Magnetic suspension equipment

Abstract

The invention relates to magnetic suspension equipment which comprises a controller and a magnetic suspension motor, the magnetic suspension motor comprises a magnetic suspension rotor, a magnetic suspension stator and a sensor module, and the magnetic suspension stator is configured to drive the magnetic suspension rotor to rotate and suspend. The sensor module is configured to detect state data of the magnetic suspension motor, convert the state data into sensor signals and feed back the sensor signals to the controller; at least one cable is connected between the magnetic suspension motor and the controller, the cable comprises at least one group of clock signal lines, and the at least one group of clock signal lines are configured to transmit clock signals of the controller to the magnetic suspension motor. According to the invention, the arrangement of a signal generator in the magnetic suspension motor can be omitted, and the reference clocks of the associated signals among the components can be ensured to be based on the global single clock source, so that the purposes of improving the signal-to-noise ratio and the anti-interference capability of the detection of the magnetic suspension equipment sensor, optimizing the structure of the magnetic suspension motor and reducing the hardware cost of the product are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of magnetic suspension motors, in particular to a magnetic suspension device. Background Art

[0002] A magnetic levitation motor is a magnetic levitation rotary drive that uses magnetic field force to suspend the rotor so that there is no mechanical contact between the rotor and the stator. The magnetic levitation motor can be a magnetic bearing motor, a bearingless motor, or a bearingless thin-film motor, etc.

[0003] A magnetic bearing motor, also known as a magnetic bearing, is a motor that combines a rotary drive motor with an axial magnetic bearing or / and a radial magnetic bearing or / and an axial-diameter hybrid magnetic bearing instead of integrating them together.

[0004] A bearingless motor is a motor that integrates motor rotation and suspension functions. A bearingless motor has an additional set of windings on top of the windings that generate a rotating drive magnetic field to generate an excitation magnetic field. The interaction between the two magnetic fields breaks the balanced distribution of the original drive magnetic field, thereby generating a radial force acting on the rotor. The rotor is suspended by controlling the radial force in the motor. Compared with a magnetic bearing motor, the magnetic suspension winding of a bearingless motor is wound on the stator and does not occupy additional radial space, which to a certain extent overcomes the shortcomings of large size and high cost of magnetic bearings. In order to achieve suspension of the motor rotor in five degrees of freedom, early bearingless motors generally required two bearingless motors and one axial magnetic bearing.

[0005] The bearingless thin-film motor is a special bearingless motor that inherits the advantages of bearingless motors. The axial length to diameter ratio of the rotor is very small and it is in the shape of a thin film, eliminating the axial magnetic bearing. The bearingless technology is used to realize the rotation of the rotor and the active suspension in the radial direction. The magnetic circuit formed by the mechanical structure is used to realize the passive suspension of the other three degrees of freedom except the radial and rotor rotation degrees of freedom. It has the characteristics of high cleanliness, no precipitation, no particles, no dynamic seal, and excellent performance. It has good application prospects in ultra-pure drive fields such as biochemistry, medical treatment, and semiconductor manufacturing.

[0006] Unless otherwise specified, the term magnetic levitation motor refers to a magnetic levitation rotary drive that uses magnetic field force to suspend the rotor so that there is no mechanical contact between the rotor and the stator.

[0007] The magnetic levitation motor can be assembled with different functional assemblies to become a magnetic levitation device for different application requirements. In one embodiment, the magnetic levitation device can be configured as a magnetic levitation pump. In the application of the magnetic levitation pump, the magnetic levitation pump includes a magnetic levitation motor and a pump head. The pump head includes a pump housing and a rotor impeller disposed in the pump housing. The magnetic levitation rotor is both the rotor of the magnetic levitation motor and a part of the rotor impeller of the pump. It can be, for example, a permanent magnet rotor or a short-circuit cage rotor or a reluctance rotor. The magnetic levitation stator is configured to drive the rotor impeller to rotate and suspend. In another embodiment, the magnetic levitation device is configured as a magnetic levitation mixer. In the application of the magnetic levitation mixer, the magnetic levitation mixer includes a magnetic levitation motor and a stirring device. The stirring device includes a stirring container and a rotor stirring head disposed in the stirring container. The magnetic levitation rotor is both the rotor of the magnetic levitation motor and a part of the rotor stirring head of the stirring device. The magnetic levitation stator is configured to drive the rotor stirring head to rotate and suspend. In another embodiment, the magnetic levitation device can also be configured as a magnetic levitation turntable, which includes a magnetic levitation motor and a rotor support platform. The rotor support platform includes a table top and a magnetic levitation rotor. The table top and the magnetic levitation rotor constitute an integral rotor. The magnetic levitation stator is configured to drive the rotor support platform to rotate and suspend.

[0008] Compared with the traditional motor using contact mechanical bearings, the magnetic levitation motor needs to perform more degrees of freedom control. This requires more sensors to be integrated in the motor body. Various sensors and sensor circuits are collectively referred to as sensor components. Various conditioning circuits that adjust and process the sensor signals containing state data output by the sensor components are collectively referred to as signal conditioning modules. The sensor components and signal conditioning modules constitute sensor modules. The state data of the magnetic levitation motor can be detected in real time through the sensor modules. The state data can include, for example, rotor displacement data, rotor angle data (rotor speed data) or current data of the electromagnetic coil. With the state data as feedback, the control host or controller of the magnetic levitation motor generates a control signal of the power amplifier as the execution part according to the control strategy. The power amplifier outputs current to excite the electromagnetic coil of the stator part of the magnetic levitation motor to achieve the suspension and / or rotation control of the rotor. The power amplifier is also called a power amplifier circuit, such as a PWM power amplifier. The power amplifier can be an output stage or output stage circuit including a PWM generator or a PWM circuit, or an output stage or output stage circuit that is only a power amplifier. Various power amplifiers including output stages or output stage circuits are collectively referred to as power amplifier modules.

[0009] At present, the magnetic levitation motor and the controller are connected by a driving cable (power cable or power line) and a sensor signal cable. Taking the magnetic levitation pump as an example, the displacement sensor signal of the magnetic levitation motor is usually very weak, especially for some low-power magnetic levitation pumps, the displacement sensor signal is even weaker. Therefore, the magnetic levitation pump sets the signal conditioning module of the displacement sensor signal inside the magnetic levitation motor (inside the motor housing), and the sensor signal is conditioned (for example, amplified, detected, filtered, etc.) by the signal conditioning module before being transmitted to the controller. The excitation and signal conditioning of the displacement sensor are based on the AC signal (excitation signal) and the reference signal (demodulation signal). Therefore, it is necessary to set an excitation module on the magnetic levitation motor side. The excitation module includes a signal generator (such as a crystal oscillator) based on the generation of a reference signal and a frequency division phase shift circuit that generates an excitation signal for sensor coil excitation based on the reference signal and a demodulation signal for detection by the signal conditioning module. At the same time, the controller's analog-to-digital conversion module (ADC) sampling and the power amplifier module's PWM modulation both require a reference clock, which means that the controller side also needs to set up a signal generator (crystal oscillator) to provide a reference clock for ADC sampling and PWM modulation of the power amplifier module. In this way, signal generators need to be set up on both the controller side and the magnetic levitation motor side. Different signal generators cannot ensure that the reference clocks provided are consistent, that is, the effective edges of the reference clocks on both sides cannot be accurately aligned, which will cause errors in the phase locking of the associated signals between the components, which will lead to a low signal-to-noise ratio and poor anti-interference ability of the entire control system. In addition, signal generators and their associated circuits are set up on both sides, resulting in a complex system structure and high hardware costs. Summary of the invention

[0010] In order to solve the above technical problems, the present invention proposes a magnetic levitation device, which can eliminate the need to set a signal generator on the magnetic levitation motor side, while ensuring that the reference clock of the related signals between the various components is based on a global single clock source, thereby improving the signal-to-noise ratio and anti-interference ability of the magnetic levitation device sensor, optimizing the structure of the magnetic levitation motor, and reducing the product hardware cost.

[0011] The present invention provides a magnetic levitation device, including a controller and a magnetic levitation motor, the magnetic levitation motor including a magnetic levitation rotor, a magnetic levitation stator and a sensor module, the magnetic levitation stator is configured to drive the magnetic levitation rotor to rotate and suspend, the sensor module is configured to detect state data of the magnetic levitation motor and convert it into a sensor signal to feed back to the controller; at least one cable is connected between the magnetic levitation motor and the controller, the cable includes at least one group of clock signal lines, and the at least one group of clock signal lines is configured to transmit the clock signal of the controller to the magnetic levitation motor.

[0012] Furthermore, the at least one cable is configured as two cables, one cable includes at least one group of sensor signal lines and at least one group of clock signal lines, and the other cable includes at least one group of drive lines, the sensor signal lines are configured to transmit the sensor signals, and the drive lines are configured to transmit electrical signals that drive the magnetic levitation rotor to rotate and suspend.

[0013] Furthermore, the at least one cable is configured as a cable, which includes at least one group of sensor signal lines, at least one group of drive lines and at least one group of clock signal lines, the sensor signal lines are configured to transmit the sensor signals, and the drive lines are configured to transmit electrical signals that drive the magnetic levitation rotor to rotate and suspend.

[0014] Furthermore, the clock signal is a square wave or a sine wave with a fixed frequency, or the clock signal is a differential square wave or a differential sine wave with a fixed frequency.

[0015] Furthermore, when the clock signal is a square wave, the duty cycle of the square wave is fixed.

[0016] Furthermore, the sensor module includes a sensor component and a signal conditioning module, the sensor component is configured to detect the state data of the magnetic levitation motor and generate a sensor signal containing the state data, and the signal conditioning module is configured to adjust and process the sensor signal containing the state data and generate a conditioned sensor signal.

[0017] Furthermore, the at least one group of clock signal lines is configured as a group of clock signal lines, and the magnetic levitation motor also includes a second clock distribution module, the clock signal line is connected to the second clock distribution module, and the second clock distribution module is configured to generate an excitation signal for exciting the sensor component and a demodulation signal for detection by the signal conditioning module based on the clock signal transmitted by the clock signal line.

[0018] Furthermore, the magnetic levitation motor also includes a motor shell, the motor shell having a main chamber and a sub-chamber connected to one side of the main chamber, the magnetic levitation stator is arranged in the main chamber, a PCB board is provided in the sub-chamber, and the second clock distribution module and the signal conditioning module are integrated on the PCB board.

[0019] Furthermore, the sensor assembly includes at least one displacement sensor for detecting the radial or axial displacement of the magnetic suspension rotor and a sensor circuit board, and the sensor circuit board is integrated with electronic components that form a sensor circuit with the at least one displacement sensor.

[0020] Furthermore, the second clock distribution module is configured as a phase shift module, and the clock signal is phase-shifted by the phase shift module to generate the excitation signal and the demodulation signal.

[0021] Furthermore, the second clock distribution module is configured as a frequency division and phase shifting module, and the clock signal is divided by the frequency division and phase shifting module to generate multiple groups of degree-of-freedom signals, and each group of degree-of-freedom signals is phase shifted by the frequency division and phase shifting module to generate an excitation signal for the sensor in the direction of the degree of freedom and a demodulation signal for the signal conditioning module in the direction of the degree of freedom.

[0022] Furthermore, the controller includes a power amplification module, an analog-to-digital conversion module and a first clock distribution module. The first clock distribution module generates the clock signal based on a reference clock of a global single clock source. The first clock distribution module also generates a sampling clock for sampling the analog-to-digital conversion module and a power amplifier clock for driving the power amplification module based on the reference clock.

[0023] Furthermore, the controller also includes a clock driver, and the clock signal is driven by the clock driver and then transmitted to the second clock distribution module via the clock signal line.

[0024] Furthermore, the clock driver is a differential clock driver, the clock signal is a differential signal, and the differential signal is driven by the differential clock driver and then transmitted to the second clock distribution module via the clock signal line.

[0025] Furthermore, the at least one group of clock signal lines is configured as two groups of clock signal lines, the clock signal transmitted by one group of clock signal lines is used as an excitation signal for exciting the sensor component, and the clock signal transmitted by the other group of clock signal lines is used as a demodulation signal for detection by the signal conditioning module.

[0026] Furthermore, the magnetic levitation motor is a magnetic bearing motor or a bearingless motor or a bearingless thin-film motor.

[0027] Furthermore, the magnetic levitation device is configured as a magnetic levitation pump or a magnetic levitation mixer or a magnetic levitation turntable.

[0028] The above technical solution of the present invention has the following advantages over the prior art: the present invention proposes a magnetic levitation device, which realizes the clock homology between the reference clock on the controller side and the reference signal of the sensor module of the magnetic levitation motor by setting a clock signal line in the cable between the controller and the magnetic levitation motor, thereby eliminating the need to set a signal generator in the magnetic levitation motor and ensuring that the reference clocks of the related signals between the various components are based on a global single clock source, thereby achieving the purpose of improving the signal-to-noise ratio and anti-interference ability of the sensor detection of the magnetic levitation device, optimizing the structure of the magnetic levitation motor, and reducing the hardware cost of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below according to specific embodiments of the present invention in conjunction with the accompanying drawings, wherein

[0030] Figure 1 It is a principle block diagram of an embodiment of the magnetic levitation device of the present invention;

[0031] Figure 2 It is a principle block diagram of another embodiment of the magnetic levitation device of the present invention;

[0032] Figure 3 It is a structural schematic diagram of an embodiment of the magnetic levitation device of the present invention;

[0033] Figure 4 It is a structural schematic diagram of an embodiment of the magnetic levitation motor of the present invention (the sub-chamber cover is hidden);

[0034] Figure 5 is a cross-sectional view of an embodiment of the magnetic levitation motor of the present invention;

[0035] Figure 6 is a structural diagram of an embodiment of a second clock distribution module of the present invention;

[0036] Figure 7 is a structural schematic diagram of another embodiment of the second clock distribution module of the present invention;

[0037] Figure 8 It is a structural schematic diagram of another embodiment of the magnetic levitation device of the present invention;

[0038] Fig. 9 is a schematic diagram of a waveform of a PWM signal of the present invention;

[0039] Fig.10 is a schematic diagram of a waveform of a sensor signal of the present invention;

[0040] Fig.11 Schematic diagram of several waveforms of the clock signal of the present invention;

[0041] Fig.12 It is a structural schematic diagram of an embodiment in which the magnetic levitation device of the present invention is configured as a magnetic levitation pump;

[0042] Fig.13 It is a structural schematic diagram of another embodiment of the magnetic levitation device of the present invention configured as a magnetic levitation pump;

[0043] Fig.14 It is a cross-sectional view of the motor and pump head of the magnetic levitation device of the present invention configured as a magnetic levitation pump;

[0044] Fig.15It is a structural schematic diagram of an embodiment in which the magnetic levitation device of the present invention is configured as a magnetic levitation stirrer;

[0045] Fig.16 It is a structural schematic diagram of an embodiment of the magnetic suspension device of the present invention configured as a magnetic suspension mixer (with a hidden stirring container);

[0046] Fig.17 It is a structural schematic diagram of an embodiment of the magnetic levitation device of the present invention configured as a magnetic levitation turntable;

[0047] Fig.18 is a schematic structural diagram of an embodiment of a cable of the present invention;

[0048] Fig.19 is a structural schematic diagram of another embodiment of the cable of the present invention;

[0049] Fig. 20 It is a structural schematic diagram of another embodiment of the cable of the present invention. DETAILED DESCRIPTION

[0050] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without creative work should fall within the scope of protection of the present invention.

[0051] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. The terms "including" and "having" and any variations thereof in the specification and claims of the present invention and the above-mentioned drawings are intended to cover non-exclusive inclusions, for example, a system, product or device comprising a series of units is not necessarily limited to those units clearly listed, but may include other units that are not clearly listed or inherent to these products or devices.

[0052] In the prior art, the magnetic levitation motor and the controller are connected through a driving line (power cable or power cable) and a sensor signal line (data cable). Taking the magnetic levitation pump as an example, the displacement sensor signal of the magnetic levitation motor is usually very weak, especially for some low-power magnetic levitation pumps, the displacement sensor signal is even weaker. Therefore, the magnetic levitation pump sets the signal conditioning module of the displacement sensor signal inside the magnetic levitation motor (inside the motor housing), and the sensor signal is conditioned (for example, amplified, detected, filtered, etc.) by the signal conditioning module before being transmitted to the controller. The excitation and signal conditioning of the displacement sensor are based on an AC signal (excitation signal) and a reference signal (demodulation signal). Therefore, an excitation module needs to be set on the magnetic levitation motor side. The excitation module includes a signal generator (such as a crystal oscillator) based on a reference signal and a frequency division phase shift circuit that generates an excitation signal for sensor coil excitation and a demodulation signal for detection by the signal conditioning module based on the reference signal. At the same time, the controller's analog-to-digital conversion module (ADC) sampling and the power amplifier module's PWM modulation both require a reference clock, which means that the controller side also needs to set up a signal generator (crystal oscillator) to provide a reference clock for ADC sampling and PWM modulation of the power amplifier module. In this way, signal generators need to be set up on both the controller side and the magnetic levitation motor side. Different signal generators cannot ensure that the reference clocks provided are consistent, that is, the effective edges of the reference clocks on both sides cannot be accurately aligned, which will cause errors in the phase locking of the associated signals between the components, which will lead to a low signal-to-noise ratio and poor anti-interference ability of the entire control system. In addition, signal generators and their associated circuits are set up on both sides, resulting in a complex system structure and high hardware costs.

[0053] In order to solve the above technical problems, the present invention proposes a magnetic suspension device. Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 6 The magnetic levitation device includes a controller 1 and a magnetic levitation motor 2, the magnetic levitation motor 2 includes a magnetic levitation rotor, a magnetic levitation stator 22 and a sensor module, the magnetic levitation stator 22 is configured to drive the magnetic levitation rotor to rotate and suspend, and the sensor module is configured to detect the state data of the magnetic levitation motor and convert it into a sensor signal to feed back to the controller 1; at least one cable 3 is connected between the magnetic levitation motor 2 and the controller 1, the cable 3 includes at least one group of clock signal lines 31, and the at least one group of clock signal lines 31 is configured to transmit the clock signal of the controller 1 to the magnetic levitation motor 2.

[0054] The present invention sets a clock signal line in the cable between the controller and the magnetic levitation motor, and transmits the clock signal of the controller side to the magnetic levitation motor side through the clock signal line, thereby realizing that the reference clock of the controller side and the clock of the reference signal of the sensor module of the magnetic levitation motor are homologous, thereby eliminating the need to set a signal generator in the magnetic levitation motor, and ensuring that the reference clocks of the related signals between the various components are based on a global single clock source, thereby achieving the purpose of improving the signal-to-noise ratio and anti-interference ability of the sensor detection of the magnetic levitation device, optimizing the structure of the magnetic levitation motor, and reducing the hardware cost of the product.

[0055] Among them, the clock signal of the controller is generated by the reference clock of the global single clock source set on the controller side, and a clock signal line is set between the controller and the magnetic levitation motor. The clock signal line provides a clock signal with the same source as the reference clock on the controller side to the magnetic levitation motor side as a reference signal, so that the reference clock on the controller side and the reference signal of the sensor module of the magnetic levitation motor can be of the same source. Based on the global single clock source, the effective edge (clock edge) of the reference clock on the controller side and the magnetic levitation motor side can be accurately aligned. On the basis of the alignment of the effective edge, the delay time between each related signal can be accurately controlled and adjusted, thereby ensuring that the phase or phase difference between the related signals of each component is determined, and then in the sensor detection or analog-to-digital conversion process, the noise and interference generated by the power amplifier module or other components can be avoided, thereby improving the signal-to-noise ratio and anti-interference ability of the system.

[0056] Among them, the type of magnetic levitation motor is not limited, and can be summarized as a magnetic levitation rotary drive that uses magnetic field force to suspend the rotor so that there is no mechanical contact between the rotor and the stator. Preferably, the magnetic levitation motor can be a magnetic bearing motor, a bearingless motor or a bearingless thin-film motor, etc.

[0057] A magnetic bearing motor, also known as a magnetic bearing, is a motor that combines a rotary drive motor with an axial magnetic bearing or / and a radial magnetic bearing or / and an axial-diameter hybrid magnetic bearing, etc., rather than integrating them together.

[0058] A bearingless motor is a motor that integrates motor rotation and suspension functions. A bearingless motor has an additional set of windings on top of the windings that generate a rotating driving magnetic field to generate an excitation magnetic field. The interaction between the two magnetic fields breaks the balanced distribution of the original driving magnetic field, thereby generating a radial force acting on the rotor. The rotor suspension is achieved by controlling the radial force in the motor.

[0059] The bearingless thin-film motor is a special bearingless motor. It inherits the advantages of the bearingless motor, and the axial length to diameter ratio of the rotor is very small, in the shape of a thin film, eliminating the axial magnetic bearing. The bearingless technology is used to realize the rotation of the rotor and the active suspension in the radial direction. The magnetic circuit composed of the mechanical structure is used to realize the passive suspension of the other three degrees of freedom except the radial and rotor rotation degrees of freedom. It has the characteristics of high cleanliness, no precipitation, no particles, no dynamic seal, and excellent performance. It has good application prospects in ultra-pure drive fields such as biochemistry, medical treatment, and semiconductor manufacturing.

[0060] Preferably, the magnetic levitation motor of the present invention is a bearingless thin-film motor. The bearingless thin-film motor can be divided into a single winding structure and a double winding structure according to different winding structures. The present invention does not limit the winding structure of the bearingless thin-film motor, which can be a single winding structure or a double winding structure. In one embodiment, a winding coil is arranged on each stator tooth of the magnetic levitation stator, and the winding coil is a concentrated winding. The winding coil is used for both rotation control and suspension control to form a single winding structure of the magnetic levitation motor. In another embodiment, two winding coils are arranged on each stator tooth of the magnetic levitation stator, and the two winding coils can be concentrated windings, or one winding coil can be a concentrated winding and the other winding coil can be a distributed winding. The two winding coils on the stator teeth are stacked together, one winding coil is used for rotation control, and the other winding coil is used for suspension control to form a double winding structure of the magnetic levitation motor. Since the single-winding magnetic levitation motor can realize the rotation and suspension of the motor rotor at the same time with only one set of winding coils, it has better performance advantages than the double-winding magnetic levitation motor.

[0061] In one embodiment, see Figure 1 and Figure 3 , at least one cable is configured as two cables 3, the controller 1 and the magnetic suspension motor 2 are connected through the two cables 3, see Figure 1, one cable includes at least one group of sensor signal lines 32 and at least one group of clock signal lines 31, and the other cable includes at least one group of drive lines 33; the sensor signal line 32 is configured to transmit sensor signals, and the drive line 33 is configured to transmit electrical signals that drive the magnetically suspended rotor to rotate and suspend. Since the power and signal strength of the clock signal transmitted by the clock signal line 31 are relatively weak compared to the electrical signal (current or voltage) that drives the magnetically suspended rotor to rotate and suspend, and both the sensor signal line and the clock signal line transmit weak signals, the clock signal line and the sensor signal line are arranged on the same cable, and it is not easy for the two to interfere with each other, which facilitates signal transmission. Among them, there is no limit to the number of sensor signal lines, and they can be configured according to actual conditions. The sensor signals transmitted by at least one group of sensor signal lines include rotor displacement signals and / or rotor angle signals and / or current signals, but are not limited to this. For example, in other embodiments, they may also include temperature signals. In one embodiment, at least one group of sensor signal lines may include multiple displacement sensor signal lines that transmit displacement signals of multiple degrees of freedom, and may also include temperature sensor signals that transmit temperature signals. As an illustration, Figure 1 Only one set of sensing signal lines 32 is illustrated in FIG. Fig.18 , multiple groups of sensing signal lines 32 are schematically shown. Similarly, there is no limit to the number of driving lines 33, which can be configured according to actual conditions. For example, at least one group of driving lines 33 can include multiple driving lines that transmit currents of multiple winding coils. As an example, Figure 1 Only one set of driving lines 33 is illustrated in FIG. Fig.19 8 sets of drive lines are shown in FIG. 3 , and each set of drive lines 33 corresponds to a winding coil of the magnetic suspension stator. It should be noted that: Figure 1 The following are only illustrative. Fig.18 and Fig.19 As shown, specifically, the sensing signal line or the clock signal line or the driving line may also include an insulating sheath and a single or multiple wire cores. For the entire cable 3, in addition to the sensing signal line 32 or the clock signal line 31 or the driving line 33, it also includes an insulating outer sheath 35 and a shielding layer 36, as well as a filler 37 filled between the wires. Fig.18 In addition to the sensor signal line 32 and the clock signal line 31, the cable 3 also includes an insulating outer jacket 35, a shielding layer 36 and a filler 37, and the filler also includes glass fiber 38, etc. Fig.19 In addition to the driving wire 33, the cable 3 also includes an insulating outer jacket 35, a shielding layer 36 and a filler 37. The filler also includes glass fiber 38, etc. In addition, according to actual needs, see Fig.18The cable 3 is also provided with other signal lines, such as a power signal line 34 for supplying power to the sensor circuit. The cable can be connected to the controller and the magnetic suspension motor by an electrical connector, such as a DB connector, and the multiple pins of the DB connector can be electrically connected to at least one set of drive lines, at least one set of sensor signal lines, and at least one set of clock signal lines of the cable according to the configuration requirements.

[0062] In another embodiment, see Figure 2 , at least one cable is configured as a cable 3, the cable includes at least one group of sensor signal lines 32, at least one group of drive lines 33 and at least one group of clock signal lines 31, the sensor signal line 32 is configured to transmit sensor signals, and the drive line 33 is configured to transmit electrical signals that drive the magnetic levitation rotor to rotate and suspend. In this embodiment, the characteristics of the cables, sensor signal lines, clock signal lines and drive lines are the same or similar to those of the embodiment configured as two cables. The difference is that in this embodiment, only one cable is set, and at least one group of sensor signal lines, at least one group of clock signal lines and at least one group of drive lines are set on the same cable, which can reduce the number of cables. The possible mutual interference problem is further solved by other technical solutions. For example, when the clock signal line and the drive line are set on the same cable, a differential clock driver can be used to drive the clock signal. By differentially driving the clock signal, common mode interference can be suppressed, and the interference problem of the drive line on the clock signal line can be solved. As an illustration, Figure 2 In the figure, only one group of clock signal lines 31, one group of sensing signal lines 32 and one group of driving lines 33 are illustrated. Fig. 20 Schematically shows a plurality of sensor signal lines 32, a clock signal line 31 and a plurality of drive lines 33. Similarly, there is no limit to the number of drive lines 33 and sensor signal lines, and they can be configured according to actual conditions. Fig. 20 As shown, similarly, the sensing signal line or the clock signal line or the driving line may also include an insulating sheath and a single or multiple wire cores. For the entire cable 3, in order to reduce the interference of the driving line on the sensing signal line and the clock signal line, preferably, see Fig. 20, at least one group of sensor signal lines 32 and at least one group of clock signal lines 31 are arranged together in an inner sheath 39 (shielding layer), and at least one group of driving lines 33 are arranged between an outer sheath 35 and the inner sheath 39, an outer shielding layer 36 is also arranged between the outer sheath 35 and at least one group of driving lines 33, and a filler 37 is also filled between the outer shielding layer and the inner sheath, and the filler also includes glass fiber 38, etc., and the gaps between the signal lines in the inner sheath are also filled with fillers. In addition, according to actual needs, other signal lines are also configured in the cable 3, such as a power signal line 34 for powering the sensor circuit. Among them, the sensor module is configured to detect the state data of the magnetic levitation motor and convert it into a sensor signal to feed back to the controller. As a preferred embodiment, the sensor module includes a sensor component and a signal conditioning module, the sensor component is configured to detect the state data of the magnetic levitation motor based on the clock signal, and generate a sensor signal containing the state data, and the signal conditioning module is configured to adjust and process the sensor signal containing the state data, and generate a conditioned sensor signal. The present invention collectively refers to various sensors and related sensor circuits as sensor components. Various conditioning circuits that adjust and process sensor signals containing status data output by the sensor components are collectively referred to as signal conditioning modules. The sensor modules can be used to detect the status data of the magnetic levitation motor in real time. The status data may include, for example, rotor displacement data, rotor angle data (rotor speed data) or current data of the electromagnetic coil.

[0063] Among them, the sensor assembly may include a speed or position angle sensor and a displacement sensor. The speed or position angle sensor is used to sense the speed of the magnetically suspended rotor for speed feedback control. The speed or position angle sensor may be a Hall sensor or a photoelectric sensor. The displacement sensor is used to sense the suspension position of the magnetically suspended rotor for rotor suspension position control. The displacement sensor generally includes an x-axis displacement sensor and a y-axis displacement sensor. Preferably, the displacement sensor may be an eddy current sensor, which has high sensitivity and is suitable for sensing the suspension position of the rotor. In other embodiments, the sensor assembly may also include a temperature sensor or a sensor for sensing other parameters.

[0064] Preferably, see Figure 5The sensor assembly 23 includes at least one displacement sensor 231 and a sensor circuit board 232 for detecting the radial displacement of the magnetic suspension rotor. The sensor circuit board is integrated with electronic components that form a sensor circuit with the at least one displacement sensor. Preferably, the at least one displacement sensor includes two sensor coils, which are radially symmetrically arranged on the magnetic suspension stator and face the magnetic suspension rotor. The electronic components are configured to include resistors and capacitors that form a bridge circuit. The sensor circuit can be configured as an LC resonant circuit. In one embodiment, the LC resonant circuit includes a sensor full-bridge circuit and a resonant capacitor; each bridge arm of the sensor full-bridge circuit is composed of a resistor and an equivalent inductance of a sensor coil, and the resonant capacitor is configured as a shared capacitor, which is connected in parallel between the output ends of the two bridge arms of the sensor full-bridge circuit; in another embodiment, the resonant capacitor includes a first capacitor and a second capacitor, the first capacitor is connected in parallel or in series with the equivalent inductance of one sensor coil of the sensor full-bridge circuit, and the second capacitor is connected in parallel or in series with the equivalent inductance of another sensor coil of the sensor full-bridge circuit, and the two equivalent inductors are used to form a differential inductance sensor. Since the two sets of sensor coils are at the same ambient temperature in the stator, the adverse effects of temperature drift can be effectively suppressed; at the same time, since the differential signal is used to obtain the relative displacement rather than the absolute displacement, the impact of manufacturing accuracy on the measurement can be reduced. Based on the differential displacement sensor, the LC resonance principle of the resonant circuit is used to further improve the signal-to-noise ratio and anti-interference ability of the sensor detection.

[0065] Since the displacement sensor signal of the magnetic levitation motor is usually very weak, especially some low-power magnetic levitation motors (such as those used in magnetic levitation pumps), and in view of the compact structure required for magnetic levitation pumps in the semiconductor and pharmaceutical fields, the displacement sensor signal is even weaker. Therefore, the sensor signal output by the sensor component, such as the displacement sensor signal, needs to be amplified, detected, filtered, and conditioned by the signal conditioning module before ADC sampling to improve the signal-to-noise ratio, accuracy, and anti-interference ability of the sensor detection. The excitation of the sensor detection and the conditioning of the signal conditioning module are based on the excitation signal and the reference demodulation signal. The prior art generally adopts an amplitude detection scheme to extract the signal of the amplitude by rectifying and filtering the terminal voltage of the displacement sensor coil. Preferably, the demodulation sampling phase detection scheme of the displacement sensor signal of the present invention is implemented. The core of the phase detection scheme is to multiply the voltage signal on the equivalent inductance of the sensor coil and a demodulation signal orthogonal to the excitation signal of the sensor coil by a multiplier and filter it to obtain a low-frequency signal containing phase information. Its advantages are that it utilizes the orthogonality of the excitation signal and the demodulation signal, eliminating the influence of irrelevant frequency signals, so it has strong anti-interference ability. In addition, the phase signal changes more obviously with the impedance of the excitation coil, so it has higher sensitivity.

[0066] In one embodiment, see Figure 1 and Figure 2 , the magnetic levitation motor also includes a second clock distribution module, the sensor module includes a sensor component and a signal conditioning module, at least one group of clock signal lines is configured as a group of clock signal lines 31, the clock signal line is connected to the second clock distribution module, and the second clock distribution module is configured to generate an excitation signal for excitation of the sensor component and a demodulation signal for detection of the signal conditioning module based on the clock signal transmitted by the clock signal line. In this way, the signal conditioning module generates an excitation signal and a demodulation signal based on the clock signal transmitted by the clock signal line, which can meet the excitation of sensor detection and the detection of the signal conditioning module. Taking the eddy current displacement sensor as an example, the excitation signal applies a high-frequency alternating current to the sensor coil, and the sensor coil generates an alternating magnetic field and an induced electric field. When a metal conductor approaches the sensor coil, the induced electric field will generate an induced eddy current on the surface of the metal conductor. The eddy current will generate an eddy current magnetic field, which is opposite to the direction of the coil magnetic field and will offset part of the coil magnetic field, thereby changing the impedance of the sensor coil. When the distance between the metal conductor and the sensor coil changes, the impedance of the sensor coil will follow the change, so that the distance between the metal conductor and the sensor coil can be measured according to the impedance. In this way, the terminal voltage of the sensor coil will contain a small change in impedance. With the terminal voltage of the sensor coil as the output, the sensor signal output by the sensor component is amplified, detected, filtered, and conditioned by the signal conditioning module. The conditioned sensor signal not only improves the signal-to-noise ratio and anti-interference ability of the signal, but also meets the requirements of ADC sampling. Among them, since the excitation signal used for sensor detection and the demodulation signal used for the signal conditioning module are both derived from the clock signal transmitted by the clock signal line, the phase difference relationship between the two is determined and simple to implement, which can effectively improve the sensitivity and anti-interference ability of sensor detection.

[0067] In one embodiment, reference Figure 4 and Figure 5 The magnetic levitation motor further comprises a motor housing 24, the motor housing having a main chamber 241 and a sub-chamber 242 connected to one side of the main chamber 241, the magnetic levitation stator 22 is arranged in the main chamber 241, a PCB board 25 is arranged in the sub-chamber 242, and the second clock distribution module and the signal conditioning module are integrated on the PCB board 25. On the magnetic levitation motor side, in order to achieve a compact structure and realize the functions of rotation and suspension, the magnetic levitation stator is usually arranged in the chamber of the motor housing, and the magnetic circuit structure of the magnetic levitation stator can be arranged in the chamber, for example, see Figure 5For a magnetic levitation stator 22 with a single winding structure, the magnetic levitation stator 22 generally includes a stator yoke 221, a plurality of stator teeth 222, and a winding coil 223 wound on the stator teeth. The stator yoke is connected to the plurality of stator teeth to perform a magnetic conductivity function. The connection between the stator yoke and the stator teeth may be an integrated type or a split type. For example, in a magnetic levitation stator with L-shaped stator teeth, the stator yoke is connected to the vertical portions of a plurality of L-shaped stator teeth in a split form. For another example, in a magnetic levitation stator with a straight-line stator teeth, the stator yoke is connected to the outer ends of a plurality of straight-line stator teeth and is formed as one piece. In other variations, a magnetic levitation stator with a dual winding structure may also be provided. See. Fig.14 The difference between the single winding structure and the double winding structure is that only one winding coil is arranged on the stator teeth of the single winding structure, and the winding coil is a centralized winding, which is used for both rotation control and suspension control. Based on the comprehensive consideration of the outgoing line connection of the winding coil (electromagnetic coil) and the signal conditioning of the sensor signal, the present invention divides the chamber of the magnetic suspension motor into a main chamber 241 and a sub-chamber 242. The main chamber 241 is used to accommodate the magnetic circuit structure and the winding coil of the magnetic suspension stator 22, and the sub-chamber 242 is used to accommodate the PCB board 25 for carrying the signal conditioning module and the second clock distribution module; the second clock distribution module is also integrated on the PCB board 25, the structural design is reasonable, does not occupy additional space, and is convenient to implement. Among them, the main chamber 241 is connected with the sub-chamber 242, which is convenient for the connection line of the winding coil in the main chamber 241 to be led out of the motor housing 24 through the sub-chamber 242. Preferably, the main chamber 241 and the sub-chamber 242 are partially connected, that is, a partition is provided between the main chamber 241 and the sub-chamber 242, which is convenient for installing the PCB board and can reduce the interference of leakage magnetic field in the main chamber on the circuit on the PCB board.

[0068] The second clock distribution module is used to generate an excitation signal and a demodulation signal based on the clock signal. Figure 6In one embodiment, the second clock distribution module is configured as a phase shift module, and the clock signal is phase shifted by the phase shift module to generate an excitation signal and a demodulation signal. The phase shift module includes a phase shifter or an FPGA or hardware delay chip or a gate circuit combination with a phase shift function. Taking the phase shifter as an example, the phase shifter can adjust the phase of the clock signal (digital signal). The phase shifter circuit can be composed of resistors, reactance elements, nonlinear elements and active devices, and the phase of the clock signal will change when it passes through the phase shifter. When adjusting the circuit parameters, the ideal phase shifter can make the phase of the passing signal change continuously between 0° and 360° without changing the amplitude of the signal, that is, the signal can pass without distortion, but the phase changes. Therefore, the clock signal is phase shifted by the phase shifter to generate an excitation signal and a demodulation signal. Since the excitation signal and the demodulation signal are used to constitute the input signal and the reference signal of the signal conditioning, the two have the same frequency, and the phase shifting processing of the phase shifter can generate an input signal and a reference signal with the same frequency and orthogonal phase difference. FPGA, or field programmable gate array, is a product further developed on the basis of programmable devices such as PAL (programmable array logic) and GAL (general array logic). Based on FPGA, the functions of timing and combinational logic circuits can be completed, and FPGA can realize the function of phase shifting. FPGA with phase shifting function performs phase shifting processing on the clock signal to generate an excitation signal and a demodulation signal. In this embodiment, the second clock distribution module can generate an excitation signal shared by sensors in multiple degrees of freedom and a demodulation signal shared by signal conditioning modules in multiple degrees of freedom. For example, in the x and y degrees of freedom directions, the same excitation signal and demodulation signal can be shared. In other embodiments, the phase shift module can also be a hardware delay chip or a gate circuit combination, etc. In particular, the phase shift module can also be an inverter, which changes the phase of the clock signal by inversion. The present invention does not limit the specific structure of the implementation of the phase shift module function. As long as it has a phase shift or delay function, it is within the protection scope of the phase shift module of the present invention.

[0069] In another embodiment, see Figure 7, the second clock distribution module is configured as a frequency division and phase shift module. The clock signal is divided by the frequency division and phase shift module to generate multiple groups of degree of freedom signals. Each group of degree of freedom signals is phase shifted by the frequency division and phase shift module to generate an excitation signal for the sensor in the direction of the degree of freedom and a demodulation signal for the signal conditioning module in the direction of the degree of freedom. Among them, the frequency division and phase shift module is a general description of the frequency division and phase shift functions. Specifically, the frequency division and phase shift module may include a frequency division phase shifter or an FPGA with a frequency division and phase shift function or a combination circuit with a frequency division and phase shift function. Taking the frequency division and phase shifter as an example, the frequency division and phase shifter includes a frequency divider and a phase shifter. The frequency divider generates multiple groups of degree of freedom signals based on the frequency division of the clock signal. The phase shifter generates an excitation signal for the sensor in the direction of the degree of freedom and a demodulation signal for the signal conditioning module in the direction of the degree of freedom based on each group of degree of freedom signals. The frequency division and phase shifter is used to realize multi-degree of freedom sensing detection, and the function of flexibly configuring frequency and phase shift is realized. The excitation signals of each degree of freedom have different frequencies and the clocks are of the same source (the phase relationship is determined), which can reduce the mutual interference between the sensors of each degree of freedom. Similarly, FPGA can realize the function of frequency division and phase shift. FPGA with frequency division and phase shift function performs frequency division and phase shift processing on the clock signal, and can generate excitation signals for sensors in different degrees of freedom directions and demodulation signals for signal conditioning modules in corresponding degrees of freedom directions. In other embodiments, the frequency division and phase shift module can also be other combination circuits with frequency division and phase shift function. The present invention does not limit the specific structure of the implementation of the function of the frequency division and phase shift module. As long as it has the frequency division and phase shift function, it is within the protection scope of the phase shift module of the present invention.

[0070] In the above embodiments, different embodiments are given for the implementation of the second clock distribution module generating the excitation signal and the demodulation signal based on the clock signal, but it is not limited thereto. In other embodiments, this function can also be implemented by other frequency division and / or phase shifting technologies.

[0071] In one embodiment, see Figure 1 and Figure 2The controller includes a power amplifier module, an analog-to-digital conversion module and a first clock distribution module. The first clock distribution module generates a clock signal based on a reference clock of a global single clock source. The first clock distribution module also generates a sampling clock for sampling the analog-to-digital conversion module and a power amplifier clock for driving the power amplifier module based on the reference clock. In this way, the power amplifier clock of the power amplifier module on the controller side, the sampling clock of the analog-to-digital conversion module and the clock signal on the magnetic levitation motor side are all from a global single clock source, that is, the reference clock on the controller side is consistent with the reference clock on the magnetic levitation motor side, which can achieve accurate alignment of the effective edge (clock edge) of the reference clock of each component in the magnetic levitation device. On the basis of the effective edge alignment, the delay time between each associated signal can be accurately controlled and adjusted, that is, the phase or phase difference between the associated signals between each component is ensured to be determined, thereby avoiding the noise and interference generated by the power amplifier module during sensor detection and analog-to-digital conversion. For example, on the basis of the effective edge alignment, the sampling time of the analog-to-digital conversion module is controlled to avoid the noise and interference generated by other components, thereby improving the signal-to-noise ratio and anti-interference ability of the system, and no additional synchronization module is required, the system structure is simple and the cost is low.

[0072] Among them, the effective edge alignment of the reference clock can be the same or different clock frequencies, and the effective edge can be a rising edge or a falling edge. Phase is also called phase time (PhaseTime), which refers to the delay time between the clock signal and the ideal signal (such as the reference clock) at the corresponding effective moment (generally refers to the rising edge or the falling edge). Phase is the instant delay. For example, one is a slow clock and the other is a fast clock. The clock frequencies of the two are different. The clock edge of the slow clock is always aligned with the clock edge of the fast clock. At the clock edge of the slow clock, the two clock phases are the same, that is, the effective edge is aligned. Taking the PWM signal of the power amplifier module and the sampling signal of the analog-to-digital conversion module as an example, if there is an error in the phase locking of the two (the effective edge is not aligned), it will affect the accuracy of displacement detection. The reference clocks on the controller side and the magnetic suspension motor side of the magnetic suspension device of the present invention are based on a global single clock source, which can ensure the accurate alignment of the effective edges (clock edges) of each clock of the magnetic suspension device. On the basis of the effective edge alignment, the delay time between each associated signal can be further accurately controlled and adjusted, thereby avoiding the noise and interference generated by the power amplifier module or other components during sensor detection and analog-to-digital conversion. In particular, the clock signal is transmitted to the magnetic levitation motor side by the clock signal line, and the clock signal is used to realize the excitation of the sensor and the detection of the signal conditioning module, which can save the need to set a signal generator in the magnetic levitation motor. The structure is very simple, and the structure of the magnetic levitation motor side can be further optimized, making the structure of the magnetic levitation motor side more compact and reducing the hardware cost of the product.

[0073] In the above embodiment, the first clock distribution module is used to generate the above clock signal, sampling clock and power amplifier clock. The first clock distribution module uniformly configures the reference clock from the global single clock source, which can meet the global clock needs of each component. In one embodiment, the first clock distribution module may include a frequency division module and a phase shift module. The frequency division module includes multiple frequency dividers. The multiple frequency dividers respectively divide the reference clock from the global single clock source to generate multiple divided clocks, including clock signals, sampling clocks and power amplifier clocks. The phase shift module includes multiple phase shifters. The multiple phase shifters correspond to the multiple frequency dividers one by one. The phase shifters adjust the phase of the divided clocks from the corresponding frequency dividers to generate multiple divided clocks after phase adjustment. By setting multiple phase shifters corresponding to the multiple frequency dividers one by one, the phase adjustment of each clock signal can be achieved. On the one hand, the clock edges of the clocks of each specific frequency can be accurately aligned through phase adjustment. On the other hand, the phase adjustment can also reduce the influence of the mechanical assembly error of the magnetic levitation motor or / and the error of the electronic components themselves on the sensor detection, thereby improving the accuracy of system detection and the consistency of mass production.

[0074] The clock signal generated by the first clock distribution module based on the reference clock can be directly transmitted to the magnetic suspension motor side through the clock signal line. But not limited to this. For example, in one embodiment, see Figure 1 and Figure 2 The controller also includes a clock driver, and the clock signal is driven by the clock driver and transmitted to the second clock distribution module on the magnetic levitation motor side through the clock signal line. Through the driving function of the clock driver, the anti-interference ability of the clock signal transmitted in the clock signal line can be improved, and the digital signal distortion and attenuation caused by the clock signal as a digital signal during the transmission process can be solved. In another embodiment, the clock driver can be a differential clock driver, and the clock signal is driven by the differential clock driver and transmitted to the second clock distribution module through the clock signal line. By differentially driving the clock signal, common mode interference can be suppressed, and when the drive line and the clock signal line are set on the same cable, the interference problem of the drive line on the clock signal line can be solved.

[0075] See also Figure 1 and Figure 2The power amplifier module is configured to generate a PWM signal based on the power amplifier signal and the power amplifier clock, and to excite the electromagnetic coil in the magnetic levitation motor based on the PWM signal. The power amplifier module, as the execution part of the magnetic levitation controller, is used to output current to excite the electromagnetic coil of the stator part of the magnetic levitation motor to achieve the suspension and / or rotation control of the rotor. The electromagnetic coil can be a winding coil for rotation control of a bearingless motor, or a winding coil for suspension control, or a winding coil with two functions. It can also be a motor coil for motor rotation of a magnetic bearing motor, or an electromagnet coil for magnetic bearings. The power amplifier module is also called a power amplifier or a power amplifier circuit, which can be an output stage or an output stage circuit including a PWM generator or a PWM circuit, or it can be only an output stage or an output stage circuit, and can also include an isolation drive circuit, etc. The present invention collectively refers to various power amplifiers including an output stage or an output stage circuit as a power amplifier module. The power amplifier module usually includes a PWM generator and an output stage. The principle of the PWM generator is that the power amplifier clock is used as a reference clock frequency to determine the period of the PWM waveform, that is, the count of the counter is controlled by the power amplifier clock. The counter increases the count value in response to the reference clock frequency, that is, the count range of the counter determines the period of the PWM signal, and the count range of the counter can be achieved by setting the count value of the counter. The comparator circuit generates a PWM signal according to the count value provided by the counter, that is, the comparison value of the comparator determines the duty cycle of the PWM signal, and the comparison value of the comparator can be achieved by setting the reference voltage of the comparator. Fig. 9 The waveform of a PWM signal is shown in FIG. Fig. 9 As an example embodiment, a PWM signal is a signal whose duty cycle varies but whose voltage remains unchanged.

[0076] The power amplifier module is usually arranged on the controller side. The power amplifier module excites the electromagnetic coil in the magnetic levitation motor and needs to transmit the current to the electromagnetic coil of the magnetic levitation motor through the cable. Figure 1 and Figure 2 The power amplifier module is electrically connected to the electromagnetic coil of the magnetic suspension stator through a driving line 33.

[0077] See also Figure 1 and Figure 2The analog-to-digital conversion module is configured to convert the conditioned sensor signal output by the signal conditioning module into a sampling signal based on a sampling clock. The analog-to-digital conversion module is also called an ADC or an analog-to-digital converter, which is used to sample the rotor displacement signal, rotor angle signal and current signal of the electromagnetic coil detected by the sensor module, and perform analog-to-digital conversion on the rotor displacement signal, rotor angle signal and current signal to generate a rotor displacement digital signal, a rotor angle digital signal and a current digital signal. The output end of the analog-to-digital conversion module is connected to the input end of the processor (including the control algorithm) of the control unit. At the sampling time of the analog-to-digital conversion module, if the switching element of the power amplifier module is switched, the sampling signal of the analog-to-digital conversion module will be interfered by the spike-shaped noise caused by the switching of the switching element, resulting in errors in the sampling of the analog-to-digital conversion module, and even causing the digital control system to crash. When the analog-to-digital conversion module is sampling, if there is an error in the phase lock between the PWM signal of the power amplifier module and the sampling signal of the analog-to-digital conversion module, it will affect the accuracy of sensor detection. To this end, the present invention uses the sampling clock from a global single clock source as a control signal to control the sampling time of the analog-to-digital conversion module. Since the sampling clock of the analog-to-digital conversion module, the power amplifier clock of the power amplifier module and the clock signal of the sensor module on the magnetic levitation motor side are of the same source, there is a definite phase difference relationship between them. In this way, on the one hand, the phase locking error between the PWM signal of the power amplifier module and the sampling signal of the analog-to-digital conversion module can be eliminated, ensuring that the positional relationship between the effective edge (clock edge) of the sampling signal of the analog-to-digital conversion module and the effective edge of the PWM signal of the power amplifier module is determined, thereby improving the accuracy of sensor detection; on the other hand, the sampling time of the analog-to-digital conversion module can avoid the switching of the switching elements of the power amplifier module, avoid the spike noise interference caused by the switching elements in the power amplifier, and improve the signal-to-noise ratio and anti-interference ability of the system.

[0078] Typically, signal data is transmitted between the signal conditioning module on the magnetic levitation motor side and the ADC on the controller side through a sensor signal line. In one embodiment, at least one group of sensor signal lines 32 are connected between the analog-to-digital conversion module and the signal conditioning module, wherein the signal transmitted by at least one sensor signal line includes a rotor displacement signal and / or a rotor angle signal and / or a current signal, etc., but is not limited thereto. For example, in other embodiments, a temperature signal, etc. may also be included. Fig.10 The waveform of a sensor signal is shown in Figure 1. Since the sensor signal reflects the state information of the rotor change, Fig.11 As an example embodiment, the sensor signal is an irregular analog signal.

[0079] See also Figure 1 and Figure 2The controller side also includes a global single clock source for generating a reference clock. As a preferred embodiment, the global single clock source can be a quartz crystal oscillator (crystal oscillator).

[0080] See also Figure 1 and Figure 2 The controller side also includes a processor, which is the core of the controller and the key to realizing the rotation and suspension operation of the motor. The displacement, angle, current and other motor conditions reflected by the sensor module are used as feedback quantities. The processor generates a control signal of the power amplifier as the execution part according to the control strategy. In the present invention, the first clock distribution module, the global single clock source, the processor and the clock driver are collectively referred to as a control unit.

[0081] In each of the above embodiments, at least one group of clock signal lines is configured as a group of clock signal lines, and the clock signal lines are connected to the second clock distribution module, and the second clock distribution module is configured to generate an excitation signal for exciting the sensor component and a demodulation signal for detecting the signal conditioning module based on the clock signal transmitted by the clock signal line. However, it is not limited to this. In another embodiment, see Figure 8 At least one group of clock signal lines can also be configured as two groups of clock signal lines, the clock signal transmitted by one group of clock signal lines is used as an excitation signal for exciting the sensor component, and the clock signal transmitted by the other group of clock signal lines is used as a demodulation signal for detection by the signal conditioning module. Figure 8As shown, the clock signals of the two groups of clock signal lines are generated by the first clock distribution module. Preferably, the first clock distribution module includes a frequency division module and a phase shift module, the frequency division module includes a plurality of frequency dividers, and the plurality of frequency dividers respectively divide the reference clock from the global single clock source to generate a plurality of divided frequency clocks. The phase shift module includes a plurality of phase shifters, and the plurality of phase shifters correspond one-to-one to the plurality of frequency dividers. The phase shifters adjust the phase of the divided frequency clocks from the corresponding frequency dividers, and the clock signal, the sampling clock, the power amplifier clock, etc. are all configured as divided frequency clocks after phase shift adjustment. Due to the errors in the mechanical assembly of the motor (such as the assembly of the winding and the core and the assembly of the sensor, etc.) and the errors in the electronic components themselves, the existing mass production consistency of the magnetic levitation motor is poor. By setting a plurality of phase shifters corresponding one-to-one to the plurality of frequency dividers, the phase adjustment of each clock can be realized. On the one hand, the clock edges of the clocks of each specific frequency can be accurately aligned through the phase adjustment. On the other hand, the phase adjustment can also reduce the influence of the mechanical assembly error of the motor or / and the error of the electronic components themselves on the sensor detection, thereby improving the accuracy of the system detection and the consistency of mass production. A crystal oscillator has only one inherent frequency, and many frequencies can be expanded through frequency division, so there is no need to equip each frequency with a crystal oscillator. For example, the original signal of the crystal oscillator is divided by N, and the frequency becomes 1 / N of the original. Multiple frequency dividers are used to generate multiple frequency-divided clocks with specific required frequencies, including the above-mentioned clock signal, sampling clock, and power amplifier clock, etc., to realize the function of the first clock distribution module.

[0082] In one embodiment, one of the multiple frequency dividers and a corresponding phase shifter are configured to generate a set of clock signals, and another of the multiple frequency dividers and a corresponding phase shifter are configured to generate a set of clock signals. However, it is not limited to this. In other embodiments, one of the multiple frequency dividers and a corresponding phase shifter are configured to generate an intermediate clock, and the phase shift module also includes a secondary phase shifter, which performs phase shifting processing on the intermediate clock and generates two sets of clock signals. The two sets of clock signals are used to constitute the input signal and reference signal of the signal conditioning, and have the same frequency. The phase shifting processing of the secondary phase shifter can generate the input signal and reference signal with the same frequency and orthogonal phase difference.

[0083] In some of the above embodiments, the clock signal is used as a reference signal for the excitation signal of the sensor component and the demodulation signal for the signal conditioning module detection. The clock signal can be a square wave or a sine wave with a fixed frequency, and can also be a differential square wave or a differential sine wave with a fixed frequency. When the clock signal is a square wave, the duty cycle of the square wave is fixed, and generally, the duty cycle is 50%. Fig.11 The following diagram shows several commonly used waveforms of clock signals. Since the clock signal is used for the excitation and demodulation of the sensor module, Fig.11As an illustration of an embodiment, the clock signal is a signal with a fixed frequency and a fixed duty cycle.

[0084] Based on different functional applications, the magnetic suspension device of the present invention can be configured as a magnetic suspension pump, a magnetic suspension mixer, or a magnetic suspension turntable, etc. The following will describe in detail the products of the present invention configured for different purposes in conjunction with the accompanying drawings.

[0085] In one application embodiment, the magnetic levitation device is configured as a magnetic levitation pump, see Fig.12 , Fig.13 and Fig.14 The magnetic levitation pump includes the controller 1 and the magnetic levitation motor 2 of the above-mentioned embodiments. For example, the magnetic levitation motor 2 includes a magnetic levitation rotor 21, a magnetic levitation stator 22 and a sensor module. The magnetic levitation stator 22 is configured to drive the magnetic levitation rotor to rotate and suspend. The sensor module is configured to detect the state data of the magnetic levitation motor 2 and convert it into a sensor signal to feed back to the controller 1. At least one cable 3 is connected between the magnetic levitation motor 2 and the controller 1. The cable includes at least one group of clock signal lines 31. The at least one group of clock signal lines 31 is configured to transmit the clock signal of the controller 1 to the magnetic levitation motor 2. The magnetic levitation pump also includes a pump head 4. The pump head 4 includes a pump housing 41 and a rotor impeller 42 arranged in the pump housing. The magnetic levitation rotor 21 is both a rotor of the magnetic levitation motor and a part of the rotor impeller of the pump. It can be, for example, a permanent magnet rotor or a short-circuit cage rotor or a reluctance rotor. The magnetic levitation stator 22 is configured to drive the rotor impeller to rotate and suspend. Among them, the functions and principles of the magnetic levitation motor 2 and the controller 1 are the same or similar to those of the above-mentioned embodiments. In particular, Fig.12 , Fig.13 and Fig.14 Embodiments of controllers and magnetic levitation motors with different appearance characteristics are illustrated.

[0086] In one embodiment, the magnetic levitation pump is a centrifugal pump. The magnetic levitation centrifugal pump has no bearings and no mechanical parts friction. The rotor impeller has no friction during the rotation process. It has a series of advantages such as high speed, no friction, no pollution, and easy maintenance. It can be widely used in medicine (artificial heart), semiconductors (pumping of ultrapure water), biotechnology (leakage-free, seamless design), electroplating (sealing design) and other fields.

[0087] In another application embodiment, see Fig.15 and Fig.16The magnetic levitation device can also be configured as a magnetic levitation mixer. In the application of the magnetic levitation mixer, the magnetic levitation mixer also includes a controller 1' and a magnetic levitation motor 2'. At least one cable 3' is connected between the magnetic levitation motor 2' and the controller 1'. The cable includes at least one group of clock signal lines. The at least one group of clock signal lines is configured to transmit the clock signal of the controller 1' to the magnetic levitation motor 2'. The magnetic levitation mixer also includes a stirring device 4'. The stirring device 4' includes a stirring container 41' and a rotor stirring head 42' arranged in the stirring container. The magnetic levitation rotor is both a rotor of the magnetic levitation motor and a part of the rotor stirring head 42' of the stirring device. The magnetic levitation stator is configured to drive the rotor stirring head 42' to rotate and suspend. Among them, the functions and principles of the magnetic levitation motor 2' and the controller 1' are the same or similar to those of the above-mentioned embodiments. In particular, Fig.15 and Fig.16 Embodiments of controllers and magnetic levitation motors with different appearance characteristics are illustrated.

[0088] In yet another application embodiment, see Fig.17 The magnetic levitation device can also be configured as a magnetic levitation turntable. Similarly, the magnetic levitation turntable includes a controller 1" and a magnetic levitation motor 2". At least one cable 3" is connected between the magnetic levitation motor 2" and the controller 1". The cable includes at least one group of clock signal lines, and the at least one group of clock signal lines is configured to transmit the clock signal of the controller 1" to the magnetic levitation motor 2". The magnetic levitation turntable also includes a rotor support platform 4". The rotor support platform 4" includes a table 41" and a magnetic levitation rotor 42". The table 41" and the magnetic levitation rotor 42" constitute an integral rotor, and the magnetic levitation stator is configured to drive the rotor support platform to rotate and suspend. Among them, the functions and principles of the magnetic levitation motor 2' and the controller 1' are the same or similar to those of the above-mentioned embodiments. In particular, Fig.17 Embodiments of controllers and magnetic levitation motors with different appearance characteristics are illustrated.

[0089] The magnetic levitation device of the present invention can also be assembled with assemblies of different functions according to other functional applications, thereby becoming a magnetic levitation device with different application requirements.

[0090] Obviously, the above embodiments are merely examples for clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the protection scope of the invention.

Claims

1. A magnetic levitation device, comprising a controller (1) and a magnetic levitation motor (2), wherein the magnetic levitation motor comprises a magnetic levitation rotor (21), a magnetic levitation stator (22) and a sensor module, wherein the magnetic levitation stator is configured to drive the magnetic levitation rotor to rotate and suspend, and the sensor module is configured to detect state data of the magnetic levitation motor and convert it into a sensor signal to feed back to the controller; characterized in that: At least one cable (3) is connected between the magnetic levitation motor and the controller, the cable comprising at least one group of clock signal lines (31), and the at least one group of clock signal lines is configured to transmit a clock signal of the controller to the magnetic levitation motor.

2. The magnetic levitation device according to claim 1, characterized in that: The at least one cable is configured as two cables (3), one cable includes at least one group of sensing signal lines (32) and the at least one group of clock signal lines (31), and the other cable includes at least one group of driving lines (33), the sensing signal lines are configured to transmit the sensor signals, and the driving lines are configured to transmit electrical signals that drive the magnetically suspended rotor to rotate and suspend.

3. The magnetic levitation device according to claim 1, characterized in that: The at least one cable is configured as a cable (3), the cable comprising at least one group of sensing signal lines (32), at least one group of driving lines (33) and at least one group of clock signal lines (31), the sensing signal lines being configured to transmit the sensor signals, and the driving lines being configured to transmit electrical signals for driving the magnetically suspended rotor to rotate and suspend.

4. The magnetic levitation device according to claim 1, characterized in that: The clock signal is a square wave or a sine wave with a fixed frequency, or the clock signal is a differential square wave or a differential sine wave with a fixed frequency.

5. The magnetic levitation device according to claim 4, characterized in that: When the clock signal is a square wave, the duty cycle of the square wave is fixed.

6. The magnetic levitation device according to claim 1, characterized in that: The sensor module comprises a sensor component (23) and a signal conditioning module, wherein the sensor component is configured to detect the state data of the magnetic levitation motor and generate a sensor signal containing the state data, and the signal conditioning module is configured to regulate and process the sensor signal containing the state data and generate a conditioned sensor signal.

7. The magnetic levitation device according to claim 6, characterized in that: The at least one group of clock signal lines is configured as a group of clock signal lines, and the magnetic levitation motor also includes a second clock distribution module, the clock signal line is connected to the second clock distribution module, and the second clock distribution module is configured to generate an excitation signal for exciting the sensor component and a demodulation signal for detection by the signal conditioning module based on the clock signal transmitted by the clock signal line.

8. The magnetic levitation device according to claim 7, characterized in that: The magnetic levitation motor further comprises a motor housing (24), the motor housing comprising a main chamber (241) and a secondary chamber (242) connected to one side of the main chamber, the magnetic levitation stator being arranged in the main chamber, a PCB board (25) being arranged in the secondary chamber, and the second clock distribution module and the signal conditioning module being integrated on the PCB board.

9. The magnetic levitation device according to claim 7, characterized in that: The sensor assembly comprises at least one displacement sensor (231) for detecting radial or axial displacement of the magnetic suspension rotor and a sensor circuit board (232), wherein the sensor circuit board is integrated with electronic components that form a sensor circuit with the at least one displacement sensor.

10. The magnetic levitation device according to claim 7, characterized in that: The second clock distribution module is configured as a phase shift module, and the clock signal is phase-shifted by the phase shift module to generate the excitation signal and the demodulation signal.

11. The magnetic levitation device according to claim 7, characterized in that: The second clock distribution module is configured as a frequency division and phase shifting module. The clock signal is divided by the frequency division and phase shifting module to generate multiple groups of degree-of-freedom signals. Each group of degree-of-freedom signals is phase shifted by the frequency division and phase shifting module to generate an excitation signal for the sensor in the direction of the degree of freedom and a demodulation signal for the signal conditioning module in the direction of the degree of freedom.

12. The magnetic levitation device according to claim 1, characterized in that: The controller includes a power amplification module, an analog-to-digital conversion module and a first clock distribution module. The first clock distribution module generates the clock signal based on a reference clock of a global single clock source. The first clock distribution module also generates a sampling clock for sampling the analog-to-digital conversion module and a power amplifier clock for driving the power amplification module based on the reference clock.

13. The magnetic levitation device according to claim 12, characterized in that: The controller further includes a clock driver, and the clock signal is driven by the clock driver and then transmitted to the second clock distribution module via the clock signal line.

14. The magnetic levitation device according to claim 13, characterized in that: The clock driver is a differential clock driver, and the clock signal is a differential signal. The differential signal is driven by the differential clock driver and then transmitted to the second clock distribution module via the clock signal line.

15. The magnetic levitation device according to claim 6, characterized in that: The at least one group of clock signal lines is configured as two groups of clock signal lines, the clock signal transmitted by one group of clock signal lines is used as an excitation signal for exciting the sensor component, and the clock signal transmitted by the other group of clock signal lines is used as a demodulation signal for detection by the signal conditioning module.

16. The magnetic levitation device according to claim 1, characterized in that: The magnetic suspension motor is a magnetic bearing motor or a bearingless motor or a bearingless sheet motor.

17. The magnetic levitation device according to any one of claims 1 to 16, characterized in that: The magnetic levitation equipment is configured as a magnetic levitation pump or a magnetic levitation mixer or a magnetic levitation turntable.

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