JPH0787716A - Motor - Google Patents

Abstract

PURPOSE:To obtain a motor adapted for a fan, etc., by considering to reduce vibration by decreasing a torque ripple electrically generated at a rotor. CONSTITUTION:Main winding groups M1, M2 and auxiliary winding groups A1, A2 are circumferentially alternately provided in a toroidal state on a yoke 4 of a core, sub-windings Ma, Mb to be connected in series with the groups M1, M2 are provided at toothed parts 5 of the groups A1, A2 adjacent to the groups M1, M2, and sub-windings Aa, Ab to be connected in series with the windings A1, A2 are provided at toothed parts 5 of the groups M1, M2 adjacent to the groups A1, A2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric motor having a winding so as to reduce vibration.

[0002]

2. Description of the Related Art In a motor such as a capacitor induction motor, when winding a core to form a stator core, main winding groups and auxiliary winding groups are alternately arranged. Then, a rotating magnetic field is created to rotate the rotor. In such an electric motor, the rotor has a plurality of teeth through which magnetic flux passes, but the teeth to which the winding is applied act on the rotor as one arm, so the magnetic flux distribution of the winding group is constant. A rectangular wave-shaped magnetic flux distribution is shown in the direction.
When the magnetic flux distribution has a rectangular wave shape in this way, the torque generated in the rotor becomes digital with respect to the rotation direction to generate a torque ripple, which appears as vibration on the output shaft.

That is, in the conventional electric motor shown in FIG. 15, the main winding group M and the auxiliary winding group A are alternately wound around the yoke 1 in a toroidal shape, as shown in FIG. Is connected to. By arranging and connecting the windings in this way, the magnetic flux distribution 2 with respect to the rotor of the stator becomes a rectangular wave shape as shown in FIG.
The rotor will generate a digital torque. Originally, ideally, if the magnetic flux is distributed as shown by the sine curve 3 shown in the figure, the torque ripple generated in the rotor is almost eliminated, and the vibration is extremely reduced.

The vibration of the rotor thus generated causes various problems, and when it is used as a fan electric motor for an air conditioner or the like, noise is transmitted to the outside of the fan through the fan, resulting in low noise. I went against the hope of today's demand.

Therefore, a method of attaching the fan and the shaft and a method of considering the material of the fan can be considered so that the vibration is not generated from the fan. In either case, however, the production of the fan is expensive. However, it is required to reduce the vibration of the electric motor itself.

In order to reduce the vibration of the electric motor, it is possible to obtain a certain effect by increasing the mass, and it has been considered to mold the casting frame or the entire stator by premixing or the like. However, casting the former frame does not match the manufacturing technology of today's electric motors in terms of workability, and therefore it is common to mold the entire stator with the latter premix.

However, the vibration of the rotor is not always sufficiently effective even if mechanical measures are taken on the stator side, such as molding with premix to increase the mass of the frame. Measures are required.

In view of the above, the present invention has been made in consideration of electrically reducing the torque ripple generated in the rotor to reduce vibration, and has as its object to obtain an electric motor suitable for fans and the like.

[0009]

The present invention has an iron core formed by extending a plurality of teeth inside a yoke formed in a donut shape, and the yoke of the iron core is formed in a toroidal shape. The main winding group and the auxiliary winding group are alternately arranged in the circumferential direction, and the auxiliary winding group adjacent to the main winding group is provided with a sub winding that is connected in series with the main winding group. The above problem is solved by providing a sub-winding connected in series with the auxiliary winding group to the tooth portion of the main winding group adjacent to the winding group.

[0010]

With the sub-winding for supplying the current of the adjacent winding group to the rectangular wave-shaped rotating magnetic field generated in the stator due to the relationship between the main winding group and the auxiliary winding group which are alternately arranged. , The distribution of magnetic flux does not have a rectangular wave shape, but comes close to a sine curve.

By arranging the sub-windings in the middle in the circumferential direction of each winding group, it is possible to add the magnetic flux of the sub-windings to the magnetic flux distribution which is structurally a rectangular wave and to approximate the sine curve.

Electrically, since the main winding group and the auxiliary winding group have different current phases, the rotating magnetic field is not digitally transferred from the main winding group to the auxiliary winding group, but is a magnetic flux. The distribution becomes wider in the rotation direction, no shocking torque is generated in the rotor, and the vibration of the rotor is reduced.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to the embodiment shown in the drawings. FIG. FIG. 2 is a plan view of a main part of a stator according to another embodiment. FIG. 3 is a plan view of an essential part showing a state in which the main winding group and the auxiliary winding group are energized. FIG. 4 is a plan view of an essential part showing a state in which the main winding group and the auxiliary winding group are energized. FIG. 5 is a plan view of an essential part showing a state in which the main winding group and the auxiliary winding group are energized. FIG. 6 is a plan view of an essential part showing a state in which the main winding group and the auxiliary winding group are energized. FIG. 7 is a plan view of an essential part showing a state in which the main winding group and the auxiliary winding group are energized. FIG. 8 is a plan view of an essential part showing a state in which the main winding group and the auxiliary winding group are energized. FIG. 9 is a plan view of a main part of a stator showing another embodiment. Figure 10
It is a connection diagram of the stator shown in FIG. FIG. 11 shows FIG.
3 is a connection diagram of the stator shown in FIG. FIG. 12 is a diagram showing a magnetic flux distribution of the stator shown in FIG. FIG. 13 is a diagram showing a magnetic flux distribution of the stator shown in FIG. 14
FIG. 6 is a diagram showing a magnetic flux distribution of a conventional electric motor. Figure 15
FIG. 7 is a plan view of a main part showing a stator of a conventional electric motor.
FIG. 16 is a connection diagram of windings of the conventional electric motor shown in FIG.

In FIG. 1, the electric motor has a plurality of tooth portions 5 formed on the inner diameter side of a doughnut-shaped yoke 4.
A plurality of windings 7 are wound around the yoke 4 by using the slots 6 formed by. The windings 7 form a winding group in which four windings are connected in series, and the two windings are connected in series and are arranged at positions opposite to each other and the main winding group is disposed. M1 and M2 and auxiliary winding groups A1 and A2 are configured. Then, the sub winding Ma, on the tooth portion 5 at the position of the auxiliary winding groups A1 and A2 adjacent to the main winding groups M1 and M2.
Mb is provided. Further, auxiliary winding groups A1 and A2
Sub windings Aa and Ab are wound around the tooth portions 5 at the positions of the main winding groups M1 and M2 adjacent to. Further, the yoke 4 is divided into two by the divided portion 9 and is configured to be joined after winding.

FIG. 2 shows another embodiment of the electric motor, which is different from the electric motor shown in FIG. 1 in that the sub windings Ma, Mb, Aa, and Ab have three teeth 5 in the circumferential direction. The point is that they are continuously applied. These 3 sub windings M
Each of a, Mb, Aa, and Ab is connected in series.

In FIG. 3, the electric motor is in the energized state in the embodiment shown in FIG. 2, and the main winding group M1,
M2 is energized and formed so as to form magnetic poles of N and S, respectively. Then, the main winding group M1, M
Main winding group M to sub windings Ma and Mb connected in series with
The same current as 1 and M2 is flowing. In FIG. 4, the electric motor shows a change with time from the state shown in FIG. 3, and the main winding groups M1 and M2 as well as the auxiliary winding groups A1 and A2 are energized. At the same time, the auxiliary winding groups A1, A
Along with 2, the sub windings Aa and Ab are energized. In FIG. 5, the electric motor further shows a change with time, and the energization of the main winding groups M1 and M2 ends and the auxiliary winding group A
1, A2 is energized and at the same time sub windings Ma, Mb, Aa,
Ab is also energized. 6 to 8 show changes with time. It should be noted that the circles and the crosses in the main winding group, the auxiliary winding group, and the sub windings in each figure indicate windings in which the current flows in opposite directions.

In FIG. 9, the electric motor shows another embodiment, which is a modification of the embodiment shown in FIG. 2, and is a sub winding 10a, 10b, 11a, so as to bind the three tooth portions 5.
11b is wound.

In FIG. 10, the wiring of the electric motor shown in FIG. 1 is shown, and the main winding group M1, M2 and the auxiliary winding group A1,
A2 is connected between the main winding group M1 and M2 with the sub winding M
a and Mb are connected in series, and auxiliary winding groups A1 and A
The sub windings Aa and Ab are connected in series between the two.
11, the wiring of the electric motor shown in FIG. 2 is shown.
Sub windings Ma and Mb are connected in series between the main winding groups M1 and M2, and three sub windings Ma and Mb form one set. Further, sub windings Aa and Ab are connected in series to the auxiliary winding groups A1 and A2 as in the case of the main winding groups M1 and M2, and three sub windings Aa and Ab are also set as one set.

In FIG. 12, the state of distribution of the magnetic flux generated in the plurality of tooth portions 5 of the electric motor shown in FIG. 1 is shown by a line 12, and the density of the central magnetic flux is large in a stepwise manner with respect to the circumferential direction. Is formed. The ideal sine curve is shown by the line 13.

In FIG. 13, the distribution state of the magnetic flux generated in the plurality of teeth 5 of the electric motor shown in FIG. 2 is shown by a line 14, and the magnetic flux density at the center is large in a stepwise manner with respect to the circumferential direction. Is formed. The ideal sine curve is shown by the line 15.

In such a structure, the electric motor has the iron core punched into a predetermined shape by a press and laminated to form a donut shape, and the winding 7 is wound with insulation and the like. This winding 7
Winding is performed on the yoke 4 in a toroidal shape through the slot 6 formed by the tooth portion 5, and the main winding groups M1 and M2 and the auxiliary winding groups A1 and A2 are circumferentially arranged. Wind alternately. In the embodiment shown in FIG. 1, a two-pole electric motor is constructed.

The sub windings Aa and Ab are wound around the tooth portions 5 at the positions of the main winding groups M1 and M2, and the auxiliary winding groups A1 and A are provided.
The sub windings Ma and Mb are wound around the tooth portion 5 at the position 2. Then, the sub windings Ma, Mb, Aa, and Ab have teeth 5
Main winding group M1, M2 in order to be wound directly around
After the winding of the auxiliary winding groups A1 and A2 is completed, the winding is performed from the inside of the stator.

A capacitor (not shown) is connected in series to the auxiliary winding groups A1 and A2 of the motor having such windings so that the phase of the current is delayed with respect to the main winding groups M1 and M2. A rotating magnetic field is generated in the stator by energizing the main winding groups M1 and M2 and the auxiliary winding groups A1 and A2, respectively. Therefore, if a rotor (not shown) is provided, the rotor will rotate as a two-pole induction motor.

The electric motor shown in FIG. 2 has a sub winding Ma,
Mb, Aa, and Ab are provided as a set of three, respectively, and only the distribution of the magnetic flux is different, and other characteristics are the same as those of the embodiment shown in FIG.

Therefore, in the embodiment shown in FIG. 2, the rotating magnetic field that causes the rotor to rotate changes as sequentially shown in FIGS. 3 to 8, and the tooth portions 5 forming the poles are changed. The distribution of the magnetic flux is as shown in FIG. 12 in the electric motor of FIG. 1 and as shown in FIG. 13 in the electric motor of FIG.

In any case, the distribution of the magnetic flux has a stepwise shape as shown by the lines 12 and 14, and FIG.
Compared with the magnetic flux distribution of the conventional electric motor shown in FIG. 4, the sine curves 3, 13 and 15 are much closer to ideal.

Therefore, the torque ripple generated in the rotor is extremely reduced, and the vibrations appearing in the rotor are reduced. Therefore, even if a load such as a fan is attached to the rotor, vibration is not transmitted to the load, noise is not caused, and a quiet electric motor can be configured.

[0028]

According to the present invention, since the yoke is provided with the main winding group and the auxiliary winding group in a toroidal shape and the tooth portions are provided with the sub windings, the distribution of the magnetic flux in the tooth portions is improved. The torque ripple that causes vibrations in the child can be extremely reduced, and an electric motor that can be operated quietly can be obtained, and the effect is extremely large.

[Brief description of drawings]

FIG. 1 is a plan view of essential parts showing a stator of an electric motor according to an embodiment of the present invention.

FIG. 2 is a plan view of a main part of a stator according to another embodiment.

FIG. 3 is a plan view of a main part showing a state in which a main winding group and an auxiliary winding group are energized.

FIG. 4 is a plan view of an essential part showing a state in which a main winding group and an auxiliary winding group are energized.

FIG. 5 is a plan view of an essential part showing a state in which a main winding group and an auxiliary winding group are energized.

FIG. 6 is a plan view of an essential part showing a state in which a main winding group and an auxiliary winding group are energized.

FIG. 7 is a plan view of an essential part showing a state in which a main winding group and an auxiliary winding group are energized.

FIG. 8 is a plan view of an essential part showing a state in which a main winding group and an auxiliary winding group are energized.

FIG. 9 is a plan view of a main part of a stator showing another embodiment.

10 is a connection diagram of the stator shown in FIG.

11 is a wiring diagram of the stator shown in FIG.

FIG. 12 is a diagram showing a magnetic flux distribution of the stator shown in FIG. 1. .

13 is a diagram showing a magnetic flux distribution of the stator shown in FIG.

FIG. 14 is a diagram showing a magnetic flux distribution of a conventional electric motor.

FIG. 15 is a plan view of an essential part showing a stator of a conventional electric motor.

16 is a connection diagram of windings of the conventional electric motor shown in FIG.

[Explanation of symbols]

 4 ... Yoke 5 ... Tooth 6 ... Slot 7 ... Winding 8 ... Sub winding M1, M2 ... Main winding group A1, A2 ... Auxiliary winding group Ma, Mb ... Sub winding Wire Aa, Ab ... Sub winding

Claims (1)

[Claims] 1. A doughnut-shaped yoke having an iron core formed by extending a plurality of teeth inside the yoke, and a main winding group and auxiliary windings formed in a toroidal shape on the yoke of the iron core. Groups are arranged alternately in the circumferential direction, and sub-windings connected in series with the main winding group are provided on the teeth of the auxiliary winding group adjacent to the main winding group. An electric motor characterized in that a sub-winding connected in series with the auxiliary winding group is applied to a tooth portion of the wire group.