JPH0576146A - Ac servo motor - Google Patents

Abstract

PURPOSE:To improve motor performance at low cost by a constitution wherein a permanent magnet rotor comprises a core composed of a plurality of core pieces having a surface layer, on the side contacting with a stator, provided with a plurality of holes extending axially along the rotational direction, and permanent magnets loaded such that the permanent magnets, adjacent to each hole, have reverse polarities in the radial direction. CONSTITUTION:A core 9 comprises a plurality of core pieces laminated in the axial direction, and a plurality of holes 9a are made in the surface layer on the opposite side to a stator while extending axially along the rotational direction M. Permanent magnets 10 are embedded in respective holes 9a such that adjacent ones have reverse polarities in the radial direction of the core 9, and the permanent magnets 10 are bonded in place through adhesive. Dimensions of each hole 9a are set slightly larger than those of the permanent magnet 10. Consequently, irregularities due to dimensional fluctuation of the permanent magnet 10 can be eliminated when the permanent magnet 10 is mounted in the hole 9a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to AC used in all fields such as FA (Factory Automation).
Servo motors.

[0002]

2. Description of the Related Art In recent years, AC servomotors (for example, synchronous servomotors) do not require brushes.
It is used in all fields including A. FIG. 6 is a front view showing a permanent magnet rotor 1 of a conventional inner rotor type AC servomotor. As shown in FIG. 6, the permanent magnet rotor 1 has a cylindrical shape having a plurality of core pieces and a thickness. And a plurality of permanent magnets 3, 3, ... Which are bonded and fixed with an adhesive along the rotation direction M of the outer peripheral surface of the core 2 and are bound by a band (not shown). Is configured. This permanent magnet rotor 1 has a core 2
It is fixed to the shaft through a shaft (not shown), and is rotatably supported by a cylindrical stator (not shown) that covers the surroundings. On the other hand, FIG. 7 shows a conventional outer rotor type A.
FIG. 3 is a front view showing a permanent magnet rotor 4 of a C servo motor. As shown in this figure, the permanent magnet rotor 4 includes a core 5 formed by stacking a plurality of core pieces in a cylindrical shape, and a core 5 of the core 5. It is configured to have a plurality of permanent magnets 6, 6, ... Adhering and fixing with an adhesive along the rotation direction M of the inner peripheral surface. The permanent magnet rotor 4 is rotatably supported by a cylindrical stator (not shown) inserted and arranged inside the permanent magnet rotor 4.

[0003]

By the way, in both the inner rotor type and the outer rotor type AC servomotors described above, a permanent magnet is used because it is a rotating field type. Various methods have been devised as a method of fixing the permanent magnet to the core. However, there are the following problems.

It is necessary to make the shape of the permanent magnets 3, 3, ..., 6, 6 ... into an arc shape, which is expensive because the machining is troublesome. Since the reliability of the bonding itself is low, the permanent magnets 3, 3 ...
6 and 6 need to be bound by bands. But,
The price increases due to the additional bands and the process of binding them together. It is difficult to perform the positioning work when the permanent magnets 3, 3, ..., 6, 6 ... Are bonded, and the greater the magnetic force, the greater the difficulty. Since variations in the thickness of the permanent magnets 3, 3, ..., 6, 6 ... Cause variations in the gap, it is necessary to improve the processing accuracy of these permanent magnets. Variations in the adhesive thickness also cause variations in the gap, making it difficult to reduce the gap. The thickness of the band causes an increase in the gap.

The present invention has been made in view of the above circumstances, and is an AC capable of solving the above problems.
The purpose is to provide a servo motor.

[0006]

SUMMARY OF THE INVENTION The present invention comprises a stator and
In an AC servomotor provided with a permanent magnet rotor rotatably supported with respect to the stator, the permanent magnet rotor is composed of a plurality of core pieces, and a surface layer on the side in contact with the stator has a rotational direction. A core in which a plurality of holes extending in the axial direction are formed, and a plurality of permanent magnets that are mounted so that those adjacent to each hole of the core have polarities opposite to each other in the radial direction of the core. It is characterized by being configured.

[0007]

According to the above construction, the core constituting the permanent magnet rotor has a structure in which a plurality of holes are formed in the surface layer on the side in contact with the stator along the rotation direction, and the permanent magnet is embedded in these holes. Therefore, each permanent magnet does not need to have an arc shape. Further, it is not necessary to bind these with a band. Further, the embedding eliminates the need for positioning work, and the unevenness can be eliminated by adjusting the embedding condition even if the thickness varies.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a front view showing a permanent magnet rotor 8 of an inner rotor type AC servomotor according to a first embodiment of the present invention, and FIG. 2 is a front view showing a core 9 constituting the permanent magnet rotor 8. .. In FIG. 2, the core 9 is composed of a plurality of core pieces that are stacked in the axial direction, and a stator (not shown).
A plurality of holes (in this case, through holes) 9a extending in the axial direction along the rotational direction M are formed in the surface layer on the side facing the.

As shown in FIG. 1, permanent magnets 10, 10, ... Are embedded in the holes 9a, 9a, ... so that adjacent ones have opposite polarities with respect to the radial direction of the core 9. , Is fixed with an adhesive. In this case, each hole 9
The dimensions of a, 9a, ... Are set slightly larger than the dimensions of the permanent magnet 10. By setting in this way, the dimensions (thickness) of the permanent magnets 10, 10, ... When the permanent magnets 10, 10, ... Are mounted in the holes 9a, 9a.
It is possible to eliminate the unevenness due to the variation. As a result, the permanent magnets 10, 10, ... May have rough intersections. In addition, the accuracy of the gap can be increased and the windage loss can be reduced. Further, no positioning jig is required when the permanent magnets 10, 10, ... Are mounted.

Next, FIG. 3 is a front view showing a permanent magnet rotor 12 which is an application example of the first embodiment. As shown in this figure, the core 13 has a plurality of holes 13a, 13a, ... Formed in the outer surface layer thereof in the axial direction along the rotational direction, and these holes 13a, 13a ,. The permanent magnets 14, 14, ... Are embedded in the same arrangement as in the first embodiment and are fixed with an adhesive. In this case, each hole 13
The shapes of a, 13a, ... Are arcuate, and the permanent magnets 14, 14 ,. In this application example, the holes 13a, 13a, ...
Since the permanent magnets 14, 14, ... Must be formed in an arc shape, there is a problem compared to the first embodiment, but a uniform magnetic field can be generated in the stator (this fact). Is the same as the conventional one, but each permanent magnet 14, 1
The advantage of embedding 4, ... In the holes 13a, 13a ,.

Next, FIG. 4 is a front view showing a permanent magnet rotor 16 of an outer rotor type AC servomotor according to a second embodiment of the present invention, and FIG. 5 is a core 17 constituting the permanent magnet rotor 16. FIG. In FIG. 5, the core 17 is made up of a plurality of core pieces that are laminated in the axial direction, as in the first embodiment, and extends in the rotation direction M on the surface layer on the side facing the stator (not shown). A plurality of holes 17a, 17a, ... Which extend in the axial direction are formed.

Further, each of the holes 17a, 17a, ...
, The permanent magnets 10, 10, ... Are arranged so that the adjacent magnets have opposite polarities with respect to the radial direction of the core 17.
Are embedded and fixed with an adhesive. In this case, the dimensions of the holes 17a, 17a, ... Are set slightly larger than the dimensions of the permanent magnet 10. Also in this second embodiment, the same effect as in the above-mentioned first embodiment can be obtained.

[0013]

As described above, according to the present invention, in an AC servomotor including a stator and a permanent magnet rotor rotatably supported by the stator, the permanent magnet rotor is , A core formed of a plurality of core pieces, in which a plurality of holes extending in the axial direction along the rotation direction are formed in the surface layer on the side in contact with the stator, and those adjacent to each hole of the core are the diameter of the core. Since it has a plurality of permanent magnets mounted so that the polarities thereof are opposite to each other in the direction, the following effects can be obtained. There is no need to bind the permanent magnet with a band. It is not necessary to make the shape of the permanent magnet into an arc shape. Therefore, the simple shape is sufficient, and the price can be reduced. By adjusting the degree of embedding of the permanent magnet, it is possible to eliminate the variation due to the adhesive thickness and the variation in the thickness of the permanent magnet, so that the gap accuracy can be improved and the motor performance can be improved. Since the irregularities on the surface of the rotor are eliminated, the windage loss is reduced and the metal powder and the like adhering to the surface can be easily cleaned. Since no positioning jig is required for bonding the permanent magnets, the working time can be shortened. The gap can be reduced by the thickness of the band.

[0014]

[Brief description of drawings]

FIG. 1 is a front view showing a permanent magnet rotor of an inner rotor type AC servomotor according to a first embodiment of the present invention.

FIG. 2 is a front view showing a core forming the permanent magnet rotor.

FIG. 3 is a front view showing a permanent magnet rotor that is an application example of the first embodiment of the present invention.

FIG. 4 is a front view showing a permanent magnet rotor of an outer rotor type AC servomotor according to a second embodiment of the present invention.

FIG. 5 is a front view showing a core constituting the permanent magnet rotor.

FIG. 6 is a front view showing a permanent magnet rotor of a conventional inner rotor type AC servomotor.

FIG. 7 is a front view showing a permanent magnet rotor of a conventional outer rotor type AC servomotor.

[Explanation of symbols]

 8, 12, 16 Permanent magnet rotor 9, 13, 17 Core 9a, 13a, 17a Hole 10, 14 Permanent magnet

Claims (1)

[Claims] 1. An AC servomotor comprising a stator and a permanent magnet rotor rotatably supported by the stator, wherein the permanent magnet rotor comprises a plurality of core pieces. A core having a plurality of holes extending in the axial direction along the rotation direction on the surface layer on the side in contact with the core, and the core adjacent to each of the holes are mounted so that polarities are opposite to each other in the radial direction of the core. An AC servomotor having a plurality of permanent magnets as described above.