Radial magnetic levitation device and method of designing a magnetic levitation device

Abstract

The existing flat magnetic suspension device can reduce the device volume, especially in the device with the requirement of axial dimension, the small volume and large suspension force can be realized. However, the flat magnetic suspension device has a large diameter, if the suspended device does not have a large diameter, the whole device will occupy a large space. Therefore, the present application proposes a radial magnetic suspension device, which is committed to provide a large suspension force for a small diameter suspended device, and a magnetic suspension device design method is proposed, which can coordinate the size design of the whole system and ensure the optimal size of the system.

Description

Technical Field

[0001] This invention relates to a radial magnetic levitation device and a design method for the magnetic levitation device. Background Technology

[0002] Magnetic levitation devices have low frictional losses due to their contactless operation. A magnetic levitation device uses the magnetic field generated by an energized coil or magnet to counteract the gravity and forces exerted on the moving part, allowing it to levitate. A fully superconducting magnetic levitation device uses superconducting materials instead of the copper coils or magnets of ordinary magnetic levitation devices. Because of the higher current density of superconductivity, the generated magnetic field is stronger, allowing for greater load-bearing capacity within the same volume.

[0003] Some existing magnetic levitation devices operate in a vacuum environment, and the superconducting materials require sealed cooling during use. However, in conventional fully superconducting magnetic levitation devices, the superconducting components are located on the stator and rotor. Since the rotor is in motion during actual use, sealing and cooling the rotor is much more difficult than cooling the stator, especially when the rotor is a high-speed rotating shaft. Therefore, the applicant invented a fully superconducting magnetic levitation bearing. However, this bearing only uses a pair of stator and rotor. To obtain a large magnetic levitation force, the axial dimension or the radius of the rotating shaft must be increased, resulting in a large bearing structure and narrow application range. Therefore, the applicant improved the device by designing a flat magnetic levitation device, reducing its size, especially in devices with axial dimension requirements, achieving a small volume and large levitation force. However, the flat magnetic levitation device has a large diameter; if the levied device does not have a large diameter, the entire device occupies a large space. Therefore, this invention proposes a radial magnetic levitation device, aiming to provide a large levitation force for small-diameter levitation devices while coordinating the overall system size. Summary of the Invention

[0004] The purpose of this invention is to provide a radial magnetic levitation device that features high load-bearing capacity, small size, strong stability, and easy-to-implement sealing and cooling, thereby solving the technical problem of large radial dimensions. The technical solution adopted is as follows:

[0005] A radial magnetic levitation device is characterized by comprising a stator, a rotor, multiple superconducting coils, and multiple high-temperature superconductors; the stator and rotor are concentrically arranged; the rotor has N radially protruding convex rings evenly spaced along its axial direction; the width of the two convex rings at both ends of the rotor is half the width of the remaining convex rings; N+1 high-temperature superconductors are fixedly connected at intervals inside the stator; the interval between the convex rings is equal to the interval between the high-temperature superconductors; the width d1 of the two high-temperature superconductors at the ends is the same as the width of the convex rings at the ends, and the width d2 of the remaining high-temperature superconductors is the same as the width of the convex rings in the middle; a superconducting coil is installed in the space between two adjacent high-temperature superconductors, and the superconducting coil is fixedly connected to the stator; there is a gap between the convex ring and its opposite high-temperature superconductor.

[0006] Furthermore, the stator, superconducting coil, and high-temperature superconductor are housed inside a sealed container.

[0007] Furthermore, high-temperature superconductors can be ring structures or multiple sector structures combined into a ring structure.

[0008] Furthermore, annular supports concentric with the stator are provided on the upper and lower end faces of the stator's sealed container. Multiple supports are evenly distributed on the annular supports, with the normal to the support surface intersecting perpendicularly with the rotor's axis. Hydraulic cylinders are installed on the support surfaces, with sliding rods slidably mounted inside the hydraulic cylinders. A ball is fixedly connected to the top of the sliding rod. Hydraulic oil inlet / outlet and valves are provided at the bottom of the hydraulic cylinders. Ball seats opposite to the support surfaces are provided on the two end faces of the rotor. The distance between the ball seat on the upper end face and the upper end face is less than the distance between the support and the upper end face of the sealed container; the distance between the ball seat on the lower end face and the lower end face is greater than the distance between the support and the lower end face of the sealed container.

[0009] Furthermore, a groove with the same diameter as the sphere is provided on the surface opposite to the surface of the ball seat and the support, and the depth of the groove is greater than the diameter of the sphere.

[0010] This invention also discloses a design method for magnetic levitation bearings, characterized by employing a design method combining flat magnetic levitation bearings and radial magnetic levitation bearings. Specifically, firstly, the number of stators used in the flat magnetic levitation bearings is determined based on the diameter of the levitation device; the corresponding magnetic levitation force is calculated. If the magnetic levitation force meets the requirements, the design is complete; if the magnetic levitation force is insufficient, the number of stator-rotor pairs is calculated based on the magnetic levitation force deficit and the magnetic levitation force generated by a single stator and rotor in the flat magnetic levitation bearing.

[0011] Specifically, the number of stator-rotor pairs = F 缺 / F 磁 If the result is not an integer, the remainder is counted as one.

[0012] The axial dimensions of the stator and rotor are increased according to the number of stator-rotor pairs. Specifically, the number of axially mounted convex rings, high-temperature superconductors, and superconducting coils is increased. The increase is prioritized from the rotor center outwards. Specifically, a pair of stator and rotor pairs is added at the center, followed by one layer added sequentially outwards until the outermost layer is reached. If the number of stator-rotor pairs is not fully utilized after the layout on the same layer is completed, another layer of stator and rotor pairs is added sequentially outwards from the center until the number of stator and rotor pairs is exhausted.

[0013] Compared with the prior art, the beneficial effects of the present invention are:

[0014] Multiple rotor rings and stator rings that cooperate with the rotor rings are evenly arranged in the axial direction of the rotating shaft, which effectively reduces the radial size of the magnetic levitation device and increases the magnetic levitation force.

[0015] By distributing the stator and rotor in a combination of axial and radial directions according to the diameter of the suspended device, the size of the suspended device can be well adapted, thereby making the structure of the entire system uniform and reducing the volume of the system structure. Attached Figure Description

[0016] Figure 1 : Cross-sectional view of radial magnetic levitation device

[0017] Figure 1 The reference numerals in the attached diagrams are: 1. Rotor, 2. Backplate, 3. High-temperature superconductor, 4. Stator, 5. Superconducting coil.

[0018] Figure 2 Cross-sectional view of a flat magnetic levitation device

[0019] Figure 2 The reference numerals in the attached diagrams are: 1. Stator, 2. Backplate, 3. Rotor, 4. High-temperature superconductor, 5. Superconducting coil, 6. Rotor connector. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0021] like Figure 1As shown, the radial magnetic levitation device includes a stator, a rotor, multiple superconducting coils, and multiple high-temperature superconductors. The stator and rotor are concentrically arranged. N radially protruding rings are evenly spaced along the axial direction on the rotor. The width of the two protruding rings at both ends of the rotor is half the width of the remaining rings. N+1 high-temperature superconductors are fixedly connected at intervals inside the stator. The interval between the protruding rings is equal to the interval between the high-temperature superconductors. The width d1 of the two high-temperature superconductors at the ends is the same as the width of the protruding rings at the ends, and the width d2 of the remaining high-temperature superconductors is the same as the width of the protruding rings in the middle. Superconducting coils are installed between the intervals of two adjacent high-temperature superconductors and are fixedly connected to the stator. There are gaps between the protruding rings and their corresponding high-temperature superconductors. The stator, superconducting coils, and high-temperature superconductors are housed inside a sealed container.

[0022] High-temperature superconductors can be in the form of a ring structure or multiple sector-shaped structures combined into a ring structure.

[0023] like Figure 1 As shown, the stator can have an annular groove in the middle, and the superconducting coil is placed inside the annular groove.

[0024] The stator may also omit the grooves, with the superconducting coils located inside the grooves formed between the convex rings of the rotor. A backplate is placed on the side of the high-temperature superconductor near the convex rings; the backplate improves system strength and magnetic field utilization. The stator, backplate, and rotor are all made of magnetically conductive material.

[0025] Superconducting coils include low-temperature superconducting coils and high-temperature superconducting coils.

[0026] Annular supports, concentric with the stator, are installed on the upper and lower end faces of the stator's sealed container. Multiple supports are evenly distributed on these supports, with the normal to the support surface perpendicular to the rotor's axis. Hydraulic cylinders are installed on the support surfaces, with sliding rods sliding within each cylinder. A ball is fixedly connected to the top of the sliding rod. Hydraulic oil inlets / outlets and valves are located at the bottom of the hydraulic cylinders. Ball seats, opposite to the support surfaces, are installed on the two end faces of the rotor. The distance between the ball seat on the upper end face and the upper end face is less than the distance between the support and the upper end face of the sealed container; the distance between the ball seat on the lower end face and the lower end face is greater than the distance between the support and the lower end face of the sealed container.

[0027] A groove with the same diameter as the sphere is provided on the surface opposite to the surface of the ball seat and the support, and the depth of the groove is greater than the diameter of the sphere.

[0028] All hydraulic cylinder inlets and outlets are connected in parallel to the same external hydraulic device. The external hydraulic device injects hydraulic oil into the hydraulic cylinder, driving the ball of the sliding rod to abut against the ball seat. After the pressure value of the external hydraulic device reaches a certain value, the valve on the hydraulic cylinder is closed, and then the connection between the external hydraulic device and the inlet and outlet of the hydraulic cylinder is disconnected. When the ball is fully abutting against the groove, the convex ring is offset from the high-temperature superconductor by 0-10mm.

[0029] After the superconducting coil enters the superconducting state, a direct current is applied to it, and then the high-temperature superconductor is cooled to induce the superconducting state. Subsequently, an external hydraulic device is used to extract the hydraulic oil from the hydraulic cylinder and close the valve. The rotor then achieves stable suspension inside the stator.

[0030] For flat magnetic levitation devices, such as Figure 2 As shown, the flat magnetic levitation device includes multiple stators, multiple rotors, superconducting coils, a high-temperature superconductor, rotor connectors, and stator connectors. The multiple stators and rotors share a common axis. Each stator is arranged in a one-to-one configuration with one of the rotors. Each rotor has two convex rings protruding in the same radial direction. A space exists between the two convex rings on the same rotor. A high-temperature superconductor is fixedly connected to the stator at the position corresponding to the convex ring. A superconducting coil is installed between the middle of each stator and rotor, and the superconducting coil is fixedly connected to the stator. The multiple stators are connected by stator connectors, and the multiple rotors are connected by rotor connectors. A gap exists between the convex ring and its corresponding high-temperature superconductor. The stators, superconducting coils, and high-temperature superconductors are housed inside a sealed container.

[0031] Specifically, such as Figure 2 As shown, the central rotor is the shaft, the remaining rotors are rings, and the stator is a ring structure. The shaft has two radially outward-facing protruding rings distributed axially. Two stators are positioned outside the shaft, and two rotors are positioned outside the two stators, alternating radially outwards. The outermost structure is a stator ring. The two stators are in close contact, and the two rotors are in close contact; alternatively, the two stators and two rotors are a single integrated structure. The two protruding rings are located on the opposing surfaces of the stators and rotors.

[0032] If the rotor at the very center is a ring, then external devices can be inserted into the center of the ring for fixation.

[0033] The outermost structure can also be a rotor ring.

[0034] High-temperature superconductors can be in the form of a ring structure or multiple sector-shaped structures combined into a ring structure.

[0035] like Figure 2 As shown, the stator can have an annular groove in the middle, and the superconducting coil is placed inside the annular groove.

[0036] The stator may also omit the grooves, with the superconducting coils located inside the grooves formed between the convex rings of the rotor. A backplate is placed on the side of the high-temperature superconductor near the convex rings; the backplate improves system strength and magnetic field utilization. The stator, backplate, and rotor are all made of magnetically conductive material.

[0037] Superconducting coils include low-temperature superconducting coils and high-temperature superconducting coils.

[0038] An annular support, concentric with the stator, is mounted on the surface of the outermost stator's sealed container. Multiple supports are evenly distributed on this annular support, with the normal to the support surface intersecting perpendicularly with the rotor's axis. A hydraulic cylinder is mounted on the support surface, with a sliding rod sliding within it. A ball is fixedly connected to the top of the sliding rod. Hydraulic oil inlet / outlet and valves are located at the bottom of the hydraulic cylinder. A ball seat, opposite the support surface, is mounted on the outermost rotor surface. A groove with the same diameter as the ball is formed on the surface of the ball seat opposite the support surface.

[0039] All hydraulic cylinder inlets and outlets are connected in parallel to the same external hydraulic device. The external hydraulic device injects hydraulic oil into the hydraulic cylinder, driving the ball of the sliding rod to abut against the ball seat. After the pressure value of the external hydraulic device reaches a certain value, the valve on the hydraulic cylinder is closed, and then the connection between the external hydraulic device and the inlet and outlet of the hydraulic cylinder is disconnected. When the ball is fully abutting against the groove, the convex ring is offset from the high-temperature superconductor by 0-10mm.

[0040] After the superconducting coil enters the superconducting state, a direct current is applied to it, and then the high-temperature superconductor is cooled to induce the superconducting state. Subsequently, an external hydraulic device is used to extract the hydraulic oil from the hydraulic cylinder and close the valve. The rotor then achieves stable suspension inside the stator.

[0041] A buffer device is provided on the surfaces opposite to the stator and rotor connector. The buffer device includes magnets respectively disposed on the rotor connector and the stator, with the magnets on the rotor connector and the stator facing each other and having opposite polarities on their opposing surfaces. The buffer device also includes balls disposed on the surfaces opposite to the stator and rotor connector, the balls being able to rotate freely on the stator surface, and the distance between the top of the balls and the stator surface being greater than the height of the stator magnets.

[0042] Furthermore, the buffer device can also be disposed between the stator connector and the rotor. Accordingly, balls are disposed on the surface of the stator connector, and magnets of opposite polarity are disposed between the opposing surfaces of the stator connector and the rotor, with the height of the balls being greater than the height of the magnets.

[0043] Furthermore, a retractable structure, such as a cylinder or spring, is provided between the balls and the stator or stator connector.

[0044] Furthermore, when the passive telescopic structure is in its maximum compressed state, the height of the ball is greater than the height of the magnet.

[0045] This invention also discloses a design method for magnetic levitation bearings, employing a combination of flat magnetic levitation bearings and radial magnetic levitation bearings. Specifically, firstly, the number of stators used in the flat magnetic levitation bearings is determined based on the diameter of the levitation device; then, the corresponding magnetic levitation force is calculated. If the magnetic levitation force meets the requirements, the design is complete; if the magnetic levitation force is insufficient, the number of stator-rotor pairs is calculated based on the magnetic levitation force deficit and the magnetic levitation force generated by a single stator and rotor in the flat magnetic levitation bearing.

[0046] Specifically, the number of stator-rotor pairs = F 缺 / F 磁 If the result is not an integer, the remainder is counted as one.

[0047] The axial dimensions of the stator and rotor are increased according to the number of stator-rotor pairs. Specifically, the number of axially mounted convex rings, high-temperature superconductors, and superconducting coils is increased. The increase is prioritized from the rotor center outwards. Specifically, a pair of stator and rotor pairs is added at the center, followed by one layer added sequentially outwards until the outermost layer is reached. If the number of stator-rotor pairs is not fully utilized after the layout on the same layer is completed, another layer of stator and rotor pairs is added sequentially outwards from the center until the number of stator and rotor pairs is exhausted.

Claims

1. A radial magnetic levitation device, characterized in that: The system includes a stator, a rotor, multiple superconducting coils, and multiple high-temperature superconductors. The stator and rotor are concentrically arranged. The rotor has N radially protruding rings evenly spaced along its axial direction. The width of the two rings at both ends of the rotor is half that of the remaining rings. N+1 high-temperature superconductors are fixedly connected at intervals inside the stator. The spacing between two adjacent rings is equal to the spacing between two adjacent high-temperature superconductors. The width d1 of the two high-temperature superconductors at the ends is the same as the width of the rings at the ends, and the width d2 of the remaining high-temperature superconductors is the same as the width of the rings in the middle. A superconducting coil is installed in the middle of the spacing between two adjacent high-temperature superconductors and is fixedly connected to the stator. There is a gap between the ring and its opposite high-temperature superconductor.

2. The radial magnetic levitation device according to claim 1, characterized in that: Annular supports concentric with the stator are provided on the upper and lower end faces of the stator's sealed container. Multiple supports are evenly arranged on the annular supports. The normals of the support surfaces intersect perpendicularly with the rotor's axis. Hydraulic cylinders are provided on the support surfaces. Sliding rods are slidably installed inside the hydraulic cylinders. A ball is fixedly connected to the top of the sliding rod. Hydraulic oil inlet and outlet and valves are provided at the bottom of the hydraulic cylinders. A groove with the same diameter as the ball is provided on the surface of the ball seat opposite to the support surface. The depth of the groove is greater than the diameter of the ball.

3. The radial magnetic levitation device according to claim 1, characterized in that: Ball seats are provided on both ends of the rotor, opposite to the support surface. The distance between the ball seat on the upper end face and the upper end face is less than the distance between the support and the upper end face of the sealed container; the distance between the ball seat on the lower end face and the lower end face is greater than the distance between the support and the lower end face of the sealed container.

4. A design method for a magnetic levitation bearing, employing a design method combining a flat magnetic levitation bearing and a radial magnetic levitation bearing, wherein the radial magnetic levitation bearing uses a radial magnetic levitation device as described in claim 1, characterized in that: First, determine the number of stators used in the flat magnetic levitation bearing based on the diameter of the levitation device; calculate the corresponding magnetic levitation force. If the magnetic levitation force meets the requirements, the design is complete; if the magnetic levitation force is insufficient, calculate the number of stator-rotor pairs based on the magnetic levitation force deficit and the magnetic levitation force generated by a single stator-rotor in the flat magnetic levitation bearing, and then increase the number of stator-rotor pairs accordingly in the axial direction.

5. The magnetic levitation bearing design method according to claim 4, characterized in that: Number of stator and rotor pairs = F 缺 / F 磁 .

6. The magnetic levitation bearing design method according to claim 5, characterized in that: The axial dimensions of the stator and rotor are increased according to the number of stator and rotor pairs.

7. The magnetic levitation bearing design method according to claim 4, characterized in that: The number of stator and rotor pairs is gradually increased from the center outwards. Specifically, a pair of stator and rotor pairs is added at the center, and then a layer is added outwards in sequence until the outermost layer is reached. If the number of stator and rotor pairs is not used up after the layout of the same layer is completed, another layer of stator and rotor pairs is added outwards from the center until the number of stator and rotor pairs is used up.

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