JPS6358031B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a method for manufacturing a small conductive motor, and particularly to a capacitor-type small induction motor in which a plurality of windings are wound around a plurality of magnetic poles provided in a stator core. The present invention relates to a manufacturing method.

(Prior art) A conventional small conductive motor is, for example, disclosed in Japanese Patent Application Laid-Open No. 55-125056.
As shown in FIGS. 1 to 3 of the publication, since the annular stator core and the magnetic poles are integrally formed, there is a drawback that it is extremely difficult to wind the windings around the magnetic poles.

In order to eliminate these drawbacks, electric motors as shown in FIGS. 4 to 6 of the above-mentioned publication and an electric motor as shown in attached FIG. 1 have been proposed.

Figure 1 shows the conventional diameter of 30m/m.
1a, 1 with a capacitor type small induction motor of
b, 1c, and 1d are the magnetic poles of the stator core with an annular pole shoe at the tip; a, b, c, and d are the parts connected to the tips of the pole shoes of each pole; and 2 is the stator yoke. , 3a, 3b, 3c,
3d is a stator winding wound around each magnetic pole 1a, 1b, 1c, and 1d, 4 is a winding frame of this winding, and 5 is a rotor.

In the electric motor shown in Fig. 1, magnetic poles 1a, 1b, 1c, 1
The tip of the pole show provided in each of d is part a,
Since they are connected to each other by b, c, and d,
A stator can be constructed by fitting a winding frame around which a winding is wound onto each magnetic pole and then press-fitting it into the yoke 2.

In this electric motor, windings 3a and 3c, and 3
When b and 3d are connected to form one phase each, a capacitor (not shown) is connected in series to one phase, and the winding of the other phase is connected to an AC power supply, a rotating field is generated in the air gap. The rotor 5 rotates, but the way the magnetic flux flows between the stator and the rotor is that the magnetic flux generated at the magnetic pole 1a enters the rotor 5 through the air gap from the pole shoe of the magnetic pole, and returns to the magnetic pole through the air gap. This is because the main flow path that flows from the pole shoe 1c through the magnetic pole 1c and through the yoke 2, and the pole shoe at the tip of the magnetic pole 1a are connected to the respective pole shoes of the adjacent magnetic poles 1b and 1d at portions a and d. There is a flow path for leakage magnetic flux that flows through the connecting part and into the yoke 2, and since this leakage magnetic flux does not pass through the rotor 5, it becomes an ineffective magnetic flux that does not contribute to the torque generation of the rotor 5, reducing the efficiency of the electric motor. However, it has the advantage that it is extremely easy to install the windings and the manufacturing cost is low, and it is widely applied to simple control motors and the like.

In particular, in applications such as control motors that only need to operate for a very short time, the magnetic flux density of the magnetic path is designed to be large, and a configuration is configured to allow large current to flow for a short period of time to generate large torque. The part a where the tip of the pole show is connected,
As a result of iron cores b, c, and d becoming saturated, a, b, c,
The magnetic resistance of the leakage flux in the d section increases, the leakage flux decreases, and the efficiency increases, making it possible to manufacture a small, high-output control motor at low cost.
On the other hand, it not only has the disadvantage that it consumes a lot of power and the temperature rises so high that it cannot withstand continuous operation, but it also generates undesirable heat and cannot be used as an internal motor of a refrigerator, for example.

(Objective of the Invention) The object of the present invention is to provide a manufacturing method that eliminates the above-mentioned drawbacks of conventional electric motors and provides a highly efficient electric motor with low power consumption and continuous operation at a low price.

(Structure of the Invention) A method for manufacturing a small induction motor of the present invention includes forming a plurality of columnar magnetic poles each having an arc-shaped pole shoe at one end, winding a stator winding around each of the magnetic poles, and winding a stator winding around each of the magnetic poles. The other end is fixed to the inner circumferential surface of the annular stator yoke so that a circular gap is formed by the inner circumferential surface of the pole shoe of each magnetic pole, and an electrical connection is made between the pole shoes of each adjacent magnetic pole. A feature is that a gap of approximately 2 degrees is formed at the corners.

(Example of the invention) Embodiments of the present invention will be described below with reference to the drawings.

In the present invention, as shown in FIGS. 2 and 3, the stator magnetic poles 1a, 1b, 1c, and 1d are columnar pole shoes whose tips are not connected to each other but are separated, and each magnetic pole has a stator winding. After winding the wire, it is fixed to the yoke, and at this time, each pole shoe is provided with a gap a′, where the air gap angle θ is approximately 2 degrees in electrical angle.
Let b′, c′, and d′ be formed.

(Effects of the Invention) According to the method of the present invention, as described above, the tips of the pole shoes of each magnetic pole are not connected but face each other with a gap between them, so the magnetic resistance of this gap is much larger than that of the iron core, and the overall magnetic resistance is much larger than that of the iron core. Even without increasing the magnetic flux density of the pole shoe, leakage magnetic flux from the tip of the pole shoe is reduced and efficiency can be increased.

On the other hand, if a gap is provided at the tip of the pole shoe, the effective area where the pole shoe faces the rotor will be reduced, which will have the opposite effect of lowering the output. Therefore, the opening angle of the tip of the pole shoe will have the effect of reducing leakage and reducing the output. It is necessary to maintain a balanced and optimal range of values.

As a result of the experiment, the output is approximately 1W, and the rotor diameter is approximately
The relationship between the gap angle θ and efficiency of the pole shoe of a 30m/m capacitor type motor is shown in Figure 4, which shows the highest efficiency when the gap angle θ is approximately 2 degrees, and this value is constant for any output and rotation. The results were also approximately the same for those with smaller diameters.

Further, to obtain the same output, the electric motor according to the present invention requires an input of about 3.3W, whereas the conventional motor requires an input of 10W.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of a conventional small induction motor, Figure 2
The figure is a longitudinal sectional front view of an induction motor obtained by the method of the present invention, FIG. 3 is a longitudinal sectional side view thereof, and FIG. 4 is a characteristic diagram thereof. 1a, 1b, 1c, 1d...magnetic poles, a, b,
c, d...part, a', b', c', d'...gap, 2...
...Yoke, 3a, 3b, 3c, 3d...Winding, 4
... winding frame, 5 ... rotor.

Claims (1)

[Claims] 1 A plurality of columnar magnetic poles each having an arc-shaped pole shoe formed at one end are formed, a stator winding is wound around each of the magnetic poles, and the other end of each of the magnetic poles is attached to the inner circumferential surface of an annular stator yoke. When fixed, a circular gap was formed by the inner peripheral surface of the pole shoe of each magnetic pole, and a gap of approximately 2 degrees in electrical angle was formed between the pole shoes of each adjacent magnetic pole. A method for manufacturing a small induction motor, characterized by the following.