JPH0589944U - Rotating body - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent contamination of the atmosphere when used in a clean room or vacuum atmosphere. When applied to an electromagnetic device, prevent performance degradation of the device. The deterioration of the magnetic performance of the magnetic material disk 11 is prevented. [Structure] A plurality of magnetic material discs 11 around the rotary shaft 2
To be laminated. The circumference of all magnetic material discs 11 is covered with a coating 15 made of a non-metallic material.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 According to the invention, for example, a rotating shaft of a magnetic bearing device that supports the rotating shaft in a non-contact state with a fixed portion, a rotor of a motor, and a shaft-shaped second joint member at the center of a hollow first joint member. The present invention relates to a rotating body used as both joint members of a magnetic joint inserted coaxially and in a non-contact state.

[0002]

[Problems to be solved by conventional techniques and devices]

 Conventionally, for example, as a rotating shaft of a magnetic bearing device, a plurality of circular plates made of a silicon steel plate, which is a magnetic material, are press-fitted and laminated around the shaft for the purpose of reducing eddy current loss, thereby forming an attracted portion, It is known that an electromagnet for attraction is arranged around the portion to be attracted in the fixed portion. Also, as a rotor of a motor, it is known that a plurality of circular plates made of a silicon steel plate, which is a magnetic material, are press-fitted and laminated around a rotating shaft.

However, in the above rotary shaft and rotor, fine particles such as dust caught between silicon steel plates during assembly cannot be removed by, for example, a baking process. Therefore, this magnetic bearing device is installed in a clean room or in a vacuum atmosphere. When used inside, there is a problem that the above-mentioned fine particles are released into the atmosphere and become a pollution source of the atmosphere. Moreover, in any of the above cases, there is a problem that the silicon steel plate is corroded when used in a special gas atmosphere.

Conventionally, for example, as two joint members of a magnetic joint, permanent magnets, which are magnetic materials, are arranged in recesses formed in circumferential surfaces facing each other, and fixed by an adhesive or screws. It has been known. Further, conventionally, for example, as a rotor of a motor, there is known a rotor in which a permanent magnet is fixed around an axis of rotation with an adhesive or a screw.

However, in the above-mentioned joint member and rotor, when the permanent magnets are fixed with an adhesive and used in a high temperature or high vacuum atmosphere, there is a problem that gas is generated from the adhesive and fine particles such as dust are generated. is there. Further, even when fixed with screws, a sintered magnet is usually used as a permanent magnet, so that when used in a high temperature or high vacuum atmosphere, fine particles are emitted from the surface of the magnet. Further, a plastic magnet may be used as the permanent magnet, but in this case, there is a problem similar to that of the adhesive. Therefore, in any case, it becomes a pollution source of the atmosphere.

Therefore, in order to solve these problems, it is considered to fit a sleeve made of, for example, non-magnetic stainless steel on the peripheral surface of the silicon steel plate or the permanent magnet. When the rollers are magnetic bearing devices, there is a problem that eddy current is generated in the sleeve and the sensor output is reduced due to the effect. In particular, when the gap is large, the decrease in sensor output is remarkable. Further, when applied to other electromagnetic devices, there is a problem that the performance is deteriorated by the eddy current.

An object of the present invention is to provide a rotating body that solves the above problems.

[0008]

[Means for Solving the Problems]

 The rotating body according to the present invention is a rotating body in which a member made of a magnetic material is arranged on the peripheral surface, and the peripheral surface of the member made of a magnetic material is covered with a coating film made of a non-metallic material.

In the above, the coating film is formed by, for example, a physical vapor deposition method or a chemical vapor deposition method. The type of material forming the coating and the film thickness are appropriately determined in consideration of the atmosphere in which the rotating body is used. The film thickness is selected within a wide range of, for example, several μm to several mm.

[0010]

[Action]

 Since the peripheral surface of the magnetic material member is covered with a coating made of a non-metallic material, a magnetic bearing device that applies this rotating body to the rotating shaft, a motor that applies to the rotor, a magnetic joint that applies to the joint member, etc. Even when used in a clean room, in a high temperature atmosphere, or in a vacuum atmosphere, the function of the coating prevents particles such as dust and gas from being released into the atmosphere. Further, even when these are used in a special gas atmosphere, the corrosion of the magnetic member is prevented. Further, since the coating is made of a non-metallic material, eddy current is prevented from being generated in the coating even when applied to an electromagnetic device such as a magnetic bearing device. Moreover, by reducing the thickness of the coating, it is possible to prevent deterioration of magnetic characteristics.

[0011]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. In the following description, the left and right in FIGS. 1 and 2 are referred to as the left and right.

Embodiment 1 This embodiment is shown in FIG. 1, in which the rotating body of the present invention is applied to a rotating shaft of a magnetic bearing device. In FIG. 1, the magnetic bearing device includes a housing (fixed portion) (1) and a rotating shaft (2) arranged in the housing (1). A radial magnetic bearing (3), a radial position detecting device (4) and a touchdown bearing (5) are provided at both left and right ends of the housing (1). Although illustration is omitted, the housing (1) is composed of a rotor provided on the rotating shaft (2) and a stator fixed to the housing (1) around the rotor and the rotating shaft (2). It is equipped with a motor that rotates the motor, an axial magnetic bearing, and an axial position detector.

The radial magnetic bearing (3) is composed of a suction electromagnet (6) fixed to the housing (1) and an attracted portion (7) provided on the rotary shaft (2). The radial position detecting device (4) comprises a radial sensor (8) provided on the housing (1) and a sensor target (9) provided on the rotary shaft (2).

Small-diameter portions (2b) are integrally formed at both left and right ends of the large-diameter portion (2a) of the rotating shaft (2). A plurality of disc-shaped silicon steel plates (members made of magnetic material) (11) are press-fitted and laminated around the part of the small diameter part (2b) near the large diameter part (2a), and the attracted part (7) is It is configured. Collar (12) is press-fitted around the small diameter part (2b) on the outer side of the suctioned part (7) in the left-right direction, and a plurality of collars (12) are placed on the outer side of the collar (12) around the small diameter part (2b). The disc-shaped silicon steel plate (magnetic member) (13) is press-fitted and laminated to form a sensor target (9). The collar (14) is press-fitted around the small diameter portion (2b) on the outer side in the left-right direction of the sensor target (9). Then, the outer peripheral surfaces of all the silicon steel plates (11), the collar (12), all the silicon steel plates (13) and the collar (14) that compose the sensor target (9) that compose the attracted part (7), In addition, the axial outer surfaces of the collars (14) at the left and right ends are covered with a non-metallic material coating (15) made of ceramics, silicon, or the like. The thickness of the coating film (15) is set to several μm.

When the above magnetic bearing device is used in a clean room or a vacuum atmosphere, the particles (15) caught between the silicon steel plates (11) and (13) are released into the atmosphere by the action of the coating (15). The atmosphere is not polluted as it is prevented. Further, even when used in a special gas atmosphere, the function of the coating film (15) prevents corrosion of the silicon steel plates (11) and (13). Moreover, since the coating (15) is made of a non-metallic material, it is possible to prevent the generation of eddy currents, and as a result, it is possible to prevent the output of the sensor (8) from decreasing. Furthermore, by reducing the thickness of the coating film (15), it is possible to prevent deterioration of magnetic performance.

In the embodiment described above, the magnetic bearing device in which the rotating body of the present invention is applied to the rotating shaft (2) rotating inside the housing (1) is shown. It is also applicable to a rotating body of a magnetic bearing device in which the body rotates around a fixed axis. Further, in the above embodiments, the disk-shaped silicon steel plate is used as the magnetic material disk, but the disk is not limited to this, and disks made of various magnetic materials can be used. Furthermore, in the above embodiment, the entire peripheral surface of the rotating shaft (2) may be covered with a coating film made of a non-metallic material.

Embodiment 2 This embodiment is shown in FIGS. 2 and 3, in which the rotating body of the present invention is applied to two joint members of a magnetic joint.

2 and 3, the magnetic joint includes a thick-walled cylindrical first joint member (20) and a cylindrical shaft-shaped second joint member (21) inserted coaxially in the center thereof. Is equipped with. The first joint member (20) is fixed to the inside of, for example, a cylindrical rotating body (not shown). The second joint member (21) is fixed around the shaft (22). The two joint members (20) and (21) are rotatably supported by bearings (not shown) such as magnetic bearings so that they can rotate about a common axis.

On the inner peripheral surface of the first joint member (20), there are four permanent magnet fitting grooves (20a) (20b) (20c) (20d) extending in the left-right direction at equal intervals in the circumferential direction. Has been formed. A recess (23) is formed on the left end surface of the first joint member (20). The permanent magnets (members made of magnetic material) (24a) to (24d), which are sintered magnets and extend in the left-right direction, are fitted into the respective permanent magnet fitting grooves (20a) to (20d), and the first joint member (20 The annular holding plate (25) is fitted in the recess (23) on the left end face of (1). The permanent magnets (24a) to (24d) are fixed to the inner surfaces of the permanent magnet fitting grooves (20a) to (20d) and the annular holding plate (25) with an adhesive. Then, including all the permanent magnets (24a) to (24d) and the annular holding plate (25), the entire inner and outer peripheral surfaces of the first joint member (20) and both left and right end surfaces are made of a non-metallic material such as ceramics or silicon. It is covered with a coating of material (26).

In the portion of the outer peripheral surface of the second joint member (21) that faces the permanent magnet fitting grooves (20a) to (20d), the permanent magnet fitting grooves (21a) (21b) extending in the left-right direction are provided. Four (21c) and (21d) are formed at equal intervals in the circumferential direction. A recess (27) is formed on the left end surface of the second joint member (21). The permanent magnets (28a) to (28d) extending in the left-right direction are fitted in the respective permanent magnet fitting grooves (21a) to (21d), and inside the recess (27) on the left end surface of the second joint member (21). An annular presser plate (29) is fitted to and stopped at. The permanent magnets (28a) to (28d) are fixed to the inner surfaces of the permanent magnet fitting grooves (21a) to (21d) and the annular holding plate (29) with an adhesive. And, including all the permanent magnets (28a) to (28d) and the annular holding plate (29), the entire outer peripheral surface and the left and right end surfaces of the second joint member (21) are made of a non-metallic material such as ceramics or silicon. It is covered with a coating (30).

The permanent magnets (24a) to (24d) of the first joint member (20) and the permanent magnets (28a) to (28d) of the second joint member (21) form two joint members (20). Permanent magnet devices (31a) (31b) (31c) (31d) are provided at four locations that equally divide the facing peripheral surface of (21) in the circumferential direction.

In each of the permanent magnet devices (31a) to (31d), left and right outer permanent magnets (24a) to (24d) fixed to the inner peripheral surface of the first joint member (20), and the second The inner permanent magnets (28a) to (28d) fixed to the outer peripheral surface of the joint member (21) and extending in the left-right direction have magnetic poles at the left and right ends, and the outer permanent magnets (24a) to (24d) and the inner permanent magnet ( In 28a) to (28d), the left and right polarities are reversed. For example, the outer permanent magnets (24a) to (24d) have the N pole at the left end and the S pole at the right end, and the inner permanent magnets (28a) to (28d) have the S pole at the left end and the N pole at the right end. The outer permanent magnets (24a) to (24d) and the inner permanent magnets (28a) to (28d) are opposite in polarity to each other at the left and right ends.

In each of the permanent magnet devices (31a) to (31d), a closed magnetic path that extends in the radial direction and the axial direction of the joint members (20) and (21) is formed, and two joint members (20) are formed. The suction force is applied to (21). Since this magnetic path is wide in the radial direction and the axial direction of the joint members (20) (21), the two joint members (20) (21) are mutually in the radial direction and the axial direction. Supported in a non-contact state.

When the above magnetic coupling is used in a clean room or a vacuum atmosphere, the coatings (26) and (30) work to fix the permanent magnets (24a) to (24d) (28a) to (28d) and this. Since the adhesive prevents the release of fine particles such as dust and gas into the atmosphere, the atmosphere is not polluted. Moreover, by reducing the thickness of the coatings (26) and (30), it is possible to prevent the performance of the magnetic joint from being degraded.

In the above-mentioned embodiment, the sintered magnet is used as the permanent magnet and is fixed by the adhesive, but the same effect can be obtained when the permanent magnet made of the plastic magnet is fixed by the screw.

[0026]

[Effect of the device]

 According to the rotating body of the present invention, as described above, the function of the coating film prevents the release of fine particles such as dust and gas into the atmosphere. It is possible to prevent pollution of the atmosphere when used inside. Further, even when used in a special gas atmosphere, the function of the coating can prevent the corrosion of the magnetic member. Moreover, since the coating is made of a non-metallic material, it is possible to prevent eddy currents from being generated in the coating even when applied to an electromagnetic device, and as a result, it is possible to prevent deterioration of performance. Further, by reducing the thickness of the coating, it is possible to prevent the magnetic performance of the magnetic material member from being deteriorated.

[Brief description of drawings]

FIG. 1 is a sectional view showing a magnetic bearing device in which a rotating body according to the present invention is applied to a rotating shaft, with an intermediate portion omitted.

FIG. 2 is a longitudinal sectional view of a magnetic joint in which the rotating body according to the present invention is applied to two joint members.

3 is a cross-sectional view of the magnetic coupling of FIG.

[Explanation of symbols]

 2 rotating shaft 11 silicon steel plate 15 coating 20 first joint member 21 second joint member 24a to 24d permanent magnets 28a to 28d permanent magnet 26 coating 30 coating

Claims (1)

[Scope of utility model registration request] 1. A rotating body having a magnetic material member arranged on a peripheral surface thereof, wherein the peripheral surface of the magnetic material member is covered with a coating film made of a non-metallic material.