JP2008111476A - Rotation drive device and rotating equipment equipped therewith - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotation drive device with a vertical type hydrodynamic gas bearing for smoothly supporting a rotating shaft. <P>SOLUTION: The vertical type rotation drive device comprises a bearing device 3 having foil bearings 30, 40 to be used as radial bearings and axial magnetic bearings 50, 60 to be used as axial bearings for supporting the rotating shaft 21 which is rotationally driven by a motor 20. The device is used in such an installation form that the rotating shaft 21 is vertical. The axial centers of the foil bearings 30, 40 are eccentric from the axis of the rotating shaft 21. The bearing device has a radial magnetic bearing to be used as a radial bearing. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a rotary drive device that drives rotary equipment such as a compressor, a blower, and a turbine.

  In a rotary drive device that drives a rotary device such as a compressor, a blower, or a turbine, a rotary shaft is rotated by using a motor as a drive source to rotate a rotating portion of the rotary device. In such a rotary drive device, a foil bearing or a magnetic bearing is used as a bearing device for supporting a rotating shaft that rotates at high speed (see Patent Document 1). Foil bearings and magnetic bearings do not require lubricating oil, so space for an oil pump or the like can be eliminated, and oil or the like need not be replaced. Furthermore, since the rotating shaft and the bearing are not in contact with each other, the durability of the bearing can be increased, and the rotational driving torque can be suppressed.

Here, the foil bearing is a dynamic pressure type air bearing and is used as a radial bearing, and is normally used in a horizontal orientation. As shown in FIG. 4, the foil bearing 30 has a configuration in which a bump foil 32 and a top foil 33 are disposed on the inner periphery of a cylindrical bearing housing 31, and the rotating shaft 21 is disposed in the top foil 33. ing. As indicated by the solid line in the figure, at the time of stopping, the rotating shaft 21 is shifted vertically downward by its own weight and is held in contact with the top foil 33. At this time, the position of the axis of the rotating shaft 21 is at a position Pg shifted by δo shifted downward from the position Pr coinciding with the axis of the foil bearing 30. During operation, when the rotating shaft 21 is rotated, a dynamic pressure is generated between the rotating shaft 21 and the top foil 33, so that the rotating shaft 21 is levitated, and the rotating shaft 21 is turned on by the gas lubrication action. 33 is supported in a non-contact state. During rotation, the rotation shaft 21 attempts to displace the center of the rotation shaft 21 from the position Pr to the position Pf, but rotates in a state of being eccentric due to the weight of the rotation shaft 21.
JP 2002-5159 A

  By the way, it is conceivable that the rotary drive device provided with the foil bearing 30 is used in a vertical orientation depending on the space in which it is arranged. In such a case, since the axis of the rotating shaft 21 is in the vertical direction and there is no shift due to the weight of the rotating shaft 21, the rotating shaft 21 cannot obtain sufficient dynamic pressure. In addition, unlike the case of using it horizontally, there is a concern that the rotating shaft 21 may be touched because the restraining force in the radial direction of the rotating shaft 21 due to its own weight does not act. In such a case, the rotating shaft 21 and the top foil 33 are in contact with each other, the rotational resistance of the rotating shaft 21 is increased, and smooth support is hindered.

  This invention is made | formed in view of such a situation, The objective is to provide the rotational drive apparatus provided with the vertical installation type dynamic-pressure-type gas bearing which can support a rotating shaft smoothly.

Hereinafter, means for achieving the above-described object and its operation and effects will be described.
According to the first aspect of the present invention, the rotating shaft that is driven to rotate by the motor is supported by a bearing device that includes a foil bearing that is used as a radial bearing and an axial magnetic bearing that is used as an axial bearing. A vertical-type rotary drive device used in a vertical installation mode, wherein the axis of the foil bearing is eccentric with respect to the axis of the rotary shaft, and used as a radial bearing in the bearing device The gist is that a radial magnetic bearing is provided.

  In a horizontal type foil bearing used as a radial bearing, a rotating shaft is shifted vertically downward by its own weight, and is in contact with a top foil disposed on the outer periphery of the rotating shaft when stopped. When the rotating shaft is rotated, dynamic pressure is generated between the rotating shaft and the top foil, and the rotating shaft is supported in a non-contact state with the top foil by gas lubrication. For this reason, when the foil bearing is used as a vertically mounted type, the rotating shaft does not shift and the dynamic pressure is unlikely to be generated unlike the case of horizontally mounted.

  According to the above configuration, even if the foil bearing used as the radial bearing is a vertical bearing, the axis of the foil bearing is eccentric with respect to the axis of the rotating shaft. Dynamic pressure is suitably generated between the inner periphery of the foil bearing. Further, while the rotating shaft rotates, the positions of the axis of the rotating shaft and the axis of the foil bearing try to coincide with each other. However, according to the above configuration, since the radial magnetic bearing is provided, it is possible to suppress the coincidence of the position of the axis of the rotating shaft and the axis of the foil bearing, and to obtain a dynamic pressure. As a result, the foil bearing can be used as a vertical bearing.

  According to a second aspect of the present invention, in the rotary drive device according to the first aspect, the amount of eccentricity of the axis of the foil bearing relative to the axis of the rotary shaft is determined by the axis of the rotary shaft and the axis of the foil bearing. The gist is to make it smaller than the gap between the outer peripheral surface of the rotating shaft and the inner peripheral surface of the foil bearing when the center is concentric.

  According to this configuration, the amount of eccentricity can be reduced by making it smaller than the gap between the outer peripheral surface of the rotary shaft and the inner peripheral surface of the foil bearing when the axis of the rotary shaft and the axis of the foil bearing are concentric. Sometimes a suitable dynamic pressure can be generated between the rotating shaft and the inner periphery of the foil bearing.

The gist of the invention described in claim 3 is that, in the rotary drive device according to claim 1 or 2, the axial magnetic bearing also serves as the radial magnetic bearing.
According to this configuration, since the axial magnetic bearing also serves as a radial magnetic bearing, the installation space can be reduced, and the required length in the axial direction can be shortened. As a result, the rotating shaft can be shortened, the natural frequency of the rotating shaft can be increased, and high-speed rotation can be supported.

  According to a fourth aspect of the present invention, in the rotary drive device according to the third aspect, the axial magnetic bearing includes a flange portion provided on the rotary shaft and an electromagnet provided opposite to the flange portion in the axial direction. The surface of the flange portion facing the electromagnet, when the rotary shaft tries to shift in the radial direction, a radial attracting force opposite to the shift direction acts on the flange portion. The gist thereof is that an annular groove is formed around the axis of the flange portion.

According to this configuration, by forming the annular groove in the flange portion, the axial magnetic bearing also acts as a radial direction bearing, so that the configuration can be simplified.
According to a fifth aspect of the present invention, in the rotary drive device according to the third aspect, the axial magnetic bearing includes a flange portion provided on the rotary shaft and an electromagnet provided opposite to the flange portion in the axial direction. The surface of the flange portion facing the electromagnet, when the rotary shaft tries to shift in the radial direction, a radial attracting force opposite to the shift direction acts on the flange portion. The gist of the invention is that the tapered surface is formed around the axis of the flange portion.

According to this configuration, since the axial magnetic bearing also acts as a radial bearing by forming a tapered surface on the flange portion, the configuration can be simplified.
The gist of a sixth aspect of the present invention is that the foil bearing and the axial magnetic bearing are integrated in the rotary drive device according to any one of the first to fifth aspects.

  According to this configuration, since the foil bearing and the axial magnetic bearing are integrated, the space can be reduced and the required length in the axial direction can be shortened. As a result, the rotating shaft can be shortened, the natural frequency of the rotating shaft can be increased, and high-speed rotation can be supported.

  A seventh aspect of the present invention is a rotating device that includes the rotational driving device according to any one of the first to sixth aspects of the present invention, and is rotationally driven by transmitting the driving force of the rotating shaft. Is the gist.

  According to this configuration, since the rotary drive device including the vertical type dynamic pressure type gas bearing capable of smoothly supporting the rotary shaft is provided, a vertical type rotary device can be provided.

  ADVANTAGE OF THE INVENTION According to this invention, the rotational drive apparatus provided with the vertical-position type dynamic-pressure type gas bearing which can support a rotating shaft smoothly can be provided.

Hereinafter, an embodiment in which a rotary drive device according to the present invention is embodied in a compressor will be described with reference to FIGS. FIG. 1 is a schematic configuration diagram illustrating a configuration of a compressor.
The compressor is used in a vertical orientation in which the axis of the rotation shaft provided in the rotation drive device is in the vertical direction. As shown in FIG. 1, the compressor is provided with a compression unit 1 and a drive unit 2 as a rotation drive device. The compression unit 1 and the drive unit 2 are provided in the compression unit casing 10a and the drive unit casing 10b of the casing 10, respectively. The compression unit 1 is located above the drive unit 2. The compression section 1 compresses the gas flowing in through the gas inflow path 12 by rotating in the compression section casing 10a and is discharged through a gas outflow path (not shown) through which the gas (air) flows. An impeller 11 is provided. The drive unit 2 is provided with a motor 20, a rotary shaft 21 that is rotationally driven by the motor 20, and a bearing device 3 that supports the rotary shaft 21. The motor 20 includes a stator 22 provided on the inner wall of the drive unit casing 10 b and a rotor 23 provided on the outer periphery of the rotating shaft 21. An impeller 11 provided in the compression unit 1 is connected to the tip of the rotating shaft 21. The bearing device 3 is provided integrally with the upper and lower foil bearings 30 and 40, and a pair of upper and lower upper and lower foil bearings 30 and 40 that are positioned vertically above and below the motor 20 and support the rotary shaft 21 in the radial direction. In addition, an upper axial magnetic bearing 50 and a lower axial magnetic bearing 60 that support the rotating shaft 21 in the axial direction are provided. A rolling bearing 27 is disposed at the end of the rotating shaft 21.

  The upper foil bearing 30 is disposed vertically above the motor 20 on the rotating shaft 21, that is, between the rotor 23 and the impeller 11. The upper foil bearing 30 includes a cylindrical bearing housing 31 fixed to the driving unit casing 10b. As shown in FIG. 2, a corrugated bump foil 32 is provided on the inner peripheral surface of the bearing housing 31. A sleeve-like top foil 33 is disposed. The rotating shaft 21 is located in the top foil 33. The bump foil 32 includes a cylindrical portion 32a formed by forming a corrugated plate material into a cylindrical shape, and an engaging portion 32b positioned radially outward at the proximal end of the cylindrical portion 32a. The top foil 33 includes a cylindrical portion 33a formed in a cylindrical shape, and an engaging portion 33b in which an end portion of the cylindrical portion 33a is bent. An engagement groove 31 b extending in the axial direction is formed on the inner peripheral surface 31 a of the bearing housing 31. The bump foil 32 and the top foil 33 are attached to the bearing housing 31 by engaging the engaging portion 32b and the engaging portion 33b with the engaging groove 31b. In the present embodiment, in order to be applied to the vertical type, the axial centers of the top foil 33 and the bump foil 32, that is, the axial center Pf of the foil bearing 30, are eccentric with the axial center Pr of the rotating shaft 21 and the eccentric amount δ. is doing. The eccentric amount δ is equal to the inner circumference of the outer peripheral surface 21a of the rotary shaft 21 and the inner circumference of the top foil 33 when the axis Pf of the foil bearing 30 and the axis Pr of the rotary shaft 21 shown in FIG. It is made smaller than the gap s with the surface 33c. In other words, it is desirable that the outer peripheral surface 21a of the rotary shaft 21 and the inner peripheral surface 33c of the top foil 33 be decentered in a range where the outer peripheral surface 21a does not contact (0 <δ <s). The lower foil bearing 40 is disposed vertically below the motor 20 on the rotating shaft 21. The lower foil bearing 40 is configured in the same manner as the upper fill bearing 30, and includes a bearing housing 41 fixed to the drive unit casing 10b, a bump foil 42, and a top foil 43 (see FIG. 2).

  As shown in FIG. 3, the upper axial magnetic bearing 50 is provided integrally with the upper foil bearing 30. The upper axial magnetic bearing 50 is an upper flange portion 51 provided so as to be integrally rotatable on the rotary shaft 21 vertically above the upper foil bearing 30, and a surface facing the upper flange portion 51 of the bearing housing 31 constituting the upper foil bearing 30. Is formed with an annular recess 31c, and an electromagnetic coil 52a is accommodated in the recess 31c. The bearing housing 31 is made of a magnetic material and also serves as an electromagnet yoke 52b. That is, the electromagnet 52 is composed of the electromagnet coil 52a and the electromagnet yoke 52b. On the surface facing the bearing housing 31 provided in the upper foil bearing 30 of the upper flange portion 51, there are a large-diameter annular groove 53 that is a large-diameter annular groove and an annular groove that is smaller in diameter than the large-diameter annular groove 53. A small-diameter annular groove 54 is formed. The large-diameter annular groove 53 is formed at a position facing the electromagnet 52. The outer surface of the upper flange portion 51 outside the large-diameter annular groove 53 and the surface between the large-diameter annular groove 53 and the small-diameter annular groove 54 are each attracted to the bearing housing 31 by the magnetic force generated by the electromagnet 52. A surface 55 and an inner suction surface 56. As a result, the axial magnetic bearing 50 has the electromagnet 52 and the both attracting surfaces 55, 55 when the outer attracting surface 55 and the inner attracting surface 56 deviate from the original position when the rotating shaft 21 is about to coincide with the electromagnet yoke 52b portion of the electromagnet 52. A radial force is generated between the upper foil bearing 30 and the upper foil bearing 30. That is, when the rotating shaft 21 rotates, the rotating shaft 21 tends to be displaced in a direction that coincides with the axis of the upper foil bearing 30. However, the attractive force of the electromagnet 52 acts on the upper flange portion 51 provided integrally with the rotary shaft 21, so that the rotary shaft 21 is kept eccentric from the axis of the upper foil bearing 30. As a result, the rotating shaft 21 can be supported also in the radial direction. As shown in FIG. 1, the lower axial magnetic bearing 60 is provided integrally with the lower foil bearing 40. Similarly to the upper axial magnetic bearing 50, the lower axial magnetic bearing 60 is composed of a lower flange portion 61 provided to be rotatable integrally with the rotary shaft 21 vertically below the lower foil bearing 40, and a magnetic body constituting the lower foil bearing 40. An electromagnet 62 including a bearing housing 41 (electromagnet yoke 62b) and an electromagnet coil 62a accommodated in a recess 41c provided on a surface facing the lower flange 61. The lower axial magnetic bearing 60, together with the upper axial magnetic bearing 50, supports the rotating shaft 21 in the axial direction and also in the radial direction.

  A position sensor 26 that detects the position of the rotating shaft 21 in the axial direction is provided at a portion facing the end of the rotating shaft 21 in the drive unit casing 10b. Based on the position of the rotating shaft 21 detected by the position sensor 26, the currents of the electromagnet coil 52a provided in the upper axial magnetic bearing 50 and the electromagnet coil 62a provided in the lower axial magnetic bearing 60 are controlled. The currents flowing through the electromagnet coils 52a and 62a are controlled such that an attractive force is generated in the axial magnetic bearings 50 and 60 that balances the force acting in the axial direction by the rotation of the impeller 11. Thereby, the rotating shaft 21 is supported in a non-contact state at a predetermined position in the axial direction.

Next, an operation mode of the compressor configured as described above will be described.
In the compressor, when the motor 20 provided in the drive unit 2 rotates, the rotation shaft 21 rotates, and the impeller 11 provided in the compression unit 1 connected to the rotation shaft 21 is rotated. Thereby, the gas which flowed in through the gas inflow path in the compression part 1 is compressed, and is discharged from the protrusion port which is not shown in the compression part casing 10a.

  When the rotating shaft 21 is rotated, the shaft center Pr of the rotating shaft 21 is eccentric by the shaft center Pf of both the foil bearings 30 and 40 and the amount of eccentricity δ. A suitable dynamic pressure is generated between the peripheral surfaces 33c and 43c. The rotating shaft 21 is supported in a non-contact state with the foil bearings 30 and 40 by the gas pressure by the dynamic pressure. In addition, a force acting in the axial direction is generated on the rotating shaft 21 by the rotation of the impeller 11. However, since the attractive force that balances the acting force is generated from the position of the rotating shaft 21 detected by the position sensor 26 in the axial magnetic bearings 50 and 60, the rotating shaft 21 is in a non-contact state at a predetermined position in the axial direction. Supported.

  In addition, during rotation, the rotating shaft 21 tends to shift to a position where the axis Pr of the rotating shaft 21 coincides with the axis Pf of the foil bearings 30 and 40, but both the electromagnet 52 of the upper axial magnetic bearing 50 and the shaft 52. A radial attracting force is generated between the attracting surfaces 55 and 56 and between the electromagnet 62 of the lower axial magnetic bearing 60 and the attracting surfaces 65 and 66, and the electromagnet 52 and the attracting surfaces 55 and 56, The electromagnet 62 and the attraction surfaces 65 and 66 are held in a matched state. As a result, the rotating shaft 21 is not eccentric, and the eccentricity δ between the axis Pr of the rotating shaft 21 and the shaft center Pf of both the foil bearings 30 and 40 is maintained, so that the axis of the rotating shaft 21 and the both foil bearings 30 and 30 are maintained. The 40 axis is kept eccentric. Therefore, the rotation shaft 21 and the foil bearings 30 and 40 can maintain rotation in a non-contact state by obtaining a suitable dynamic pressure.

As described above, according to the embodiment described above, the following effects can be obtained.
(1) Even if both the foil bearings 30 and 40 used as radial bearings are vertical bearings, the shaft centers Pf of both the foil bearings 30 and 40 are eccentric with the shaft center Pr of the rotating shaft 21 and the amount of eccentricity δ. Therefore, when the rotating shaft 21 rotates, dynamic pressure is suitably generated between the outer peripheral surface 21a of the rotating shaft 21 and the inner peripheral surfaces 33c and 43c of the foil bearings 30 and 40. Further, while the rotating shaft 21 rotates, the positions of the axis Pr of the rotating shaft 21 and the axes Pf of the foil bearings 30 and 40 try to coincide with each other. However, according to the above configuration, since both the axial magnetic bearings 50 and 60 as radial bearings are provided, the positions of the axis Pr of the rotating shaft 21 and the axes Pf of the foil bearings 30 and 40 coincide with each other. It can suppress and can obtain a dynamic pressure suitably. As a result, both foil bearings 30 and 40 can be used as vertical bearings.

  (2) By making the amount of eccentricity δ smaller than the clearance s between the outer peripheral surface 21a of the rotating shaft 21 and the inner peripheral surfaces 33c and 43c of the foil bearings 30 and 40, the outer peripheral surface 21a of the rotating shaft 21 and both foils are rotated. An appropriate dynamic pressure can be generated between the inner peripheral surfaces 33c and 43c of the bearings 30 and 40.

  (3) Since both axial magnetic bearings 50 and 60 also serve as radial magnetic bearings, the space can be reduced and the required length in the axial direction can be shortened. As a result, the rotating shaft 21 can be shortened, the natural frequency of the rotating shaft 21 can be increased, and high-speed rotation can be supported.

  (4) Since the foil bearings 30 and 40 and the axial magnetic bearings 50 and 60 are respectively integrated, the space can be reduced and the required length in the axial direction can be shortened. As a result, the rotating shaft 21 can be shortened, the natural frequency of the rotating shaft 21 can be increased, and high-speed rotation can be supported.

In addition, the said embodiment can be implemented with the following forms which changed this suitably.
In the above embodiment, the annular grooves 53 and 54 are formed in the flange portions 51 and 61 of the axial magnetic bearings 50 and 60 in order to support the rotating shaft 21 in the radial direction, but as shown in FIG. The surface of the flange portion 51 that faces the electromagnet 52 is a tapered surface 51a. Correspondingly, a surface facing the flange portion 51 of the bearing housing 31 and the electromagnetic coil 52a is a tapered surface. Similarly, the surface of the flange portion 61 facing the electromagnet 62 and the surface of the bearing housing 41 and the electromagnet coil 52a facing the flange portion 61 are tapered surfaces. According to this configuration, when the rotating shaft 21 is eccentric, there is a radial direction between the electromagnet 52 and the flange portion 51 of the upper axial magnetic bearing 50 and between the electromagnet 62 and the flange portion 61 of the lower axial magnetic bearing 60. Therefore, the rotating shaft 21 acts so as to keep the foil bearings 30 and 40 in an eccentric state. The taper direction may be such that the thickness in the axial direction becomes thinner as it goes toward the outer periphery as shown in the figure, or conversely, the thickness in the axial direction may become thinner as it goes toward the inner periphery.

  In the above embodiment, both the foil bearings 30 and 40 are provided integrally with the axial magnetic bearings 50 and 60, and both the axial magnetic bearings 50 and 60 are also used as radial bearings. However, as shown in FIG. Instead of the upper axial magnetic bearing 50, an axial magnetic bearing 70 that acts only as an axial direction bearing, and a radial magnetic bearing 80 as a radial direction bearing instead of the lower axial magnetic bearing may be provided. That is, the axial magnetic bearing 70 includes a flange portion 71 provided on the rotary shaft 21 vertically above the foil bearing 30, an electromagnet 72 provided on a surface facing the flange portion 71 of the bearing housing 31 provided on the foil bearing 30, and And a permanent magnet 73 fixed to a surface of the driving unit casing 10b facing the flange portion 71. The electromagnet 72 is configured such that the electromagnet coil 72a is housed in an annular recess 31c formed on the surface of the bearing housing 31 facing the flange portion 71, so that the bearing housing 31 formed of a magnetic material replaces the electromagnet yoke 72b. Also serves as. The electromagnet 72 includes an electromagnet coil 72a and an electromagnet yoke 72b. When the rotating shaft 21 is displaced in the axial direction, the displacement of the rotating shaft 21 in the axial direction is controlled by controlling the current flowing through the electromagnet coil 72a based on the detection of the position sensor 26. Further, the radial magnetic bearing 80 is positioned vertically below the foil bearing 40, and the two sets of electromagnets 81 and the radial of the rotary shaft 21 disposed opposite to each other on the circumference centering on the axis of the rotary shaft 21. A plurality of radial displacement sensors 82 for detecting directional displacement are provided. The radial magnetic bearing 80 controls the position of the rotating shaft 21 by controlling the current flowing through the electromagnet 81 based on the displacement detected by the radial displacement sensor 82. According to this configuration, since the radial magnetic bearing 80 as the radial bearing is provided, it is possible to suppress the coincidence between the position of the axis Pr of the rotating shaft 21 and the position of the axis Pf of the foil bearings 30 and 40. Dynamic pressure can be obtained.

In the above embodiment, the bump bearing type is used as the foil bearings 30 and 40, but other foils such as a leaf foil type and a back foil type may be used.
In the above embodiment, the rotary drive device is applied to the compressor, but it may be used for a rotary device such as a blower or a turbine.

The longitudinal cross-sectional view of a compressor. The cross-sectional view of a foil bearing. The expanded longitudinal cross-sectional view of foil bearing vicinity. The cross-sectional view of the conventional foil bearing. The enlarged longitudinal cross-sectional view of an axial magnetic bearing. The longitudinal cross-sectional view of a compressor.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Compression part, 2 ... Drive part, 3 ... Bearing apparatus, 10 ... Casing, 10a ... Compression part casing, 10b ... Drive part casing, 11 ... Impeller, 12 ... Gas inflow path, 20 ... Motor, 21 ... Rotary shaft 21a ... outer peripheral surface, 22 ... stator, 23 ... rotor, 26 ... position sensor, 27 ... rolling bearing, 30 ... upper fill bearing, 40 ... lower foil bearing, 31, 41 ... bearing housing, 31a, 41a ... inner peripheral surface , 31b, 41b ... engaging groove, 31c, 41c ... recess, 32, 42 ... bump foil, 33, 43 ... top foil, 33a, 43a ... cylindrical part, 33b, 43b ... engaging part, 33c, 43c ... inner circumference Surface, 50 ... Upper axial magnetic bearing, 60 ... Lower axial magnetic bearing, 51 ... Upper flange, 61 ... Lower flange, 51a ... Tapered surface, 52, 62 ... Electromagnet, 52a 62a ... Electromagnetic coil, 52b, 62b ... Electromagnetic yoke, 53, 63 ... Large diameter annular groove, 54, 64 ... Small diameter annular groove, 55, 65 ... Outer suction part, 56, 66 ... Inner suction part, 70 ... Axial magnetic bearing 71 ... Flange portion, 72 ... Electromagnet, 72a ... Electromagnet coil, 72b ... Electromagnet yoke, 73 ... Permanent magnet, 80 ... Radial magnetic bearing, 81 ... Electromagnet, 82 ... Radial displacement sensor, [delta], [delta] o ... Eccentricity, s ... Clearance, Pf, Pr ... axis.

Claims (7)

The rotating shaft driven by the motor is supported by a bearing device including a foil bearing used as a radial bearing and an axial magnetic bearing used as an axial bearing, and used in an installation mode in which the rotating shaft is vertical. A vertical-type rotary drive device,
The axis of the foil bearing is eccentric with respect to the axis of the rotary shaft,
The rotary drive device, wherein the bearing device is provided with a radial magnetic bearing used as a radial bearing. The rotary drive device according to claim 1,
The amount of eccentricity of the axis of the foil bearing with respect to the axis of the rotating shaft is such that the axis of the rotating shaft and the axis of the foil bearing are concentric with the outer peripheral surface of the rotating shaft and the foil bearing. A rotational drive device characterized by being smaller than a gap with an inner peripheral surface. In the rotation drive device according to claim 1 or 2,
The rotational drive device, wherein the axial magnetic bearing also serves as the radial magnetic bearing. In the rotation drive device according to claim 3,
The axial magnetic bearing includes a flange portion provided on the rotating shaft and an electromagnet provided opposite to the flange portion in the axial direction.
The surface of the flange portion facing the electromagnet should be applied with a radial attracting force opposite to the displacement direction on the flange portion when the rotation shaft is about to deviate in the radial direction. An annular groove is formed around the axis of the flange portion. In the rotation drive device according to claim 3,
The axial magnetic bearing includes a flange portion provided on the rotating shaft and an electromagnet provided opposite to the flange portion in the axial direction.
The surface of the flange portion facing the electromagnet should be applied with a radial attracting force opposite to the displacement direction on the flange portion when the rotation shaft is about to deviate in the radial direction. A taper surface is formed around the axis of the flange portion. In the rotation drive device according to any one of claims 1 to 5,
The rotary drive device, wherein the foil bearing and the axial magnetic bearing are integrated.   A rotary device comprising the rotary drive device according to claim 1, wherein the rotary device is driven to rotate by transmitting a driving force of the rotary shaft.

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