JP4914312B2 - Magnetic bearing device - Google Patents

Description

  The present invention relates to a magnetic bearing device. Specifically, the present invention relates to a magnetic bearing device that conveys a signal between a magnetic bearing main body and a control device using an AC coupling.

  The magnetic bearing control system, which includes an actuator and a magnetic bearing main body on which a turbo molecular pump or the like is mounted, and a control device composed of a displacement detection sensor signal processing circuit, a compensation circuit, a motor drive circuit, etc., are integrated as a large structure as a whole Thus, restrictions on the installation location and deterioration of maintainability occur. Therefore, a configuration in which the magnetic bearing main body portion and the control device are arranged at different locations, and a dedicated cable is connected between them.

  FIG. 9 illustrates a block diagram of a conventional magnetic bearing device 100X. In FIG. 9, the magnetic bearing control device 100X includes a magnetic bearing main body 10X, a control device 20X, and a dedicated cable 30X for connecting them. The magnetic bearing body 10 </ b> X includes a position displacement detection sensor 52 and a signal processing circuit 53 in addition to the magnetic bearing electromagnet 51. The magnetic bearing electromagnet 51 supports the rotating shaft by magnetic levitation by the magnetic force acting between two pairs of radial electromagnets facing each other across the magnetic rotating shaft and the magnetic force acting between the pair of axial electromagnets. The position of the rotating shaft is controlled by the balance. The position displacement detection sensor 52 detects the position displacement of the rotating shaft, and the signal processing circuit 53 outputs the detected position displacement signal to the compensation circuit 54 at the next stage as an appropriate level signal. The output of the signal processing circuit 53 is transmitted to the compensation circuit 54 of the control device 20X via a signal line stored in the dedicated cable 30X. The control device 20X includes a compensation circuit 54, a bearing drive power amplifier 55, and a circuit drive power supply 56. The bearing drive power amplifier 55 generates a magnetic force for magnetically levitating and rotating the magnetic rotating body to the electromagnet constituting the two radial magnetic bearings and the electromagnet constituting the one axial magnetic bearing, and the magnetic force of the electromagnet. A direct current for adjusting the displacement of the magnetic rotating body is supplied by balancing the two. The compensation circuit 54 supplies a compensation current to the electromagnets constituting the respective magnetic bearings 10X corresponding to the position displacement amount to the bearing drive power amplifier 55. The circuit drive power supply 56 supplies power to the electromagnet, motor, sensor, electric circuit, and other necessary parts constituting the magnetic bearing device. These electric powers are supplied from the control device 20X to the magnetic bearing body 10X via the dedicated cable 30X.

  The inventors are a magnetic bearing device configured to connect the magnetic bearing main body and the control device with a dedicated cable. The magnetic bearing main body is equipped with an adjustment unit for a position displacement detection sensor, and is displaced to the control device through the dedicated cable. By transmitting a detection signal, controlling the drive circuit of the magnetic bearing electromagnet via the compensation circuit, and again supplying the drive power via the dedicated cable, the magnetic force is adjusted by the adjustment unit. It was possible to eliminate variations in individual bearing body parts in the design, and to reduce the cost of the entire system by freely combining the magnetic bearing body part and the control device.

  In addition, the combination of the magnetic bearing body with a high-speed rotating body such as a turbo molecular pump and its control device has different compensation characteristics required for magnetic bearing control due to structural differences on the pump side. In order to prevent the occurrence of abnormal control, several methods for identifying the magnetic bearing main body have been proposed. For example, a specific element such as a resistor or an inductive element is provided inside the pump, and the model is identified by its specific characteristics, or the electrical characteristics of the motor installed in the pump are detected to detect the specific characteristics of the model. The method of identifying the characteristics, the method of measuring the control characteristics of the magnetic bearing itself to identify the uniqueness of the model, the method of identifying the model by installing the mechanism that stores the control characteristics data in the pump itself and reading the data when the power is turned on Etc. have been advocated.

  FIG. 10 illustrates a block diagram of a conventional magnetic bearing device 100Y that performs model discrimination. In FIG. 10, the magnetic bearing device 100Y includes a magnetic bearing main body 10Y, a control device 20Y, and a dedicated cable 30Y for connecting them. In addition to the magnetic bearing electromagnet 51, the magnetic bearing body 10Y includes a position displacement detection sensor 52, a temperature sensor 57, a rotation sensor 58, and a motor drive coil 59. The magnetic bearing electromagnet 51 and the position displacement detection sensor 52 function in the same manner as that of the magnetic bearing control device 100X of FIG. The temperature sensor 57 detects the temperature at a predetermined position by the magnetic bearing body 10Y provided with a heater such as a turbo molecular pump, and the rotation sensor 58 detects the rotation speed of the magnetic material rotation shaft. The motor drive coil 59 is a motor drive coil, and typically supplies a three-phase alternating current to three stators to rotationally drive a magnetic rotating shaft as a rotor. The control device 20Y includes a compensation circuit 54, a bearing drive power amplifier 55, a circuit drive power supply 56, a motor drive inverter 61, and a multi-signal processing circuit 62. The compensation circuit 54, the bearing drive power amplifier 55, and the circuit drive power supply 56 function in the same manner as that of the magnetic bearing device 100X in FIG. The motor driving inverter 61 supplies three-phase AC power to the motor driving coil 59. The multi-signal processing circuit 62 converts the rotation speed and temperature detected by the rotation sensor 58 and the temperature sensor 57 into signals that can be easily processed by the motor drive inverter 61 or a temperature controller (not shown).

JP 2001-352114 A (paragraphs 0017 to 0023, FIGS. 3 to 5 etc.)

However, in the structure in which the magnetic bearing main body and the control device are separately provided, including the configuration proposed by the inventor, the dedicated cable supplies electric power and control signals such as magnetic bearing driving power and motor power, so that many internal core wires are used. However, the workability for installing the magnetic bearing device was poor because the cable structure had poor flexibility and the weight of the cable itself increased.
In addition, in the conventional method for identifying specificity, it is necessary to add a dedicated wiring for a specific element. It becomes difficult to select between models with similar motor characteristics. Depending on conditions, the identification function itself is normal. There were problems such as not functioning.

  An object of the present invention is to solve the problem of workability for installing the magnetic bearing device by eliminating or saving signal lines in a dedicated cable. It is another object of the present invention to provide a method for easily identifying the type of a magnetic bearing main body by adding a small amount of components without adding the number of cable core wires.

  The present invention utilizes a power supply line as a signal line by AC coupling a signal such as a displacement detection signal of a displacement detection sensor and a signal for model identification to a power supply line from a control device to a magnetic bearing body. This makes it possible to eliminate or save signal lines in a dedicated cable.

  In order to solve the above-described problem, the magnetic bearing device according to the first aspect of the present invention generates a magnetic force for magnetically levitating and rotating the magnetic rotating body 11, as shown in FIGS. 1 and 2, for example. A magnetic bearing main body 10 having an electromagnet 12M functioning as a bearing (radial electromagnet 12Ax1 and the like and axial electromagnet 13z1 and the like are shown together), and a power supply 27 for supplying power to the magnetic bearing main body 10 (circuit drive power supply in FIG. 2) And a control device 20 having control signal generation means 25 (compensation circuit in FIG. 2) for generating a control signal for adjusting the magnetic force and controlling the floating position of the magnetic rotating body 11, and from the control device 20 to the magnetic bearing body 10 The magnetic bearing main body 10 includes a carrier signal wave generating means 22 (a modulation carrier circuit in FIG. 2) for generating a carrier signal wave, and a carrier A first AC coupling unit 23A that AC-couples the carrier signal wave generated by the signal wave generating unit 22 to the power supply line 30L and transmits the carrier signal wave to the control device 20, and the control device 20 is connected to the power supply line 30L. A second AC coupling unit 23B that separates the carrier signal wave that is AC-coupled, and carrier signal wave detection means 24 that detects the carrier signal wave separated by the second AC coupling unit 23B (carrier wave demodulation circuit in FIG. 2). And have.

  Here, the magnetic rotating body may be connected to a rotating body in a turbo molecular pump, an excimer laser device, a manipulator, or other vacuum equipment. Further, the rotation support includes both a radial direction and an axial direction. A plurality of electromagnets may function as magnetic bearings, and a plurality of electromagnets such as radial electromagnets and axial electromagnets may function as magnetic bearings. Further, not only simply rotating the magnetic rotating body but also having a function of controlling the position of the rotating shaft. The power supply and power supply line that supplies power to the magnetic bearing main body may supply power to any part of the magnetic bearing main body such as an electromagnet, a motor, a sensor, and an electric circuit. The power may be supplied collectively, or the power may be supplied separately. Further, the power supply line may supply DC power, or supply low-frequency AC power that is used for commercial purposes. Further, the control device may generate a control signal for controlling the flying position without directly controlling the flying position of the magnetic rotating body. For example, the control device generates a control signal for controlling the flying position by a compensation circuit, and generates a magnetic bearing current. A control signal may be transmitted to the control means (bearing drive power amplifier), and the flying position may be indirectly controlled using the magnetic bearing current control means. Further, the carrier signal wave is a wave obtained by combining a carrier wave and a signal wave, but is not necessarily modulated. For example, a carrier wave having a different frequency or a signal wave having a different pulse period may be used to detect the frequency or period on the detection side. The AC coupling unit may have a function of AC-coupling the carrier signal wave to the power supply line or a function of separating the AC-coupled carrier signal wave from the power supply line. May be used by changing the time interval, and a plurality of types of carrier waves or a plurality of types of signal waves may be separately coupled or separated by a series circuit or a parallel circuit. The separation may be partial separation. The carrier signal generation means may be a modulation carrier circuit that generates a carrier signal and modulates it, and the carrier signal wave detection means may be a carrier wave demodulation circuit that detects the carrier signal wave and demodulates the carrier signal.

  If comprised in this way, signals, such as a displacement detection signal of a displacement detection sensor, and a signal for model identification, will be AC-coupled to the power supply line from the control device to the magnetic bearing main body, so that the power supply line becomes a signal line. It can be used, and signal lines in the dedicated cable can be eliminated or saved. Further, it is possible to provide a method for easily introducing model identification of the magnetic bearing main body without changing the system configuration and without adding the number of cable cores. Further, by making it possible to eliminate the signal line in the dedicated cable, the dedicated cable itself can be structurally slimmed and lightened, and the copper material can be reduced as a material unit price.

In addition, the magnetic bearing device of the second aspect, as shown in FIGS. 1 and 4, for example, generates a magnetic force for magnetically levitating and rotating the magnetic rotating body 11 and has a magnet 12M that functions as a magnetic bearing. A control signal generator for generating a control signal for controlling the floating position of the magnetic rotating body 11 by adjusting the magnetic force, and a power source 27 (circuit driving power source in FIG. 4) for supplying power to the bearing body 10 and the magnetic bearing body 10 A control device 20 having means 25 (compensation circuit in FIG. 4), and a first power supply line 30LA and a second power supply line 30LB which are different from each other and supply power from the control device 20 to the magnetic bearing body 10. The magnetic bearing main body 10 includes a first carrier signal wave generating unit 22A (first modulation carrier circuit in FIG. 4) that generates a first carrier signal wave, and a first carrier signal wave generating unit 22A. Living The first carrier signal wave is AC coupled to the first power supply line 30LA and transmitted to the control device 20, and the control device 20 includes the first power supply line. A second AC coupling unit 23B that separates the first carrier signal wave AC-coupled to 30LA, and a first carrier signal wave that detects the first carrier signal wave separated by the second AC coupling unit 23B 24A (first carrier wave demodulating circuit in FIG. 4), and the control device 20 further includes second carrier signal wave generating means 22B (in FIG. 4, the second carrier signal wave generating circuit). And the second carrier signal wave generated by the second carrier signal wave generating means 22B is AC-coupled to the second power supply line 30LB and transmitted to the magnetic bearing body 10 . The magnetic bearing main body 10 has an AC coupling portion 23C. In addition, the fourth AC coupling unit 23D that separates the second carrier signal wave that is AC-coupled to the second power supply line 30LB, and the second carrier signal wave that is separated by the fourth AC coupling unit 23D Second carrier signal wave detecting means 24B (second carrier demodulating circuit in FIG. 4) for detecting.
If comprised in this way, a bidirectional | two-way signal can be conveyed to the electric power supply line from a control apparatus to a magnetic bearing main-body part, and the exclusion or saving of the signal line in a dedicated cable is attained further.

  Moreover, the 3rd aspect WHEREIN: In the magnetic bearing apparatus of a 1st aspect, as shown, for example in FIG. 2, the magnetic bearing main-body part 10 detects the displacement detection sensor 18 (18A-18C) which detects the displacement of the magnetic rotating body 11. As shown in FIG. The carrier signal wave generating means includes a modulation carrier circuit 22 that modulates a carrier wave with a detection signal from the displacement detection sensor 18 to generate a modulated wave as a carrier signal wave, and includes a first alternating current The coupling unit 23A AC couples the modulated wave generated by the modulation carrier circuit 22 to the power supply line 30L and transmits it to the control device 20, and the control device 20 adjusts the magnetic force of the electromagnet 12M based on the control signal. The carrier signal wave detection means has a carrier wave demodulation circuit 24 that demodulates the detection signal from the modulated wave separated by the second AC coupling unit 23B; System The signal generation means includes a compensation circuit 25 that generates a compensation signal as a control signal for correcting the displacement of the magnetic rotating body 11 from the detection signal demodulated by the carrier wave demodulation circuit 24 and supplies the compensation signal to the magnetic bearing drive current control unit 26. The magnetic bearing drive current control unit 26 adjusts the magnetic force of the electromagnet 12M based on the compensation signal and controls the floating position of the magnetic rotating body 11 so as to reduce the displacement.

  Here, the carrier signal wave generating means may be the modulation carrier circuit itself or may be configured to include the modulation carrier circuit. Further, the carrier signal wave detection means may be a carrier demodulation circuit itself or may be configured to include a carrier demodulation circuit. Further, the control signal generating means may be the compensation circuit itself or may be configured to include the compensation circuit. If comprised in this way, the signal line for a displacement detection can be excluded or saved from an exclusive cable by carrying out the alternating current coupling of the displacement detection signal of a displacement detection sensor to the electric power supply line from a control apparatus to a magnetic bearing main-body part.

The fourth aspect is the magnetic bearing device of the third aspect, wherein the electromagnet is a radial electromagnet 12Ax1 or the like that adjusts the radial position of the magnetic rotating body 11 (A is B, x is y, 1 is 2) The displacement detection sensor includes a radial displacement detection sensor 18Ax that detects the radial displacement of the magnetic rotating body 11 (A can be changed to B and x can be changed to y), and a magnetic bearing drive current control unit 26 adjusts the magnetic force of the radial electromagnet 12Ax1 or the like based on the detection signal of the radial displacement detection sensor 18Ax or the like. The displacement detection sensor includes an axial displacement detection sensor 18C that detects the axial displacement of the magnetic rotating body 11, and the magnetic bearing drive current control unit 26 includes an axial displacement. Detection signals of the detection sensor 18C to adjust the magnetic force of the axial electromagnet 13z1,13z2 based on.
Here, in the case of “and”, there are a plurality of electromagnets and displacement detection sensors, the radial electromagnet and the axial electromagnet are separate, and the radial displacement detection sensor and the axial displacement detection sensor are separate. If comprised in this way, the displacement of a magnetic rotating body can be adjusted efficiently by adjusting the magnetic force of a radial electromagnet or an axial electromagnet.

Further, the fifth aspect is the magnetic bearing device according to the fourth aspect, in which the power supply line includes the motor 14, the radial electromagnet 12Ax1, the axial electromagnets 13z1, 13z2, the radial displacement detection sensor 18Ax, the axial displacement detection sensor 18C, Alternatively, the wiring 30L supplies power to any one of the electric circuits 21, 22, and 28.
Here, the electric circuit may be an arbitrary electric circuit installed in the magnetic bearing body 10. If comprised in this way, the existing wiring in a dedicated cable can be used for power line conveyance, and a signal line can be excluded or saved. Note that it is preferable to select the power supply line to the electric circuit as the power supply line to be AC-coupled because there is little influence from the electromagnet and the displacement detection sensor.

  The sixth aspect is the magnetic bearing device according to any of the third to fifth aspects, wherein the modulation in the modulation carrier circuit 22 includes an amplitude modulation method, a frequency modulation method, a phase modulation method, a spread spectrum modulation method, or These combinations are used. If comprised in this way, the position displacement amount detected by the displacement detection sensor can be expressed by the degree of modulation, and the displacement of the magnetic rotating body can be adjusted with high accuracy.

  According to a seventh aspect, in the magnetic bearing device according to any one of the third to fifth aspects, a plurality of frequency regions are used for the carrier wave. If comprised in this way, the signal of a different displacement detection sensor will be allocated for every frequency area | region, and it will become possible to carry a some electric power line by one electric power supply line.

  In addition, according to an eighth aspect, in the magnetic bearing device according to any one of the third to seventh aspects, for example, as illustrated in FIG. 3, the magnetic bearing main body 10 receives a detection signal from the displacement detection sensor 18 as A / An A / D conversion circuit 28 that performs D (analog-digital) conversion and supplies the modulated carrier circuit 22 is provided. The control device 20 performs D / A (digital analog) conversion on the detection signal demodulated by the carrier wave demodulation circuit 24. The D / A conversion circuit 29 is then supplied to the compensation circuit 25. If comprised in this way, since the power line is conveyed by a digital signal, the reliability of conveyance is high. In addition, high-precision processing is possible by increasing the number of digits of the position displacement amount.

  In the ninth aspect, in the magnetic bearing device according to any one of the third to eighth aspects, for example, as shown in FIG. 3, the magnetic bearing body 10 performs signal processing on a detection signal from the displacement detection sensor 18. The signal processing circuit 21 supplies the signal to the modulation carrier circuit 22 via the modulation carrier circuit 22 or the A / D conversion circuit 28. Here, the signal processing is, for example, noise processing, filter processing, amplification processing, and conversion processing to displacement. With this configuration, the signal processing circuit converts the signal into a signal at a level that can be easily processed by the modulation carrier circuit or the A / D conversion circuit, so that the processing in the next stage can be facilitated.

  According to a tenth aspect, in the magnetic bearing device according to any one of the third to ninth aspects, the magnetic bearing main body 10 detects a monitor signal such as the number of rotations and the temperature of the magnetic rotating body 11, and performs modulated conveyance. The circuit 22 modulates the carrier wave with these monitor signals to generate a modulated wave. If comprised in this way, since power line conveyance can be applied also to monitor signals, such as rotation speed and temperature, a power line can be utilized widely.

In the eleventh aspect, in the magnetic bearing device according to the first aspect, the magnetic bearing body 10 adjusts the magnetic force of the electromagnet 12M based on the displacement detection sensor 18 that detects the displacement of the magnetic rotating body 11 and the control signal. And a carrier signal wave generating means including a modulation carrier circuit 22 that modulates a carrier wave with a detection signal from the displacement detection sensor 18 to generate a modulated wave as a carrier signal wave. The first AC coupling unit 23A AC-couples the modulated wave generated by the modulation carrier circuit 22 to the power supply line 30L and transmits it to the control device 20. In the control device 20, the carrier signal wave detection means is the second carrier wave detection means. The carrier demodulating circuit 24 demodulates the detection signal from the modulated wave separated by the AC coupling unit 23B, and the control signal generating means detects the displacement of the magnetic rotating body 11 from the detection signal demodulated by the carrier wave demodulating circuit 24. A compensation circuit 25 that generates a compensation signal as a control signal for correction and supplies the compensation signal to the magnetic bearing drive current control unit 26 is provided. The magnetic bearing drive current control unit 26 adjusts the magnetic force of the electromagnet 12M based on the compensation signal. Then, the flying position of the magnetic rotating body 11 is controlled so as to reduce the displacement.
If comprised in this way, since a magnetic bearing drive current control part will exist in a magnetic bearing main-body part, a magnetic bearing and a magnetic-bearing drive current control part which drives the electromagnet will be matched, and a magnetic bearing main-body part and a control apparatus will be taken. Increased freedom of combination.

Further, the twelfth aspect is the magnetic bearing device of the second aspect. For example, as shown in FIG. 4, the magnetic bearing main body 10 includes a displacement detection sensor 18 for detecting the displacement of the magnetic rotating body 11, and a control signal. And a magnetic bearing drive current control unit 26 that adjusts the magnetic force of the electromagnet 12M based on the first carrier signal wave generation means that modulates the first carrier wave with the detection signal from the displacement detection sensor 18 to adjust the first carrier wave. A first modulation carrier circuit 22A that generates a first modulated wave as a carrier signal wave is provided, and the first AC coupling unit 23A AC couples the first modulated wave to the first power supply line 30LA. The first carrier signal demodulation means 24A demodulates the detection signal from the first modulated wave separated by the second AC coupling unit 23B. And the control signal generating means is the first And a compensation circuit 25 for generating a compensation signal as a control signal for correcting the displacement of the magnetic rotating body 11 from the detection signal demodulated by the carrier wave demodulation circuit 24A. The signal wave generating means has a second modulation carrier circuit 22B that modulates the second carrier wave with the compensation signal from the compensation circuit 25 to generate a second modulated wave as the second carrier signal wave, The AC coupling unit 23C AC couples the second modulated wave to the second power supply line 30LB and transmits the second modulated wave to the magnetic bearing main body unit 10. In the magnetic bearing main unit 10, the second carrier signal wave detection means is further provided. Has a second carrier wave demodulation circuit 24B that demodulates the compensation signal from the second modulated wave separated by the fourth AC coupling unit 23D and supplies it to the magnetic bearing drive current control unit 26, and controls the magnetic bearing drive current control. Unit 26 is a compensation signal Adjusting the magnetic force of the electromagnet 12M based, it controls the floating position of the magnetic rotating body 11 so as to reduce the displacement.
If comprised in this way, a bidirectional | two-way signal can be conveyed to the electric power supply line from a control apparatus to a magnetic bearing main-body part, and the exclusion or saving of the signal line in a dedicated cable is attained further.

Further, the thirteenth aspect is that in the magnetic bearing device according to the first aspect, for example, as shown in FIG. 5 or FIG. The first AC coupling unit 23E couples the high-frequency signal oscillated by the high-frequency oscillating means 34 to the power supply line 30L as a carrier signal wave and transmits it to the control device 20, and the control device 20 The AC coupling unit 23F separates the high-frequency signal AC-coupled to the power supply line 30L, and the carrier signal wave detecting means includes a frequency detection circuit 38 that detects the frequency from the high-frequency signal separated by the second AC coupling unit 23F. And the control device 20 has a uniqueness determining means 36 (in FIG. 5 or FIG. 6 for identifying the uniqueness of the magnetic bearing body 10 based on the frequency detected by the frequency detection circuit 38). A signal processing circuit).
Here, the uniqueness determining means 36 may be a signal processing circuit having a uniqueness determining function. If comprised in this way, the method of identifying the model of a magnetic bearing main-body part easily can be provided by adding a small amount of components, without adding the number of cable core wires.

Further, the fourteenth aspect is that in the magnetic bearing device of the first aspect, as shown in FIG. 7, for example, in the magnetic bearing main body 10, the carrier signal wave generating means generates a pulse oscillation circuit 41 (see FIG. The first AC coupling unit 23A couples the pulse signal oscillated by the pulse oscillation circuit 41 to the power supply line 30L as a carrier signal wave and transmits it to the control device 20 for control. In the device 20, the second AC coupling unit 23B separates the pulse signal AC-coupled to the power supply line 30L, and the carrier signal wave detecting means calculates the pulse period from the pulse signal separated by the second AC coupling unit 23B. The control unit 20 has a pulse cycle detection circuit 45 (pulse demodulator circuit in FIG. 7) that detects the magnetic bearing body based on the pulse cycle detected by the pulse cycle detection circuit 45. Uniqueness determination means 36 identifies the uniqueness of 10 having a (7-multi signal processing circuit).
If comprised in this way, the method of identifying the model of a magnetic bearing main-body part easily can be provided by adding a small amount of components, without adding the number of cable core wires.

  The fifteenth aspect is the wiring for supplying electric power to the electric circuit in the magnetic bearing device of the thirteenth or fourteenth aspect. Here, the electric circuit may be an arbitrary electric circuit installed in the magnetic bearing body 10. Such a configuration is preferable because there is little influence from the electromagnet and the displacement detection sensor.

  According to a sixteenth aspect, in the magnetic bearing device according to the thirteenth aspect, the magnetic bearing body 10 has a filter circuit that allows a high-frequency signal from the high-frequency oscillation means 34 to pass within a specific range. . If comprised in this way, the frequency range of a carrier wave can be selected according to the model of a magnetic-bearing main-body part, and a some high frequency oscillation means can identify several models.

  According to a seventeenth aspect, in the magnetic bearing device according to the second aspect, in the magnetic bearing main body 10, the first carrier signal wave generating means includes high frequency oscillation means 34 for oscillating a high frequency signal. The AC coupling unit 23A couples the high-frequency signal oscillated by the high-frequency oscillating means 34 as a carrier signal wave to the first power supply line 30LA and transmits it to the control device 20, and in the control device 20, the second AC coupling unit 23B separates the high-frequency signal AC-coupled to the first power supply line 30LA, and the first carrier signal wave detection means detects the frequency from the high-frequency signal separated by the second AC-coupling unit 23B. The control device 20 includes uniqueness determination means 36 for identifying the uniqueness of the magnetic bearing main body 10 based on the frequency detected by the frequency detection circuit 38. If comprised in this way, a bidirectional | two-way signal can be conveyed to the electric power supply line from a control apparatus to a magnetic bearing main-body part, and the exclusion or saving of the signal line in a dedicated cable is attained further.

  According to an eighteenth aspect, in the magnetic bearing device according to the second aspect, in the magnetic bearing main body 10, the first carrier signal wave generating means includes a pulse oscillation circuit 41 that oscillates a pulse signal. The AC coupling unit 23A AC couples the pulse signal oscillated by the pulse oscillation circuit 41 to the first power supply line 30LA as a carrier signal wave and transmits the carrier signal wave to the control device 20. In the control device 20, the second AC coupling unit 23B separates the pulse signal AC-coupled to the first power supply line 30LA, and the first carrier signal wave detection means detects the pulse period from the pulse signal separated by the second AC coupling unit 23B. The control device 20 includes a detection circuit 45 and a uniqueness determination unit 36 that identifies the uniqueness of the magnetic bearing body 10 based on the pulse cycle detected by the pulse cycle detection circuit 45.If comprised in this way, a bidirectional | two-way signal can be conveyed to the electric power supply line from a control apparatus to a magnetic bearing main-body part, and the exclusion or saving of the signal line in a dedicated cable is attained further.

  According to a nineteenth aspect, in the magnetic bearing device according to the first aspect, the magnetic bearing body 10 has a displacement detection sensor 18 for detecting the displacement of the magnetic rotating body 11, and the carrier signal wave generating means is a displacement detection sensor. 18 includes a modulation carrier circuit 22 that modulates a carrier wave with a detection signal from 18 to generate a modulated wave as a carrier signal wave, and the first AC coupling unit 23A supplies power to the modulated wave generated by the modulation carrier circuit 22 The control device 20 has a magnetic bearing drive current control unit 26 that adjusts the magnetic force of the electromagnet 12M based on the control signal, and the carrier signal wave detection means is the second signal. The carrier wave demodulating circuit 24 demodulates the detection signal from the modulated wave separated by the AC coupling unit 23B, and the control signal generating means corrects the displacement of the magnetic rotating body 11 from the detection signal demodulated by the carrier wave demodulating circuit 24. A compensation circuit 25 that generates a compensation signal as a control signal and supplies the compensation signal to the magnetic bearing drive current control unit 26. The magnetic bearing drive current control unit 26 adjusts the magnetic force of the electromagnet 12M based on the compensation signal, The flying position of the magnetic rotating body 11 is controlled so as to reduce the displacement. Further, in the magnetic bearing main body 10, the carrier signal wave generating means has a high frequency oscillation means 34 for oscillating a high frequency signal, and the first AC coupling. The unit 23A AC-couples the high-frequency signal oscillated by the high-frequency oscillation means 34 as a carrier signal wave to the power supply line 30L and transmits it to the control device 20. In the control device 20, the second AC coupling unit 23B is a power supply line. A frequency detection circuit that separates a high-frequency signal that is AC-coupled to 30L, and the carrier signal wave detection means detects a frequency from the high-frequency signal that is separated by the second AC-coupling unit 23B. Having 8, the control unit 20 has a unique property determination means 36 identifies the uniqueness of the magnetic bearing main unit 10 based on the frequency detected by the frequency detection circuit 38.

  Here, the power supply line and the first and second AC coupling units used for power line conveyance may be the same or different. With this configuration, the power supply line is used as a signal line by AC coupling a signal such as a model identification signal together with a displacement detection signal of the displacement detection sensor to the power supply line from the control device to the magnetic bearing body. It can be used, and signal lines in the dedicated cable can be eliminated or saved.

  According to a twentieth aspect, in the magnetic bearing device according to the first aspect, the magnetic bearing main body 10 has a displacement detection sensor 18 for detecting the displacement of the magnetic rotating body 11, and the carrier signal wave generating means is a displacement detection sensor. 18 includes a modulation carrier circuit 22 that modulates a carrier wave with a detection signal from 18 to generate a modulated wave as a carrier signal wave, and the first AC coupling unit 23A supplies power to the modulated wave generated by the modulation carrier circuit 22 The control device 20 has a magnetic bearing drive current control unit 26 that adjusts the magnetic force of the electromagnet 12M based on the control signal, and the carrier signal wave detection means is the second signal. The carrier wave demodulating circuit 24 demodulates the detection signal from the modulated wave separated by the AC coupling unit 23B, and the control signal generating means corrects the displacement of the magnetic rotating body 11 from the detection signal demodulated by the carrier wave demodulating circuit 24. A compensation circuit 25 that generates a compensation signal as a control signal and supplies the compensation signal to the magnetic bearing drive current control unit 26. The magnetic bearing drive current control unit 26 adjusts the magnetic force of the electromagnet 12M based on the compensation signal, The flying position of the magnetic rotating body 11 is controlled so as to reduce the displacement, and in the magnetic bearing main body 10, the carrier signal wave generating means has a pulse oscillation circuit 41 that oscillates a pulse signal, and the first AC coupling The unit 23A AC-couples the pulse signal oscillated by the pulse oscillation circuit 41 to the power supply line 30L as a carrier signal wave and transmits it to the control device 20. In the control device 20, the second AC coupling unit 23B is a power supply line. The pulse signal which isolate | separates the pulse signal AC-coupled to 30L, and a carrier signal wave detection means detects a pulse cycle from the pulse signal isolate | separated by the 2nd AC coupling part 23B. Have knowledge circuit 45, the control unit 20 has a unique property determination means 36 identifies the uniqueness of the magnetic bearing main body 10 on the basis of the detected pulse period in the pulse cycle detection circuit 45.

  With this configuration, the power supply line is used as a signal line by AC coupling a signal such as a model identification signal together with a displacement detection signal of the displacement detection sensor to the power supply line from the control device to the magnetic bearing body. It can be used, and signal lines in the dedicated cable can be eliminated or saved.

  In the twenty-first aspect, in the magnetic bearing device of the nineteenth or twentieth aspect, the compensation circuit 25 generates a compensation signal based on the uniqueness of the magnetic bearing main body 10 identified by the uniqueness determining means 36. Parameters can be set according to the model. With this configuration, it is possible to automatically set a parameter for generating a compensation signal by combining the model discrimination function of the magnetic bearing device and the displacement adjustment function of the magnetic rotating body.

  A rotating system according to a twenty-second aspect of the present invention includes any one of the first to twenty-first magnetic bearing devices, the magnetic rotating member 11 that is magnetically levitated and rotated by the magnetic bearing device, and the magnetic rotating member 11. And a rotating rotor main body. Here, the magnetic rotating body and the rotor main body may be configured integrally, or may be configured separately and connected by a connecting device. If comprised in this way, it will become possible to use an electric power supply line as a signal wire | line using the magnetic bearing apparatus by this invention, and the exclusion or the saving of the signal wire | line in the exclusive cable of a rotation system will be attained.

  A turbo molecular pump according to a twenty-third aspect of the present invention includes the rotation system according to the twenty-second aspect. If comprised in this way, it will become possible to utilize an electric power supply line as a signal wire | line using the magnetic bearing apparatus by this invention, and the signal wire | line in the cable for exclusive use of a turbo molecular pump will be eliminated or saved.

  A semiconductor manufacturing apparatus according to a twenty-fourth aspect of the present invention includes the rotation system according to the twenty-second aspect. If comprised in this way, it will become possible to use an electric power supply line as a signal wire | line using the magnetic bearing apparatus by this invention, and the signal wire | line in the exclusive cable of a semiconductor manufacturing apparatus will be exclusionable or saving.

According to the present invention, the power supply line is used as a signal line by AC coupling a signal such as a displacement detection signal of the displacement detection sensor and a model identification signal to the power supply line from the control device to the magnetic bearing body. It can be used, and signal lines in the dedicated cable can be eliminated or saved.
According to a preferred aspect of the present invention, it is possible to provide a method for easily identifying the type of the magnetic bearing main body by adding a small amount of components without adding the number of cable cores.

  Embodiments of the present invention will be described below with reference to the drawings.

[First Embodiment]
FIG. 1 shows a configuration example of a bearing mechanism of a magnetic bearing control system in the first embodiment. In this embodiment, an example will be described in which the amount of positional displacement detected by a displacement detection sensor is conveyed through a power line by AC coupling. The magnetic bearing device 100 includes a magnetic bearing main body 10, a control device 20, and a dedicated cable 30 that connects them. The magnetic bearing body 10 is equipped with a magnetic rotating body 11 protruding at one end, and the magnetic rotating body 11 is composed of two radial magnetic bearings 12A and 12B made of radial electromagnets and one axial magnetic bearing 13 made of axial electromagnets. Magnetic levitation is supported. A motor 14 for rotationally driving the magnetic rotating body 11 is disposed between the radial magnetic bearings 12A and 12B. A rotor 15 made of a magnetic material is fixedly arranged around the magnetic rotating body 11, and three electromagnets 14a, 14b, 14c (not shown) are installed at equal intervals corresponding to, for example, three-phase alternating current on the motor 14. And functions as a stator for the rotor 15. The magnetic rotator 11 includes radial magnetic bearing targets 16A and 16B, axial magnetic bearing targets 16C, and position displacement detection sensor targets 17A, 17B, and 17C made of a magnetic material, respectively. ) Is fixedly arranged. The radial displacement detection sensor targets 17A and 17B are disposed in the vicinity of the radial magnetic bearing targets 16A and 16B, respectively, and the axial displacement detection sensor target 17C is disposed in the vicinity of the axial magnetic bearing target 16C.

  Assuming that the axial direction of the magnetic rotating body 11 is the Z direction, for example, the magnetic bearing 12A includes a radial magnetic bearing target 16A fixedly arranged around the magnetic rotating body 11, and the magnetic rotating body 11 and the radial magnetic bearing target 16A. The magnetic rotator 11 is magnetically levitated and supported by a magnetic force acting between two pairs of radial electromagnets opposed to each other, and a magnetic force balance between the pair of radial electromagnets 12Ax1 and 12Ax2 in the X direction. The position is controlled, and the position of the magnetic rotating body 11 in the Y direction is controlled by the balance of magnetic force between the other pair of radial electromagnets 12Ay1 and 12Ay2 (not shown), and the magnetic bearing 12B is placed around the magnetic rotating body 11. A fixedly arranged radial magnetic bearing target 16B is sandwiched between the magnetic rotating body 11 and the radial magnetic bearing target 16B. The magnetic rotating body 11 is magnetically levitated and supported by the magnetic force acting between the two pairs of opposing radial electromagnets, and the position of the magnetic rotating body 11 in the X direction is adjusted by the balance of the magnetic force between the pair of radial electromagnets 12Bx1 and 12Bx2. The position of the magnetic rotating body 11 in the Y direction is controlled by the balance of the magnetic force between the other pair of radial electromagnets 12By1 and 12By2. Further, the magnetic rotating body 11 is generated by a magnetic force acting between an axial magnetic bearing target 16C fixedly disposed around the magnetic rotating body 11 and a pair of axial electromagnets 13z1 and 13z2 facing each other with the axial magnetic bearing target 16C interposed therebetween. Is magnetically levitated and the position of the magnetic rotating body 11 in the Z direction is controlled by the balance of the magnetic force between the axial electromagnets 13z1 and 13z2.

  The radial displacement detection sensors 18A and 18B are disposed near the periphery of the radial displacement detection targets 17A and 17B, respectively, and detect the displacement of the magnetic rotating body 11. The radial displacement detection sensor 18A is composed of, for example, two sensors 18Ax and 18Ay (not shown), and the sensors 18Ax and 18Ay (not shown) are respectively in the X and Y directions at the position of the radial displacement detection target 17A of the magnetic rotating body 11. The displacement is detected, and the radial displacement detection sensor 18B is composed of, for example, two sensors 18Bx and 18By (not shown), and the sensors 18Bx and 18By (not shown) are respectively at the position of the radial displacement detection target 17B of the magnetic rotating body 11. The displacement in the X and Y directions is detected. The axial displacement detection sensor 18C is disposed on the axis of the magnetic rotator 11 in the vicinity of the axial displacement detection target 17C, and detects the displacement of the magnetic rotator 11 in the Z direction at the position of the axial displacement target 17C. As the position displacement detection sensor used in the magnetic bearing, a non-contact displacement detection sensor using an electromagnetic technique such as a magnetic self-excited oscillation type can be used.

  FIG. 2 illustrates a block diagram of the magnetic bearing device 100 according to the first embodiment. In FIG. 2, the magnetic bearing main body 10 includes a magnetic bearing electromagnet 12M (radial electromagnet 12Ax1 and the like and axial electromagnet 13z1 and the like are shown together), a displacement detection sensor 18 (shown collectively as 18A to 18C), and signal processing. The circuit 21, the modulation carrier circuit 22, and the first AC coupling unit 23 </ b> A are included. The displacement detection sensor 18 has two radial displacement detection sensors 18A and 18B and one axial displacement detection sensor 18C. The displacement detection signals detected by these position displacement detection sensors 18 are signal processing circuit 21. It is processed.

  The signal processing circuit 21 includes, for example, a preamplifier unit, an addition circuit unit, an offset output unit, and a gain adjustment circuit unit, and adjusts the signal to a predetermined detection sensitivity level. The detected displacement signal is adjusted to a signal level that is easy to process once in the preamplifier unit, and the signal output from the preamplifier unit is added to the offset adjustment signal output from the offset output unit in the addition circuit unit to detect the position. The offset adjustment of the signal is performed, and as a final output adjustment, the gain adjustment circuit unit adjusts the signal to a detection sensitivity level determined in advance, and outputs the signal to the modulation carrier circuit 22 as an appropriate level signal.

  The modulation carrier circuit 22 includes, for example, a signal wave generation circuit, a carrier wave generation circuit, a modulation wave generation circuit, and a modulation wave transmission circuit as carrier signal wave generation means. The modulation may be AM modulation, FM modulation, or PM modulation. The signal wave generation circuit receives the output signal of the signal processing circuit 21 and generates a signal wave of 10 kHz to 450 KHz, for example, with a positional displacement amount of modulation m1 for AM modulation, modulation index m2 for FM modulation, and phase φm for PM modulation. To do. Here, when the displacement of the magnetic rotator 11 occurs, it is usually sufficient to quantitatively detect the amount of positional displacement with little change over time, so that a signal wave may be generated periodically. The carrier wave generation circuit generates a carrier wave having a frequency higher than the electric frequency 50/60 Hz, for example, 1 MHz to 30 MHz, in order to superimpose a signal on the power line. The modulation wave generation circuit modulates the carrier wave with the signal wave generated by the signal wave generation circuit to generate a modulation wave as a carrier signal wave, and the modulation wave transmission circuit transmits the modulation wave to the first AC coupling unit 23A. The first AC coupling unit 23A AC couples the modulated wave generated by the modulation carrier circuit 22 to the power line. The coupling may be either inductive coupling or capacitive coupling. The combined modulated wave is conveyed from the magnetic bearing main body 10 to the control device 20 on the power line 30 </ b> L accommodated in the dedicated cable 30. The power line to be AC-coupled may be any power line housed in the dedicated cable 30, but it is better to couple to the common power line from the circuit drive power supply 27 to the electric circuit in order to avoid the influence on the electromagnet and the sensor. Yes, this is the case in this embodiment.

  The control device 20 includes a second AC coupling unit 23B, a carrier wave demodulation circuit 24, a compensation circuit 25, a bearing drive power amplifier 26, and a circuit drive power supply 27. The second AC coupling unit 23B separates the modulated wave carried on the power line. For the separation, either inductive coupling or capacitive coupling may be used.

  The carrier wave demodulation circuit 24 includes, for example, a modulation wave reception circuit, a modulation wave demodulation circuit, and a demodulation signal processing circuit as carrier signal wave detection means. The modulated wave receiving circuit performs noise removal and waveform shaping on the modulated wave separated by the second AC coupling unit 23B, and the modulated wave demodulating circuit passes the shaped modulated wave to the carrier wave through a high-pass filter or a band-pass filter. For example, in the case of AM modulation, the extracted carrier wave is envelope-processed by an envelope processing circuit, the signal wave is demodulated, the modulation degree m1 is obtained from the demodulated signal wave by a peak hold circuit, and FM modulation is performed. For example, the modulation index m2 is obtained by a frequency discriminating circuit, and in the case of PM modulation, the phase difference φm between the carrier wave and the modulated wave is obtained to restore the position displacement amount, and the demodulated signal processing circuit restores the restored position displacement. The amount is adjusted to a signal having a detection sensitivity level that is easily handled by the compensation circuit 25 determined in advance by removing the offset by the gain / offset adjustment circuit.

  The bearing drive power amplifier 26 has, for example, two radial magnetic bearings 12A (four radial electromagnets 12Ax1, 12Ax2, 12Ay1, 12Ay2), 12B (four radials) as magnetic bearing electromagnets as magnetic bearing drive current control units. Electromagnetics 12Bx1, 12Bx2, 12By1, and 12By2) and one axial magnetic bearing 13 (having two axial electromagnets 13z1 and 13z2) generate magnetic force that magnetically floats and rotates the magnetic rotating body 11 In addition, a direct current is supplied for adjusting the displacement of the magnetic rotating body 11 by balancing the magnetic force of the electromagnet.

  The compensation circuit 25 serves as a control signal generating means, for example, a relationship with a compensation current as a control signal supplied to each radial electromagnet by the bearing drive power amplifier 26 corresponding to the positional displacement amount of the magnetic rotating body 11 in the X and Y directions. And a compensation table storing the relationship between the compensation current as a control signal supplied to the axial electromagnet from the bearing drive power amplifier 26 corresponding to the amount of displacement in the Z direction of the magnetic rotating body 11 and restored. The position displacement amount is collated with the compensation table, and the compensation current to each electromagnet corresponding to the position displacement amount is supplied to the bearing drive power amplifier 26. That is, the position displacement detected by the radial displacement detection sensor 18Ax is the compensation current for the radial electromagnets 12Ax1 and 12Ax2, and the position displacement detected by the radial displacement detection sensor 18Ay is the compensation current for the radial electromagnets 12Ay1 and 12Ay2. The position displacement detected by 18Bx is converted to a compensation current for the radial electromagnets 12Bx1 and 12Bx2, and the position displacement detected by the radial displacement detection sensor 18By is converted to a compensation current for the current of the radial electromagnets 12By1 and 12By2, and is applied to each radial electromagnet. Supplied. Further, the position displacement amount detected by the axial displacement detection sensor 18C is converted into a compensation current for the axial electromagnets 13z1 and 13z2 and supplied to each axial electromagnet. The displacement of the magnetic rotating body 11 is not only determined by the excitation current of the electromagnets that make up each pair of bearings, but is also determined simply by the influence of the excitation currents of other electromagnet pairs and the excitation current of other bearings. However, for a minute displacement in the vicinity of the balance state, the relationship between the amount of displacement of the magnetic rotating body 11 and the compensation current supplied to the bearing driving electromagnet may be regarded as a one-to-one correspondence. A compensation table is created for each balance state.

  The circuit drive power supply 27 is a power supply for supplying power to the magnetic bearing main body 10 and supplies power to the electric circuits 21, 22, 24, 25, 26, the motor 14, the sensor 18, and other necessary parts constituting the magnetic bearing device. To do. In addition, you may supply electric power to the motor 14 and the sensor 18 which are not shown in figure by another system. The power supply to the electric circuit and the power supply to the motor 14, the sensor 18 and the like are separated and the power supply line to the electric circuit is selected as the power supply line to be AC-coupled. Less and preferred.

  The dedicated cable 30 accommodates a power line from the control device 20 to the magnetic bearing body 10. That is, 20 power lines from the bearing drive power amplifier 26 to the electromagnets 12Ax1, 12Ax2, 12Ay1, 12Ay2, 12Bx1, 12Bx2, 12By1, 12By2, 13z1, 13z2, a power line to the motor 14 (three-phase alternating current), a position displacement detection sensor Ten power lines to 18Ax, 18Ay, 18Bx, 18By, and 18C and one common power line from the circuit drive power supply 27 to the signal processing circuit 21 and the modulation carrier circuit 22 are accommodated. The present embodiment is characterized in that there are no signal lines from the sensor or other parts in the cable.

  As described above, the position displacement detection sensors 18Ax, 18Ay, 18Bx, 18By, and 18C detect the positions of the position displacement detection sensor targets 17A, 17B, and 17C (that is, the position of the magnetic rotating body 11), and the detection signal is used as the compensation circuit 25. The magnetic attraction force or magnetic repulsive force generated in the opposing radial electromagnets 12Ax1, 12Ax2, etc. with the electromagnet excitation current obtained by the bearing driving power amplifier 26 and the opposing axial electromagnet 13z1. , 13z2 controls the magnetic attraction force or magnetic repulsion force, and the radial position displacement detection sensor target 17A fixed to the magnetic rotating body 11 has a predetermined position such as between the radial electromagnets 12Ax1 and 12Ax2 and the radial position displacement detection sensor target. 17B radial power Each at a predetermined position between the stones 12Bx1,12Bx2 like magnetically levitated control in a non-contact manner. Further, the magnetic position support sensor 17C is controlled to be magnetically levitated in a non-contact manner at a predetermined position between the axial electromagnets 13z1 and 13z2. The predetermined position is, for example, an intermediate position between electromagnets.

[Second Embodiment]
FIG. 3 illustrates a block diagram of a magnetic bearing device 100A according to the second embodiment. An example in which an A / D conversion circuit 28 and a D / A conversion circuit 29 are provided between the input and output of a signal between the magnetic bearing main body 10 and the control unit 20 in the first embodiment, and signal transmission is converted into a digital signal. Show.

  In the magnetic bearing body 10, an A / D conversion circuit 28 is provided between the signal processing circuit 21 and the modulation carrier circuit 22, and the output of the signal processing circuit 21 is converted from an analog signal to a digital signal and output to the modulation carrier circuit 22. . The modulation carrier circuit 22 modulates the carrier wave with a digital signal, generates a modulated wave as a carrier signal wave for carrying the digital signal, and AC-couples the power line with the first AC coupler 23A. In the control device 20, the carrier wave demodulation circuit 24 decodes the modulated wave separated by the second AC coupler 23B to restore the digital signal. A D / A conversion circuit 29 is provided between the carrier wave demodulation circuit 24 and the compensation circuit 25, and the restored digital signal is converted into an analog signal and output to the compensation circuit 25. Power is supplied to the A / D conversion circuit 28 and the D / A conversion circuit 29 through a common power line from the circuit drive power supply 27.

According to the present embodiment, since the digital signal is used for conveyance, the conveyance reliability is high. In addition, high-precision processing is possible by increasing the number of digits of the position displacement amount.
Other configurations are the same as those of the first embodiment, and the same effects as those of the first embodiment are obtained.

[Third Embodiment]
FIG. 4 illustrates a block diagram of a magnetic bearing device 100B according to the third embodiment. In the first embodiment, power line conveyance using AC coupling is only in one direction from the magnetic bearing main body 10 to the control device 20, but in the third embodiment, the magnetic bearing main body 10 and the control device 20 are used. An example in which bidirectional power line conveyance is performed will be described. That is, the magnetic bearing body 10 has the first modulation carrier circuit 22A and the first AC coupling unit 23A, the control device 20 has the second AC coupling unit 23B and the first carrier demodulation circuit 24A, In addition to carrying the power line on the first power supply line 30LA from the magnetic bearing body 10 to the control device 20, the control device 20 has a second modulation carrier circuit 22B and a third AC coupling portion 23C. The magnetic bearing body 10 has a fourth AC coupling portion 23D and a second carrier demodulation circuit 24B, and carries the power line on the second power supply line 30LB from the control device 20 to the magnetic bearing body 10. For example, the bearing drive power amplifier 26 installed in the control device 20 in the first embodiment is installed in the magnetic bearing main body 10 in this embodiment, and is connected to the magnetic bearing electromagnet 12M in the magnetic bearing main body 10. An exciting current is supplied to control the position of the magnetic rotating body 11. In addition, power is supplied from the circuit drive power supply 27 to the signal processing circuit 21, the first and second modulation carrier circuits 22A, and the first and second carrier demodulation circuits 24A and 24B through the first power supply line 30LA. Electric power is supplied to the bearing drive power amplifier 26 through the second power supply line 30LB. Further, the positional displacement amount detected by the positional displacement detection sensor 18 is a power line via the first modulation carrier circuit 22A, the first AC coupling unit 23A, the second AC coupling unit 23B, and the first carrier wave demodulation circuit 24A. The signal is transferred to the compensation circuit 25, and the output signal from the compensation circuit 25 passes through the second modulation carrier circuit 22B, the third AC coupling unit 23C, the fourth AC coupling unit 23D, and the second carrier demodulation circuit 24B. And is supplied to the bearing drive power amplifier 26. Here, the first modulation carrier circuit 22A modulates the first carrier wave with the detection signal from the displacement detection sensor 18 to generate a first modulation wave, and the first AC coupling unit 23A performs the first modulation wave. Is AC-coupled to the first power supply line 30LA and transmitted to the control device 20. The first carrier demodulation circuit 24A demodulates the detection signal from the first modulated wave separated by the second AC coupling unit 23B. The compensation circuit 25 generates a compensation signal as a control signal for correcting the displacement of the magnetic rotating body 11 from the detection signal demodulated by the first carrier wave demodulation circuit 24A. Further, the second modulation carrier circuit 22B modulates the second carrier wave with the compensation signal from the compensation circuit 25 to generate a second modulation wave, and the third AC coupling unit 23C converts the second modulation wave into the second modulation wave. AC power is coupled to the second power supply line 30 </ b> LB and transmitted to the magnetic bearing body 10 . The second carrier wave demodulation circuit 24B demodulates the compensation signal from the second modulated wave separated by the fourth AC coupling unit 23D and supplies it to the bearing drive control unit 26.

In this case, the number of power supply lines from the control device 20 to the bearing drive power amplifier 26 mounted on the magnetic bearing main body 10 is about 2 to 3, and the control device 20 includes the bearing drive power amplifier 26 and the magnetic bearing main body portion. Compared to about 20 when driving power is supplied to the electromagnet 12M mounted on 10, the number of wires inside the dedicated cable can be drastically reduced.
Further, although not shown, appropriate signal processing amplifiers are also mounted on various abnormality detection signals other than the displacement detection sensor 18 mounted on the magnetic bearing body 10, and the first and second modulation carrier circuits 22A and 22B, AC By carrying the power line via the coupling units 23A to 23D and the carrier wave demodulation circuits 24A and 24B, it is possible to supply an abnormal signal to the control device side without adding special wiring to the dedicated cable 30. Become.

[Fourth Embodiment]
In the magnetic bearing device, the example in which the position displacement detected by the displacement detection sensor is conveyed from the magnetic bearing body 10 to the control device 20 by the AC coupling is described in the magnetic bearing device. In the embodiment, an example will be described in which a model identification signal of the magnetic bearing body 10 is conveyed from the magnetic bearing body 10 to the control device 20 by AC coupling.
According to the present embodiment, it is possible to provide a method for easily identifying the type of the magnetic bearing main body by adding a small amount of components without adding the number of cable cores.

  FIG. 5 illustrates a block diagram of a magnetic bearing device 100C according to the fourth embodiment. The specific structure of the bearing mechanism of the magnetic bearing body 10 in the fourth embodiment is the same as that shown in FIG. In FIG. 5, the magnetic bearing body 10 has a drive coil 31, a position displacement detection sensor 18, a temperature sensor 32, and a rotation sensor 33 for the motor 14 (see FIG. 1) in addition to the magnetic bearing electromagnet 12M. The high-frequency oscillation circuit 34 and the first AC coupling circuit 35 (including the first AC coupling unit 23E) have a signal supplied from the high-frequency oscillation circuit 34 to the power supply line 30L to the motor drive coil 31 that drives the motor 14. Are AC coupled. In addition to the bearing drive power amplifier 26 and the compensation circuit 25, the control device 20 includes a multi-signal processing circuit 36, a motor drive inverter 37 that supplies power to the motor drive coil 31, a frequency detection circuit 38, and a second alternating current. A coupling circuit 39 (including the second AC coupling unit 23F) is provided, and the signal of the high-frequency oscillation circuit 34 is AC-coupled from the power supply line 30L from the motor driving inverter 37 to the motor driving coil 31 that drives the motor 14. Detected.

  In the magnetic bearing body 10, the functions of the magnetic bearing electromagnet 12M, the motor 14, and the position displacement detection sensor 18 are the same as those in the first embodiment. Further, the function of the first AC coupling unit 23E is the same as the function of the first AC coupling unit 23A in the first embodiment. The motor drive coil 31 is a coil for driving the motor 14 and supplies a three-phase alternating current to the three stators to rotationally drive the magnetic rotating body 11 that is a rotor. The temperature sensor 32 detects the temperature at a predetermined position by the magnetic bearing main body 10 provided with a heater such as a turbo molecular pump, and the rotation sensor 33 detects the rotation speed of the magnetic rotating body 11. The temperature sensor 32 is mounted with a thermal element such as a thermistor on the stator side, for example. Further, the rotation sensor 33 is an encoder-like mechanism, for example, having a target portion on the magnetic rotating body 11 side in the magnetic bearing main body portion 10 and non-contact monitoring the target material on the stator side of the magnetic bearing main body portion 10. The target such as a groove cut in the target material is detected, and signal processing is performed as a rotation speed pulse. For example, the high-frequency oscillation circuit 34 generates a high-frequency signal of 100 kHz to 30 MHz that is higher than an alternating current of 50 to 60 Hz. The first AC coupling circuit 35 supplies the high-frequency signal generated by the high-frequency oscillation circuit 34 to the first AC coupling unit 23E, AC-couples it to the power supply line, and conveys it on the power supply line 30L. Since the oscillation frequency of the high frequency signal is changed depending on the model, the high frequency signal may be directly coupled to the power supply line 30L, and there is no need to perform modulation such as AM modulation, FM modulation, and PM modulation. In addition, by using a filter circuit that allows the frequency range of the high-frequency signal to pass within a specific range, the frequency range of the carrier wave can be selected according to the model of the magnetic bearing body, and a plurality of models can be selected with one high-frequency oscillation means. Identification becomes possible.

  In the control device 20, the functions of the bearing drive power amplifier 26 and the compensation circuit 25 are the same as those in the first embodiment. The function of the second AC coupling unit 23F is the same as the function of the second AC coupling unit 23B in the first embodiment. The motor drive inverter 37 supplies power to the motor drive coil 31. The second AC coupling circuit 39 separates the high-frequency signal AC-coupled to the power supply line 30L from the second AC coupling unit 23F and supplies it to the frequency detection circuit 38. The frequency detection circuit 38 detects the frequency of the high frequency signal supplied from the second AC coupling circuit 39. The multi-signal processing circuit 36 converts the rotation speed and temperature detected by the rotation sensor 33 and the temperature sensor 32 into signals that can be processed easily by a motor drive inverter 37 or a temperature controller (not shown), and further, a frequency detection circuit 38 detects the signal. The model of the magnetic bearing main body 10 is specified from the obtained frequency.

Note that the AC coupling means in the first AC coupling unit 23E and the second AC coupling unit 23F may be inductive or electrostatic coupling, but in this embodiment, the inductive type is used.
Thus, according to the present embodiment, a small number of components, the high-frequency oscillation circuit 34, the frequency detection circuit 38, and the first and second AC coupling circuits 35, 39, without adding the number of cable cores, By adding the uniqueness discriminating means (multi-signal processing circuit) 36, it is possible to provide a method for easily identifying the type of the magnetic bearing main body.

[Fifth Embodiment]
FIG. 6 illustrates a block diagram of a magnetic bearing device 100D according to the fifth embodiment. In the fourth embodiment, an example in which the AC coupling is an inductive coupling type has been described, but the fifth embodiment shows an example of a capacitance type. Which of the inductive coupling type and the electrostatic capacitance type is advantageous depends on conditions on the power line side to be coupled. For example, in the case of the inductive coupling type, the main power supply is supplied to the circuit on the power line side, so that a sufficient capacity for the main power supply is required as the current capacity, whereas the capacitance type is supplied to the power line. Depending on the size of the main power supply, the voltage capacity of the coupling element that can be used is limited.
Other configurations are the same as those of the fourth embodiment, and the same effects as those of the fourth embodiment are obtained.

[Sixth Embodiment]
FIG. 7 illustrates a block diagram of a magnetic bearing device 100E according to the sixth embodiment. In the fourth embodiment, an example in which a high-frequency signal is AC-coupled to a power supply line as it is has been described, but in this embodiment, an example in which a pulse signal is used as a signal wave will be described.

In the present embodiment, a specific pulse oscillation circuit 41, a carrier wave generation circuit 42, and an AM / FM modulation circuit 43 are provided instead of the high frequency oscillation circuit 34 in the fourth embodiment. Further, a demodulation modulation circuit 44 and a pulse demodulation circuit 45 are provided instead of the frequency detection circuit 38 in the fourth embodiment. The specific pulse oscillation circuit 41 as a pulse oscillation circuit oscillates a pulse with a specific period as a signal wave. The carrier wave generation circuit 42 generates a carrier wave and functions in the same manner as the carrier wave generation circuit of the first embodiment. The AM / FM modulation circuit 43 AM modulates or FM modulates the carrier wave using the signal wave, and transmits the modulated wave to the first AC coupling circuit 35. In this case, the model can be identified by modulation, for example, by changing the modulation degree or modulation index according to the model number. The demodulation modulation circuit 44 separates the carrier wave and the pulse signal from the modulated wave carried on the power line, and obtains the modulation degree and the modulation index. The pulse demodulating circuit 45 obtains a pulse period from the pulse signal separated by the demodulating / modulating circuit 44 as a pulse period detecting circuit. The modulation degree, modulation index, and pulse period are transmitted to the multi-signal processing circuit 36, and the model is specified by the multi-signal processing circuit 36. That is, the multi-signal processing circuit 36 has a function as uniqueness determination means.
In this embodiment, there are three types: (a) identifying with a pulse signal, (b) identifying with a carrier wave, and (c) identifying with a combination of both.

  FIG. 8 shows an example of a carrier wave and a pulse signal in the sixth embodiment. FIG. 8A shows a basic carrier wave. The horizontal axis is time (ns) and the carrier wave is about 5 MHz. 8B and 8C are examples in which the carrier wave is the same and the period of the pulse signal which is a signal wave is changed. In FIG. 8B, the period of the pulse signal A is about 250 kHz, and in FIG. 8C, the period of the pulse signal B is about 33 kHz. By detecting this, it is possible to determine the model of the magnetic bearing main body. In addition, when the carrier wave is AM-modulated with a signal wave, the pulse intensity changes. In this case, the pulse demodulating circuit 45 detects the pulse intensity, so that the model of the magnetic bearing main body can be determined. FIG. 8D shows an example in which the frequency of the carrier wave is changed. The carrier frequency is changed by FM modulation. The carrier frequency A is about 5 MHz and the carrier frequency B is about 500 kHz. By changing the carrier frequency in this way and detecting the carrier frequency by the demodulation and modulation circuit 44, the type of the magnetic bearing main body can be identified. is there. The signal processing circuit is configured by using the same carrier wave for the oscillation frequency and modulating a specific pulse signal with the carrier wave for each model, or by changing the carrier frequency for each model with the same pulse signal. By limiting the frequency processing band to a narrow range, a plurality of models can be identified.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and it is obvious that various modifications can be made to the embodiments.

  For example, in the above embodiment, the example in which the position displacement amount detected by the displacement detection sensor is conveyed on the power line and the example in which the model identification signal of the magnetic bearing main body is conveyed on the power line are described separately. It can also be transported. In this case, the power supply line and the first and second AC coupling units used for power line conveyance may be the same or different. In this case, bidirectional power line conveyance may be performed between the magnetic bearing main body and the control device. In addition, the power line carrying mode of the position displacement amount and the power line carrying mode of the model identification signal can be various. In the above embodiment, the example of using the high-frequency oscillation circuit and the example of using the pulse oscillation circuit are separately described for identifying the model of the magnetic bearing main body, but both may be mounted and switched. 2 to 4, the power supply lines to the motor, the motor, and the position displacement detection sensor are not illustrated, but these power supply lines may be included in the dedicated cable. Further, although monitor signal systems such as a temperature sensor and a rotation sensor are not shown, these monitor signals may be conveyed on the power line. 5-7, although the system which carries out the power line conveyance of the positional displacement amount detected by the displacement detection sensor is not shown in figure, you may carry these through a power line.

  Moreover, about AC coupling, the power supply line used for power line conveyance and the first and second AC coupling units may be the same or different. The same applies to the first and second power supply lines and the first to fourth AC coupling portions. The AC coupling method may be an inductive type or a capacitive type. When the power supply line and the first and second AC coupling units used for power line transportation are used in common, they may be switched by dividing time or may be simultaneously transported by using carrier waves having different frequencies. The power supply line may be a direct current or a commercial low frequency alternating current. The power supply for supplying power is not limited to one, and may be separated into a plurality of power supplies, and the dedicated cable is not limited to one and may be separated into a plurality of cables. In addition, the number of bearings, rotational drive motors, the number of these electromagnets, the number of position displacement detection sensors, the arrangement, and the like can be variously changed according to the design. In the above embodiment, the connection destination of the magnetic rotating body of the magnetic bearing main body is not particularly described. Typically, the rotating shaft of the turbo molecular pump, the rotating shaft of the gas stirring fan of the excimer laser is typically used. The rotating shaft of the rotating mechanism in the semiconductor manufacturing apparatus and the rotating shaft of the rotating mechanism of the manipulator are connected to various rotating shafts. In particular, it is preferable to use a magnetic bearing without friction for a rotating mechanism in a high vacuum.

  The present invention is used in a magnetic bearing device.

It is a figure which shows the structural example of the bearing mechanism of the magnetic bearing control system in 1st Embodiment. It is an example of the block diagram of the magnetic bearing apparatus in 1st Embodiment. It is an example of the block diagram of the magnetic bearing apparatus in 2nd Embodiment. It is an example of the block diagram of the magnetic bearing apparatus in 3rd Embodiment. It is an example of the block diagram of the magnetic bearing apparatus in 4th Embodiment. It is an example of the block diagram of the magnetic bearing apparatus in 5th Embodiment. It is an example of the block diagram of the magnetic bearing apparatus in 6th Embodiment. It is a figure which shows the example of the carrier wave and pulse signal in 6th Embodiment. It is an example of the block diagram of the conventional magnetic bearing apparatus. It is an example of the block diagram of the conventional magnetic bearing apparatus which performs model discrimination | determination.

Explanation of symbols

10, 10X, 10Y Magnetic bearing body 11 Magnetic rotating body 12M Electromagnets 12A, 12B Radial magnetic bearings 12Ax1, 12Ax2, 12Ay1, 12Ay2, 12Bx1, 12Bx2, 12By1, 12By2 Radial electromagnet 13 Axial magnetic bearing 13z1, 13z2 Axial electromagnet 14 Motor 14a , 14b, 14c Motor electromagnet 15 Rotor 16A, 16B Radial magnetic bearing target 16C Axial magnetic bearing target 17A, 17B Radial displacement detection sensor target 17C Axial displacement detection sensor target 18A, 18B Radial displacement detection sensor 18Ax, 18Ay, 18Bx, 18By Radial Displacement detection sensor 18C Axial displacement detection sensors 20, 20X, 20Y Control device 21 Signal processing circuit 22 Carrier signal Generating means (modulation carrier circuit)
22A, 22B First and second carrier signal wave generating means (first and second modulation carrier circuits)
23A-23D 1st-4th AC coupling part 24 Carrier signal wave detection means (carrier wave demodulation circuit)
24A, 24B First and second carrier signal wave detection means (first and second carrier wave demodulation circuits)
25 Control signal generation means (compensation circuit)
26 Magnetic bearing drive current controller (bearing drive power amplifier)
27 Power supply (circuit drive power supply)
28 A / D conversion circuit 29 D / A conversion circuits 30, 30X, 30Y Dedicated cable 30L Power supply lines 30LA, 30LB First and second power supply lines 31 Motor drive coil 32 Temperature sensor 33 Rotation sensor 34 High-frequency oscillation means ( High frequency oscillation circuit)
35 First AC coupling circuit 36 Uniqueness determining means (multi-signal processing circuit)
37 Inverter for motor drive 38 Frequency detection circuit 39 Second AC coupling circuit 41 Pulse oscillation circuit (specific pulse oscillation circuit)
42 Carrier wave generation circuit 43 AM / FM modulation circuit 44 Demodulation modulation circuit 45 Pulse period detection circuit (pulse demodulation circuit)
51 Magnetic Bearing Electromagnet 52 Position Displacement Detection Sensor 53 Signal Processing Circuit 54 Compensation Circuit 55 Bearing Drive Power Amplifier 56 Circuit Drive Power Supply 57 Temperature Sensor 58 Rotation Sensor 59 Motor Drive Coil 61 Motor Drive Inverter 62 Multi-Signal Processing Circuits 100, 100A to 100E , 100X, 100Y Magnetic bearing device

Claims (17)

A magnetic bearing main body having an electromagnet that generates a magnetic force for magnetically levitating and rotating the magnetic rotating body and functions as a magnetic bearing;
A control device having a power source for supplying electric power to the magnetic bearing main body, and a control signal generating means for generating a control signal for adjusting the magnetic force and controlling the floating position of the magnetic rotating body;
A first power supply line and a second power supply line different from each other for supplying power from the control device to the magnetic bearing body;
The magnetic bearing main body includes a first carrier signal wave generating unit that generates a first carrier signal wave, and a first carrier signal wave generated by the first carrier signal wave generating unit. A first AC coupling unit that is AC coupled to the power supply line and transmits to the control device;
The control device includes: a second AC coupling unit that separates the first carrier signal wave that is AC coupled to the first power supply line; and the first AC coupling unit that is separated by the second AC coupling unit. First carrier signal wave detection means for detecting a carrier signal wave;
The control device further includes a second carrier signal wave generating unit that generates a second carrier signal wave, and a second carrier signal wave generated by the second carrier signal wave generating unit. A third AC coupling portion that is AC coupled to a power supply line and transmits to the magnetic bearing body portion ;
The magnetic bearing main body is further separated by a fourth AC coupling unit that separates the second carrier signal wave that is AC-coupled to the second power supply line, and the fourth AC coupling unit. Second carrier signal wave detecting means for detecting the second carrier signal wave;
Magnetic bearing device. The magnetic bearing main body includes a displacement detection sensor that detects the displacement of the magnetic rotating body, and a magnetic bearing drive current control unit that adjusts the magnetic force of the electromagnet based on the control signal, and the first transport signal. The wave generation means includes a first modulation carrier circuit that modulates a first carrier wave with a detection signal from the displacement detection sensor to generate a first modulation wave as the first carrier signal wave, An AC coupling unit that couples the first modulated wave to the first power supply line and transmits the first modulated wave to the control device;
In the control device, the first carrier signal wave detection means includes a first carrier demodulation circuit that demodulates the detection signal from the first modulated wave separated by the second AC coupling unit, Control signal generating means has a compensation circuit for generating a compensation signal as the control signal for correcting the displacement of the magnetic rotating body from the detection signal demodulated by the first carrier wave demodulation circuit;
In the control device, the second carrier signal wave generating means further modulates a second carrier wave with a compensation signal from the compensation circuit to generate a second modulated wave as the second carrier signal wave. A second modulated carrier circuit, wherein the third AC coupling unit couples the second modulated wave to the second power supply line and transmits the second modulated wave to the magnetic bearing body unit ;
In the magnetic bearing main body, the second carrier signal wave detecting means further demodulates the compensation signal from the second modulated wave separated by the fourth AC coupling unit to control the magnetic bearing driving current. A second carrier demodulation circuit for supplying to the unit;
The magnetic bearing drive current control unit adjusts the magnetic force of the electromagnet based on the compensation signal and controls the floating position of the magnetic rotating body so as to reduce the displacement;
The magnetic bearing device according to claim 1 . The electromagnet includes a radial electromagnet that adjusts a radial position of the magnetic rotating body, and the displacement detection sensor includes a radial displacement detection sensor that detects a radial displacement of the magnetic rotating body, and drives the magnetic bearing. A current control unit adjusts the magnetic force of the radial electromagnet based on a detection signal of the radial displacement detection sensor;
Alternatively, the electromagnet includes an axial electromagnet that adjusts an axial position of the magnetic rotating body, and the displacement detection sensor includes an axial displacement detection sensor that detects an axial displacement of the magnetic rotating body, The magnetic bearing drive current control unit adjusts the magnetic force of the axial electromagnet based on a detection signal of the axial displacement detection sensor;
The magnetic bearing device according to claim 2 . The first power supply line and the second power supply line are wires that supply power to any of a motor, the radial electromagnet, the axial electromagnet, the radial displacement detection sensor, an axial displacement detection sensor, or an electric circuit. Is
The magnetic bearing device according to claim 3 . For modulation in the first modulation carrier circuit and the second modulation carrier circuit , an amplitude modulation method, a frequency modulation method, a phase modulation method, a spread spectrum modulation method, or a combination thereof is used;
The magnetic bearing device according to any one of claims 2 to 4 . A plurality of frequency regions are used for the first carrier and the second carrier ;
The magnetic bearing device according to any one of claims 2 to 4 . The magnetic bearing main body has an A / D conversion circuit for A / D converting a detection signal from the displacement detection sensor and supplying the detection signal to the first modulation carrier circuit;
The control device includes a D / A conversion circuit that D / A converts the detection signal demodulated by the first carrier demodulation circuit and supplies the detection signal to the compensation circuit;
The magnetic bearing device according to any one of claims 2 to 6. Said magnetic bearing main body, the displacement from the sensor detection signal a signal processing to the first modulation carrier circuit or the A / D via the conversion circuit the first signal processing circuit for supplying a modulation carrier circuit Having:
The magnetic bearing device according to any one of claims 2 to 7. Said magnetic bearing main body, the rotation speed of the magnetic rotary member, detecting the monitoring signal such as temperature, the first modulation carrier circuit the first modulating said first carrier by these monitors signals Generate a modulated wave;
The magnetic bearing device according to any one of claims 2 to 8. In the magnetic bearing main body, the first carrier signal wave generating means includes high frequency oscillating means for oscillating a high frequency signal, and the first AC coupling part receives the high frequency signal oscillated by the high frequency oscillating means . AC coupled to the first power supply line as one carrier signal wave and transmitted to the control device;
In the control device, the second AC coupling unit separates the high-frequency signal AC-coupled to the first power supply line, and the first carrier signal wave detecting means is the second AC coupling unit. A frequency detection circuit for detecting a frequency from the separated high-frequency signal;
The control device has a uniqueness determining means for identifying the uniqueness of the magnetic bearing main body based on the frequency detected by the frequency detection circuit;
The magnetic bearing device according to claim 2. In the magnetic bearing main body, the first carrier signal wave generating means has a pulse oscillation circuit that oscillates a pulse signal, and the first AC coupling unit receives the pulse signal oscillated by the pulse oscillation circuit . AC coupled to the first power supply line as one carrier signal wave and transmitted to the control device;
In the control device, the second AC coupling unit separates the pulse signal AC-coupled to the first power supply line, and the first carrier signal wave detecting means is the second AC coupling unit. A pulse period detection circuit for detecting a pulse period from the separated pulse signal;
The control device includes uniqueness determining means for identifying the uniqueness of the magnetic bearing body based on the pulse period detected by the pulse period detection circuit;
The magnetic bearing device according to claim 2. The first power supply line or the second power supply line is a wiring for supplying power to an electric circuit;
The magnetic bearing device according to claim 10 or 11 . The magnetic bearing body has a filter circuit that allows a high-frequency signal from the high-frequency oscillation means to pass within a specific range.
The magnetic bearing device according to claim 10 . Based on the uniqueness of the magnetic bearing main body identified by the uniqueness discriminating means, the compensation circuit can set parameters corresponding to the model when generating the compensation signal;
The magnetic bearing device according to claim 2 . A magnetic bearing device according to any one of claims 1 to 14 , and
A magnetic rotating body that is magnetically levitated and rotated by the magnetic bearing device;
A rotor main body connected to the magnetic rotating body and rotating;
Rotating system. A turbo molecular pump comprising the rotation system according to claim 15 . A semiconductor manufacturing apparatus comprising the rotation system according to claim 15 .

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