherein the commutator is a resin-made commutator core, which is arranged on the outer periphery of the commutator core and externally. A plurality of commutator pieces of a conductor through which a current is guided through a brush, and a plurality of commutator feet each of which is bent and extended radially outward integrally from the commutator pieces, and the resin-made commutator core is A commutator foot receiving portion corresponding to the plurality of commutator foot portions, a core insertion portion arranged toward the core direction on the outer periphery of the shaft for positioning with respect to the core, and a wall portion are integrally formed, and the disc-shaped The spark extinction element is arranged close to the commutator foot on the outer periphery of the core insertion portion, and the wall is positioned on the outer periphery side of the spark elimination element, so that the spark extinction element is separated from the winding. thing Small motor according to claim. 2. A plurality of space-like commutator foot insertion portions are formed on an inner peripheral side of the commutator foot receiving portion, so that the commutator foot portions are exposed, and the commutator foot portions of the wall portion are exposed. 2. The small motor according to claim 1, wherein a side facing the child foot insertion part is cut out, and the commutator foot part exposed in the commutator foot insertion part and the electrode of the arranged spark extinction element are soldered. 3. 3. The small motor according to claim 1, wherein the spark quenching element is a varistor, and the height of the wall is equal to or greater than the thickness of the varistor.