JP2008128484A - Motor having magnetic fluid baring mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor having a magnetic fluid bearing structure, which effectively stores lubricant within a bearing by a generated magnetic field and suppresses the wear of lubricant. <P>SOLUTION: The motor includes a rotator having a rotating shaft; a stator set in conformation to the rotator; and the magnetic fluid bearing structure including at least one bearing, at least one magnetic element and a magnetic fluid, in which the bearing is fitted onto the rotating shaft, the magnetic element is provided adjacently to the bearing, the magnetic fluid is kept between the bearing and the rotating shaft, and leak of lubricant from the bearing is prevented by a magnetic attracting effect between the magnetic fluid and the magnetic element. The hydraulic pressure of the magnetic fluid applies pressure in the axial/radial directions of the rotating shaft to stably rotate the rotating shaft relative to the bearing. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a motor, and more particularly to a motor having a magnetic fluid bearing mechanism.

  Due to the smoothness and stability of the motor's high speed rotation, the prior art uses bearings to support the rotating shaft. As shown in FIG. 1, the motor 1 includes a stator 11, a rotating shaft 12, a bearing 13, and an oil seal 14. The bearing 13 can be an oil-impregnated bearing, and the oil seal 14 can be a stop ring or a metal ring. The oil seal 14 is installed above the bearing 13, is provided around the rotating shaft 12, and stores lubricating oil in the bearing 13. When the motor 1 rotates, the bearing 13 provides lubrication of the rotating shaft 12 using the adhesiveness of the lubricating oil itself, and can be operated smoothly.

    However, since the oil seal 14 is provided around the rotary shaft 12, the space for storing the lubricating oil cannot be completely sealed. Therefore, as the motor 1 is operated at a high speed for a long time, the lubricating oil is gradually leaked, the lubricity of the rotating shaft 12 and the bearing 13 is reduced, and the reliability and service life of the motor 1 are reduced.

    Therefore, one of the important issues is how to effectively store the lubricating oil in the bearing, suppress the consumption of the lubricating oil, and increase the reliability and service life of the motor.

    In view of the above problems, an object of the present invention is to provide a motor having a magnetic fluid bearing structure that effectively stores lubricating oil in a bearing by a generated magnetic field and suppresses consumption of the lubricating oil. Further, since the magnetic field generates a further axial / radial support force by the magnetic fluid, the reliability and service life of the motor can be increased.

    Therefore, in order to achieve the above object, a magnetic fluid bearing mechanism according to the present invention includes at least one bearing, at least one magnetic element, and a magnetic fluid. The bearing is fitted on the rotating shaft, and the magnetic element is provided adjacent to the bearing. The magnetic fluid is located between the bearing and the rotating shaft, and prevents the lubricating oil from leaking from the bearing due to an attractive action of magnetic force between the magnetic fluid and the magnetic element. Further, the hydraulic pressure of the magnetic fluid applies an axial / radial pressure of the rotating shaft, and the rotating shaft is stably rotated by the bearing.

    In order to achieve the above object, a motor according to the present invention includes a rotor, a stator, and a magnetic fluid bearing mechanism. The rotor has a rotation shaft, and the stator is installed corresponding to the rotor. The magnetic fluid bearing mechanism includes at least one bearing, at least one magnetic element, and a magnetic fluid. The magnetic element is installed adjacent to the bearing, and the magnetic fluid is between the bearing and the rotating shaft. The magnetic fluid attracting action between the magnetic fluid and the magnetic element prevents leakage of the lubricating oil of the bearing, and the hydraulic pressure of the magnetic fluid applies pressure in the axial / radial direction of the rotary shaft, Is stably rotated on the bearing.

  The motor of the magnetic fluid bearing mechanism of the present invention prevents the leakage of the lubricating oil of the bearing by the magnetic action between the magnetic fluid accommodated between the bearing and the rotating shaft and the magnetic element, and the generated hydraulic pressure is Pressure is applied in the axial / radial direction of the rotating shaft, and the rotating shaft is stably rotated on the bearing. Compared to the prior art, the present invention uses a magnetic field generated by a magnetic loop to generate a further axial and radial support hydraulic pressure with a magnetic fluid. Therefore, it is possible to provide a support action even when the rotation shaft is rotated or not rotated. In addition to improving the rotational stability of the rotating shaft, the present invention effectively stores the lubricating oil in the bearing by the magnetic force attracting action of the magnetic element, and suppresses the consumption of the lubricating oil, The reliability and service life of the motor can be increased.

    In order that the objects, features, and advantages of the present invention will be more clearly understood, embodiments will be described below in detail with reference to the drawings.

  As shown in FIG. 2A, the motor 2 according to the first embodiment of the present invention includes a rotor 22, a stator 21, and a magnetic fluid bearing mechanism 23. The rotor 22 has a rotation shaft 221 and a magnet 222. The rotating shaft 221 does not have magnetic permeability. The stator 21 is installed corresponding to the rotor 22 and is positioned between the magnet 222 and the rotating shaft 221. The magnetic fluid bearing mechanism 23 includes at least one bearing 231, at least one magnetic element 232, and a magnetic fluid 233. In this embodiment, the magnetic fluid bearing mechanism 23 has two bearings 231 and two magnetic elements 232. The magnetic element 232 may be formed of a permanent magnet, an electromagnet, or a magnet, but is not limited thereto. The magnetic fluid 233 can include iron, cobalt, nickel, or an alloy thereof.

  The motor 2 further includes a first fixing element 28 and a second fixing element 29. The first fixing element 28 has magnetic permeability or no magnetic permeability. The second fixing element 29 is annular. In this embodiment, the magnetic fluid bearing mechanism 23 is accommodated in the shaft tube portion 24 of the motor 2. The bearing 231 is fitted to the rotary shaft 221 and is in contact with and supports the first fixing element 28 to form the accommodation space 30 and accommodate the lubricating oil of the bearing 231. The magnetic element 232 is adjacent to the outer peripheral side of the bearing 231 and is supported in contact with the shaft tube portion 24. One end of the rotating shaft 221 is fitted into the bottom portion adjacent to the shaft tube portion 24 by the second fixing element 29. Moreover, the axial tube part 24 can match | combine each element engage | inserted in the inside on the same circle center. The magnetic fluid 233 is located between the bearing 231 and the rotating shaft 221 in the shaft tube portion 24.

    The protection principle and process of lubrication provided by the magnetic fluid bearing structure 23 to the motor 2 will be described below. When the motor 2 is not in operation, each magnetic element 232 has the N and S poles arranged in the axial direction, so the magnetic loop C and the rotating shaft 221 have an axial distribution, and the bearing 231 also rotates. Provides support for the shaft 221. Since the bearing 231 has magnetic permeability when the motor 2 is in an operating state, the magnetic loop C generated by the magnetic element 232 adsorbs the magnetic fluid 233 by the bearing 231, and between the bearing 231 and the rotating shaft 221. It can be distributed in the axial direction. As the magnetic flux density increases, the hydraulic pressure of the magnetic fluid 233 also increases, providing better lubrication and support effect for the bearing 231 and the rotating shaft 221 and reducing the friction loss between the rotating shaft 221 and the bearing 231. In the case of the magnetic fluid bearing mechanism 23, the oil seal structure is formed in the same manner by the attractive action of the magnetic force provided by the magnetic element 232, so that consumption of the lubricating oil can be prevented.

    Referring to FIG. 2B, the configuration and function of the motor 2 a according to the second embodiment of the present invention are the same as those of the motor 2. The difference is that the N and S poles of each magnetic element 232 are in the radial direction with respect to the arrangement of the rotating shaft 221, and therefore the magnetic loop C1 and the rotating shaft 221 have a radial distribution. Since the bearing 231 is magnetically permeable when the motor 2a is in an operating state, the magnetic loop C1 generated by the magnetic element 232 adsorbs the magnetic fluid 233 by the bearing 231 and is directly proportional to the magnetic flux density in the radial direction. Lubricating and supporting functions are provided between the rotating shaft 221 and the rotating shaft 221, friction loss between the rotating shaft 221 and the bearing 231 can be reduced, and an oil seal structure can be formed in the same manner to prevent the consumption of lubricating oil.

    As shown in FIG. 3A, the motor 3 according to the third embodiment of the present invention includes a rotor 22, a stator 21, and a magnetic fluid bearing mechanism 33. The configuration and function of the motor 3 are the same as those of the motor 2 of the first embodiment. The difference is that the rotating shaft 221 has magnetic permeability, and the magnetic fluid bearing mechanism 33 has two bearings 331, a magnetic element 332, and a magnetic fluid 333. The magnetic element 332 is formed of a permanent magnet ring, is installed adjacent to the outer peripheral side of the bearing 331, and has a fixing function of the first fixing element 28. The magnetic fluid 333 is located between the bearing 331 in the shaft tube portion 24 and the rotating shaft 221.

    When the motor 3 is in an operating state, the bearing 331 and the rotating shaft 221 are magnetically permeable, and the N and S poles of the magnetic element 332 are arranged in the axial direction, so that the magnetic loop C2 generated by the magnetic element 332 is generated. Can adsorb the magnetic fluid 333 by the bearing 331 and the rotating shaft 221, and can be distributed between the bearing 331 and the rotating shaft 221 in the axial direction. It should be noted that since the rotating shaft 221 is magnetically permeable, the portion where the rotating shaft 221 and the bearing 331 are not fitted also attracts the magnetic fluid 233, and as the magnetic flux density increases, the hydraulic pressure of the magnetic fluid 333 increases. It is also possible to obtain a better lubrication and support effect, to form an oil seal structure in the same way, and to prevent the consumption of lubricating oil.

    Referring to FIG. 3B, the configuration and function of the motor 3a according to the fourth embodiment of the present invention are the same as those of the motor 3. The difference is that the N and S poles of the magnetic element 332 are in the radial direction with respect to the arrangement of the rotation shaft 221, and therefore the magnetic loop C 3 and the rotation shaft 221 have a radial distribution. Since the bearing 331 and the rotating shaft 221 are magnetically permeable, the magnetic loop C3 generated by the magnetic element 332 adsorbs the magnetic fluid 333 on the contact surface between the bearing 231 and the rotating shaft 321 and is directly proportional to the magnetic flux density in the radial direction. Thus, it is possible to provide lubrication and support action between the bearing 331 and the rotating shaft 221, reduce friction loss between the rotating shaft 221 and the bearing 331, and form the oil seal structure in the same manner to prevent the consumption of lubricating oil. .

    As shown in FIG. 4A, the motor 4 according to the fifth embodiment of the present invention includes a rotor 22, a stator 21, and a magnetic fluid bearing structure 43. The configuration and function of the motor 4 are the same as those of the motor 3 of the third embodiment. The difference is that the magnetic fluid bearing mechanism 43 has a configuration in which the magnetic element 432 is fitted in the bearing 431. The magnetic element 432 includes a permanent magnet ring. The magnetic fluid 433 is between the bearing 431 and the rotating shaft 221. In this embodiment, the first fixing element can be deleted in the same manner, and the oil seal, lubrication, and supporting action provided to the motor by the magnetic fluid bearing structure 43 are the same as described above, and are omitted here. .

    Refer to Figure 4B. The configuration and function of the motor 4a according to the sixth embodiment of the present invention are the same as those of the motor 4. The difference is that the magnetic fluid bearing mechanism 43 has a configuration in which two magnetic elements 432 are fitted in the bearing 431, and the magnetic element 432 is formed of a permanent magnet ring.

  The preferred embodiments of the present invention have been described above, but this does not limit the present invention, and a few changes and modifications that can be made by those skilled in the art without departing from the spirit and scope of the present invention. It is possible to add. Accordingly, the scope of the protection claimed by the present invention is based on the scope of the claims.

It is the schematic of the conventional motor. It is the schematic of the motor based on Example 1 of this invention and its magnetic fluid bearing mechanism. It is the schematic of the motor based on Example 2 of this invention, and its magnetic fluid bearing mechanism. It is the schematic of the motor based on Example 3 of this invention, and its magnetic fluid bearing mechanism. It is the schematic of the motor based on Example 4 of this invention, and its magnetic fluid bearing mechanism. It is the schematic of the motor based on Example 5 of this invention, and its magnetic fluid bearing mechanism. It is the schematic of the motor based on Example 6 of this invention, and its magnetic fluid bearing mechanism.

Explanation of symbols

1, 2, 2a, 3, 3a, 4, 4a Motor 11, 21 Stator 12, 22 Rotor 23, 33, 43 Magnetic fluid bearing mechanism 24 Shaft tube portion 28 First fixing element 29 Second fixing element 30 Accommodating space 221 Rotating shaft 222 Magnet 231, 331, 431 Bearing 232, 332, 432 Magnetic element 233, 333, 433 Magnetic fluid C, C1, C2, C3 Magnetic loop

Claims (10)

A rotor having a rotation axis;
A stator installed corresponding to the rotor; at least one bearing; at least one magnetic element; and a magnetic fluid; the bearing is fitted to the rotating shaft; and the magnetic element is adjacent to the bearing. A magnetic fluid bearing mechanism is provided, in which the magnetic fluid is interposed between the bearing and the rotating shaft, and prevents the leakage of lubricating oil of the bearing by an attractive action of magnetic force between the magnetic fluid and the magnetic element;
The motor according to claim 1, wherein the magnetic fluid hydraulic pressure applies pressure to the axis / radial direction of the rotating shaft to stably rotate the rotating shaft corresponding to the bearing.     The motor according to claim 1, wherein the magnetic fluid bearing structure is accommodated in a shaft tube portion of the motor, and the stator is fitted to the shaft tube portion.     The motor according to claim 1, further comprising at least one first fixing element in contact with and supporting the bearing and having magnetic permeability or non-magnetic permeability.     The motor according to claim 1, wherein the motor is installed in contact with and supports the rotating shaft and adjacent to one end of the rotating shaft.     The motor according to claim 1, wherein a fluid storage space is provided between the rotating shaft and the bearing to store the magnetic fluid.     The motor according to claim 1, wherein the bearing has magnetic permeability.     The motor according to claim 1, wherein the magnetic loop of the magnetic element forms an axial distribution or a radial distribution with the rotation axis.     The motor according to claim 1, wherein the N pole and the S pole of the magnetic element are arranged in an axial direction or a radial direction corresponding to a rotation axis.     The motor according to claim 1, wherein the magnetic element is fitted into the bearing, and the magnetic element is a permanent magnet ring.     The motor according to claim 1, wherein two magnetic elements are fitted to the bearing.

Images