Vertical hybrid magnetic suspension bearing with gravity compensation

Abstract

The invention belongs to the technical field of magnetic suspension bearings, and particularly relates to a vertical hybrid magnetic suspension bearing with gravity compensation, which comprises a frame main body, a rotor and at least one bearing assembly fixed on the frame main body, the two ends of the bearing assembly are respectively provided with an upper end cover and a lower end cover, the upper end cover and the lower end cover are located at the two ends of the bearing assembly respectively to fix the bearing assembly, and the rotor penetrates through the bearing assembly and is suspended in the bearing assembly; a first magnetic part is arranged on the upper end cover, a second magnetic part corresponding to the first magnetic part is arranged on the rotor, and the first magnetic part and the second magnetic part are matched to generate attraction force or repulsive force in the axial direction of the magnetic suspension bearing so as to carry out gravity compensation on the rotor. In order to solve the problem that a high-precision vertical magnetic suspension bearing is difficult to assemble, a reliable magnetic force compensation scheme is provided through the synergistic effect of a magnetic part and a split type axial magnetic element.

Description

[0001] Priority application This application claims priority to Chinese Invention Patent Application No. 2025112824049, filed on September 9, 2025, entitled "A Vertical Hybrid Magnetic Suspension Bearing with Gravity Compensation", which is incorporated herein by reference in its entirety. Technical Field

[0002] This invention belongs to the field of magnetic levitation bearing technology, specifically relating to a vertical hybrid magnetic levitation bearing with gravity compensation. Background Technology

[0003] Magnetic levitation bearings utilize magnetic force to stably levitate the rotor, offering significant advantages such as no mechanical contact, no friction, no lubrication, high speed, and long lifespan. They have been widely used in high-speed and ultra-high-speed applications such as high-speed centrifuges, flywheel energy storage, and turbine machinery.

[0004] In vertical machine tool spindle applications, the direction of gravity of the rotor system (including the spindle, motor rotor, and cutting tool) is parallel to the spindle axis and is entirely borne by the axial magnetic bearing. Furthermore, during machining, the axial magnetic bearing must also withstand the enormous reaction force from the workpiece. This makes the axial magnetic bearing the component with the highest load and most demanding operating conditions in the entire suspension system.

[0005] Currently, traditional solutions primarily employ purely electromagnetic active magnetic bearings. This approach relies entirely on current flowing through axial control coils to generate the necessary electromagnetic attraction to balance rotor weight and overcome machining disturbances. However, this method has several inherent drawbacks: First, to generate a strong magnetic field sufficient to support the entire weight of the rotor, the axial coil requires a continuously applied, very large bias current. This not only leads to a sharp increase in coil energy consumption and high operating costs, but also causes severe coil overheating. The overheating problem must be addressed through a complex cooling system, increasing the system's complexity and size. Second, the enormous steady-state current also demands a large-capacity power amplifier, increasing manufacturing costs and thermal management difficulties. Third, the temperature rise caused by overheating can alter the properties of the core and coil materials, potentially affecting the accuracy and stability of the control system, which is particularly detrimental to ultra-precision machining. Finally, generating a strong magnetic field often requires more coil turns and a larger core cross-section, which objectively limits the miniaturization and lightweight design of axial magnetic bearing structures, contradicting the need for compact integration with machine tool spindles.

[0006] In summary, the pure electromagnetic axial bearings used in the magnetic levitation spindles of vertical machine tools in the existing technology have become a technical bottleneck restricting their further promotion and application due to their high energy consumption, large heat generation, stringent requirements on power amplifier capacity, and constraints on structural compactness.

[0007] Therefore, there is an urgent need for a new type of magnetic levitation bearing solution that can effectively compensate for the main static load of rotor gravity, fundamentally reduce the burden on the electromagnetic coil, thereby achieving miniaturization of the magnetic levitation bearing and optimizing its various performance characteristics. Summary of the Invention

[0008] The purpose of this invention is to provide a vertical hybrid magnetic levitation bearing with gravity compensation, so as to reduce the burden on the electromagnetic coil and improve the performance of the magnetic levitation bearing.

[0009] To solve the aforementioned technical problems, the present invention specifically adopts the following technical solution: A vertical hybrid magnetic levitation bearing with gravity compensation includes a frame body, a rotor, and a bearing assembly fixed to the frame body. The bearing assembly has an upper end cover and a lower end cover at its two ends, which are located at the two ends of the bearing assembly and fix it thereto. The rotor passes through the bearing assembly and is suspended inside the bearing assembly. The upper end cover is provided with a first magnetic element, and the rotor is provided with a second magnetic element corresponding to the first magnetic element. The first magnetic element and the second magnetic element cooperate to generate an attractive force or a repulsive force along the axial direction of the magnetic levitation bearing to compensate for the gravity of the rotor. The bearing assembly includes a three-degree-of-freedom bearing, which includes a radial core, an axial disk, and a split axial magnetic element disposed between the radial core and the axial disk in sequence. The inner wall of the axial disk is provided with an axial coil in the circumferential direction. The split axial magnetic element includes at least four magnetic units. The inner wall of the radial core is provided with four radial coils, each corresponding to one of the four magnetic units. The magnetic units and the radial coils correspond one-to-one to form at least four magnetic field control paths.

[0010] As an improvement, a pose monitoring module is also provided between the radial core and the axial disk. The pose monitoring module includes a bracket and at least four position sensors disposed on the bracket. The bracket and the axial magnetic element at least partially overlap in the axial direction of the bearing assembly. The four position sensors are staggered with the four magnetic units.

[0011] As an improvement, the inner wall of the bracket protrudes radially outward to form at least four receiving grooves, and a mounting portion is formed between two adjacent receiving grooves. The position sensor is disposed on the mounting portion, and the magnetic unit is located in the receiving groove.

[0012] As an improvement, the mounting portion is recessed radially inward to form an open mounting area located outside the bracket. The mounting portion is provided with a mounting hole, through which the probe of the position sensor passes and is located inside the bracket. At least a portion of the position sensor is located within the mounting area.

[0013] As an improvement, the width of the mounting area gradually decreases from the outside to the inside, making the mounting part "V" shaped.

[0014] As an improvement, at least four limiting portions are provided on the opposite side of the radial core and / or the axial disk, and the four magnetic units are respectively confined within the limiting portions.

[0015] As an improvement, the axial disk includes a first disk and a second disk arranged in an overlapping manner, the first disk and the second disk cooperating to form a coil slot for accommodating the axial coil.

[0016] As an improvement, the wall thickness of the two sides of the coil slot is the same. The magnetic unit has an S pole on the side closer to the axial disk and an N pole on the side closer to the radial iron core. This allows the bias magnetic flux generated by the magnetic unit to start from the N pole, pass through the radial iron core, and be evenly distributed to the first disk and the second disk, and finally converge to the S pole to form a closed and uniform second magnetic circuit.

[0017] As an improvement, the bearing assembly also includes a two-degree-of-freedom bearing and at least one protective bearing.

[0018] As an improvement, a portion of the rotor's sidewall extends radially outward to form an annular protrusion.

[0019] The principle and beneficial technical effects of this invention are as follows: For high-precision vertical magnetic levitation bearings, especially addressing the assembly difficulties caused by rotor gravity during assembly, a gravity compensation scheme with ordered interaction of multiple magnetic fields is provided. That is, through the synergistic effect of magnetic components and bearing assemblies with a split sandwich structure design, a reliable magnetic compensation scheme is provided.

[0020] Specifically, by setting corresponding magnetic components (i.e., magnetic field arrays) on the end cap and rotor, the first and second magnetic components cooperate to generate attractive or repulsive forces along the axial direction of the magnetic levitation bearing, thereby compensating for the gravity of the rotor. Simultaneously, multiple magnetic units form independent magnetic circuits with the radial coils, which can, to a certain extent, avoid the ineffective magnetic field generated in the non-operating area of ​​traditional integrated axial magnetic elements (to ensure ease of installation, existing systems use inherent integrated permanent magnets; the part of this permanent magnet that does not overlap with the radial coil is the "non-operating area," which is highly likely to generate unnecessary ineffective magnetic fields, i.e., generate "unintended magnetic flux," potentially leading to decreased control accuracy or increased sensor measurement noise), improve the uniformity of the magnetic field, and thus reduce the adverse effects of non-uniform magnetic fields on the magnetic field array, ensuring the compensation effect of the magnetic field array.

[0021] Furthermore, the application also provides a magnetic circuit uniformity control scheme, which optimizes the magnetic field from the perspective of structure and magnetic pole distribution, further reducing the possibility of magnetic field array being interfered with by magnetic field. Specifically, this application divides the magnetic circuit into two paths by directional magnetic pole distribution of magnetic unit and combining first disk and second disk with consistent thickness, so that the magnetic force in the magnetic circuit is always uniform, thereby reducing the possibility of non-uniform magnetic field interfering with magnetic field array.

[0022] Furthermore, this application employs a staggered sandwich design for the split axial magnetic element and the pose monitoring module. In other words, the pose monitoring module is sandwiched between the radial iron core and the axial disk, while multiple magnetic units are sandwiched in various parts of the bracket, which can make efficient use of space and facilitate the miniaturization of the bearing. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. The elements or parts in the drawings are not necessarily drawn to scale. Obviously, the drawings described below are some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0024] Figure 1 This is a three-dimensional structural diagram of a three-degree-of-freedom bearing in an embodiment of the present invention; Figure 2 This is a front view of a three-degree-of-freedom bearing in an embodiment of the present invention; Figure 3 This is a partial structural schematic diagram of a three-degree-of-freedom bearing in an embodiment of the present invention; Figure 4This is an exploded view of the front view of the three-degree-of-freedom bearing in an embodiment of the present invention; Figure 5 This is a schematic diagram of the magnetic circuit distribution of the hybrid magnetic levitation bearing in an embodiment of the present invention; Figure 6 This is an exploded structural diagram of a vertical hybrid magnetic levitation bearing with gravity compensation in an embodiment of the present invention; Figure 7 This is a cross-sectional view of a vertical hybrid magnetic levitation bearing with gravity compensation in an embodiment of the present invention. Figure 8 This is a schematic diagram illustrating the principle of providing attraction through a Halbach magnetic field array in an embodiment of the present invention; Figure 9 This is a schematic diagram illustrating the principle of providing repulsive force through a Halbach magnetic field array in an embodiment of the present invention.

[0025] In the diagram, the markings are as follows: 100, radial core; 200, axial disk; 210, first disk; 211, first housing; 212, second housing; 220, second disk; 300, magnetic unit; 400, radial coil; 500, pose monitoring module; 510, bracket; 511, receiving slot; 512, mounting part; 513, mounting area; 520, position sensor; 521, probe; 522, adjusting element; 600, coil slot; 700. 1. Limiting part; 800. Axial coil; 30. First magnetic circuit; 31. Second magnetic circuit; 32. Third magnetic circuit; 33. Fourth magnetic circuit; 34. Fifth magnetic circuit; 35. Sixth magnetic circuit; 1. Upper end cover; 2. Bearing cover; 3. Protective bearing; 4. Three-degree-of-freedom bearing; 5. Two-degree-of-freedom bearing; 6. Angular contact bearing; 7. Lower end cover; 8. Rotor; 9. Frame body; 10. First magnetic component; 11. Second magnetic component; 12. Protrusion; 13. Gasket. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0027] In this document, suffixes such as "module," "component," or "unit" used to denote elements are used solely for the purpose of illustrative purposes and have no specific meaning in themselves. Therefore, "module," "component," or "unit" may be used interchangeably. In this document, terms such as "upper," "lower," "inner," "outer," "front," "rear," "one end," and "the other end," indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are used only for the convenience of describing the invention and for simplifying the description, and 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 of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0028] In this document, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," and "connected," etc., should be interpreted broadly. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. In this document, "multiple" means two or more, that is, it includes two, three, four, five, etc.

[0029] Example 1 See Figures 1-5 This invention provides a hybrid magnetic levitation bearing for in-situ measurement, comprising at least one bearing assembly. The bearing assembly includes a radial iron core 100, an axial disk 200 arranged sequentially, and a split axial magnetic element disposed between the radial iron core 100 and the axial disk 200. An axial coil 800 is circumferentially disposed on the inner wall of the axial disk. The split axial magnetic element includes at least four magnetic units 300. At least four radial coils 400, each corresponding to a magnetic unit, are disposed on the inner wall of the radial iron core 100. The magnetic units 300 and the radial coils 400 correspond one-to-one to form at least four independent magnetic field control paths.

[0030] A pose monitoring module 500 is also provided between the radial core 100 and the axial disk 200. The pose monitoring module 500 includes a bracket 510 and at least four position sensors 520 disposed on the bracket 510. The bracket 510 and the axial magnetic element at least partially overlap in the axial direction of the bearing assembly. The four position sensors 520 are staggered with the four magnetic units 300.

[0031] In some embodiments, the probe of the position sensor 520 is oriented toward the center of the bracket 510.

[0032] Compared with existing technologies (such as Chinese invention patent CN107222132A) that place the sensor externally on the side wall of the bearing assembly, this application uses a split sandwich structure design to enable the bearing to be miniaturized while measuring the rotor's position and orientation in situ, thereby improving measurement accuracy.

[0033] Specifically, in order to avoid the magnetic field inside the bearing assembly from interfering with the sensor, the traditional approach is to perform pose measurement outside the bearing assembly at the expense of some accuracy. However, this application is quite different. It provides a multi-magnetic field orderly interaction scheme built into the sensor through a split sandwich structure design. While realizing in-situ measurement, the magnetic field interference on the sensor can be effectively controlled, thereby achieving higher accuracy pose measurement.

[0034] In some embodiments, the magnetic unit can be a permanent magnet. Four magnetic units are evenly disposed between the radial iron core and the axial disk, forming independent magnetic circuits (permanent magnet biasing magnetic circuits) in four directions. The four radial coils are paired up to form two independent magnetic circuits (electromagnetic control magnetic circuits) for real-time adjustment and control of the magnetic field force. When the radial coils control the magnetic field force of the magnetic units, they form certain control paths, namely the above-mentioned at least four independent magnetic field control paths. It should be noted that the four radial coils are connected in series or in parallel to form two sets of control units, providing magnetic force in two directions (such as directions a and b), but each electrical path (each radial coil) can still be regarded as an independent control path.

[0035] In some embodiments, the inner wall of the bracket 510 protrudes radially outward to form at least four receiving grooves 511, and a mounting portion 512 is formed between two adjacent receiving grooves 511. The position sensor 520 is disposed on the mounting portion 512, and the magnetic unit 300 is located within the receiving groove 511. Here, "outward" means extending radially along the center of the bracket. That is, "outer" and "inner" in this text refer to the region where the outer diameter of the bracket is located and the region where the center is located, respectively. Through the staggered arrangement, the position sensor 520 and the magnetic unit 300 are independent of each other, while the bracket 510 can also limit the movement of the magnetic unit 300.

[0036] In some embodiments, the mounting portion 512 is recessed radially inward to form an open mounting area 513 located outside the bracket 510 (see [reference]). Figure 3The mounting portion 512 is provided with mounting holes, and the probe of the position sensor 520 passes through the mounting holes and is located inside the bracket 510. At least a portion of the position sensor 520 is located within the mounting area 513. That is, the mounting area 513 is also staggered with the receiving groove 511. The bracket 510 divides the space between the radial core 100 and the axial disk 200 into different functional areas, such as a limiting area for mounting the magnetic unit and restricting its position, an open mounting area for facilitating the installation of the position sensor, and a fixing area for fixing the position sensor probe. This significantly improves space utilization while enhancing the independence of each component and the uniformity of the magnetic field distribution, facilitating the miniaturization design of the bearing assembly. The position of the position sensor 520 can be adjusted by the adjusting member 522.

[0037] In some embodiments, the width of the mounting area 513 gradually decreases from the outside to the inside, making the mounting portion 512 V-shaped. When mounting the position sensor 520 on the bracket, the position sensor 520 is aligned with the mounting hole through the open mounting area 513 and then assembled, which is convenient and quick.

[0038] In some embodiments, at least four limiting portions 700 are provided on the radial core 100 and / or the axial disk 200, and the four magnetic units 300 are respectively constrained within the limiting portions 700. That is, at least four limiting portions 700 are provided on the opposite side of the radial core 100 and the axial disk 200, for example, the radial core 100 is closer to the axial disk 200, or the axial disk 200 is closer to the radial core 100. Preferably, the limiting portions 700 are provided on the radial core 100 and correspond to the radial core 100. By limiting the magnetic units 300 with the limiting portions 700, it is possible to help the split magnetic units 300 to be quickly aligned, reduce the installation complexity, and improve the correspondence accuracy between the magnetic units 300 and the radial coil 400.

[0039] In some embodiments, the four radial coils 400 are divided into two magnetic groups, each magnetic group including two radial coils 400. The two magnetic groups generate magnetic forces pointing in a first direction a and a second direction b, respectively. The angle between the first direction and the horizontal plane is 1°-90°, and the angle between the second direction and the horizontal plane is 90°-180°.

[0040] In some embodiments, the angle between the first direction and the horizontal plane is 45°, and the angle between the second direction and the horizontal plane is 135°. For horizontal magnetic levitation bearings, this application also provides a gravity compensation scheme, which, by dividing the magnetic force groups, generates an upward magnetic force to compensate for the rotor's own weight.

[0041] In some embodiments, the axial disk includes a first disk 210 and a second disk 220 arranged in an overlapping manner, the first disk 210 and the second disk 220 cooperating to form a coil slot 600 for accommodating the axial coil 800.

[0042] In some embodiments, the wall thickness of both sides of the coil slot 600 is the same, the magnetic unit has an S pole near the axial disk and an N pole near the radial core, so that the bias magnetic flux generated by the magnetic unit starts from the N pole, passes through the radial core, and is evenly distributed to the first disk and the second disk, and finally converges to the S pole to form a closed and uniform second magnetic circuit 31 (see Figure 5 , Figure 5 An exemplary illustration shows the magnetic circuit distribution of a five-degree-of-freedom magnetic bearing system incorporating the three-degree-of-freedom bearing assembly (left side) of the present invention.

[0043] In some embodiments, the first disk 210 includes a first housing 211 extending axially along the bearing and a second housing 212 extending radially along the bearing. The second disk 220 is parallel to the second housing 212 and fits against the sidewall of the first housing 211 to form the coil slot 600 with an internal opening. The axial coil 800 is mounted to the coil slot 600 through the opening, which faces the rotor.

[0044] Based on the above bearing assembly, this solution provides an exemplary circuit diagram of a five-degree-of-freedom magnetic bearing system, see [link / reference]. Figure 5 The left side shows the aforementioned bearing assembly (three-degree-of-freedom bearing assembly), and the right side shows the two-degree-of-freedom bearing assembly. First, the bias magnetic flux generated by the magnetic unit of the three-degree-of-freedom bearing assembly starts from the N-position, passes through the radial iron core, enters the air gap between the bearing assembly and the rotor 8, and then flows through the rotor 8 to the first and second disks respectively. It then converges at the S-position of the magnetic unit to form a complete second magnetic circuit 31, providing both axial magnetic force bias magnetic flux in two directions and radial magnetic force bias magnetic flux simultaneously. Similarly, the bias magnetic flux generated by the two-degree-of-freedom bearing starts from the N-position of the magnetic element, passes through the radial iron core, enters the air gap, and then flows through the rotor 8 to the axial disk on the other side, converging at the S-position of the magnetic element to form a complete fifth magnetic circuit 34, providing radial magnetic force bias magnetic flux.

[0045] When current is passed through the radial coils inside the three-degree-of-freedom and two-degree-of-freedom systems, the magnetic flux generated by the coils passes through the axial disk, and the rotor 8 forms closed-loop magnetic circuits of different degrees of freedom (including the third magnetic circuit 32, the fourth magnetic circuit 33, and the sixth magnetic circuit 35), and works with the second magnetic circuit 31 and the fifth magnetic circuit 34 to adjust the magnitude and direction of the radial magnetic levitation force.

[0046] When current is passed through the three-degree-of-freedom axial coil, the magnetic flux generated by the coil passes through the first disk, the shoulder of the rotor 8, and the second disk to form a first magnetic circuit 30, which, together with the second magnetic circuit 31 that can provide two axial directions, adjusts the magnitude and direction of the axial magnetic levitation force.

[0047] By combining the directional magnetic poles of the magnetic unit with the split axial disk, a magnetic circuit uniformity control scheme is provided. Specifically, this application optimizes the magnetic field in terms of structure and magnetic pole distribution. When the magnetic flux generated by the magnetic unit flows directionally from the N-pole to the axial disk, it is uniformly distributed to the split first and second disks of the same thickness, which can further improve the uniformity of the magnetic field inside the bearing, thereby reducing the interference that non-uniform magnetic fields may cause to the sensor.

[0048] In summary, this application provides a multi-magnetic field ordered interaction scheme built into the sensor through a split sandwich structure design. While realizing in-situ measurement, the magnetic field interference experienced by the sensor can be effectively controlled, thereby achieving higher precision pose measurement.

[0049] Specifically, this application firstly sets up a split axial magnetic element and a position monitoring module, which adopt an interleaved sandwich design. That is, the position monitoring module is sandwiched between the radial iron core and the axial disk, while multiple magnetic units are sandwiched in various parts of the bracket. On the one hand, this can make efficient use of space and facilitate the miniaturization of the bearing. On the other hand, multiple magnetic units form independent magnetic field control paths with the radial coil, which can reduce the invalid magnetic field generated by the non-active area of ​​the traditional integrated axial magnetic element to a certain extent (in order to ensure the convenience of installation, existing ones all use an inherent integrated permanent magnet, and the part of the permanent magnet that does not overlap with the radial coil is the "non-active area", which is very likely to generate an unnecessary invalid magnetic field in the magnetic circuit). This reduces the magnetic interference to the sandwich-designed sensor and improves the detection accuracy of the sensor.

[0050] Furthermore, this application also provides a magnetic circuit uniformity control scheme, which optimizes the magnetic field from the perspective of structure and magnetic pole distribution, further reducing the possibility of magnetic field interference to the position sensor set in the sandwich structure. Specifically, this application divides the magnetic circuit into two paths by directional magnetic pole distribution of the magnetic unit and combining the first disk and the second disk with the same thickness, so that the magnetic force in the magnetic circuit is always uniform, thereby reducing the interference that non-uniform magnetic field may cause to the sensor. At the same time, it simplifies the structure of the rotor and bearing assembly and simplifies their assembly, achieving miniaturization.

[0051] Furthermore, the modularly designed posture monitoring module, in conjunction with the separate axial magnetic element, requires only one alignment during installation. For example, the axial magnetic element is first installed on the radial iron core, and then the posture monitoring module can be automatically aligned through the positioning function of the axial magnetic element, thereby improving the ease of bearing assembly.

[0052] Furthermore, for horizontal magnetic levitation bearings, this solution also provides a gravity compensation scheme. By dividing the magnetic force groups, an upward magnetic force is generated on the bearing, which can reduce the possibility of the entire bearing, especially during installation, shifting.

[0053] Example 2 This embodiment provides an assembly method for a hybrid magnetic levitation bearing based on in-situ measurement, and includes the following steps: S100, The position sensor is mounted on the bracket, and the probe of the sensor is adjusted to the zero position to form a pose monitoring module; S200, the split axial magnetic element is fixed to the radial iron core; wherein, multiple magnetic units can be positioned by the limiting part on the side wall of the radial iron core to facilitate the quick installation of the split axial magnetic element; S300, The pose monitoring module is installed on the radial iron core on which the axial magnetic element is fixed; S400, the radial iron core and the axial disk are combined to form the bearing assembly as a whole.

[0054] In combination with the above assembly method, this application actually provides a modular installation solution that can be quickly assembled even for a split sandwich structure design. Specifically, the split magnetic unit is first quickly assembled using the limiting part, then the pose monitoring module is quickly installed as a whole onto the radial iron core, and finally the radial iron core and axial disk are combined to complete the assembly, which is convenient and quick.

[0055] Example 3 See Figures 1-7This embodiment provides a vertical hybrid magnetic levitation bearing with gravity compensation, including a frame body 9, a rotor 8, and a bearing assembly fixed to the frame body 9. The bearing assembly has an upper end cover 1 and a lower end cover 7 at its two ends, respectively, which are located at the two ends of the bearing assembly and fixed within the frame body 9. The rotor 8 passes through the bearing assembly and is suspended within it. The upper end cover 1 is provided with a first magnetic element 10, and the rotor 8 is provided with a second magnetic element 11 corresponding to the first magnetic element 10 (preferably, the second magnetic element 11 is located at the end of the rotor 8). The first magnetic element 10 and the second magnetic element 11 cooperate to generate an attractive or repulsive force along the axial direction of the magnetic levitation bearing to compensate for the gravity of the rotor.

[0056] Specifically, when the magnetic levitation bearing is placed upright, the lower end cover is at the bottom, and the upper end cover is at the top of the lower end cover. The first magnetic element 10 and the second magnetic element 11, which have the same magnetic properties, work together to generate an upward vertical attraction force to provide gravity compensation for the rotor 8. When the magnetic levitation bearing is placed upside down (see details...), Figure 7 At this point, the lower end cover is located at the top, and the upper end cover is located at the bottom of the lower end cover. The first magnetic element 10 and the second magnetic element 11, with different magnetic properties, work together to generate an upward repulsive force, providing gravity compensation for the rotor 8. In other words, by selecting the magnetic properties of the two magnetic elements (for example, the opposing surface magnetic poles of the first and second magnetic elements are opposite, thus generating an upward attractive force; the opposing surface magnetic poles of the first and second magnetic elements are the same, thus generating an upward repulsive force), gravity compensation for the magnetic levitation bearing under different operating conditions (upright and inverted) can be addressed. For example, see the Halbach magnetic field array. Figure 8 and Figure 9 The figure shows schematic diagrams of the circumferential Halbach magnetic field array providing attraction and repulsion, respectively. That is, the attraction or repulsion is achieved by different arrangements of magnets inside the Halbach magnetic field array.

[0057] It should be noted that the terms "upper end cover" and "lower end cover" in this application are merely for the convenience of distinguishing the two end covers, and do not represent their positional relationship. For example, when the magnetic levitation bearing is placed upside down, the lower end cover is located above the upper end cover.

[0058] The bearing assembly includes a three-degree-of-freedom bearing 4, which includes a radial iron core 100, an axial disk 200 arranged sequentially, and a split axial magnetic element disposed between the radial iron core 100 and the axial disk 200. An axial coil 800 is circumferentially disposed on the inner wall of the axial disk 200. The split axial magnetic element includes at least four magnetic units 300. The inner wall of the radial iron core 100 is provided with four radial coils 400, each corresponding to one of the four magnetic units 300. The magnetic units 300 and the radial coils 400 correspond one-to-one to form at least four independent magnetic field control paths.

[0059] In some embodiments, a pose monitoring module 500 is further provided between the radial core 100 and the axial disk 200. The pose monitoring module 500 includes a bracket 510 and at least four position sensors 520 disposed on the bracket 510. The bracket 510 and the axial magnetic element at least partially overlap in the axial direction of the bearing assembly. The four position sensors 520 are staggered with the four magnetic units 300.

[0060] In some embodiments, the inner wall of the bracket 510 protrudes radially outward to form at least four receiving grooves 511, and a mounting portion 512 is formed between two adjacent receiving grooves 511. The position sensor 520 is disposed on the mounting portion 512, and the magnetic unit 300 is located in the receiving groove 511.

[0061] In some embodiments, the mounting portion 512 is recessed radially inward to form an open mounting area 513 located outside the bracket 510. The mounting portion 512 is provided with a mounting hole, through which the probe of the position sensor 520 passes and is located inside the bracket 510. At least a portion of the position sensor 520 is located within the mounting area 513.

[0062] In some embodiments, the width of the mounting area 513 gradually decreases from the outside to the inside, making the mounting portion "V" shaped.

[0063] In some embodiments, at least four limiting portions 700 are provided on the opposite side of the radial core 100 and / or the axial disk 200, and the four magnetic units 300 are respectively limited within the limiting portions 700.

[0064] In some embodiments, the axial disk includes a first disk 210 and a second disk 220 arranged in an overlapping manner, the first disk 210 and the second disk 220 cooperating to form a coil slot 600 for accommodating the axial coil 800.

[0065] In some embodiments, the wall thickness of both sides of the coil slot 600 is the same, the magnetic unit has an S pole near the axial disk and an N pole near the radial core, so that the bias magnetic flux generated by the magnetic unit starts from the N pole, passes through the radial core, and is evenly distributed to the first disk and the second disk, and finally converges to the S pole to form a closed and uniform second magnetic circuit 31 (see Figure 5 ).

[0066] In some embodiments, the bearing assembly further includes a two-degree-of-freedom bearing 5, at least one protective bearing 3, and at least one angular contact bearing 6.

[0067] In some embodiments, a bearing cover 2 is also provided between the three-degree-of-freedom bearing 4 and the upper cover 1. The first magnetic element 10 and the second magnetic element are located on the first side of the bearing cover 2, and the three-degree-of-freedom bearing 4 is located on the second side of the bearing cover. The first side and the second side are opposite to each other. That is to say, by providing the bearing cover, on the one hand, the position of the bearing can be restricted, and on the other hand, the magnetic field inside the entire magnetic levitation bearing (especially the magnetic field generated between the magnetic field inside the three-degree-of-freedom bearing and the magnetic field between the first magnetic element 10 and the second magnetic element 11) is effectively isolated, further improving the "orderliness" of the magnetic field inside the magnetic levitation bearing, thereby further reducing the magnetic field interference experienced by the sensor.

[0068] In some embodiments, a gasket is provided between the bearing cover 2 and the upper cover 1. By installing gaskets of different thicknesses, the distance between the first magnetic element 10 and the second magnetic element 11 can be adjusted, thereby adjusting the magnitude of the attraction or repulsion between them to meet different gravity compensation requirements.

[0069] In some embodiments, a portion of the sidewall of the rotor 8 extends radially outward to form an annular protrusion 12 to increase the installation stability of the rotor 8.

[0070] In some embodiments, the first magnetic element 10 and the second magnetic element 11 are Halbach magnetic field arrays.

[0071] In some embodiments, the three-degree-of-freedom bearing may adopt the structure of the bearing assembly in Embodiment 1.

[0072] To address the challenges of assembling high-precision vertical magnetic levitation bearings, particularly the difficulties caused by rotor gravity during assembly, this application provides a multi-magnetic field ordered interaction scheme based on a split bearing assembly. By cooperating with the magnetic components and the split sandwich structure of the bearing assembly, gravity compensation is achieved through magnetic force, while the magnetic fields inside and outside the bearing assembly (mainly the magnetic field between the first and second magnetic components) can operate independently and stably in an orderly manner, thus providing a reliable magnetic gravity compensation scheme.

[0073] Specifically, firstly, by setting corresponding magnetic components on the end cap and rotor, the first and second magnetic components cooperate to generate an attractive or repulsive force along the axial direction of the magnetic levitation bearing, thereby compensating for the gravity of the rotor. Simultaneously, multiple magnetic units form independent magnetic field control paths with the radial coils, which can, to a certain extent, avoid the ineffective magnetic field generated in the non-operating area of ​​traditional integrated axial magnetic elements (to ensure ease of installation, existing systems use inherent integrated permanent magnets; the part of this permanent magnet that does not overlap with the radial coil is the "non-operating area," which is highly likely to generate unnecessary ineffective magnetic fields in the magnetic circuit), improve the uniformity of the magnetic field, and thus reduce the adverse effects of non-uniform magnetic fields on the magnetic field array, ensuring the compensation effect of the magnetic field array.

[0074] Furthermore, the application also provides a magnetic circuit uniformity control scheme, which optimizes the magnetic field from the perspective of structure and magnetic pole distribution, thereby further reducing the possibility of magnetic field array being interfered with by magnetic field. Specifically, this application divides the magnetic circuit into two paths by directional magnetic pole distribution of magnetic unit and combining first disk and second disk with the same thickness, so that the magnetic force in the magnetic circuit is always uniform, thereby further reducing the possibility of non-uniform magnetic field interfering with magnetic field array.

[0075] Furthermore, this application employs a staggered sandwich design for the split axial magnetic element and the pose monitoring module. In other words, the pose monitoring module is sandwiched between the radial iron core and the axial disk, while multiple magnetic units are sandwiched in various parts of the bracket, which can make efficient use of space and facilitate the miniaturization of the bearing.

[0076] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0077] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present invention.

Claims

1. A vertical hybrid magnetic levitation bearing with gravity compensation, characterized in that, The assembly includes a frame body (9), a rotor (8), and a bearing assembly fixed to the frame body (9). The bearing assembly has an upper end cover (1) and a lower end cover (7) at its two ends. The upper end cover (1) and the lower end cover (7) are located at the two ends of the bearing assembly and fix it thereto. The rotor (8) passes through the bearing assembly and is suspended inside the bearing assembly. The upper end cover (1) is provided with a first magnetic element (10), and the rotor (8) is provided with a second magnetic element (11) corresponding to the first magnetic element (10). The first magnetic element (10) and the second magnetic element (11) cooperate to generate an attractive force or a repulsive force along the axial direction of the magnetic levitation bearing to compensate for the gravity of the rotor (8). The bearing assembly includes a three-degree-of-freedom bearing (4), which includes a radial core (100), an axial disk (200) arranged sequentially, and a split axial magnetic element disposed between the radial core (100) and the axial disk (200). The inner wall of the axial disk (200) is circumferentially provided with an axial coil (800). The split axial magnetic element includes at least four magnetic units (300). The inner wall of the radial core (100) is provided with four radial coils (400) that correspond to the four magnetic units (300) respectively. The magnetic units (300) and the radial coils (400) correspond one-to-one to form at least four magnetic field control paths.

2. The vertical hybrid magnetic levitation bearing with gravity compensation according to claim 1, characterized in that, A pose monitoring module (500) is also provided between the radial core (100) and the axial disk (200). The pose monitoring module (500) includes a bracket (510) and at least four position sensors (520) disposed on the bracket (510). The bracket (510) and the axial magnetic element at least partially overlap in the axial direction of the bearing assembly. The four position sensors (520) are staggered with the four magnetic units (300).

3. The vertical hybrid magnetic levitation bearing with gravity compensation according to claim 2, characterized in that, The inner wall of the bracket (510) protrudes outward along its radial direction to form at least four receiving grooves (511), and a mounting part (512) is formed between two adjacent receiving grooves (511). The position sensor (520) is disposed on the mounting part (512), and the magnetic unit (300) is located in the receiving groove (511).

4. The vertical hybrid magnetic levitation bearing with gravity compensation according to claim 3, characterized in that, The mounting portion (512) is recessed radially inward to form an open mounting area (513) located outside the bracket (510). The mounting portion (512) is provided with a mounting hole. The probe (521) of the position sensor (520) passes through the mounting hole and is located inside the bracket (510). At least a portion of the position sensor (520) is located within the mounting area (513).

5. The vertical hybrid magnetic levitation bearing with gravity compensation according to claim 4, characterized in that, The width of the mounting area (513) gradually decreases from the outside to the inside, making the mounting part (512) V-shaped.

6. The vertical hybrid magnetic levitation bearing with gravity compensation according to claim 1, characterized in that, At least four limiting portions are provided on the opposite side of the radial core (100) and / or the axial disk (200), and the four magnetic units (300) are respectively limited within the limiting portions.

7. The vertical hybrid magnetic levitation bearing with gravity compensation according to claim 1, characterized in that, The axial disk (200) includes an overlapping first disk (210) and a second disk (220), which cooperate to form a coil slot (600) for accommodating the axial coil (800).

8. The vertical hybrid magnetic levitation bearing with gravity compensation according to claim 7, characterized in that, The wall thickness of the two sides of the coil slot (600) is the same. The magnetic unit (300) has an S pole on the side closer to the axial disk (200) and an N pole on the side closer to the radial iron core (100). This allows the bias magnetic flux generated by the magnetic unit (300) to start from the N pole, pass through the radial iron core (100), and be evenly distributed to the first disk (210) and the second disk (220), and finally converge to the S pole to form a closed and uniform second magnetic circuit (31).

9. The vertical hybrid magnetic levitation bearing with gravity compensation according to claim 1, characterized in that, The bearing assembly also includes a two-degree-of-freedom bearing (5) and at least one protective bearing (3).

10. The vertical hybrid magnetic levitation bearing with gravity compensation according to claim 1, characterized in that, One portion of the sidewall of the rotor (8) extends radially outward to form an annular protrusion (12).

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