JPS60109736A - Rotary magnet type motor - Google Patents

Abstract

PURPOSE:To reduce the weight of a rotor and to enable to decrease the cost by forming a hollow yoke of a hollow material of a ferromagnetic material. CONSTITUTION:A plate material (e.g., a ferromagnetic material such as SPC or the like) is formed substantially in a hollow sector shape, the outside A is formed at the bore of a magnet 3, the inside B is formed in an arcuated shape having a radius coinciding with the outer diameter of a rotational shaft 1, and the arcuate magnet 3 and the shaft 1 are secured to the faces. The end C of the plate material is disposed at the inside B. A hollow member 9a thus formed is contacted at the flat portion D, integrally by bonding or welding to form a hollow yoke 9 of a magnet rotary type motor.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an inner rotor type magnet-rotating electric motor.Constitution of a conventional example and its problemsThe general constitution of a conventional example is shown in Figs. 1 and 2. It will be explained in.

Reference numeral 1 denotes a rotating shaft to which a magnet 3 is fixed via a yoke 2. This is called the lower rotor. A stake 6 around which a coil 4 is wound is disposed around the outer periphery of the rotor.

6.7 is a bearing 8 for receiving the rotating shaft 1, which is a motor case. Note that the stator has a rectifier (not shown) for generating a rotating magnetic field in the stator.

Describing the function of the yoke 2 in the magnet-rotating electric motor configured as described above, one is the yoke of the magnet 3, and the other is the function of the yoke of the magnet 3. It acts as a medium for transmitting information, and also serves as a fixed body for magnets.

Therefore, as a yoke, magnet 3. In a magnetic circuit consisting of a yoke 2° and a stator 6, one magnet 3 and the stator 5
It is sufficient that the magnetic flux is strong enough to withstand torque transmission without causing a large hunting resistance in order to obtain the necessary magnetic flux in the air gap.

However, the yoke 2 of the rotor in the conventional example has a hollow part except for the shaft fixing hole, and is considerably heavy, which causes a high moment of inertia of the rotor. This is especially true if the rotor has a large diameter. In addition, it requires a large amount of materials and cannot be ignored in terms of cost.

OBJECTS OF THE INVENTION The present invention solves the above-mentioned problems and provides a magnet-rotating electric motor with a lightweight and low-cost yoke.

Structure of the Invention The magnet rotating electric motor of the present invention includes a rotor having a magnet fixed to a rotating shaft via a yoke, and a stator having a coil wound around the outer periphery of the rotor with a gap.

The stator has a rectifying section that generates a rotation generating field, and the yoke is made of a plurality of ferromagnetic metal-strengthening members, thereby reducing the weight and cost of the rotor.

DESCRIPTION OF EMBODIMENTS An embodiment of the magnet rotating electric motor of the present invention will be described with reference to FIGS. 3 to 5. For the sake of convenience, the one in FIG. 1 is used for the overall integrated structure, and the explanation is omitted. ○ FIG. It is a diagram. In this case, the hollow yoke 9 is composed of two hollow members 9a, but
As shown in this figure, a piece of material (for example, a ferromagnetic material such as SPC) is processed into a substantially hollow fan shape, and its outer surface (A) is a magnet 3.
The inner surface (B) is formed in an arc shape with a radius matching the outer diameter of the rotation shaft 1, and the arc-shaped magnet 31 rotation shaft 1 is fixed to each surface. Also.

The end (0) of the plate material is formed so as to be located on the inner surface (B). The reason for this is considering the centrifugal force during rotation.

This is because this position is optimal and is also suitable for fixing the one-rotation shaft 1 by press-fitting or the like.

Each of the hollow members 9a configured in this way has a plane portion CD).
The hollow yoke 9 of the magnet-rotating motor of the present invention is constructed by abutting with each other and integrating them by adhesion or welding.

FIG. 4 shows a perspective view of the hollow yoke 9 with the arc-shaped magnet 3 fixed thereto.

As shown in FIG. 4, the hollow yoke 9 according to the present invention has a hollow part, and it goes without saying that it is lighter than the conventional one, and also has good strength against centrifugal force.
The flat part (D) is made strong by adhesion or welding, and has sufficient durability. However, the size of the individual hollow openings.

It is necessary to calculate the centrifugal force according to the rotation conditions and take into consideration the thickness of the plate material of the hollow member 9a.

Also, there are methods such as press-fitting the fixing part of the rotating shaft 1 on the inner surface (B).
Since the end (G) functions as an elastic body, it is possible to have a considerable degree of freedom in manufacturing dimensions.
The press-fitting tolerance can also be made more precise and rougher than in the conventional yoke 2. If there is a concern about slippage due to high torque, slippage can be eliminated by making the inner surfaces (B) of the rotating shaft 1 and the hollow yoke 9 into an occluded shape.

As described above, the yoke is lighter than the conventional yoke and does not require tighter press-fitting tolerances, making it easier to assemble.

Also, for high torque, the method described in item 1 can be considered, and it can be adequately addressed in terms of strength and plate material thickness. Although the hollow member 9a was formed of a plate material in the first embodiment, it may be made into a half-moon shape or a cylindrical shape by casting or extrusion if possible. The same effect can be achieved if the weight can be reduced by using a hollow yoke.

Next, taking a magnetic circuit with 12 poles as an example, the flat part (D
), the magnetic circuit is constructed in the form shown in FIG. 6 by arranging the joints of the two magnets so that they are located at the center of each (N or S pole) magnet. It is assumed that the broken line of this magnetic circuit passes through the stator. The solid line part shows the yoke 90 passage, but part of it is the circumferential part of the yoke 90, and part of it is the flat part (D).
From there, it passes through the rotating shaft 1 and again through the plane part (D). In other words, it does not cross the plane part (D), but only one plane part (D)
It is not subject to magnetic resistance due to the air gap. In the conventional example, a magnetic circuit as shown in FIG. 2 is constructed. In this conventional example, since the yoke 2 is solid, the magnetic resistance of this yoke is low. However, as a practical matter, the conventional example can be sufficiently coped with without any particular configuration. That is, in a magnetic circuit constituted by the hollow yoke 9 of the present invention, the magnetic resistance of the hollow yoke 9 may be designed to a predetermined value.

Effects of the Invention As described above, in the magnet-rotating electric motor of the present invention, the hollow yoke is formed from a ferromagnetic hollow material, so the rotor can be made lighter and at a lower cost. When a press-fitting method is used to fix the rotary shaft to the hollow yoke, the press-fitting tolerance can be increased. Also - as another example, the magnetic poles are 2
In the case of a pole, if the center of the arc-shaped magnet is placed around the junction of two hollow members, the magnetic resistance of the gap or the like at the junction will change accordingly.

As mentioned above, the effect is clear! 7-It is of high value in the industry.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional view of a general magnet rotating electric motor - Fig. 2 is a cross sectional view of a rotor of a conventional example - Fig. 3 is a perspective view of a processed sheet metal member of a yoke of a magnet rotating electric motor of the present invention - Fig. 4 6 is a perspective view of the yoke with magnets fixed to it, and FIG. 6 is a cross-sectional view of the rotor using the yoke. 9... Yoke, 9a... Sheet metal processed member constituting the yoke - (C)... End of plate material - (D
)...Joint part, (E)-...Hollow part. Figure 1 Figure 2

Claims (4)

[Claims] (1) A rotor having a magnet fixed to a rotating shaft via a yoke, a stator having a coil wound around the outer periphery of the rotor with a gap in between, and a rectifying section that applies a rotating magnetic field to the stator, and the yoke A magnet-rotating electric motor made of a hollow ferromagnetic material with a hollow yoke. (2) The hollow yoke is composed of a plurality of hollow members made of plate materials, and the hollow members are comprised of an arc-shaped outer surface to which the magnet is fixed, an arc-shaped inner surface to which the rotating shaft is fixed, and the ends of the outer surface and the inner surface. 2. The magnet-rotating electric motor according to claim 1, which is bent into a substantially hollow fan shape having a plane portion connecting the two. (3) A clockwise rotation according to claim 2, wherein the abutting portion of the plates of the hollow member formed by bending the plate material into a substantially hollow fan shape is located on the inner surface of the circular arc to which the rotating shaft is fixed. type electric motor. (4) A magnet-rotating electric motor according to claim 2, wherein a plurality of substantially hollow sector-shaped hollow members are abutted and joined at their plane parts, and a central part of an arcuate magnet is arranged and fixed to this joined part.