Axial magnetic suspension bearing and magnetic suspension rotating machine
By integrating a self-sensing displacement sensing component into the axial magnetic levitation bearing, the problems of increased shaft length and installation complexity caused by the independent setting of sensors in traditional magnetic levitation bearings are solved. This enables the miniaturization and compact design of the equipment and reduces costs, thereby improving the rotational speed and dynamic stability of rotating machinery.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-01-26
- Publication Date
- 2026-03-27
AI Technical Summary
Traditional displacement measurement methods use separate axial and radial displacement sensors in magnetic levitation bearings, which increases the axial length of the shaft, limits the miniaturization and compact design of the equipment, and is also complex and costly to install.
A self-inductive displacement sensing component is integrated between the first and second bearing stators of the axial magnetic levitation bearing to form an axial displacement adjustment gap. The sensor stator component is integrated on the outer circumferential wall of the thrust disk, and the self-inductive displacement sensing component is used to detect axial and radial displacement.
It reduces the axial space occupied by the shaft, lowers installation costs, simplifies assembly processes, improves manufacturing efficiency, and enhances the dynamic stability and maximum allowable speed of the magnetic levitation system.
Smart Images
Figure CN121739014A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of magnetic levitation bearing design technology, specifically relating to an axial magnetic levitation bearing and magnetic levitation rotating machinery. Background Technology
[0002] Sensors are tools for information acquisition, the "five senses" of machines, and one of the three pillars of information technology. Sensor technology is the source technology of the information "acquisition-processing-transmission" chain, and a fundamental technology for the automation and intelligence of modern industrial production. Its development level represents a country's level of industrialization. Any operating machine, as long as there is motion or mechanical deformation, needs displacement sensors for measurement and control.
[0003] During the operation of magnetic levitation bearings, shaft displacement monitoring plays a crucial role in the stable and efficient operation of the system. Traditional displacement measurement schemes employ separate axial displacement sensors and radial displacement sensors (such as...). Figure 1 As shown), this brings about a series of problems:
[0004] First, in rotating machinery such as compressors, independent sensors are usually installed outside the bearings, occupying additional axial space and significantly increasing the axial length of the shaft. Especially in applications with limited axial space (such as air compressors), this arrangement restricts the miniaturization and compact design of the equipment, limits the potential for increasing the shaft speed, and cannot meet the requirements of high-speed operating equipment for a compact structure.
[0005] Secondly, the layout of multiple sensors complicates the installation process, requiring precise calibration of the positional relationships of multiple components. This not only increases installation costs but also makes measurements inaccurate due to installation errors. Summary of the Invention
[0006] Therefore, the present invention provides an axial magnetic levitation bearing and a magnetic levitation rotating machine, which can overcome the shortcomings of the related technology where the self-inductive displacement sensor and the axial magnetic levitation bearing are set up separately. When applied to the corresponding rotating machine, they occupy the axial space of the rotating machine shaft, increase the axial length of the shaft, which is not conducive to the miniaturization and compact design of the equipment, and require separate calibration of the position, which increases the installation cost.
[0007] To address the aforementioned problems, this invention provides an axial magnetic levitation bearing, comprising a bearing assembly including a first bearing stator, a second bearing stator, and a bearing rotor. The first bearing stator has a first axial winding, and the second bearing stator is arranged parallel to and spaced apart from the first bearing stator. The second bearing stator has a second axial winding, and an axial displacement adjustment gap is formed between the second axial winding and the first axial winding. The thrust disk of the bearing rotor is located within the axial displacement adjustment gap. The invention also includes a self-sensing displacement sensing component, comprising a sensor stator assembly and a sensor detection ring. The sensor detection ring is fitted onto the outer circumferential wall of the thrust disk. The sensor stator assembly is clamped between the first and second bearing stators and is located radially outside the first and second axial windings. The sensor stator assembly is fitted radially outside the sensor detection ring.
[0008] In some embodiments, the sensor stator assembly includes a stator core and an induction winding. The stator core has a core yoke, and spacer rings are respectively provided at both axial ends of the core yoke. Each spacer ring is clamped between the first bearing stator and the core yoke or between the second bearing stator and the core yoke to prevent the induction winding from contacting the first bearing stator or the second bearing stator.
[0009] In some embodiments, an assembly ring groove is formed on the end face of the spacer ring away from the stator core, and the radial outer edges of the first bearing stator and the second bearing stator are respectively assembled in the assembly ring groove.
[0010] In some embodiments, the first bearing stator and the second bearing stator have inner annular pole posts and outer annular pole posts spaced apart from the inside to the outside along the radial direction of the bearing rotor on the side end face facing the thrust disk. A winding receiving annular groove is formed between the inner annular pole posts and the outer annular pole posts. The first axial winding is received and wound in the winding receiving annular groove, and the outer diameter of the outer annular pole post is not greater than the outer diameter of the thrust disk.
[0011] In some embodiments, the self-sensing displacement sensing component is a composite radial and axial displacement sensing component.
[0012] In some embodiments, the stator core includes a radial core, a first axial core, and a second axial core. The first axial core and the second axial core are respectively located on the axial end faces of the radial core. The first axial core and / or the second axial core are formed by stacking first silicon steel laminations. The first silicon steel lamination includes a first ring body and a plurality of first probe pairs evenly spaced along the circumferential direction of the bearing rotor. Each first probe pair has two first probes. The two first probes in each first probe pair are respectively wound with first coils in a self-inductive manner, and the magnetic poles generated by the two first coils are opposite in polarity. The first coils in each first probe pair of the first axial core are connected in series to form a first axial detection inductance circuit. The first coils in each first probe pair of the second axial core are connected in series to form a second axial detection inductance circuit. The first axial detection inductance circuit and the second axial detection inductance circuit are differentially connected to form an axial displacement differential detection circuit.
[0013] In some embodiments, the radial core is formed by stacking second silicon steel laminations, the second silicon steel laminations including a second ring body and a plurality of second probe pairs evenly spaced along the circumferential direction of the bearing rotor, each second probe pair having two second probes, the circumferential width of the first probe being b2, the circumferential width of the second probe being b1, and b2 > b1.
[0014] In some embodiments, the second probe pair has an even number of probes, and each of the two second probes in each second probe pair has a second coil wound in a self-inductive manner, with the magnetic poles generated by the two second coils having opposite polarities. The two second coils are connected in series to form a radial detection inductance circuit. The radial detection inductance circuit of one of the two pairs of second probe pairs symmetrical about the rotation axis of the bearing rotor is differentially connected to the radial detection inductance circuit of the other probe pair to form a radial displacement differential detection circuit.
[0015] In some embodiments, on the projection obtained by projecting onto any radial plane of the bearing rotor, the first axial core and the second axial core coincide, and the projections of each first probe pair of the first axial core and each second probe pair of the radial core have no overlap.
[0016] In some embodiments, the number of turns of each first coil wound on each first probe and the number of turns of each second coil wound on each second probe are equal; and / or, on the projection obtained by projecting onto any radial plane of the bearing rotor, each pair of first probes on the first axial core and each pair of second probes on the radial core are uniformly spaced and alternately arranged in the circumferential direction of the bearing rotor.
[0017] In some embodiments, when the self-inductive displacement sensing assembly is in its initial position, the axial thickness center plane of each first probe of the first axial core coincides with the first end face of the sensor detection ring of the bearing rotor, and the axial thickness center plane of each first probe of the second axial core coincides with the second end face of the sensor detection ring.
[0018] The present invention also provides a magnetically levitated rotating machine, including the above-mentioned axial magnetic levitation bearing.
[0019] The axial magnetic levitation bearing and magnetic levitation rotating machinery provided by this invention have the following beneficial effects:
[0020] Integrating the self-inductive displacement sensing component between the first and second bearing stators of a traditional axial magnetic levitation bearing, and placing it outside the operating area of the axial magnetic levitation bearing, achieves component integration, reduces axial space occupation of the shaft, reduces shaft length, reduces assembly component calibration positions, and thus lowers installation costs. This does not negatively impact the working performance of the axial magnetic levitation bearing, ensuring reliable and stable axial displacement adjustment. The simple structure facilitates miniaturization and compact design of the equipment. The reduced shaft length allows for increased maximum allowable speed of the corresponding rotating machinery, improved space utilization, and enhanced dynamic stability of the magnetic levitation system. Furthermore, the integrated design significantly simplifies assembly processes, effectively reduces manufacturing complexity and production costs, and improves manufacturing efficiency. Attached Figure Description
[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or related technologies, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. The drawings described below are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.
[0022] Figure 1 This is a schematic diagram of the internal cross-section of a magnetically levitated rotating machine (such as a magnetically levitated motor) in the prior art. The diagram shows the state of the separately assembled radial displacement sensor and axial displacement sensor.
[0023] Figure 2 This is a schematic diagram of the internal cross-section (radial cross-section) of the circumferential magnetic levitation bearing in an embodiment of the present invention.
[0024] Figure 3 yes Figure 2 A three-dimensional structural diagram (expanded structural diagram) of the axial magnetic levitation bearing in the diagram.
[0025] Figure 4 yes Figure 2A three-dimensional structural diagram of the self-inductive displacement sensing component is shown in the figure, which illustrates part of the rotating shaft structure.
[0026] Figure 5 yes Figure 4 A schematic diagram of the three-dimensional structure after omitting the coils;
[0027] Figure 6 yes Figure 4 A schematic diagram of the axial projection of the first silicon steel sheet in the process;
[0028] Figure 7 yes Figure 4 A schematic diagram of the axial projection of the second silicon steel sheet in the process;
[0029] Figure 8 This is a schematic diagram of the self-inductive displacement sensing component of this invention installed in the initial position of the radial outer side of the rotating shaft (the rotating shaft is simply shown in the figure).
[0030] Figure 9 This is a schematic diagram showing the relative positional relationship between the first axial core and the second axial core of the self-inductive displacement sensing component in the embodiment of the present invention and the sensor detection ring on the thrust plate at the initial position.
[0031] Figure 10 This is a schematic diagram of the coil winding on a pair of second probes symmetrical about the axis of rotation of the radial iron core of the self-inductive displacement sensing component according to an embodiment of the present invention.
[0032] Figure 11 This is a schematic diagram of the polar coordinate detection of the self-inductive displacement sensing component when the shaft deflects.
[0033] Figure 12 This is a schematic diagram of the coil winding connection principle of the axial displacement differential detection circuit in this embodiment of the invention;
[0034] Figure 13 This is a schematic diagram of the coil winding connection principle of the radial displacement differential detection circuit in this embodiment of the invention;
[0035] Figure 14 This is a schematic diagram of the internal structure of the magnetically levitated rotating machinery in an embodiment of the present invention.
[0036] The attached figures are labeled as follows:
[0037] 10. Bearing assembly; 101. First bearing stator; 1011. First axial winding; 102. Second bearing stator; 1021. Second axial winding; 1031. Inner annular pole; 1032. Outer annular pole; 201. Thrust plate; 30. Self-inductive displacement sensing assembly; 301. Sensor detection ring; 302. Spacer pressure ring; 3021. Assembly ring groove; 303. Sensor stator assembly; 1. Radial core; 2. First axial core; 3. Second axial core; 4. First silicon steel lamination; 41. First ring body; 42. 421. First probe pair; 51. First coil; 52. Second coil; 6. Second silicon steel lamination; 61. Second ring; 62. Second probe pair; 621. Second probe; 700. Rotating shaft; 701. Motor rotor; 702. Motor stator; 7031. Front radial magnetic levitation bearing; 7032. Rear radial magnetic levitation bearing; 7041. Self-inductive radial displacement sensor; 7042. Self-inductive axial displacement sensor; 7051. Front bearing housing; 7052. Rear bearing housing; 706. Axial magnetic levitation bearing. Detailed Implementation
[0038] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0039] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.
[0040] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90° or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.
[0041] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.
[0042] See also Figures 2 to 14As shown in the figure, according to an embodiment of the present invention, an axial magnetic levitation bearing is provided, including a bearing assembly 10. The bearing assembly 10 includes a first bearing stator 101, a second bearing stator 102, and a bearing rotor (not indicated in the figure). The first bearing stator 101 is provided with a first axial winding 1011. The second bearing stator 102 is arranged parallel to and spaced apart from the first bearing stator 101. The second bearing stator 102 is provided with a second axial winding 1021. An axial displacement adjustment gap is formed between the second axial winding 1021 and the first axial winding 1011. The thrust disk 201 of the bearing rotor is located within the axial displacement adjustment gap. It can be understood that by adjusting and changing the direction and magnitude of the current in the first axial winding 1011 and the second axial winding 1021, the magnitude of the force applied to both sides of the aforementioned thrust disk 201 can be adjusted, thereby adjusting the axial position of the shaft of the corresponding device. The aforementioned shaft rotor is fixedly connected to the shaft of the corresponding device during specific use. The axial magnetic levitation bearing also includes a self-inducting type... The displacement sensing component 30, a self-sensing displacement sensing component 30, includes a sensor stator assembly 303 and a sensor detection ring 301. The sensor detection ring 301 is fitted onto the outer circumferential wall of the thrust disk 201. The sensor stator assembly 303 is clamped between the first bearing stator 101 and the second bearing stator 102 and is located radially outside the first axial winding 1011 and the second axial winding 1021. The sensor stator assembly 303 is fitted radially outside the sensor detection ring 301, that is, a radial annular gap is formed between the sensor stator assembly 303 and the sensor detection ring 301 to ensure that the two do not contact each other. Specifically, the sensor detection ring 301 can be formed by stacking silicon steel sheets. In a specific embodiment, the sensor detection ring 301 is interference-fitted onto the radially outer surface of the thrust disk 201 and integrated with the thrust disk 201 by precision machining to ensure its coaxiality with the bearing rotor and the rotating shaft 700 of the equipment, thereby ensuring the detection accuracy of the sensing component.
[0043] In this technical solution, the self-inductive displacement sensing component 30 is integrated between the first bearing stator 101 and the second bearing stator 102 of the traditional axial magnetic levitation bearing, and is located outside the working area of the axial magnetic levitation bearing. This integration reduces the axial space occupied by the rotating shaft 700, reduces the shaft length, reduces the number of assembly component calibration positions, and thus reduces installation costs, while not adversely affecting the working performance of the axial magnetic levitation bearing. It ensures the reliable stability of the axial displacement adjustment of the rotating shaft. The structure is simple and conducive to the miniaturization and compact design of the equipment. The reduction in the shaft length can help increase the maximum allowable speed of the corresponding rotating machinery, improve space utilization, and enhance the dynamic stability of the magnetic levitation system. In addition, the integrated design of the components can significantly simplify the assembly process, effectively reduce manufacturing complexity and production costs, and improve manufacturing efficiency.
[0044] It should be noted that, compared to the improved solution of integrating the self-inductive displacement sensing component 30 into the radial magnetic levitation bearing, the present invention integrates it into the axial magnetic levitation bearing, which can make the non-working gap between the two bearing stators of the axial magnetic levitation bearing usable, ensuring structural compactness while also reducing the adverse effects on the axial control magnetic field.
[0045] In some embodiments, the sensor stator assembly 303 includes a stator core (not labeled in the figure) and an induction winding (not labeled in the figure). The stator core has a core yoke (not labeled in the figure, but in one specific embodiment, it is a ring body). The axial ends of the core yoke are respectively provided with spacer rings 302. Each spacer ring 302 is clamped between the first bearing stator 101 and the core yoke or between the second bearing stator 102 and the core yoke to prevent the induction winding from contacting the first bearing stator 101 or the second bearing stator 102.
[0046] In this technical solution, by setting spacer rings 302 at both ends of the axial direction of the sensor stator assembly 303, the two bearing stators and stator cores can be assembled and connected into a reliable whole. This improves the assembly efficiency of the sensor stator assembly 303 within the axial magnetic levitation bearing. Simultaneously, the spacer rings 302 also act as spacers between the stator core and the bearing stator, preventing contact between the induction winding and the bearing stator. This minimizes magnetic circuit interference between the self-inductive displacement sensing component 30 and the bearing assembly 10, ensuring the accuracy of displacement detection. The aforementioned spacer rings 302 are specifically made of non-magnetic materials, such as aluminum or copper.
[0047] In some embodiments, an assembly ring groove 3021 is formed on the end face of the spacer ring 302 away from the stator core. The radial outer edges of the first bearing stator 101 and the second bearing stator 102 are respectively assembled in the assembly ring groove 3021. In a specific embodiment, the first bearing stator 101 and the second bearing stator 102 can be fixedly connected in the assembly ring groove 3021 by adhesive bonding. Of course, bolt connection can also be used. The aforementioned first bearing stator 101 and second bearing stator 102 can be formed by stacking silicon steel sheets.
[0048] In this technical solution, a corresponding assembly ring groove 3021 is provided on the outer end face of the spacer ring 302, and the radial outer edges of the first bearing stator 101 and the second bearing stator 102 are assembled in the assembly ring groove 3021. This can further reduce the axial thickness of the axial magnetic levitation bearing and further reduce the axial space occupied by the rotating shaft 700.
[0049] The inner end face of the aforementioned spacer ring 302 and the aforementioned self-sensing displacement sensing component 30 can be connected as one unit by bolts, or other connection methods such as adhesive can be used.
[0050] In some embodiments, the first bearing stator 101 and the second bearing stator 102 have an inner annular pole post 1031 and an outer annular pole post 1032 spaced apart from the inside to the outside along the radial direction of the bearing rotor on one end face facing the thrust disk 201. A winding receiving annular groove is formed between the inner annular pole post 1031 and the outer annular pole post 1032. The first axial winding 1011 is received and wound in the winding receiving annular groove, and the outer diameter of the outer annular pole post 1032 is not greater than the outer diameter of the thrust disk 201.
[0051] In this technical solution, the outer diameter of the outer annular pole post 1032 of the first bearing stator 101 and the second bearing stator 102 is not greater than the outer diameter of the thrust disk 201. This makes the axial control magnetic circuit formed by the first axial winding 1011 and the second axial winding 1021 confined to the axial annular area area opposite to the thrust disk 201. Meanwhile, the induction magnetic circuit formed by the induction coil and the sensor detection ring 301 is confined to the radial annular area outside the radial outer wall of the thrust disk 201. This effectively prevents the coupling of the induction magnetic field and the displacement control magnetic field within the thrust disk 201, ensuring the accuracy of displacement adjustment and displacement sensing.
[0052] In some embodiments, the self-sensing displacement sensing component 30 is a radial and axial displacement composite sensing component, that is, the self-sensing displacement sensing component 30 is configured to simultaneously sense and detect the axial and radial displacements of the rotating shaft 700, which can further improve the structural compactness of the axial magnetic levitation bearing.
[0053] In some embodiments, the stator core includes a radial core 1, a first axial core 2, and a second axial core 3. The first axial core 2 and the second axial core 3 are respectively located on the axial end faces of the radial core 1. The first axial core 2 and / or the second axial core 3 are formed by stacking first silicon steel laminations 4 (in one specific embodiment, both the first axial core 2 and the second axial core 3 are formed by stacking first silicon steel laminations 4). The first silicon steel lamination 4 includes a first ring body 41 (which is objectively part of the aforementioned yoke ring, and together with the subsequent second ring body 61, forms the aforementioned yoke ring after stacking) and a plurality of first probe pairs 42 evenly spaced along the circumferential direction of the bearing rotor. Each first probe pair 42... The first axial core 2 has two first probes 421. Each pair of first probes 421 has a first coil 51 wound around its two first probes 421 in a self-inductive manner, with the magnetic poles of the two first coils 51 having opposite polarities (i.e., the free end of one first probe 421 is positive, and the free end of the other first probe 421 is negative). The first coils 51 in each pair of first probes 42 of the first axial core 2 are connected in series to form a first axial detection inductor circuit. The first coils 51 in each pair of first probes 42 of the second axial core 3 are connected in series to form a second axial detection inductor circuit. The first axial detection inductor circuit and the second axial detection inductor circuit are differentially connected to form an axial displacement differential detection circuit. Figure 12 As shown. It can be understood that each of the aforementioned first probes 421 extends radially toward the side closer to the axis of rotation.
[0054] In this technical solution, on the one hand, a first axial core 2 and a second axial core 3 are set at both ends of the radial core 1. The detection area of the first probe 421 of the two axial cores is larger, which can significantly improve the detection accuracy of the axial displacement of the shaft and is beneficial for the accurate detection of the displacement of shafts with small shaft diameters. On the other hand, since the first axial core 2 and the second axial core 3 are respectively connected by a differential connection of the first axial detection inductance circuit and the second axial detection inductance circuit formed by the first coil 51 of each other, the coupling effect in the XY direction during the detection process can be reduced, and the sensitivity of the axial displacement detection of the shaft can be improved.
[0055] See details Figure 6 As shown, in a specific embodiment, both the first axial core 2 and the second axial core 3 have four pairs of first probes 42, that is, two pairs of first probes 42, that is, each axial core includes a total of eight first probes 421.
[0056] In some embodiments, the radial core 1 is formed by stacking second silicon steel laminations 6. The second silicon steel lamination 6 includes a second ring 61 and a plurality of second probe pairs 62 evenly spaced along the circumferential direction of the bearing rotor. Each second probe pair 62 has two second probes 621. The circumferential width of the first probe 421 is b2, and the circumferential width of the second probe 621 is b1, where b2 > b1.
[0057] In this technical solution, the circumferential width of the first probe 421 of the first axial core 2 and the second axial core 3 is greater than the circumferential width of the second probe 621 of the radial core 1. This can help to increase the inductance of the axial coil (i.e., the first coil 51), thereby increasing the axial sensitivity of the sensor and meeting the requirements of high-precision axial displacement measurement.
[0058] In some implementations, the second probe pair 62 has an even number; in one specific embodiment, such as... Figure 7 As shown, the aforementioned second probe pair 62 has two components. Each of the two second probes 621 within the second probe pair 62 has a second coil 52 wound on it in a self-inductive manner. The magnetic poles generated by the two second coils 52 are opposite in polarity, and the two second coils 52 are connected in series to form a radial detection inductance circuit. The radial detection inductance circuit of one of the two pairs of second probe pairs symmetrical about the rotation axis of the bearing rotor is differentially connected to the radial detection inductance circuit of the other probe pair to form a radial displacement differential detection circuit. See [link to relevant documentation]. Figure 13 As shown. See details. Figure 10 As shown, in this embodiment, the radial core 1 has two pairs of second probes 62. One pair of second probes 62 is used to detect the radial displacement of the bearing rotor in the X-axis direction, and the other pair of second probes 62 is used to detect the radial displacement of the bearing rotor in the Y-axis direction. Each pair of second probes 62 detects the radial displacement in the X-axis and Y-axis respectively via the aforementioned radial displacement differential detection circuit configured accordingly. The aforementioned first coil 51 and second coil 52 constitute the aforementioned induction coil.
[0059] In this technical solution, the radial detection inductance circuits of two second probes 62 that are symmetrical about the rotation axis of the bearing rotor are differentially connected to form a radial displacement differential detection circuit. This can eliminate the adverse effects of XY coupling and improve the detection accuracy of the radial displacement of the bearing rotor by the sensor.
[0060] In some embodiments, on the projection obtained by projecting onto any radial plane of the bearing rotor, the first axial core 2 and the second axial core 3 completely coincide, and the projections of each first probe pair 42 of the first axial core 2 and each second probe pair 62 of the radial core 1 have no overlapping portion.
[0061] That is, the second probe pairs 62 of the radial iron core 1 are offset from the first probe pairs 42 of the first axial iron core 2 and the second axial iron core 3 in the circumferential direction of the bearing rotor. This can effectively prevent the axial dimension of the sensor from increasing due to the overlap between the two, that is, it can further reduce the axial dimension of the self-sensing displacement sensing component 30, thereby further reducing the occupation of the self-sensing displacement sensing component 30 in the axial space of the bearing rotor and shortening the shaft length of the bearing rotor.
[0062] In some embodiments, on the projection obtained by projecting onto any radial plane of the bearing rotor, each first probe pair 42 on the first axial iron core 2 and each second probe pair 62 on the radial iron core 1 are uniformly spaced and alternately arranged in the circumferential direction of the bearing rotor (that is, the angle between the radial center lines of two adjacent first probe pairs 42 and second probe pairs 62 is 45°). This ensures that the number of turns of the coil wound on each probe is at a reasonable level, which is beneficial to further reduce the size of the sensor and avoid magnetic circuit interference. It should be noted that, since the first probe pair 42 and the second probe pair 62 are uniformly spaced in the circumferential direction of the bearing rotor, the smaller the circumferential width of the second probe 621 in the second probe pair 62, the larger the circumferential width of the first probe 421 in the first probe pair 42 can be designed. This is beneficial to further improve the sensor's detection sensitivity for the axial displacement of the bearing rotor.
[0063] In some embodiments, the number of turns of each first coil 51 wound on each first probe 421 and the number of turns of each second coil 52 wound on each second probe 621 are equal.
[0064] In this technical solution, the number of turns of each first coil 51 and second coil 52 is designed to be equal. The same number of turns ensures that the self-inductance value (L) of all probes is completely consistent, thereby achieving strict symmetry of the displacement-self-inductance relationship: the sensitivity of the X-axis and Y-axis sensors is matched, the magnetic field coupling coefficient is balanced, and cross interference is effectively eliminated (such as the problem of false increase of Y-axis signal caused by X offset). In addition, it should be emphasized that the coils in this invention adopt differential connection. If the same number of coil turns is not guaranteed, the nonlinear error of the sensor will increase, affecting the detection accuracy of the sensor.
[0065] In some embodiments, when the self-sensing displacement sensing component 30 is in its initial position, the axial thickness center plane of each first probe 421 of the first axial core 2 (i.e., the radial plane passing through the midpoint of the axial length of the first probe 421) coincides with the first end face of the sensor detection ring 301 of the bearing rotor, and the axial thickness center plane of each first probe 421 of the second axial core 3 coincides with the second end face of the sensor detection ring 301 to ensure that both the first axial core 2 and the second axial core 3 have a large applicable detection range for the axial displacement detection of the bearing rotor. Figure 8 The value shown as l represents the axial displacement detection range of the two axial iron cores. Specifically, as... Figure 8 As shown, when the self-inductive displacement sensing component 30 and the bearing rotor are in their initial positions, the radial plane corresponding to the midpoint of the axial length of the sensor detection ring 301 coincides with the radial plane corresponding to the midpoint of the axial length (i.e., the stack thickness) of the radial iron core 1. The axial length la of the sensor detection ring 301 should be greater than the axial length lb of the radial iron core 1, i.e., la > lb. This is because the axial self-inductive displacement sensing component 30 detects the displacement change of the rotating shaft by changing the inductance of the probe coil through the change in the magnetic area corresponding to the coil probe and the rotating shaft. To ensure that the sensor has axial displacement detection capability, both sides of the sensor detection ring 301 must be non-magnetic. In this invention, non-magnetic properties are achieved through air at both ends of the axial direction of the sensor detection ring 301, so that the material of the rotating shaft corresponding to the first axial iron core 2 and the second axial iron core 3 below the self-inductive displacement sensing component 30 is a magnetic material. The unidirectional axial vector range of the sensor is the distance l from the end face of the first axial iron core 2 and the second axial iron core 3 to the two end faces of the axial direction of the sensor detection ring 301, respectively.
[0066] Figure 9 The diagram shows the sensor's operation when the shaft axially deviates. When the shaft moves in the Z+ direction, the overlapping area of the first probe 421 on the first axial core 2 and the sensor detection ring 301 increases, while the overlapping area of the first probe 421 on the second axial core 3 and the sensor detection ring 301 decreases. When the shaft moves in the Z- direction, the overlapping area of the first probe 421 on the second axial core 3 and the sensor detection ring 301 increases, while the overlapping area of the first probe 421 on the first axial core 2 and the sensor detection ring 301 decreases. Therefore, by differentially calculating the inductance changes of the first probe 421 on the first axial core 2 and the first probe 421 on the second axial core 3, the sensitivity k of the axial self-inductive displacement sensing component 30 can be derived as follows:
[0067]
[0068] in The total change in inductance after differential connection of the coils of the first axial core 2 and the second axial core 3 (i.e., the aforementioned first coil 51), , This represents the total change in coil inductance of the first axial core 2 and the second axial core 3 after the shaft shifts. This refers to the axial displacement of the shaft. Where N is the air gap permeability; N is the number of turns of each first coil 51; l is the initial distance from the two end faces of the sensor detection ring 301 to the inner end faces of the first axial core 2 and the second axial core 3, respectively. Combining the sensor axial detection principle and the above formula, it can be concluded that the change in axial inductance of the sensor is related to the area of the sensor's rotating shaft and the sensor's toothed probe, as well as the number of coil turns. That is, when the area of ...
[0069] Figure 10 The diagram shows the sensor's operation when the shaft is radially offset. Figure 10 The orientation shown is for reference. When the bearing rotor is radially offset downward, the radial gap between the second probe pair 62 below the circumference of the radial core 1 and the bearing rotor decreases, while the radial gap between the second probe pair 62 above the circumference of the radial core 1 and the bearing rotor increases. Finally, the inductance change signals of the corresponding probe coils (i.e., the second coil 52) above and below the circumference of the radial core 1 are differentially processed to obtain the radial displacement of the bearing rotor.
[0070] Assuming that when the bearing rotor is at its center of rotation without radial displacement, the initial radial clearance between the upper and lower pairs of second probes 62 and the bearing rotor is... The number of turns of each coil (i.e., the second coil 52) is N (the same as the number of turns of the first coil 51), the magnetic area of each coil is A0, and the initial inductance is L. 01 L 02 L 03 L 04 The input voltage is ,but:
[0071]
[0072] When the bearing rotor undergoes radial displacement downwards... At that time, the radial gap between the second probe pair 62 below the circumference of the radial core 1 and the bearing rotor. (i.e. As the inductances L3 and L4 decrease, the radial clearance between the second probe pair 62 above the circumference of the radial core 1 and the bearing rotor increases. (i.e. As the inductance L1 increases, the inductances L2 decrease. At this time:
[0073]
[0074] Therefore, the radial output voltage of radial core 1 (which is objectively the output voltage of the aforementioned radial displacement differential detection circuit) is: .
[0075] According to an embodiment of the present invention, see details. Figure 13 As shown, a magnetically levitated rotating machine is also provided, including the aforementioned axial magnetic bearing. Since the axial magnetic bearing integrates a self-sensing displacement sensing component 30, the rotor can be reliably supported by magnetic levitation by only arranging the aforementioned axial magnetic bearing and two radial magnetic bearings on the rotating shaft 700. This results in fewer assembly parts, lower installation costs, and the bearings on the rotating shaft 700 can be designed to be smaller. Therefore, the rotational speed of the rotating machine can be designed to be higher. The aforementioned magnetically levitated rotating machine can specifically be a magnetic levitation motor or a magnetic levitation centrifugal compressor, etc.
[0076] It will be readily understood by those skilled in the art that, without conflict, the advantageous technical features of the above-mentioned methods can be freely combined and superimposed.
[0077] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention. The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the protection scope of the present invention.
Claims
1. An axial magnetic levitation bearing, characterized in that, The bearing assembly (10) includes a first bearing stator (101), a second bearing stator (102), and a bearing rotor. The first bearing stator (101) is provided with a first axial winding (1011). The second bearing stator (102) is arranged parallel to and spaced apart from the first bearing stator (101). The second bearing stator (102) is provided with a second axial winding (1021). An axial displacement adjustment gap is formed between the second axial winding (1021) and the first axial winding (1011). The thrust disk (201) of the bearing rotor is located in the axial displacement adjustment gap. The gap also includes a self-sensing displacement sensing component (30), which includes a sensor stator assembly (303) and a sensor detection ring (301). The sensor detection ring (301) is fitted on the outer circumferential wall of the thrust disk (201). The sensor stator assembly (303) is clamped between the first bearing stator (101) and the second bearing stator (102) and is located radially outside the first axial winding (1011) and the second axial winding (1021). The sensor stator assembly (303) is fitted radially outside the sensor detection ring (301).
2. The axial magnetic levitation bearing according to claim 1, characterized in that, The sensor stator assembly (303) includes a stator core and an induction winding. The stator core has a core yoke, and spacer rings (302) are respectively provided at both ends of the core yoke. Each spacer ring (302) is clamped between the first bearing stator (101) and the core yoke or between the second bearing stator (102) and the core yoke to prevent the induction winding from contacting the first bearing stator (101) or the second bearing stator (102).
3. The axial magnetic levitation bearing according to claim 2, characterized in that, An assembly ring groove (3021) is formed on the end face of the spacer ring (302) away from the stator core, and the radial outer edges of the first bearing stator (101) and the second bearing stator (102) are respectively assembled in the assembly ring groove (3021).
4. The axial magnetic levitation bearing according to claim 2, characterized in that, The first bearing stator (101) and the second bearing stator (102) have an inner annular pole post (1031) and an outer annular pole post (1032) arranged radially from the inside to the outside along the bearing rotor on one end face facing the thrust disk (201). A winding receiving annular groove is formed between the inner annular pole post (1031) and the outer annular pole post (1032). The first axial winding (1011) is received and wound in the winding receiving annular groove, and the outer diameter of the outer annular pole post (1032) is not greater than the outer diameter of the thrust disk (201).
5. The axial magnetic levitation bearing according to claim 2, characterized in that, The self-sensing displacement sensing component (30) is a composite sensing component for radial and axial displacement.
6. The axial magnetic levitation bearing according to claim 5, characterized in that, The stator core includes a radial core (1), a first axial core (2), and a second axial core (3). The first axial core (2) and the second axial core (3) are located on the axial end faces of the radial core (1), respectively. The first axial core (2) and / or the second axial core (3) are formed by stacking first silicon steel laminations (4). The first silicon steel lamination (4) includes a first ring (41) and a plurality of first probe pairs (42) evenly spaced along the circumferential direction of the bearing rotor. Each first probe pair (42) has two first probes (421). Each of the two first probes (421) in (42) is wound with a first coil (51) in a self-inductive manner, and the magnetic poles generated by the two first coils (51) are opposite. The first axial core (2) has each first probe pair and each first coil (51) in (42) connected in series to form a first axial detection inductance circuit. The second axial core (3) has each first probe pair and each first coil (51) in (42) connected in series to form a second axial detection inductance circuit. The first axial detection inductance circuit and the second axial detection inductance circuit are differentially connected to form an axial displacement differential detection circuit.
7. The axial magnetic levitation bearing according to claim 6, characterized in that, The radial core (1) is formed by stacking second silicon steel laminations (6). The second silicon steel lamination (6) includes a second ring (61) and a plurality of second probe pairs (62) evenly spaced along the circumferential direction of the bearing rotor. Each second probe pair (62) has two second probes (621). The circumferential width of the first probe (421) is b2, and the circumferential width of the second probe (621) is b1, where b2 > b1.
8. The axial magnetic levitation bearing according to claim 7, characterized in that, The second probe pair (62) has an even number of probes. Each second probe pair (62) has a second coil (52) wound on two second probes (621) in a self-inductive manner. The magnetic poles generated by the two second coils (52) are opposite in polarity. The two second coils (52) are connected in series to form a radial detection inductance circuit. The radial detection inductance circuit of one of the two pairs of second probe pairs (62) symmetrical about the rotation axis of the bearing rotor is differentially connected to the radial detection inductance circuit of the other probe pair to form a radial displacement differential detection circuit.
9. The axial magnetic levitation bearing according to claim 8, characterized in that, On the projection obtained by projecting onto any radial plane of the bearing rotor, the first axial core (2) coincides with the second axial core (3), and the projections of each first probe pair (42) of the first axial core (2) and each second probe pair (62) of the radial core (1) have no overlap.
10. The axial magnetic levitation bearing according to claim 9, characterized in that, The number of turns of each first coil (51) wound on each first probe (421) and the number of turns of each second coil (52) wound on each second probe (621) are equal; and / or, on the projection obtained by projecting onto any radial plane of the bearing rotor, each pair of first probes (42) on the first axial core (2) and each pair of second probes (62) on the radial core (1) are evenly spaced and alternately arranged in the circumferential direction of the bearing rotor.
11. The axial magnetic levitation bearing according to claim 6, characterized in that, When the self-sensing displacement sensing component 30 is in its initial position, the axial thickness center plane of each first probe (421) of the first axial core (2) coincides with the first end face of the sensor detection ring (301) of the bearing rotor, and the axial thickness center plane of each first probe (421) of the second axial core (3) coincides with the second end face of the sensor detection ring (301).
12. A magnetically levitated rotating machine, characterized in that, Includes the axial magnetic levitation bearing according to any one of claims 1 to 11.