JPH10146025A - Brush structure of dc machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the brush structure of a DC machine which can stabilize the sliding of a brush and a commutator with simple structure and prevent the production of the noise caused by the vibration of a brush and besides is inexpensive. SOLUTION: This is the brush structure of a DC machine where the brush body 10 generates a component by making the face on which to arrange a biasing means 30 an incline 40, and the brush body 10 is pressed against the sidewall of a brush holder 20. One end side 11b of the sliding incline 11 at the brush body 10 is made into a curved form which contacts with a commutator 50 and roughly conforms to the periphery of a commutator 50, and also the other side 11a of the sliding incline 11 is made into curved form which roughly conforms to the circumference of a circle having a center C2 slid in reverse direction to the direction W of rotation of the commutator 50 from the center C1 of the commutator 50.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brush structure of a DC machine, and more particularly to a brush structure of a DC machine for suppressing self-excited vibration of a brush caused by sliding of a brush and a commutator and abnormal noise caused by the vibration. The present invention relates to a brush structure of a DC machine that slides a brush and a commutator in a stable state.

[0002]

2. Description of the Related Art In a DC machine, a brush and a commutator are used to obtain a rectifying action, as is well known. Conventionally used brush holding devices include, for example, a brush holding device for accommodating a brush and a spring as a biasing means for elastically pressing the brush against a commutator.

In such a brush and a brush holder, since there is a clearance between the brush and the brush holder, the brush is laterally displaced or inclined in the brush holder due to sliding friction when the commutator rotates. Alternatively, the lateral displacement or the inclined state of the brush changes due to the change in the sliding friction state, and the brush sliding state becomes unstable. As a result, it is empirically known that the brush not only causes self-excited vibration and deteriorates the rectifying action, but also generates an unusual sound due to the self-excited vibration and gives the user discomfort.

As a countermeasure against the above problem, the rear end of the brush is formed so as to be inclined with respect to the longitudinal axis of the brush,
By pressing the brush against the side wall of the brush holder, the brush and the brush holder are held in a surface contact state, and the brush is held in a state of sliding in the contact surface with the brush holder. There was a way to control. However, in this method, the force for pressing against the side wall changes depending on the assembled state of the brush holder, and a sufficient effect cannot be obtained.

To solve the above problem, Japanese Patent Laid-Open No. 61-21 / 1986 discloses a technique for ensuring frictional sliding between a brush and a brush holder.
No. 6282 is disclosed. As shown in FIG. 9, a spring structure for applying a side pressure is used to press the brush 110 against the side wall of the brush holder 120. As a means for pressing the brush 110 from the side, a leaf spring 130 formed in a U-shape is used. By using this leaf spring 130,
The leaf spring 130 is fixed by being inserted into the notch at the rear end of the brush holder 120 at the same time as the spring stopper 140 having a projection on a part of its surface. According to this technique, since the projection is provided on a part of the spring stopper 140, the thin plate spring 130 can be locked without rattling.

[0006]

However, according to the prior art shown in the figure, the brush 110 can be pressed and held from the side, but it is necessary to use the leaf spring 130 and the stopper 140 for the spring. Along with the increase in the number of components, there is a problem that the manufacturing cost increases due to the complicated structure and assembly.

An object of the present invention is to provide an inexpensive brush structure of a DC machine which can stabilize sliding of a brush and a commutator with a simple structure and can prevent generation of noise due to vibration of the brush. is there.

[0008]

According to a first aspect of the present invention, there is provided a brush structure for a DC machine, comprising: a brush body having a sliding contact inclined surface inclined at a predetermined angle with respect to an outer peripheral surface of a commutator; Urging means disposed on the opposite side to press the brush body toward the commutator side, and a brush holder that houses the brush body and the urging means and has a space between the brush body and Comprising, the brush body,
A brush structure of a DC machine for generating a component force by making a surface on which the urging means is disposed an inclined surface and pressing the brush body against a side wall of the brush holder, wherein a sliding contact inclination in the brush body is provided. One end of the surface comes into contact with the commutator and is formed into a curved shape substantially matching the outer peripheral surface of the commutator, and the other end of the sliding contact inclined surface rotates the commutator with respect to the center of the commutator. It is characterized in that it is formed in a curved shape that substantially matches the circumference of a circle having a center shifted in the direction opposite to the direction.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The brush structure of a DC machine according to the present invention is as follows.
A brush body 10 having a sliding contact inclined surface 11 inclined at a predetermined angle with respect to an outer peripheral surface 51 of the commutator 50, and a brush body 1 disposed on a surface 12 opposite to the sliding contact inclined surface 11.
The brush body 10 includes a coil spring 30 as urging means for pressing the brush body 10 toward the commutator 50, and a brush holder 20 that houses the brush body 10 and the coil spring 30 and has a space between the brush body 10 and the brush body 10. Is a coil spring 3
By making the surface on which the “0” is disposed an inclined surface 40, a component force is generated, and the brush body 10 is pressed against the side wall of the brush holder 20.

One end 11b of the sliding contact slope 11 of the brush body 10 is in contact with the commutator 50 and is formed into a curved shape substantially matching the outer peripheral surface 51 of the commutator 50. Other end 11a
Is characterized in that it is formed in a curved shape substantially matching the circumference of a circle having a center shifted in the direction opposite to the rotation direction of the commutator with respect to the center of the commutator 50.

As described above, according to the present invention, in the DC machine, the component force by the inclined surface 40 of the brush body 10
The brush main body 10 is rotated by rotating the brush main body 10 by rotating the brush main body 10 by rotating one end side 11b of the brush main body 10 in sliding contact with the commutator 50 and the other end side 11a of the sliding main body 11 in different shapes. By positively pressing in the direction W, the sliding between the brush main body 10 and the commutator 50 can be stabilized, and generation of noise due to vibration of the brush can be prevented. Also, since no special parts are required,
Vibration and noise can be prevented at low cost.

[0012]

An embodiment of the present invention will be described below with reference to the drawings. The members, arrangements, and the like described below do not limit the present invention, and can be variously modified within the scope of the present invention.

FIGS. 1 to 8 show a specific embodiment according to the present invention. FIG. 1 is a perspective view showing a brush body.
2 is a perspective view of FIG. 1, FIG. 3 is a perspective view of FIG. 1, and FIG.
5 and 6 are explanatory views showing a commutator and a brush main body, FIG. 7 is an explanatory view showing a state of wear of the brush main body, and FIG. 8 is a view for explaining an operation by an inclined surface of the brush main body. FIG.

The brush structure of the DC machine in this embodiment is shown in FIG.
As shown in (1), the brush main body 10, the brush holder 20, and the coil spring 30 as urging means are constituted as main components, and are joined to the commutator 50. The brush body 10 of the present embodiment is formed using the same members as those conventionally used in this type of apparatus, and is formed in a prismatic shape.

FIG. 1 shows a commutator 50 of the brush body 10.
1 shows an end portion on the side in contact with. The brush body 10 of this example is joined to the outer peripheral surface 51 of the commutator 50 at one end of the brush body 10 in the direction of the center line L1.

On the other hand, as shown in FIG. 6, an inclined surface 40 is formed on the surface 12 of the brush body 10 where the coil spring 30 is arranged. Thereby, when the brush body 10 is pressed against the commutator 50 by the coil spring 30, a component force is generated. This operation will be described with reference to FIG.

In FIG. 8, NS, a force acting perpendicular to the inclined surface 40 is applied to the direction of the long axis 10a of the brush body 10.
The angle of the inclined surface 40 is defined as θ. The force NS generates a component force in the direction of the center line L <b> 1 of the brush main body 10 and in a direction orthogonal to the direction due to the inclined surface 40.

Between the force NS and the component force in the direction of the center line L1 of the brush body 10, an opening having the same angle as the inclination angle θ is generated, so that the component force in the direction of the center line L1 is NS · cos θ. expressed. The component force generated in the direction orthogonal to the center line L1 is expressed as NS · sin θ. And NS-cos
The force represented by θ is the commutator 50 in the direction of the center line L1.
Acts to press.

The force represented by NS · sin θ is a force directed in a direction orthogonal to the center line L1. That is, this force acts to press the brush body 10 against the wall surface of the brush holder 20.

For this reason, the joint end 11 of the brush body 10
The brush body 10 is pressed along the direction of travel of the commutator rotation, and is combined with the component force generated by the inclined surface 40 of the brush body 10 so that the brush body 10 is positioned along the wall of the brush holder 20 on the direction of travel of the commutator rotation.

As shown in FIG. 6, the brush holder 20 and the commutator 50 are arranged so that the center C1 of the commutator 50 exists on the center line L2 of the brush holder 20. The center line L1 of the brush body 10 housed in the brush holder 20 is the center line L2 of the brush holder 20.
Than the commutator 50 in the rotation direction W side by ΔZ. A gap of 2ΔZ is provided between the brush body 10 and the brush holder 20.

Next, the shapes of the brush body 10 and the brush holder 20 in this embodiment will be described. As shown in FIG. 1, the end of the brush body 10 of the present embodiment on the side to be joined to the commutator 50 is inclined with respect to the commutator 50 to form a sliding contact inclined surface 11. Side 1 on this sliding contact slope 11
1b is formed so as to be joined to the commutator 50. The side 11b is formed in a curved shape that substantially matches the outer peripheral surface 51 of the commutator 50 when the side 11b contacts the commutator 50.

On the other hand, the side 11a of the sliding contact inclined surface 11 which is separated from the commutator 50 by a predetermined distance is the side 11b
It is formed in a curved shape different from that of FIG. If the curved shape of the side 11a is described with reference to FIG. 1, the center C1 of the commutator 50 is
Is formed in a curved shape that substantially matches the circumference of a circle having a center C2 shifted by a predetermined distance in a direction opposite to the rotation direction of the commutator 50.

That is, the center C1 of the commutator 50 is shifted by ΔX as shown in FIG. At this time, the brush body 10 is inclined at the sliding contact inclined surface 11, so that the circumference of a circle formed with the same radius R as the radius of the commutator 50 has a further distance Y so that a curved shape can be formed on the side 11a. Move to specify the center point C2. At this time, ΔX can be set at a predetermined value regardless of ΔZ.

An engaging projection 60 is provided on the inclined surface 40 of the brush body 10 opposite to the center line L1 with respect to the sliding contact inclined surface 11, and the engaging projection 60 is provided on the inclined surface 40. One end of a coil spring 30 as an urging means is externally fitted.

Further, the brush holder 20 of this embodiment is formed in a bottomed cylindrical shape having an opening on one side in accordance with the shape of the brush main body 10, and accommodates the brush main body 10 and the coil spring 30. I have. One end of a coil spring 30 is fixed to the bottom of the brush holder 20 of this example, and the coil spring 30 presses the brush body 10 toward the commutator 50.

The brush holder 20 of this embodiment is provided on the side wall.
A slit (not shown) having an appropriate length is formed, and the brush holder 20 is fixed to a motor housing (not shown).

The commutator 50 of the present embodiment has a well-known configuration, and does not particularly have a special configuration for the present invention. Note that the commutator 50 is supported by the rotating shaft 70.

As described above, the brush body 10 of the present embodiment is formed in such a shape that one side 11b of the sliding contact slope 11 coincides with the outer peripheral surface of the commutator 50, and the other side 11a has a curved shape of the commutator 50. The center C1 of the commutator 50 is formed in a curved shape substantially matching the circumference of a circle having a center C2 shifted by a predetermined distance with respect to the center of the commutator 50. Therefore, as shown in FIG. The inclination of 11 is different depending on each position of the sliding contact inclined surface 11. FIG. 4 is a view of the brush body 10 in FIG. 1 as viewed from the F side.
The slope on the A side is smaller than the slope on the B side.

Therefore, the brush body 10 is connected to the commutator 5
When the commutator 50 is rotated in contact with 0, the portion on the A side where the inclination angle is small approaches the commutator 50 more, so that the contact surface with the commutator 50 increases. FIG. 7 shows a worn state of the brush main body 10 in this example. The brush main body 10 is worn from the side A where the contact surface with the commutator 50 is large.

In the brush body 10, even if the wear on the side 11b that is in sliding contact with the commutator 50 from the beginning progresses, in the brush body 10, the portion on the A side having a larger inclination angle is always larger than the portion on the B side. Commutator 50
, There are many contact surfaces with the commutator 50, and as the wear progresses, the entire surface on the A side comes into contact immediately.

As described above, since the commutator 50 slides along the worn portion of the brush main body 10, the brush main body 10 is always slid at the joint with the commutator 50 while being pressed in the rotation direction W of the commutator 50. Move.

In the brush body 10 of this embodiment, since the sliding contact inclined surface 11 is formed in a tapered shape, the commutator 5 is formed.
In the pressure contact with 0, since the joint surface and the brush are joined at a higher pressure, the abrasion speed of the comb surface and the brush is faster than that in a case where the sliding contact inclined surface 11 of the brush body 10 is not formed in a tapered shape. Therefore, the sliding surface due to the initial wear can be obtained more quickly.

It should be noted that the brush body 10 is
It may not be set so that the side 11 b of the sliding contact inclined surface 11 in the brush main body 10 coincides with the commutator outer peripheral surface 51 when pressed against the side surface.

[0035]

As described above, since the degree of wear progress of the brush contacting the commutator of the DC machine is made different, the brush tip is pressed toward the commutator rotation direction, and the brush rear end is further pressed. In combination with the taper force, the brush is stabilized along the wall of the brush holder in the direction of the commutator rotation, thereby suppressing the generation of noise.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a brush main body according to the present invention.

FIG. 2 is a view as viewed in a direction D in FIG. 1;

FIG. 3 is a view as viewed from E in FIG. 1;

FIG. 4 is a view as viewed from F in FIG. 1;

FIG. 5 is an explanatory diagram showing a sliding contact state between a commutator and a brush body.

FIG. 6 is an explanatory diagram showing a sliding contact state between a commutator and a brush main body.

FIG. 7 is an explanatory view showing a worn state of the brush main body.

FIG. 8 is an explanatory diagram for explaining an operation by the inclined surface of the brush main body.

FIG. 9 is an explanatory diagram showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Brush main body 11 Sliding contact inclined surface 20 Brush holder 30 Coil spring 40 Inclined surface 50 Commutator 60 Locking part 70 Rotation axis W Rotation direction ΔX distance Y distance

Claims (1)

[Claims] 1. A brush body having a slidable inclined surface inclined at a predetermined angle with respect to an outer peripheral surface of a commutator, and a brush body disposed on a surface opposite to the slidable inclined surface to move the brush body toward a commutator. A brush holder that stores the brush body and the biasing means and has a space between the brush body and the brush body, wherein the brush body has a surface on which the biasing means is disposed. A brush structure of a DC machine for generating a component force by forming an inclined surface and pressing the brush body against a side wall of the brush holder, wherein one end side of a sliding contact inclined surface in the brush body is the commutator. Is formed in a curved shape substantially matching the outer peripheral surface of the commutator, and the other end of the sliding contact inclined surface is shifted from the center of the commutator in a direction opposite to the rotation direction of the commutator. A brush structure for a DC machine, wherein the brush structure is formed in a curved shape that substantially matches the circumference of a circle having.