JP2581236Y2 - Motor rotor - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotor of an electric motor used for a hermetic compressor or the like, and more particularly to a rotor having a permanent magnet field.

[0002]

2. Description of the Related Art Rotors equipped with magnets used in hermetic compressors are intended to reinforce magnets so that they do not scatter due to centrifugal force and to seal magnet powder and the like as little as possible outside the rotor. The outer peripheral portion and the axial end portions of the rotor are respectively covered by protective members.

FIGS. 3 and 4 are cross-sectional views showing the structure of the rotor, which is disclosed, for example, in Japanese Patent Application Laid-Open No. 2-246748. In this rotor, a plurality of tile-shaped magnets 2 are arranged on the outer peripheral portion of a thick cylindrical yoke 1, and a thin cylindrical protective member 3 is mounted on the outer peripheral portion of the magnet 2, while the shaft of the magnet 2 is mounted. End plates 4 and 5 are attached to both ends in the direction.

The yoke 1 has a shaft hole 6, a swaging pin insertion hole 7, and a projection 8 for positioning a magnet, and is generally formed by laminating a large number of circular thin iron plates.
Numeral 13 denotes a balance hole provided in the yoke 1 for imparting unbalance weight to the rotor by a local cavity to correct imbalance on the load side. The magnet 2 is formed of a hard magnetic material such as ferrite,
Since a cylindrical member cannot be integrally formed, a plurality of tile-shaped members are used, arranged in a substantially equal shape, and fixed by tightening the protective member 3. Incidentally, reference numeral 11 denotes a divided portion of each piece of the magnet which is formed in a substantially equal arrangement, and a gap is formed in this portion. If necessary, the gap around the magnet 2 is filled with resin to enhance the fixing. If the magnet 2 is magnetized in advance, it will be attracted to the surrounding magnetic material, which may hinder the work when assembling the rotor or assembling the stator with the motor as a pair, as well as iron powder or the like. Foreign matter adheres to the rotor. For this reason, the magnet 2 is magnetized in the final step after the rotor is assembled as an electric motor. This is a method in which a magnetizing current flows through a stator winding to magnetize a magnet, which is a method generally called built-in magnetization.

[0005] The protective member 3 on the outer peripheral portion is for reinforcing for centrifugal force resistance and sealing the outer peripheral portion. The protective member 3 has excellent tensile strength and is made of a non-magnetic material. Fit by fit or press fit. The end plates 4 and 5 seal both ends of the magnet 2 in the axial direction, and are made of a non-magnetic circular plate such as brass. The yoke 1 and the end plates 4 and 5 are fixed to each other by a plurality of caulking pins 9 which penetrate the inside of each of them in the axial direction.

[0006]

When the rotor is assembled together with the stator in, for example, a hermetic compressor and the rotor magnet is magnetized, the magnet is divided into a plurality of tiles. It is preferable that the division of the magnet is performed so as to match between the magnetic poles of the magnetizing magnetic field. Because, if there is the above-mentioned divided portion which is a non-magnetized portion in the magnetic pole of the magnetized magnet,
This is because the total magnetic flux decreases and the motor characteristics deteriorate, and the magnetomotive force distribution is distorted to cause vibration and the like. However, since the rotor is configured so that the outer periphery is covered with a can and the axial end is covered with an end plate, the position of each magnet is unknown in appearance, and the position of the magnet and the position of the magnetized magnetic poles are unknown. There was a problem that can not be matched.

[0007] In order to solve this problem, for example, in a configuration in which a balance weight is attached to an end face in the axial direction of the rotor, the attachment position of the balance weight is used as a mark, or a mark is provided on the balance weight. be able to. However, as described above, if a balance hole or the like is provided in the yoke to impart imbalance, a compact rotor can be constructed by eliminating the balance weight on the rotor end face.In this case, the rotor has an axial end portion. Only the end plates as shown in FIGS. 3 and 4 are present. Of course, it is possible to determine to some extent by the position of the caulking pin, but the number and relative position of the caulking pins are not always in a fixed relationship with the magnet due to design reasons, and the caulking position is on the inner peripheral side. Since there is a distance between the outer peripheral portion and the stator, accurate positioning cannot be performed. Further, when a notch is provided in a part of the end plate, a problem occurs that the magnet is exposed and the sealing effect is impaired.

[0008]

SUMMARY OF THE INVENTION The present invention is directed to a portion of an end plate corresponding to at least one of divided portions of a magnet , and
The part where the relative positional relationship with the balance hole is determined is on the back side
The above problem is solved by swelling and providing a local concave portion on the front end surface.

[0009]

According to the present invention, an appropriate shadow is formed on the end face of the rotor due to a local concave portion provided in the end plate, whereby one of the divided portions of the magnet can be determined, and the position of the magnet and the position of the magnetized magnetic pole can be matched. it can. At the same time, the balance
The rotor position on the shaft
Position can be determined. On the other hand, due to the formation of the concave portion, the end plate is deformed and a bulge is generated on the back side, but since the bulge corresponds to the divided portion of the magnet,
The end plate does not incline into the gap generated between the magnets and is configured without being inclined.

[0010]

1 and 2 show a rotor according to an embodiment of the present invention. FIG. 1 is a perspective view of an axial end portion, and FIG. 2 is a front sectional view taken along the same cross section as FIG. Except for the end plate 4a, the cross section is the same as that shown in FIG.

The difference from the prior art is a local concave portion indicated by reference numeral 10. This concave portion is formed by stamping when the end plate 4a is formed by stamping a brass plate or the like.
Usually, in order to confirm the position of the divided portion 11 of the magnet 2 at the time of magnetizing, the concave portion 10 is provided only in the end plate 4a on the side suitable for the confirmation.
However, if the number of parts is increased and assembly is hindered, the other end plate 5 may be made of the same parts as the end plate 4a.

In mounting the end plate 4a, the end plate 4a is mounted so that the concave portion 10 corresponds to at least one of the divided portions 11 of the magnet 2. The projection of the concave portion 10 causes a bulge 12 on the back side of the end plate. However, since the bulge 12 fits into the gap between the divided portions 11 of the magnet 2, the end plate 4a does not tilt. . In addition, due to the action of the concave portion 10 fitting into the divided portion 11, the positioning at the time of mounting the end plate 4a is extremely easy.

The shape of the concave portion 10 can be arbitrarily determined, for example, a planar shape such as a rectangle or an ellipse, within a range restricted by the shape of the gap existing in the divided portion 11 of the magnet. When the concave portion 10 is to be visually determined, the concave portion 1 is used.
The depth of 0 may be such that an appropriate shadow is generated, and it is preferable that the depth is as deep as possible when discrimination is performed by an optical sensor or the like. The surface of the end plate 4a such as a brass plate or the like is in a state where it is difficult to visually determine a mark due to its gloss. For example, when a convex portion is provided on a surface, it is difficult to distinguish the convex portion from another flat surface due to diffuse reflection, and workability is significantly deteriorated. On the other hand, in the case of a concave portion, a dark place is generated, so that it is easy to see, easy and reliable. Can be determined.

A balance hole 1 provided in the yoke 1 is provided.
3 also becomes unclear in appearance, but by determining the relative positional relationship with the concave portion 10 on the end plate, the position of the balance weight provided on the rotor can be known. It is possible to determine the position when the child is mounted on the crankshaft of the hermetic compressor. In the illustrated example, the balance hole 13 is made to coincide with one of the divided portions 11 of the magnet, and the concave portion 10 is located in the divided portion.

[0015]

According to the present invention, even if only a thin end plate is present at the axial end of the rotor, the divided portions of the magnet can be easily and reliably determined. Therefore, the magnetized portion can be magnetized so as to match between the poles of the magnetized magnetic field, and a motor having good characteristics and no vibration or the like can be constructed. Further, in a rotor having a balance weight inside the yoke, the rotor can be mounted on the shaft without mistaking the position of the balance weight.

[Brief description of the drawings]

FIG. 1 is a perspective view of a main part of a rotor showing an embodiment of the present invention.

FIG. 2 shows an embodiment of the present invention, in which the rotor is A-O of FIG. 3;
FIG. 2 is a front sectional view cut along line B.

FIG. 3 is a plan sectional view of a rotor.

FIG. 4 is a front sectional view showing a conventional example and showing a rotor cut along a line AOB in FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Yoke 2 Magnet 3 Can 4, 4a, 5 End plate 9 Caulking pin 10 Depression 11 Magnet division

Claims (1)

(57) [Scope of request for utility model registration] 1. A yoke having a balance hole,
A plurality of magnets are arranged on the outer periphery of the yoke, the outer periphery of the magnet is covered with a protective member, and the magnet is hermetically sealed by covering the axial end with an end plate. A position corresponding to at least one of the divided portions of the magnet, and a relative positional relationship with the balance hole is determined.
A rotator characterized in that a given portion is bulged to the back side and a local concave portion is provided on the front end surface.