JPH05252714A - Brushless motor - Google Patents

Abstract

PURPOSE:To provide a thin, high-property, and high-efficiency brushless motor by the shape of a stator core, in a brushless motor used for each kind of electric apparatus. CONSTITUTION:The thickness of stator cores 8a in piles can be increased by constituting the projecting tooth 10 of the stator core 8a of a brushless motor, and also outside diameter can be enlarged, and the winding space can also be increased, and further when using a rotor magnet 3 of high energy product, the length of the projecting tooth 10 can be elongated, so it is hard to saturate with magnetism, and magnetic loss can be suppressed, and a thin and small brushless motor of high property and high efficiency can be gotten.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the shape of a stator core of a brushless motor.

[0002]

2. Description of the Related Art In recent years, brushless motors have become smaller, thinner, and more demanded for higher characteristics and higher efficiency as the set becomes lighter, thinner, and smaller.

A conventional brushless motor will be described below. FIG. 3 shows the structure of a conventional brushless motor. In FIG. 3, a rotor magnet 3 is fixed to a rotor yoke 2 fixed to a shaft 1.
A winding 9 is wound around a stator core 8 provided at a position facing the rotor magnet 3. The housing 4 includes a stator core 8, a printed circuit board 5, an upper bearing 6,
The lower bearing 7 is attached.

The operation of the brushless motor constructed as above will be described below. The rotor magnet 3 is excited by a magnetic field generated by the stator core when the winding 4 is energized, and a rotational torque is generated in the rotor yoke 2.

[0005]

However, in the above-mentioned conventional structure, the component for generating the rotational torque has not been effectively utilized. In order to maximize the rotational torque, the energy product of the rotor magnet 3 is increased, the outer diameter of the stator core 8 is increased, or the stacked thickness of the stator core 8 is increased, or the winding amount of the winding 9 is increased. However, in the brushless motor having the conventional configuration, there is no alternative but to increase the energy product of the rotor magnet 3. But the rotor magnet 3
If the energy product is too high, the stator core 8 is magnetically saturated and magnetic loss is apt to occur, and there is a problem that a compact and thin brushless motor with high characteristics and high efficiency cannot be obtained.

The present invention solves the above-mentioned conventional problems, and an object thereof is to provide a small and thin brushless motor having high characteristics and high efficiency.

[0007]

In order to achieve this object, the brushless motor of the present invention has a structure in which the projecting tooth portion of the stator core is plastically worked into a conical shape having the apex on the center line of the stator core.

[0008]

With this configuration, the stacking thickness of the stator core can be increased and the outer diameter can be increased, the winding space can be effectively utilized, and the conical protruding teeth can be used to form a rotor magnet with a high energy product. When used, it is possible to adopt an advantageous structure for magnetic saturation of the protruding teeth.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. The same components as those of the conventional example are designated by the same reference numerals and the description thereof will be omitted.

In FIGS. 1 and 2, the stator core 8a has a structure having a conical projecting tooth portion 10 whose apex is on the center line, and is located at a position facing the rotor magnet 3 mounted on the rotor yoke 2. The projecting tooth portion 10 is located, and is attached to the housing 4 so that the winding 9 wound around the stator core 8a can be effectively wound.

The projecting tooth portion 10 may have a conical shape which is bent at a certain angle on the center line of the stator core 8a.

The operation of the brushless motor configured as described above will be described. Conical protruding tooth 1
By using the stator core 8a having 0, the stacking thickness of the stator core 8a can be increased to increase the outer diameter, the winding space can be increased, and further, when the rotor magnet 3 of high energy product is used, Since the length of the tooth portion 10 can be increased, magnetic saturation is less likely to occur and magnetic loss can be suppressed.

As described above, according to this embodiment, by providing the projecting tooth portion 10 on the stator core 8a, the stacking thickness of the stator core 8a can be increased to increase the outer diameter and the winding space can be increased. The brushless motor can have high characteristics and high efficiency.

[0014]

As is apparent from the above description of the embodiment, the present invention has a small and thin high characteristic and high efficiency by forming the projecting tooth portion of the stator core into a conical shape having an apex on the center line of the stator core. The brushless motor can be realized.

[Brief description of drawings]

FIG. 1 is a sectional view of a brushless motor according to a first embodiment of the present invention.

FIG. 2A is a sectional view of the stator core, and FIG. 2B is a plan view of the stator core.

FIG. 3 is a sectional view of a conventional brushless motor.

[Explanation of symbols]

 8a Stator core 10 Projecting tooth portion

Claims (1)

[Claims] 1. A brushless motor obtained by plastically working the whole or a part of a projecting tooth portion of a stator core into a conical shape having an apex on the center line of the stator core.