JPS61295849A - Permanent magnet field motor - Google Patents

Abstract

PURPOSE:To improve the yield of a permanent magnet piece and to enhance the dimensional accuracy of a field by forming a flat portion at the prescribed position of the inner surface of a yoke, securing the flat permanent magnet thereto, and further mounting a magnetic member having an arcuate surface thereon. CONSTITUTION:A flat portion 1a is formed at the prescribed position on the inner surface of a yoke 1. A flat permanent magnet 2 is mounted on the portion 1a. A magnetic member 3 having an arcuate surface 3a opposed to a rotor is mounted thereon to form a field. Thus, since the magnet may not be formed in an arcuate shape, the yield of the magnet piece can be improved, and the positioning can be facilitated. Further, since the piece 2 is coated with the member 3, it is not exfoliated to drop due to temperature change.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a permanent magnet field motor with a good yield of permanent magnet pieces and a high field dimensional accuracy.

(Prior Art) Conventionally, series motors have been used as starter motors for vehicles, but recently there has been a trend toward the use of permanent magnet field motors with no current loss.

As a conventional permanent magnet field motor, for example, there is one shown in FIG. 4 (Japanese Unexamined Patent Publication No. 513-58157), which has a structure in which a permanent magnet 2 is fixed to a yoke l with an adhesive.

However, such conventional permanent magnet field motors have the following problems because the permanent magnets have an arc shape.

In other words, thin, high-magnetic-force magnets are used to miniaturize electric motors, and such thin magnets are usually manufactured using the sintering method, but the precise circular arc required for sintering is Not only is it difficult to make a mold of the shape, but dimensional accuracy is poor because the permanent magnet pieces shrink due to temperature changes after sintering.
Therefore, the yield of permanent magnet pieces also deteriorates.

Therefore, in order to increase dimensional accuracy, there is a method of sintering the magnet thickly and then grinding the arc part, but in this case, the magnet material of the ground part is wasted, and it is economical because the magnet material is expensive. It's not a good idea.

(Object and Structure of the Invention) The present invention has been made in view of the above points, and aims to improve the yield of permanent magnet pieces and improve the dimensional accuracy of the field in a permanent magnet electric motor. In order to achieve this, in a permanent magnet field motor, a flat part is provided at a predetermined position on the inner surface of the yoke of the motor, a permanent magnet piece is fixed on the flat part, and a permanent magnet piece is fixed on the flat part facing the rotor. A magnetic field was constructed by fixing a magnetic section with an arc-shaped surface.

(Example) The present invention will be explained below based on the drawings.

FIG. 1(a) is a shaft side view of an embodiment of a permanent magnet field motor according to the present invention, and FIG. In a certain figure 0, 1 is a yoke, and plane portions 1a are provided at four locations (every 900) on its inner surface. 2 is a high performance permanent magnet (SmC
The flat part 1a is a rectangular thin flat plate and is provided on the inner surface of the yoke 1 with adhesive.
is glued to. 3 is a magnetic member having an arcuate surface 3a, and is adhered to the permanent magnet 2 with an adhesive.

With this configuration, the permanent magnet 2 does not need to be in an arc shape, but is in the form of a flat plate, so it can be easily manufactured and the yield can be improved. Furthermore, the dimensional accuracy of the arcuate surface 3a of the magnetic member 3 can be increased by machining, so that the gap with the rotor can be kept constant and as small as possible.

Next, FIG. 2 shows another embodiment of the permanent magnet field motor according to the present invention, in which the same components as in FIG. 1 are given the same reference numerals. In this embodiment, the flat part 1a of the yoke 1 is provided with a concave part ib, while the permanent magnet 2 is provided with a convex part 2.
a is provided, and the concave part lb and the convex part 2a form a church, and the permanent magnet 2
This makes positioning easier.

In the above embodiment, the uneven portions are provided on the flat portion 1& of the balk l and the permanent magnet 2, but uneven portions may also be provided between the flat portion 3b of the magnetic member 3 and the permanent magnet 2. , the concave and convex portions may also be reversed.

Next, FIG. 3 shows a third embodiment of a permanent magnet field motor according to the present invention, in which the same components as in FIG. 1 are given the same reference numerals.

In this embodiment, a commutative pole part 3C is provided on a part of the magnetic member 3 (end part in the rotational direction), which is directly bonded to the flat part 1a of the yoke 1 without using the permanent magnet 2. The output of the electric motor can be improved.

(Effects of the Invention) As explained above, in the present invention, a flat part is provided on the inner surface of the yoke of a permanent magnet field motor, a permanent magnet piece is fixed on the flat part, and a permanent magnet piece is further fixed on the flat part. Since the field is constructed by fixing a magnetic member whose surface facing the rotor is arc-shaped, the permanent magnet piece itself does not need to be arc-shaped, and can be flat plate-shaped, making it easy to manufacture and improving yield. Since the magnetic member fixed on the permanent magnet piece is manufactured by machining, the dimensional accuracy of the arc shape can be improved.

Furthermore, in the present invention, since the permanent magnet pieces are sandwiched and fixed between the yoke and the magnetic member, it is possible to prevent the problem of the permanent magnets being peeled off due to temperature changes during operation of the motor, and the rotor being locked by the pieces. .

Furthermore, according to the embodiment shown in FIG. 2, the positioning of the permanent magnet is facilitated, and according to the embodiment shown in FIG. 3, the output of the motor can be easily improved by providing a commutating pole in the motor.

[Brief explanation of the drawing]

FIG. 1(a) is a shaft side view of an embodiment of a permanent magnet field motor according to the present invention, and FIG. 1(b) is a cutaway plan view of the motor.
2 and 3 are cutaway plan views showing other embodiments of the permanent magnet field motor according to the present invention, and FIG. 4 (A), respectively.
1 is a side view of the shaft of a conventional permanent magnet field motor, and FIG. 1-Fist yoke, la fist...flat part, 2-fight/permanent magnet, 3 fist...magnetic member, 3a fist φ/arc surface patent applicant
Nissan Motor Co., Ltd. Representative Patent Attorney Hiroshi Suzuki #11 Figure 2 (B) Figure 31 Figure 4 (A) (B)

Claims (1)

[Claims] A magnetic field is constructed by fixing a permanent magnet piece on a flat part provided at a predetermined position on the inner surface of the yoke, and fixing a magnetic member whose surface facing the rotor has an arc shape on the permanent magnet piece. Permanent magnet field motor.