JPH04285315A - Magnetic bearing - Google Patents

Abstract

PURPOSE:To produce a magnetic bearing which can be interchangeably used with a radial bearing. CONSTITUTION:Conical magnets 51, 52 which are magnetized perpendicularly to a shaft 2 and have equal thickness are attached to both the ends of the base body 61 of a movable part to which the shaft 2 is attached, and steady magnets 41, 42 which are opposite to the movable magnets 51, 52 and have equal thickness are arranged in a housing 7 serving as a steady part at an interval, and magnetized in a direction where the magnets 41, 42 repulse the magnets 51, 52. Thus a magnetic bearing is formed.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic bearing using permanent magnets.

0002

2. Description of the Related Art FIG. 2 shows an example of a conventional technique in which one rotating body is supported by two magnetic bearings. 1 is a rotating body,
2 is a rotating shaft, 3 is the neck of the rotating shaft, 4 is a cylindrical fixed magnet arranged with a certain gap along the side of the movable part magnet, and 5 is a cylindrical movable part that is open toward the tip. It's a magnet.

[0003] Here, the fixing of the rotating shaft 2 and the magnetic bearing is as follows.
As is clear from the figure, the neck 3 provided at the tip of the rotating shaft
is arranged inside the cylindrical part of the movable part magnet 5, and has a structure in which the movable part magnet 5 is locked by the cylindrical inclined part and the axially outward component force of the magnetic bearing.

0004

[Problems to be Solved by the Invention] As already explained, in the above bearing, the rotary shaft 2 and the magnetic bearing are fixed by the inner inclined part of the movable part magnet 5 and the axially outward component force of the magnetic bearing. It has a structure that locks the movable part magnet 5. This can be said to be a rational structure that utilizes the external repulsive force of the magnetic bearing to fix the rotary shaft 2 and the magnetic bearing, but there is a big problem in assembling it. That is, the problem is that unlike mechanical radial bearings, it is not possible to bring a completed bearing and attach it to the shaft of a rotating body. To assemble this, it is necessary to prepare the rotating body 1, pull the movable part magnet 5 into a predetermined position against the repulsive force of the fixed part magnet 4, and adjust and fix it. In this way, the spacing caused by the bearing's repulsive force can only be adjusted by adjusting the positional relationship of the three parts: the rotating body, the moving part of the magnetic bearing, and the fixed part of the magnetic bearing, which requires assembly time, labor, and skill. It is.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems and provide a magnetic bearing that can be easily installed in the same way as conventional radial bearings.

[0006]

[Means for Solving the Problems] The means adopted by the bearing of the present invention to achieve the above object is that two conical shapes made of plates of equal thickness are arranged with their bottoms facing each other. It consists of a movable part magnet through which the rotating shaft passes through the center, and a fixed part magnet that is placed opposite to the surface of the movable part magnet with a certain gap, and the movable part magnet is magnetized in a direction perpendicular to the rotating shaft and fixed. The part magnet is characterized in that it is magnetized in a direction that repels the movable part magnet.

[0007]

[Operation] With the above structure, the magnetic bearing of the present invention maintains the movable part magnet and the fixed part magnet at an appropriate distance by repulsive force due to their inclination angle, and is independent of the rotating body. Since it can be completed as a complete part, it can be used simply and in the same way as mechanical bearings.

[0008]

[Embodiment] An embodiment of the present invention will be explained based on FIG. 1 is a rotating body, 2 is a rotating shaft, 41 and 42 are fixed part magnets, 5
1 and 52 are movable part magnets, 6 is a movable part, 61 is a movable part base, 7 is a housing, and 71 and 72 are housing halves. A movable part base 61 is firmly fitted and fixed to the rotating shaft 2 of the rotating body 1. The movable part base 61 has a cylindrical shape with both ends tapered to form a substantially conical shape, and movable part magnets 51 and 52 of equal thickness are firmly fitted into the surface of the movable part base 61 with their bottoms facing each other in a conical shape. The movable part 6 is shaped like an abacus bead as a whole. The magnetic poles of the magnet are magnetized at right angles to the axis, with the outside being S pole and the inside being N pole.

The housing 7 is divided into two parts 71 and 72, which are assembled to form a substantially cylindrical shape. The inner side thereof is formed so as to surround the movable part 6 with a certain gap provided therebetween. Fixed part magnet 41
, 42 are located inside the half parts 71, 72 of the housing 7, and are fixed so as to be spaced apart and parallel to the movable part magnets 51, 52.

To assemble the magnetic bearing of the present invention, the movable part 6 is first prepared. Then, the housing halves 71 and 72, to which the fixed part magnets 41 and 42 are attached inside, are fitted from both ends of the movable part 6, and when they abut, they are fixed and assembled. Movable part magnets 51, 52 and fixed part magnet 4
1 and 42 are formed to have the same thickness, thereby eliminating variations in permeance due to shape effects. In addition, in the case of a small bearing, the angle of inclination of the magnet is suitably between about 5 degrees and 45 degrees. The thus formed magnetic bearing exhibits its function by causing the movable part magnets 51, 52 and the fixed part magnets 41, 42 to repel each other and maintain a constant gap without contact.

[0011]

[Effects of the Invention] As is clear from the above explanation, the structure is simple and assembly is easy. Furthermore, since the magnetic bearing can be formed as an independent component, it can be easily used in the same way as a mechanical radial bearing.

[Brief explanation of the drawing]

FIG. 1 is an explanatory cross-sectional view showing an embodiment of the present invention.

FIG. 2 is an explanatory cross-sectional view showing a conventional magnetic bearing.

[Explanation of symbols]

1 Rotating body 2 Rotation axis 3 Rotating shaft neck 4, 41, 42 Fixed part magnet 5, 51, 52 Movable part magnet 6 Movable parts 61　Movable part base 7 Housing

Claims (1)

[Claims] 1. A movable part magnet, which has two conical shapes made of plates of equal thickness and are arranged with their bottoms facing each other, with a rotating shaft passing through the center thereof, and a fixed gap between the surfaces of the movable part magnets. and a fixed part magnet arranged to face each other, the movable part magnet being magnetized in a direction perpendicular to the rotation axis, and the fixed part magnet being magnetized in a direction repelling the movable part magnet. magnetic bearing.