JPS62293946A - Rotor for miniature rotary electric machine - Google Patents

Abstract

PURPOSE:To increase output torque, by making the length of the rotation- direction salient section of the arm of a salient pole piece, smaller than the length of a counterrotation-direction salient section. CONSTITUTION:A rotor R is provided with a core 20 fitted coaxially on the intermediate section of a rotary shaft 10, and on the core 20, salient pole pieces 21 and slots 22 are formed radially and alternately on by one toward the inner peripheral surface of a stator S from the central section of the core 20. The salient pole pieces 21 are respectively composed of legs 21a extended in the radial direction from the central section of the core 20, and arms 21b formed in the shape of 'L' in the counter rotational direction of the core 20 from the external ends of the legs 21a. As a result, starting torque and other torque can increased without increasing profile dimension and weight.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention [Field of Industrial Application] The present invention relates to various small-sized rotating electric machines such as commutator motors and small-sized DC motors, and particularly relates to stators of the rotating electric machines. This invention relates to an improvement of a rotor that is rotatably supported within the rotor.

[Prior art]

Conventionally, in the case of a small electric motor that can be cited as an example of this type of rotating electric machine, for example,
As disclosed in the above publication, each salient pole piece of the core provided on the rotor in the stator has a leg extending radially from the center of the core and a T-shape at the outer end of the leg. There are some that have different configurations depending on the formed arms.

(Problem to be Solved by the Invention) By the way, in such a configuration, when trying to improve the torque characteristics of a small electric motor, it is necessary to increase the thickness of the stator yoke or increase the thickness of each protrusion of the iron core. One possible method is to increase the external dimensions of the legs and arms of the pole piece to reduce the magnetic resistance of the magnetic circuit, but even if the torque characteristics of the small electric motor are improved, the weight and external dimensions of the small electric motor will be reduced by such a method. The problem is that it increases.

On the other hand, the present inventors experimentally investigated the amount of effective magnetic flux passing through the protrusion in the rotation direction, the protrusion in the counter-rotation direction, and the peak of each arm of each salient pole piece of the above-mentioned iron core. However, although the rotational direction protrusion and the counter-rotation direction protrusion are formed symmetrically with respect to the outer ends of the legs, the amount of effective magnetic flux passing through the rotational direction protrusion is greater than the amount of effective magnetic flux passing through the rotational direction protrusion. It was confirmed that the amount of magnetic flux was greater than the effective amount of magnetic flux passing through the protrusion in the rotational direction.

Therefore, in order to deal with the above-mentioned problems, the present invention has the following features:
Based on the above experimental results, we focused on the fact that the magnetic resistance of the rotor core could be reduced by making the amount of effective magnetic flux passing through the protrusion in the rotational direction as much as possible through the protrusion in the counter-rotation direction. The present invention aims to provide a rotor that improves torque characteristics while maintaining the external dimensions and weight of the machine as before.

[Means for solving problems]

In solving this problem, the structural features of the present invention are as follows:
A plurality of salient pole pieces and a plurality of slots are coaxially and rotatably supported in a stator of a small rotating electric machine, and are alternately arranged one by one in the circumferential direction so as to face the inner circumferential surface of the stator. each salient pole piece is formed by a leg extending radially from the center of the core, and an arm formed along the circumferential direction of the core at the outer end of the leg. In the rotor configured, the length of the protrusion in the rotation direction of the arm of each salient pole piece is shorter than the length of the protrusion in the counter rotation direction of the arm of each salient pole piece, or is zero. It's what I did.

(effect). By configuring the present invention in this way,
At least a part of the amount of magnetic flux that should pass through the protrusions in the rotational direction of each of the salient pole pieces merges with the effective amount of magnetic flux that should pass through the protrusions in the counter-rotation direction, and passes through each of the protrusions in the counter-rotation direction. Since the magnetic reluctance of the salient pole pieces is substantially reduced, the output torque of this type of rotating electric machine can be increased without increasing its external dimensions and weight.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.
In the figure and FIG. 2, the symbol M indicates a commutator motor, and this commutator motor M is constructed by coaxially and rotatably assembling a rotor R according to the present invention in a stator S. There is. The rotor R has a rotating shaft 10, and the rotating shaft 10 is rotatably supported at both end portions of the stator S at the center portion of both ends via both bearings B, B. There is. In addition, in FIG. 1 and FIG. 2, each code|symbol m shows a field magnet, respectively.

Further, the rotor R has an iron core 20 fitted coaxially to the intermediate portion of the rotating shaft 10, and this iron core 20 includes a plurality of salient pole pieces 21 to 21 and a plurality of slots 22 to 22. but,
They are alternately formed one by one radially from the center of the iron core 20 toward the inner circumferential surface of the stator S. A plurality of salient pole pieces 21~
21 is a leg 2 extending in the radial direction from the center of the iron core 20.
1a, and an arm 21b formed in an L-shape from the outer end of the leg 21a in the counter-rotational direction of the iron core 20. In addition, in FIG. 2, the symbol C indicates a commutator, and the symbol W indicates a winding.

In this embodiment configured in this way, each salient pole piece 21
Since the arms 21b protrude only in the counter-rotation direction as described above, all seven effective magnetic fluxes passing through the legs 21a of each salient pole piece 21 pass through each arm 21b, and as a result, the magnetic resistance of the iron core 20 can be reduced. Therefore, in order to rotate the iron core 20 in the rotation direction shown in FIG.
1M, the starting torque and other torques of the commutator motor M can be increased based on the above-mentioned reduction in magnetic resistance without increasing the external dimensions and weight of the commutator motor M. Incidentally, when the starting torque of the commutator motor M was compared with that of a conventional commutator motor, the starting torque τa of the former was greater than the starting torque τb of the latter, as shown in Fig. 3. I was able to confirm that it was.

In addition, in the above embodiment, the arm 21 of each salient pole piece 21
4, the entire arm 21b of each salient pole piece 21 is made to protrude in the counter-rotational direction from the outer end of each leg 21a, but the present invention is not limited to this. As shown in FIG. Each arm 2
Even if the length of the protrusion q in the counter-rotational direction from the outer end of WE21a of 1b is made shorter than the length corresponding to the center angle θ2,
Similar effects to the previous embodiment can be achieved.

Further, in the above embodiment, an example was explained in which the present invention is applied to the rotor R of a commutator motor M, but the present invention is not limited to this, and the present invention can be applied to the rotor of various small rotating electric machines such as a small DC motor. It may be applied and implemented. In such a case, it goes without saying that the present invention can be similarly applied to a rotating electrical machine equipped with a stator having a field winding.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of the commutator motor with the windings removed;
The figure is a longitudinal sectional view of the same, Figure 3 is a graph showing a comparison of the starting torque of the commutator motor in Figure 1 with the conventional one, and Figure 4 is a half sectional view showing a modification of the iron core in Figure 1. It is. Explanation of symbols M... Commutator motor, R... Rotor, S... Stator, 20... Iron core, 21... Salient pole piece, 21a...
Legs, 21b...arms, 22...slots. Applicant: Aisan Industries Co., Ltd. Rotation direction

Claims (1)

[Claims] A plurality of salient pole pieces and a plurality of slots are coaxially and rotatably supported in a stator of a small rotating electric machine, and are alternately arranged one by one in the circumferential direction so as to face the inner circumferential surface of the stator. each salient pole piece is formed by a leg extending in a radial direction from the center of the iron core, and an arm formed along the circumferential direction of the iron core at the outer end of the leg. In the rotor configured, the length of the protrusion in the rotation direction of the arm of each salient pole piece is shorter than the length of the protrusion in the counter rotation direction of the arm of each salient pole piece, or is zero. A rotor for a small rotating electric machine characterized by: