JPS6343541A - Stator of motor - Google Patents

Abstract

PURPOSE:To reduce needless exciting current and to improve motor efficiency, by providing a nonmagnetic material on the outside circumference of projections of an iron core fitted to motor housings. CONSTITUTION:Projections 2 of a stator 112 are provided at four spots in equal intervals of the outside circumference of an iron core 1 over which coils 113 are wound around respectively. Grooves 3 are provided at two spots on each outside circumference of the projections 2. At two spots cut-and-raise sections 5 are formed to forcibly fit into the grooves 3 so that the tips will get close each other on both sides of a nonferrous platelike nonmagnetic substance 4. The nonmagnetic substance 4 is brought into contact with the inside circumferen tial surface of motor housings 110 and 111, so that the iron core 1 is fitted and fixed. Thus, the magnetic flux flowing into the motor housings is so reduced that the motor efficiency can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a stator for a small motor having a toroidal coil wound around an iron core.

BACKGROUND OF THE INVENTION Conventionally, the stator of this type of motor has generally been constructed as shown in FIGS. 9 and 10. That is, the stator 112 fixed inside the motor housings 110 and 111 made of iron plates is placed at four equally spaced positions on the outer periphery of the iron core 114 around which the toroidal coil 113 is wound. The motor housing 11o is fixed with a predetermined insulation distance between the surface and the coil 113.

A protrusion 115 that fits into the inner circumferential surface of 111 is provided.

Note that inside the stator 112, a rotor 117 into which a shaft 116 was press-fitted was supported by a bearing 118 and provided concentrically to form a motor.

Problems to be Solved by the Invention In such a conventional configuration, the magnetic flux excited in the coil 113 flows from the iron core 114 to the rotor 117 and from the iron core 114 to the motor housing 110 passing through the protrusion 116.
, 111, and the former rotor 11
The flow of magnetic flux to the motor housings 110 and 111 is effective in generating torque of the motor, but the flow of magnetic flux to the latter motor housings 110 and 111 is an ineffective flow that does not contribute at all to the generation of torque of the motor. Therefore, this motor housing 110.
Since an unnecessary excitation current that creates a flow of magnetic flux to 111 also flows, there is a problem that the efficiency of the motor decreases.

The present invention is intended to solve these problems, and aims to improve the efficiency of the motor by reducing unnecessary excitation current that creates ineffective magnetic flux.

Means for Solving the Problems In order to solve all of these problems, the present invention provides an iron core around which a coil is wound, and this iron core. A housing made of an iron plate to be accommodated and a portion of the iron core that abuts the housing are provided with four protrusions at equal intervals, and a plate-shaped non-ferrous metal non-magnetic material is sandwiched between the protrusions and the housing. The non-magnetic material has a plurality of protrusions, and the protrusions are inserted into recesses provided in the protrusions of the iron core to form a stator of a motor.

With this configuration, a non-magnetic material is provided on the outer periphery of the protruding part of the iron core that fits into the motor housing, so the magnetic resistance at this fitting part is large and the magnetic resistance from the iron core 2 to the motor housing is reduced. The magnetic flux flow is reduced, and therefore the excitation current that creates the magnetic flux flow is reduced, increasing the efficiency of the motor.

EXAMPLE Hereinafter, an example of the present invention will be described based on FIGS. 1 to 8. Note that the same components as those in the prior art are given the same reference numerals, and the description thereof will be omitted.

The feature of this embodiment is that the protrusions 2 are provided on four concentric circles protruding from the outer periphery of the iron core 1 at four equal intervals. That is, grooves 3 are provided at two locations on the outer periphery of each of the protrusions 2, and cutouts 6 are formed at two locations on both ends of the plate-shaped nonferrous metal nonmagnetic material 4 so that their tips approach each other. It is press-fitted into the groove portion 3.

Then, the non-magnetic material 4 is brought into contact with the inner peripheral surface of the motor housing 10.11, and the iron core 1 is fitted and fixed.

In the above configuration, the magnetic flux excited by the coil 113 flows from the iron core 1 to the rotor 117, and from the iron core 1 to the protrusion 2.
The flow of magnetic flux to the motor housings 110 and 111 is divided into two parts: the flow to the motor housings 110 and 111, which all pass through, and the flow to the motor housings 110 and 111. Since the non-magnetic material 4 made of non-ferrous metal is provided on the outer periphery of the protrusion 2, the magnetic resistance between the iron core 1 and the motor housings 110, 111 increases and decreases.

As described above, according to this embodiment, since the non-magnetic material 4 made of non-ferrous metal is provided on the outer periphery of the protrusion 2 of the iron core 1, the magnetic resistance between the motor housings 110, 111 and the iron core 1 is increased. Therefore, the flow of magnetic flux to the motor housing 110, 111 is reduced, and therefore the excitation current that creates this flow of magnetic flux is also reduced, improving the efficiency of the motor.

Note that the operation and effect of the cut and raised portions of the non-magnetic material are the same in the following embodiments.

Example a Two cut-out portions 5a are formed in each of the non-magnetic materials 4a in the same direction so that the tips thereof are spaced apart from each other.

Embodiment Cut-and-raised portions 6b are provided at two locations from the center of both ends of the non-magnetic material 4b so that their tips approach each other.

Example C A semicircular protrusion 5c is formed on the nonmagnetic material 4c.

Example d Cut-and-raised portions 6d are completely formed at two locations in the center of the non-magnetic material 4d in the same direction and with their tips spaced apart from each other.

Example e Two cut-outs 5e are formed in the center of both ends of the non-magnetic material 4 in the same direction and with their tips spaced apart from each other.

Moreover, the two groove portions may be combined into one groove portion.

Effects of the Invention As described above, according to the present invention, since a non-magnetic material made of a non-ferrous metal is provided on the outer periphery of the protrusion of the iron core, the magnetic resistance increases and the flow of magnetic flux to the motor housing is reduced. Therefore, the excitation current that creates the flow of magnetic flux is reduced, resulting in the effect that the efficiency of the motor is improved.

[Brief explanation of drawings]

Fig. 1 is a partially cutaway plan view of a motor using a motor stator according to an embodiment of the present invention, Fig. 2 is a partially cutaway pressure surface view of the same motor, and Fig. 3 is an iron core of the motor. Assembly diagram of non-magnetic material,
Figures 4 to 8 are perspective views of non-magnetic materials according to other embodiments of the present invention, Figure 9 is a partially broken pressure surface view of a motor using a conventional motor stator, and Figure 10 is a view of the same motor. FIG. 3 is a partially cutaway plan view. 1... Iron core, 2... Protrusion, 3...
...Groove, 4...Nonmagnetic material, 6...
Cut-out portion, IIO, IIL...Motor housing, 113...Coil. Name of agent: Patent attorney Toshio Nakao and one other person I
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Claims (1)

[Claims] An iron core around which a coil is wound, a motor housing made of an iron plate that houses the iron core, and a portion of the iron core that comes into contact with the motor housing has four protrusions equally spaced apart,
A plate-shaped non-magnetic material made of non-ferrous metal is interposed between the protrusion and the motor housing, the non-magnetic material has a plurality of protrusions, and the protrusions are provided on the protrusion of the iron core. A motor stator that is inserted into a recess.