JPS5939832Y2 - Rotor of small DC motor - Google Patents

Description

[Detailed description of the invention] This invention relates to a small DC motor rotor in which two windings are wound around one pole, and the slit between the commutator pieces is kept insulated.
This ensures that the efficiency of the motor does not decrease and its lifespan remains the same.

Normally, the slits formed between each of the multiple arc-shaped commutator pieces centered around the rotation axis are clogged with abrasion powder caused by the sliding of the brush and commutator, which impairs the insulation between the commutator pieces. , to some extent conductive foreign matter due to electric sparks generated between commutator pieces,
In other words, the insulation is maintained by burning the wear particles mentioned above.

However, in the rotor 1a of the mechanically controlled three-pole compact DC motor, which reduces the number of speed governors and can control the rotation with one speed governor 10, as shown in FIG. 1, each of the two poles has one winding. Wires 2a and 3a are wound, but the other pole has windings 4a and 5.
Since a has two windings, the voltage generated between commutator pieces 4a' and 5a' corresponding to these windings 4a and 5a is the voltage between other commutator pieces, that is, Surin) 7 a t 8 a
This is very small compared to the voltage generated at t 9 a.

That is, since the windings 4a and 5a are wound around the core of the same pole, the mutual inductance between the windings 4a and 5a is large, which acts in the direction of canceling out the voltage generated by the inductance of the respective windings 4a and 5a. It is for this purpose.

Therefore, the sulin between commutator pieces 4a/ and 5a/)6
A is difficult to generate sparks and is easily clogged with conductive foreign matter, so other Surin)? Compared to A, 8A, and 9A, insulation cannot be maintained, the efficiency of the motor is lowered, and the life of the motor is further shortened.

Therefore, in the present invention, in order to solve the above-mentioned drawbacks, only the width of the slit 6a is made wider than the other slit widths.

An embodiment of the present invention will be explained below with reference to FIG. 2. The rotor 1 of a mechanically governed three-pole small DC motor has only a governor 10, and it rotates by itself. In order to control the windings, windings 2 and 3 are wound around each of the two poles, while windings 4 and 5 are wound around the other pole. Arc-shaped commutator pieces 2', 3', and 4' corresponding to 4.5.

5' is a three-pole motor, so the commutator pieces 4' and 5' are half the width of the other commutator pieces z and 3', and furthermore, the widths of the commutator pieces 6, 7, and 5' are provided between each commutator piece. 8.9, the width of the slit 6 between the commutator pieces 4' and 5' corresponding to the windings 4 and 5 is larger than the width of the other slits 7.8.9.

In this way, by making only the width of the slit 6 larger than the others, even though it is difficult for electrical sparks to occur in the slit 6, the distance between the commutator pieces is long, so no electrical continuity occurs until a certain amount of conductive foreign matter accumulates. , dielectric breakdown is caused by other surin)7
, 8.9 can be prevented.

By the way, according to experiments, the width of the slit 7.8°9 was set to 0.
3 mm, and by setting only the width of the slit 6 to 0.35 mm, the efficiency and life of the motor were significantly improved compared to a case where all slit widths were 0.3 mm.

Also, compared to a model in which all slits have a width of 0.35 mm, the efficiency and lifespan are about the same, but the sliding noise between the brush and commutator is much smaller.

As described above, the rotor of a small DC motor has windings wound around each of the multiple poles and an arc-shaped commutator piece (this includes not only cylindrical commutators but also disc-shaped commutators, etc.) connected to each winding. In this method, two windings are wound around one pole, the width of each commutator piece connected to these two windings is approximately half the width of the other commutator piece, and the width between these two commutator pieces is Compared to the conventional example shown in Figure 1, in the rotor of a small DC motor in which the width of the slit is larger than the width of other slits, performance such as efficiency and life can be improved by simply making one part of the slit wider than the other. can be improved.

[Brief explanation of the drawing]

FIG. 1 is a rotor winding connection diagram of a conventional three-pole motor with one speed governor. Figure 2 is an embodiment diagram showing the rotor of a three-pole motor with one speed governor according to the present invention.・・・
...Slit, 10... Speed governor.

Claims (1)

[Scope of utility model registration request] In the rotor of a small DC motor, in which a winding is wound around each of the multiple poles and each winding is connected to an arc-shaped commutator piece arranged in the same role through a slit, two windings are formed on one pole. The width of each independent commutator piece connected to these two windings is approximately half the width of the other commutator pieces, and the width of the slit between these two commutator pieces is set to the width of the other slit. A small DC motor rotor that is larger than its width.