JP2546576Y2 - Magnetic bearing spindle device - Google Patents

Description

Detailed description of the invention [Industrial application field] This invention relates to a magnetic bearing spindle device,
The rotating shaft is magnetically bearing by a magnetic bearing having an electromagnet,
The present invention relates to a magnetic bearing spindle device that controls the magnetic bearing by rotating the rotating shaft with a motor and detecting the position of the rotating shaft with a position sensor.

[Prior Art] Conventionally, a turbo-molecular pump used for space equipment, nuclear power, fusion reactor equipment and the like has been known. This turbo-molecular pump is a vacuum pump that obtains a high vacuum by rotating blades at a high speed in a vacuum, and has a structure in which a rotor for the turbo-molecular pump is mounted on a magnetic bearing spindle, and stationary vanes and a casing are incorporated. Things.

FIG. 4 is a sectional view showing a conventional magnetic bearing spindle. Note that the pump rotor is shown in a simplified manner.
A conventional magnetic bearing spindle will be described with reference to FIG. A rotor 102 for a turbo molecular pump is fixed to one end of the rotating shaft 101 by bolts 103. Rotor
An upper case 104 is provided on the inner surface of 102, and the upper case 104 is fixed on a lower case 105. An upper touch-down bearing 106 is mounted at substantially the same position as the upper surface of the upper case 104. On the inner surface of the upper case 104, a radial magnetic bearing 108 is mounted on the upper part thereof, and a radial position sensor 107 for detecting the position of the rotating shaft 101 in the radial direction is provided on the upper part of the radial magnetic bearing 108. . A thrust magnetic bearing 110 is provided below the radial magnetic bearing 108 on the inner surface of the upper case 104. Under the thrust magnetic bearing 110, the radial magnetic bearing 111
A radial position sensor for detecting the position of the rotating shaft 101 in the radial direction is provided below the radial magnetic bearing 111.
112 are provided. A motor 113 for rotating the rotating shaft 101 is provided on the lower inner surface of the lower case 105, and further below the lower touchdown bearing.
114 are provided. Further, a thrust position sensor 109 for detecting the position of the rotating shaft 101 in the thrust direction is provided facing the bottom surface of the rotating shaft 101.

Next, the magnetic bearing control of the conventional magnetic bearing spindle will be described. First, the radial direction of the rotating shaft 101 is controlled by radial magnetic bearings 108 and 111. That is, the radial position of the rotary shaft 101 is detected by the radial position sensor 107, and the current flowing through the coil of the radial magnetic bearing 108 is controlled based on the detection signal. The same operation is performed for the radial magnetic bearing 111 and the radial position sensor 111. Rotation axis 101
The thrust direction is controlled by the thrust magnetic bearing 110. That is, the position of the rotating shaft 101 in the thrust direction is
The current supplied to the coil of the thrust magnetic bearing 110 is controlled based on the detection signal detected by the thrust position sensor 109. By performing such control, the rotating shaft 101 is magnetically bearing with high precision, and the rotating shaft 101 is rotated by the motor 113 in this state.

[Problem to be Solved by the Invention] As described above, in the conventional magnetic bearing spindle, the radial direction of the rotating shaft 101 is controlled by the radial magnetic bearing, and the thrust direction is controlled by the thrust magnetic bearing.

However, when the turbo-molecular pump constituted by the magnetic bearing spindle is installed near a nuclear fusion reactor or a nuclear reactor, the components constituting the turbo-molecular pump are exposed to radiation. If an abnormality occurs in the turbo-molecular pump in such a state, it is impossible for a person to approach and repair the turbo-molecular pump, and there is an inconvenience of waiting for hundreds of years until the radiation level decreases.
Also, when a turbo molecular pump is used as a space device, even if it can be repaired by humans, the repair parts are not always complete, and the function as a turbo molecular pump is eventually completed. There is also a problem that it cannot be recovered.

That is, in the conventional magnetic bearing spindle, the magnetic bearing spindle is used in an environment where human beings cannot approach when the magnetic bearing spindle fails due to disconnection of coils or sensors inside the magnetic bearing spindle. In this case, there is a problem that the failure of the magnetic bearing spindle cannot be recovered.

The present invention has been made in order to solve the above-described problems, and to provide a magnetic bearing spindle capable of returning a failure from the outside without approaching the device when the device fails. With the goal.

[Means for Solving the Problems] The magnetic bearing spindle device according to claim 1 includes a first control system and a second control system. The first control system includes a first control system provided for each of the motor and the magnetic bearing.
And a first sensor for detecting the position of the rotating shaft. The second control system includes a second coil provided in each of the motor and the magnetic bearing, and a second sensor that detects a position of the rotating shaft. Then, when the first control system becomes abnormal, the first control system is disabled and the second control system is activated. Further, the magnetic bearing includes a radial magnetic bearing and a thrust magnetic bearing. In a radial magnetic bearing, a first coil and a second coil are wound around the same stator core. In the thrust magnetic bearing, the first and second sensors are arranged concentrically around the axis of the rotating shaft.

According to a second aspect of the present invention, in the configuration of the first aspect, the magnetic bearing has a drive control direction of 45 when the first coil is driven and 45 when the second coil is driven. ° It is characterized by including a radial magnetic bearing that changes.

[Operation] In the magnetic bearing spindle device according to claim 1, a second control system is provided in addition to the first control system, and the first control system is operated in response to an abnormality of the first control system. Is disabled and the second control system is activated, so that when an abnormality occurs due to a device failure or the like, drive control is performed from the first coil and the first sensor to the second coil and the second sensor. Is switched. Accordingly, when a failure occurs in the device, the failure can be recovered from the outside without approaching the device. Further, by configuring the magnetic bearing so as to include a radial magnetic bearing in which the first coil and the second coil are wound on the same stator core, the second control system in addition to the first control system is provided. Even if it is provided, the structure becomes compact without complicating the structure, and the positional relationship between the stator core of the radial magnetic bearing and the rotating shaft does not change between the first control system and the second control system. ,
Even when the first control system is disabled and the second control system is activated, the rotation axis can be controlled with the same positional relationship as the first control system. Also, since the magnetic bearing is configured to include a thrust magnetic bearing in which the first and second sensors are arranged concentrically about the axis of the rotating shaft, the end face facing the sensor of the rotating shaft. Even if is tilted, the position of the lowermost end of the rotating shaft can be accurately detected by both the first control system and the second control system without being affected by the tilt.

In the magnetic bearing spindle device according to claim 2,
Since the drive control direction is changed by 45 ° between when the first coil is driven and when the second coil is driven, the control is more easily switched.

FIG. 1 is a configuration diagram of a radial magnetic bearing used in a magnetic bearing spindle according to an embodiment of the present invention. With reference to FIG.
When the main coils 1, 2, 3, 4, 5, 6, 7, and 8 are wound around the inner surface of the stator 150 and driven in a steady state, and when the main coils 1 to 8 are not driven due to a failure or the like, Detects the radial position of the auxiliary coils 11, 12, 13, 14, 15, 16, 17, 18 that are driven instead and the rotating shaft used in the steady state where the main coils 1 to 8 are driven Position sensors 21 and 22
And auxiliary position sensors 31 and 32 for detecting the radial position of the rotary shaft used simultaneously when an abnormality occurs in driving the auxiliary coils 11 to 18.

Next, a control operation of the radial magnetic bearing will be described. First, in a steady state, power is supplied to the main coils 1 to 8 and driven. The magnetic loops generated by driving the main coils 1 to 8 are the magnetic loops 41, 42, 43 and 44, and the position sensors used in this case are the position sensors 21 and 22. Here, for example, when the control in the Y-axis direction is considered, a position detection signal of the position sensor 21 is given to a magnetic bearing controller (MSC1) described later and subjected to signal processing. By adjusting the magnetic loop 41 generated by the main coils 1 and 2 and the magnetic loop 43 generated by the main coils 5 and 6 based on the signal processing, the rotation axis is held at a predetermined position. On the other hand, if any abnormality occurs in the main coils 1 to 8 and the position sensors 21 and 22 and the control becomes impossible, x 'obtained by rotating the coordinate axes x and y axes by 45 °
Control around the y and y 'axes. That is, the y'-axis will be described. The signal of the auxiliary position sensor 31 is given to a magnetic bearing controller (MSC2), which will be described later, and the signal is processed. Based on the signal processing, the auxiliary coils 12 and 13 and the auxiliary coils 16 and 17 are driven and the magnetic loops 51 and 53 are driven.
Occurs, whereby the rotation axis is held in a predetermined position. In the present embodiment, only one position sensor and one auxiliary position sensor are provided for each control direction, but they may be provided on the side opposite to this. This makes it possible to obtain excellent characteristics with respect to noise and temperature changes.

FIG. 2 is a configuration diagram of a thrust magnetic bearing used in a magnetic bearing spindle showing an embodiment of the present invention. Second
Referring to the drawing, the thrust magnetic shaft includes an upper bearing 110a and a lower bearing 110b. In the upper bearing 110a,
The main coil 71 and the auxiliary coil 81 are wound, and the main coil 72 and the auxiliary coil 82 are wound around the lower bearing 110b. Here, the main coils 71 and 72 are used in a normal state, and the auxiliary coils 81 and 82 are used in place of the main coils 71 and 72 when an abnormality occurs. In addition, rotating shaft 1
A position sensor 61 and an auxiliary position sensor 62 are provided so as to face the lower end surface of 01. The position sensor 61 is used in a steady state, and the auxiliary position sensor 62 is used when an abnormality occurs. Since the position sensor 61 and the auxiliary position sensor 62 are arranged concentrically around the axis of the rotary shaft 101, for example, the end faces of the rotary shaft 101 facing the position sensor 61 and the auxiliary position sensor 62 are inclined. Even if it is, the position of the rotating shaft 101 in the thrust direction can be accurately detected without being affected by the inclination.

Next, as an operation, in a steady state, the position in the thrust direction of the rotating shaft 101 is detected by the position sensor 61, and based on the detection result, the main coils 71 and 72 are controlled so that the rotating shaft 101 is set to a predetermined correct position. Held in position. When an abnormality occurs, the position of the rotating shaft 101 in the thrust direction is detected by the auxiliary position sensor 62, and based on the detection result, the auxiliary coils 81 and 82 are controlled to
1 is held in the correct position.

FIG. 3 is a block diagram for explaining a control system for controlling a magnetic bearing spindle according to an embodiment of the present invention. Referring to FIG. 3, the magnetic bearing spindle control system includes an MSC1 (magnetic bearing controller 91) for controlling a magnetic bearing portion (not shown) of the magnetic bearing spindle 94 in a steady state, and a magnetic bearing spindle device. Including an MSC2 (magnetic bearing controller 92) for controlling the magnetic bearing unit 94 when an abnormality occurs, and an INVERTER (motor driving device 93) for driving and controlling a motor unit (not shown) of the magnetic bearing spindle 94 . The motor driving device 93 has only one circuit because it can be repaired. However, the magnetic bearing controllers 91 and 92 have a two-circuit structure because a failure may occur due to disconnection of an element in the magnetic bearing controller. It was made.

As described above, in the present embodiment, the coil and the position sensor included in the magnetic bearing spindle are configured to have two circuits, and the magnetic bearing controller that controls the magnetic bearing of the magnetic bearing spindle is configured to have two circuits. Accordingly, even if the magnetic bearing fails for some reason, it is possible to recover the abnormality of the device without approaching the magnetic bearing spindle device. As a result, even if a failure occurs in an environment where humans cannot approach or when used in space equipment, the failure of the magnetic bearing spindle can be easily recovered.

[Advantage of the Invention] In the invention according to claim 1, the first control system is disabled in response to the abnormality of the first control system, and the second control system is activated, whereby the device of the device is realized. When an abnormality occurs due to a failure or the like, the drive control is switched from the first coil and the first sensor to the second coil and the second sensor. The fault can be recovered from outside. Also,
By configuring the magnetic bearing so as to include a radial magnetic bearing in which the first coil and the second coil are wound around the same stator core, the positional relationship between the stator core and the rotating shaft in the radial magnetic bearing is set to the first position. Control system and the second
The first control system is disabled and the second control system is activated, so that the rotation axis has the same positional relationship as that of the first control system. Radial control is possible. In addition, the magnetic bearing is
And that the second sensor includes a thrust magnetic bearing concentrically arranged about the axis of the rotating shaft, thereby being affected by the inclination of the end face of the rotating shaft facing the thrust position sensor. Therefore, the position of the lowermost end of the rotating shaft can be accurately detected in both the first and second control systems, and as a result, accurate thrust bearing control can be performed.

According to the second aspect of the present invention, in addition to the effect of the first aspect, the drive control direction is changed by 45 ° between the time when the first coil is driven and the time when the second coil is driven. The control can be switched to any other state, and as a result, even if a failure occurs in the apparatus, the apparatus can be easily restored.

[Brief description of the drawings]

FIG. 1 is a block diagram of a radial magnetic bearing used in a magnetic bearing spindle according to an embodiment of the present invention, and FIG. 2 is a thrust magnetic bearing used in a magnetic bearing spindle according to an embodiment of the present invention. FIG. 3 is a block diagram for explaining a control system for controlling a magnetic bearing spindle according to an embodiment of the present invention, and FIG. 4 is a sectional view showing a conventional magnetic bearing spindle. is there. In the figure, 1,2,3,4,5,6,7,8 are the main coils, 11,12,13,1
4,15,16,17,18 are auxiliary coils, 21,22 are position sensors, 31,3
2 is an auxiliary position sensor, 41, 42, 43, 44, 51, 52, 53, 54 are magnetic loops, 61 is a position sensor, 62 is an auxiliary position sensor, 71 and 72 are main coils, 81 and 82 are auxiliary coils, 92 is MSC1 (magnetic bearing controller), 92 is MSC2 (magnetic bearing controller), 93
Is an INVERTER (motor drive unit), and 94 is a magnetic bearing spindle. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (2)

(57) [Scope of request for utility model registration] 1. A magnetic bearing spindle device for supporting a rotating shaft by a magnetic bearing having an electromagnet, rotating the rotating shaft by a motor, detecting the position of the rotating shaft by a position sensor, and controlling the magnetic bearing. A first control system including a first coil provided on each of the motor and the magnetic bearing and a first sensor for detecting a position of the rotating shaft; A second control system including a second coil provided for each of the first and second sensors and a second sensor for detecting a position of the rotary shaft, in response to an abnormality in the first control system. The first
Disabling the control system and activating the second control system, wherein the magnetic bearing comprises: a radial magnetic bearing in which the first coil and the second coil are wound around the same stator core; A magnetic bearing spindle device, wherein the first and second sensors include a thrust magnetic bearing arranged concentrically about the axis of the rotating shaft. 2. The magnetic bearing according to claim 1, further comprising a radial magnetic bearing whose drive control direction changes by 45 ° between when the first coil is driven and when the second coil is driven. The magnetic bearing spindle device according to claim 1, wherein: