JPH11178288A - Motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a motor in which the cleaning effect on the surface of a commutator is obtained by a method, wherein the inclination of the shaft of a rotor core is prevented, a loss between the shaft of the rotor and a bearing is reduced, an increase in a current is prevented, and the shortening of life of the bearing is prevented. SOLUTION: In a motor 1, a pair of brushes 5 for power supply which come into contact with a commutator 4 fixed to the shaft 3 of a rotor core are not arranged facing in opposite positions. A nonconductive dummy brush 8 is arranged, so as to come into contact with the commutator 4 in a position which is different from the pair of brushes 5, for power supply on the rotation track 6 of the commutator 4. The load of the pair of brushes 5 for power supply, which is applied to the shaft 3 of the rotor core is constituted in such a way that its balance with the load of the dummy brush 8 is maintained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a motor,
More specifically, the present invention relates to a brushed motor in which a pair of power supply brushes are not arranged at opposing positions.

[0002]

2. Description of the Related Art As a conventional motor, Japanese Patent Publication No. 49-12
522 and Japanese Utility Model Publication No. 58-56578. As an example, as shown in FIG. 8 and FIG. 9A, a magnet 9 having N poles and S poles alternately magnetized is fixed to a case 12 and at a position facing the magnet 9 with a gap. 3
There is known a structure in which a rotor core 2 having magnetic poles is rotatably arranged. The shaft 3 is press-fitted into the center of the rotor core 2, and both ends of the shaft 3 are rotatably supported by bearings 14 (or bearings). Rotor core 2
Is connected to a riser 16 of the commutator 4 fixed to the shaft 3. A pair of power supply brushes 5 (anode brush, cathode brush) are in contact with the outer peripheral surface of the commutator 4. The pair of power supply brushes 5 are arranged in a direction of 90 °, and power is supplied to the commutator 4 via each power supply brush 5. It should be noted that 19 in FIG.
Is a brush spring, 4a in FIG. 9A is a commutator segment, and 18 is a short-circuit line.

[0003]

By the way, when a pair of power supply brushes 5 are arranged in a 90 ° direction as in the prior art, as shown in FIG. 9B, the brush pressures F ₁ , F
₂ of synthesis pressure F ₃ is generated, the shaft 3 of the rotor core 2 is pushed in one direction inclination θ is generated as shown in FIG. 9 (c), rotating in a state where the inclined shaft 3 of the rotor core 2 It will be. For this reason, there is a problem that the loss between the shaft 3 of the rotor core 2 and the bearing 14 increases and the current increases, and that the life of the bearing 14 is shortened. In other words, if the pair of power supply brushes 5 are arranged in a 180 ° direction facing each other, F ₁
= F ₂ , for example, when the commutator 4 of the three-pole rotor core 2 is divided into six segments 4 a as shown in FIG. Since it is necessary to correspond to the N pole and the S pole, it is necessary to dispose them in a direction of 90 °, and the above problem occurs.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional example, and an object of the present invention is to provide a rotor core which is driven by a load of a power supply brush when a pair of power supply brushes are not arranged at opposing positions. Prevents the shaft from tilting, reduces the loss between the shaft of the rotor core and the bearing, prevents an increase in current, prevents the life of the bearing from shortening, and constantly activates the commutator surface Accordingly, it is an object of the present invention to provide a motor capable of reducing the contact resistance between the commutator and the power supply brush and stabilizing the power supply.

[0005]

According to the present invention, a pair of power supply brushes 5 contacting a commutator 4 fixed to a shaft 3 of a rotor core 2 comprises a pair of rotating brushes for rotating the commutator 4. A motor which is arranged on a locus 6 so as not to be symmetrical with respect to its rotation center 7, and is located at a position different from the pair of power supply brushes 5 on the rotational locus 6 of the commutator 4. A non-conductive dummy brush 8 is arranged so as to be in contact with the brush, and the load of the pair of power supply brushes 5 applied to the shaft 3 of the rotor core 2 and the load of the dummy brush 8 are balanced. With this configuration, the inclination of the shaft 3 of the rotor core 2 can be prevented by the dummy brush 8, the loss between the shaft 3 of the rotor core 2 and the bearing is reduced, and the current is reduced. The bearing can be prevented from increasing It is possible to prevent life shortening.
Also, due to the cleaning effect of the dummy brush 8,
The surface of the commutator 4 is always activated, so that the contact resistance between the commutator 4 and the power supply brush 5 can be reduced and the conduction can be stabilized.

Further, according to the present invention, a pair of power supply brushes 5 contacting the commutator 4 fixed to the shaft 3 of the rotor core 2 are symmetrical with respect to the rotation center 7 on the rotation locus 6 of the commutator 4. A motor that is staggered so that it does not
Elastic pressing body 10 for pressing shaft 3 of rotor core 2 in one direction
And the load of the pair of power supply brushes 5 applied to the shaft 3 of the rotor core 2 and the load of the elastic pressing body 10 are kept in balance. Can be prevented, the loss between the shaft 3 of the rotor core 2 and the bearing can be reduced to prevent an increase in current, and to shorten the life of the bearing.

Further, according to the present invention, a pair of power supply brushes 5 in which a magnet 9 is arranged opposite to the rotor core 2 and which contacts a commutator 4 fixed to the shaft 3 of the rotor core 2 are rotated by the rotation of the commutator 4. A motor which is arranged on a locus 6 so as not to be symmetrical with respect to its center of rotation 7, wherein gaps G ₁ , G ₂ between the rotor core 2 and the magnet 9 are set non-uniformly in the circumferential direction. In addition, the load of the pair of power supply brushes 5 applied to the shaft 3 of the rotor core 2 and the rotor core 2
And the suction force of the rotor core 2 is maintained by the suction force of the rotor core 2.
Therefore, the loss between the shaft 3 of the rotor core 2 and the bearing can be reduced to prevent an increase in current, and to shorten the life of the bearing.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below. As shown in FIGS. 1 and 2, the motor 1 of the present embodiment includes a pair of power supply brushes (anode brush, cathode brush) on a commutator 4 fixed to a shaft 3 of a rotor core (not shown). 5 are slidably in contact. The pair of power supply brushes 5 are arranged on the rotation locus 6 of the commutator 4 so as not to be symmetric with respect to the rotation center 7 thereof. In the embodiment shown in FIG. 1, the pair of power supply brushes 5 is 90 °.
It is arranged in the direction of. The magnet disposed opposite to the rotor core has an N-pole and an S-pole alternately magnetized.
The point of being a pole is the same as the conventional one (FIG. 9). Each of the power supply brushes 5 is pressed by a spring 19 and is in contact with the commutator 4, so that power is supplied from the power supply brush 5 to the commutator 4. 1, 21 is a brush holder, 22 is a fixed boss, 23 is a connection line, 24 is a housing, and 26 in FIG. 2 is an insulating plate.

[0009] In addition, on the rotation locus 6 of the commutator 4,
In a position different from the pair of power supply brushes 5 shown in FIG.
(A) As shown in FIG.
A dummy brush 8 is disposed as a sliding member. Da
Me brush 8 is made of a material having good cleaning properties.
Is preferred. In the present embodiment, a pair of commutators 4
A position opposite to the power supply brush 5 and one power supply brush
At one place at an interval of about 135 ° from Rashi 5,
The dummy brush 8 is fixed by a fixing boss 27. Dami
-The brush 8 is pressed by the dummy brush spring 20 and adjusted.
The brush pressure of the dummy brush 8
F_FourIs the brush pressure F of the power supply brush 5 ₁, F_Twoof
It is set equal to the composite pressure, and the brush pressure F_Fourof
The direction is set opposite to the direction of the combined pressure of the power supply brush 5.
As a result, the composite pressure of the power supply brush 5 and the
-Brush pressure F of brush 8_FourAnd the balance is maintained.

Therefore, when a pair of power supply brushes 5 contacting the commutator 4 are arranged in a 90 ° direction, the load balance is maintained by using a non-conductive dummy brush 8 separately from the power supply brushes 5. As the dummy brush 8 is used, the inclination of the shaft 3 of the rotor core can be eliminated by the dummy brush 8, so that the loss between the shaft 3 and the bearing 14 can be reduced, the current can be prevented from increasing, and the life of the bearing 14 can be extended. Can be.
Further, since the dummy brush 8 is made of a non-conductive sliding material, it is possible to prevent the segments of the commutator 4 from being short-circuited by the dummy brush 8, which hinders the power supply brush 5 from energizing the commutator 4. In addition, since only one dummy brush 8 need be provided, the assembly can be prevented from being complicated. If the dummy brush 8 is made of a material having good cleaning properties, the effect of cleaning the surface of the commutator 4 by the dummy brush 8 can be obtained, and the surface of the commutator 4 can be always activated.
It is possible to reduce the contact resistance between the power supply brush 5 and the power supply brush 5 and stabilize the conduction.

The number of the dummy brushes 8 is not particularly limited. As shown in FIG. 2, a pair of dummy brushes 8 are provided at positions opposed to a pair of power supply brushes 5 arranged in a 90 ° direction. They may be arranged. In this case, dummy brushes 8 made of a non-conductive sliding material are arranged at two positions, and the balance between the brush pressures F ₁ and F _{2 of} the power supply brush 5 and the brush pressures F ₅ and F ₆ of the dummy brushes 8 is obtained. Is maintained, the inclination of the shaft 3 can be eliminated by the dummy brush 8, and the same operation and effect as in FIG. 1 can be obtained. In addition, the cleaning effect is further enhanced by increasing the number of the dummy brushes 8, and when the mounting positions of the pair of dummy brushes 8 are determined, the pair of power supply brushes 5 and the pair of power supply brushes 5 are each 180 °.
Since the dummy brushes 8 need only be positioned at the opposing positions, there is an advantage that the setting of the mounting position of the dummy brush 8 is easy, and the mounting work is easy. By the way, although the power supply brush 5 is shortened due to electric wear and mechanical wear between the commutator 4 and the non-conductive dummy brush 8, only the mechanical wear is applied. Different rates of wear. Therefore, power supply brush was in the initial time of for example 1/2 of the brush pressure F ₁ of power supply brushes 5 which faces the brush pressure F ₅ of one dummy brush 8, facing the brush pressure F ₆ of the other dummy brush 8 1/2 of the brush pressure F ₂ of 5 by setting each kept in the initial-end of power supply brushes 5, F ₁ and F _5, and F ₂ and F ₆ is a state close to equilibrium at all times It is possible to do so. This is the same in the embodiment of FIG.

FIGS. 4 and 5 show another embodiment of the present invention. In FIG. 4, a shaft 3 is press-fitted into the center of a rotor core 2 around which a coil 15 is wound, and both ends of the shaft 3 are rotatably supported by bearings 14 (or bearings). In FIG. 4A, 9 is a magnet, 28 is a fan, and 29 is a washer. In the present embodiment, 9
In order to prevent the shaft 3 of the rotor core 2 from tilting due to the load of the pair of power supply brushes 5 arranged in the 0 ° direction, an elongated plate-shaped elastic pressing body 10 which is a non-conductive sliding member is used. is there. The elastic pressing body 10 is disposed outside the motor 1 and presses the shaft 3 of the rotor core 2 in one direction to maintain the load balance with the power supply brush 5. The end is screw-fixed to the housing 24, and the tip is in elastic contact with the exposed portion of the shaft 3 of the rotor core 2. Then, as the load F ₇ of the elastic pressing member 10 is substantially equal to the brush pressure F _1, F ₂ of the synthesis pressure of the pair of power supply brushes 5, by pressing the shaft 3 of the rotor core 2 in one direction, The same operation and effect as the embodiment of FIG. 1 can be obtained, and the elastic pressing body 10 is brought into direct contact with the shaft 3 of the rotor core 2 exposed to the outside of the motor 1,
After the motor 1 is assembled, the elastic pressing body 10 can be attached by retrofitting, so that the mounting operation of the elastic pressing body 10 is facilitated. Further, since only one elastic pressing body 10 needs to be added, the number of parts can be reduced, and assembly can be performed. The effect that the workability is further improved can be obtained.

FIGS. 6 and 7 show still another embodiment of the present invention.
Is shown. In FIG. 6, facing the rotor core 2
The magnet 9 is provided, and the magnet 9 is
The gap G is fixed to the magnet 9 while being fixed.₁,
G_TwoThe rotor core 2 is rotatable at the opposite position
A pair of power feeders that are arranged and contact the commutator 4
Brush 5 is arranged in the 90 ° direction. This embodiment
Then, the gap G between the rotor core 2 and the magnet 9₁,
G_TwoIs uneven in the circumferential direction (for example, G₁<G _Two)
And thus the shaft 3 of the rotor core 2
The load of the pair of power supply brushes 5 and the suction force of the rotor core 2
Is balanced. In other words, the power supply brush 5 side
The inner diameter A of the gnet 9 is increased, and on the power supply brush 5 side
G between rotor core 2 and magnet 9₁The small
By increasing the suction force of the rotor core 2,
On the other hand, on the other hand
Reduce the inner diameter B (> A) of
The gap between the rotor core 2 and the magnet 9 on the side
Top G_Two(> G₁) By increasing the rotor
The suction force of the iron core 2 is reduced. Therefore, FIG.
As shown in (b), the brush pressure F of the power supply brush 5₁,
F_TwoPressure and suction force F of rotor core 2₈Balance with
The dummy brush 8 of the above embodiment,
The shaft 3 of the rotor core 2 is provided without providing the elastic pressing body 10.
The effect of preventing the inclination of
Mechanical abrasion when the brush 8 and the elastic pressing body 10 are provided
There is also an effect that it is not necessary to consider.

In each of the above embodiments, the case where the pair of power supply brushes 5 are arranged in the direction of 90 ° has been exemplified. However, the present invention is not limited to this.
Alternatively, they may be arranged in a direction of 90 ° or more.

[0015]

As described above, according to the first aspect of the present invention, the pair of power supply brushes that contact the commutator fixed to the shaft of the rotor iron core are arranged on the rotation trajectory of the commutator. A motor that is displaced so as not to be symmetrical with respect to the center of rotation, and is non-conductive so as to contact the commutator at a position different from the pair of power supply brushes on the rotation trajectory of the commutator. Since the dummy brush is arranged and the load of the pair of power supply brushes applied to the shaft of the rotor core and the load of the dummy brush are configured to be balanced, the rotor core due to the load of the power supply brush is maintained. The inclination of the shaft can be eliminated by the dummy brush, the loss between the shaft of the rotor core and the bearing can be reduced, and the current can be prevented from increasing, and the life of the bearing can be extended. In addition, since the dummy brush is made of a non-conductive sliding material, it is possible to prevent the commutator segments from being short-circuited by the dummy brush, and to obtain a commutator surface cleaning effect by the dummy brush. As a result, the contact resistance between the commutator and the power supply brush can be reduced, and the conduction can be stabilized.

According to a second aspect of the present invention, in addition to the effect of the first aspect, a pair of dummy brushes are arranged at positions symmetrical to the pair of power supply brushes, so that the mounting positions of the dummy brushes are provided. Can be easily understood, workability is improved, and the effect of cleaning the commutator surface can be further improved by increasing the number of dummy brushes.

According to a third aspect of the present invention, a pair of power supply brushes that are in contact with a commutator fixed to a shaft of a rotor iron core are not symmetrical with respect to the center of rotation of the commutator on the rotation trajectory. A motor that is staggered,
With the elastic pressing body that presses the axis of the rotor core in one direction, since the load of the pair of power supply brushes applied to the axis of the rotor core and the load of the elastic pressing body are configured to be balanced, The inclination of the shaft of the rotor core can be prevented by the elastic pressing body. Therefore, the loss between the shaft of the rotor core and the bearing can be reduced to prevent an increase in current, and also to shorten the life of the bearing. Further, the elastic pressing body can be brought into direct contact with the shaft of the rotor core exposed to the outside of the motor, and in this case, the elastic pressing body can be retrofitted after the motor is assembled, so that the assembling workability is improved.

According to a fourth aspect of the present invention, a pair of power supply brushes, in which a magnet is disposed to face the rotor core and is in contact with a commutator fixed to the shaft of the rotor core, are arranged on the rotation path of the commutator. A motor arranged so as not to be symmetrical with respect to its rotation center, wherein a gap between a rotor core and a magnet is set to be non-uniform in a circumferential direction, and a pair of power feeds applied to an axis of the rotor core. Since the configuration is such that the load of the brush and the suction force of the rotor core are balanced, the inclination of the rotor core axis can be prevented by the suction force of the rotor core. Loss can be reduced to prevent an increase in current, and also to shorten the life of the bearing. Moreover, it is not necessary to separately add a special part for maintaining the balance of the load applied to the shaft of the rotor core, so that the shaft of the rotor core can be prevented from tilting with a simple structure.

[Brief description of the drawings]

1A and 1B show an example of an embodiment of the present invention, and FIG. 1A is a side view illustrating an arrangement of a power supply brush and a dummy brush;
(B) is an explanatory view of the load of the power supply brush and the load of the dummy brush applied to the shaft of the rotor core.

FIG. 2A is a cross-sectional view showing the vicinity of a power supply brush according to the first embodiment;
(B) is a side view of (a).

3A and 3B show an example of another embodiment, in which FIG. 3A is a side view illustrating an arrangement of a power supply brush and a dummy brush, and FIG. 3B is a view showing a load of the power supply brush applied to an axis of a rotor core and a dummy brush; It is explanatory drawing of a load.

4A and 4B show still another embodiment, in which FIG. 4A is a side view of a motor, and FIG.

5A is a side view for explaining the arrangement of the elastic pressing member of FIG. 4, and FIG. 5B is an explanatory diagram of a load of a power supply brush and a load of the elastic pressing member on a shaft of a rotor core.

FIGS. 6A and 6B show still another embodiment, in which FIG. 6A is a left side view of the motor, and FIG.

7A is a right side view of the motor of FIG. 6, and FIG. 7B is an explanatory diagram of a load of a power supply brush applied to a shaft of a rotor core and an attraction force of the rotor core.

8A is a side view of a conventional motor, and FIG. 8B is a cross-sectional view.

9A is a side view for explaining the arrangement of a conventional power supply brush, FIG. 9B is an explanatory view of a load of the power supply brush applied to the axis of the rotor core, and FIG. 9C is the inclination of the axis of the rotor core. FIG.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 motor 3 rotor core shaft 4 commutator 5 power supply brush 6 rotation locus 7 rotation center 8 dummy brush 9 magnet 10 elastic pressing body G ₁ , G ₂ gap

Claims (4)

[Claims] 1. A motor in which a pair of power supply brushes that are in contact with a commutator fixed to a shaft of a rotor core are displaced on the rotation locus of the commutator so as not to be symmetric with respect to the center of rotation. A non-conductive dummy brush is arranged at a position different from the pair of power supply brushes on the rotation trajectory of the commutator so as to contact the commutator, and a pair of power supply brushes on the shaft of the rotor core. A motor configured to maintain a balance between a brush load and a dummy brush load. 2. The motor according to claim 1, wherein a pair of dummy brushes are arranged at positions symmetrical to the pair of power supply brushes. 3. A motor in which a pair of power supply brushes in contact with a commutator fixed to a shaft of a rotor core are displaced on a rotation locus of the commutator so as not to be symmetric with respect to the center of rotation. And an elastic pressing member that presses the axis of the rotor core in one direction, and is configured such that the load of the pair of power supply brushes applied to the axis of the rotor core and the load of the elastic pressing member are balanced. Motor. 4. A pair of power supply brushes, in which a magnet is arranged to face the rotor core and which contacts a commutator fixed to the shaft of the rotor core, is symmetrical with respect to the center of rotation of the commutator on the rotation locus of the commutator. A gap between the rotor core and the magnet is set to be non-uniform in the circumferential direction, and the load of the pair of power supply brushes applied to the shaft of the rotor core and the rotation of the rotor core. A motor characterized in that a balance with suction force is maintained.