Five-degree-of-freedom permanent magnet biased magnetic suspension bearing

Abstract

The utility model discloses a five-degree-of-freedom permanent magnet biased magnetic suspension bearing, which comprises an outer stator group and an inner rotor group, the outer stator group comprises a stator iron core and two stator magnetic rings respectively arranged at two end parts of the stator iron core, a plurality of stator teeth are arranged on the inner wall of the stator iron core along the radial direction, and coils are wound on the stator teeth; the inner rotor set comprises a rotor core and two rotor permanent magnets arranged at the two ends of the rotor core respectively. The rotor core and the stator teeth are arranged oppositely in the radial direction and are in clearance fit. The two stator magnetic rings and the two rotor permanent magnets are magnetized in the axial direction, the magnetizing directions of the two stator magnetic rings are opposite, and meanwhile the magnetizing direction of any stator magnetic ring is opposite to the magnetizing direction of the rotor permanent magnet opposite to the stator magnetic ring in the radial direction. According to the utility model, a static bias magnetic field is provided by the permanent magnet acting force between the stator magnetic ring and the rotor permanent magnet, dynamic suspension auxiliary adjustment is carried out by using electromagnetism, the power consumption of the system is obviously reduced, the size is small, and the weight is light.

Description

Technical Field

[0001] The utility model relates to the technical field of bearings, and particularly relates to a five-degree-of-freedom permanent magnet biased magnetic levitation bearing. Background Art

[0002] Traditional mechanical bearings have defects such as large frictional losses, serious heating, and limited service life under high-speed rotation conditions. To overcome these problems, magnetic levitation bearing technology has emerged. In modern industries, medical fields, etc., magnetic levitation bearings have been more and more widely used due to their advantages such as non-contact, frictionless, and lubrication-free.

[0003] With the continuous progress of technology, multi-degree-of-freedom magnetic levitation bearings have become a hot topic in research and application. However, there are still some significant problems in the actual application of existing multi-degree-of-freedom magnetic levitation bearings. On the one hand, although traditional magnetic levitation bearings can achieve a certain degree of suspension and control, they often consume high power, which not only increases the operating cost of the system but also may cause related problems such as heat dissipation, restricting their application in environments with limited energy supply or harsh heat dissipation conditions, such as implantable blood pumps. This is a significant limiting factor affecting the stability and safety of blood pumps in the in-vivo environment. On the other hand, the existing magnetic levitation bearing designs are usually large and complex. In equipment with limited space, such as implantable blood pumps, the excessive volume not only increases the surgical difficulty and patient trauma but also affects the patient's comfort and recovery process. Therefore, it is still a major challenge to achieve good performance in applications such as blood pumps that require extremely high precision and stability, while meeting the requirements of low power consumption and small volume. Summary of the Utility Model

[0004] The problem to be solved by the utility model is to provide a five-degree-of-freedom permanent magnet biased magnetic levitation bearing to overcome the defects of high power consumption, large volume, and large weight of existing magnetic levitation bearings.

[0005] The technical solution adopted by the present utility model to solve its technical problems is as follows: A five-degree-of-freedom permanent magnet biased magnetic suspension bearing includes an outer stator group and an inner rotor group. The inner rotor group is disposed in the outer stator group. The outer stator group includes an annular stator core and two stator magnetic rings respectively disposed at both ends of the stator core. A plurality of stator teeth are radially provided on the inner wall of the stator core and are distributed at equal intervals in a ring shape, and a coil is wound around each stator tooth. The inner rotor group includes a rotor core and two rotor permanent magnets respectively disposed at both ends of the rotor core. The rotor core is disposed radially opposite to the plurality of stator teeth and is in clearance fit therewith. Among them, the two stator magnetic rings and the two rotor permanent magnets are all magnetized axially, and the magnetization directions of the two stator magnetic rings are opposite to each other. At the same time, the magnetization direction of any one of the stator magnetic rings is also opposite to the magnetization direction of a rotor permanent magnet radially opposite thereto.

[0006] As a further improvement of the present utility model, the stator magnetic ring and the rotor permanent magnet on the same axial side are distributed radially opposite to each other, and can jointly form a closed magnetic circuit with the stator core and the rotor core.

[0007] As a further improvement of the present utility model, the stator magnetic ring and the rotor permanent magnet on the same axial side have the same thickness and the same height.

[0008] As a further improvement of the present utility model, the coils wound around each stator tooth work independently of each other.

[0009] As a further improvement of the present utility model, the number of the stator teeth is more than three.

[0010] As a further improvement of the present utility model, both the outer stator group and the inner rotor group are provided with two groups arranged axially, and non-magnetic washers are installed between the two outer stator groups and between the two inner rotor groups.

[0011] As a further improvement of the present utility model, a plurality of convex rings arranged at intervals axially are provided on the outer circumferential surface of the rotor core, and a plurality of convex teeth are provided on the inner side surface of each stator tooth. The plurality of convex teeth are distributed in one-to-one correspondence with the plurality of convex rings.

[0012] As a further improvement of the present utility model, the outer stator group further includes two stator yokes, and the two stator yokes are respectively disposed at one end of the two stator magnetic rings facing away from each other; the inner rotor group further includes two rotor yokes, and the two rotor yokes are respectively disposed at one end of the two rotor permanent magnets facing away from each other; the stator magnetic ring and the rotor permanent magnet on the same axial side can jointly form a closed magnetic circuit with the stator core, the rotor core, the stator yoke and the rotor yoke.

[0013] As a further improvement of the present utility model, an annular inner flange extends radially inwards from the stator yoke, and an annular outer flange extends radially outwards from the rotor yoke. The inner flange of the stator yoke and the outer flange of the rotor yoke located on the same axial side are distributed radially opposite to each other and are in clearance fit.

[0014] As a further improvement of the present utility model, two sets of the outer stator group and the inner rotor group are both arranged in an axial arrangement, and non-magnetic washers are installed between the two sets of the outer stator group and the two sets of the inner rotor group.

[0015] The beneficial effects of the present utility model are as follows:

[0016] 1. The present utility model provides a five-degree-of-freedom permanent magnet biased magnetic suspension bearing. By adopting the form of a combination of permanent magnet and electromagnetic, and using the permanent magnet force between the stator magnetic ring and the rotor permanent magnet to provide a static bias magnetic field, and at the same time using the electromagnet composed of the stator teeth and the coil as a dynamic suspension auxiliary adjustment, it not only maintains the low power consumption characteristics of the permanent magnet bearing, but also realizes high-precision suspension and adjustment through electromagnetic control, achieving five-degree-of-freedom suspension. It can not only reduce the bias current required for electromagnetic control, significantly reduce the power consumption of the system, making the bearing more advantageous in application scenarios that require long-term operation or limited energy supply, but also enables the bearing to have higher load-bearing capacity and better stability, and can adapt to various complex working conditions;

[0017] 2. The present utility model is provided with permanent magnets at both the upper and lower ends of the stator core and the rotor core, and the permanent magnets on the upper and lower sides can form two closed magnetic circuits through the stator teeth of the middle stator core and the rotor core, making the magnetic force utilization rate higher. Under the same magnetic force requirement, the volume can be made smaller, the structure is more compact, it can provide a stable static bias magnetic field, and at the same time the bias current required for electromagnetic control is small, thus realizing a five-degree-of-freedom permanent magnet biased magnetic bearing with low power consumption, small volume and light weight;

[0018] 3. The present utility model can enhance the magnetic circuit structure, improve the magnetic force conduction efficiency, reduce the magnetic force loss, enhance the static bias magnetic field provided by the stator magnetic ring and the rotor permanent magnet, improve the suspension stability effect, and at the same time have a better effect of reducing power by arranging the stator yoke on the outer rotor group and the rotor yoke on the inner rotor group;

[0019] 4. The present utility model further improves the suspension stability of the inner rotor group in the axial and radial directions, and has a better constraint effect on the axial and radial degrees of freedom, especially on the radial deflection degree of freedom of the inner rotor group by arranging two sets of the outer stator group and two sets of the inner rotor group and relying on the permanent magnet forces between four pairs of stator magnetic rings and rotor permanent magnets to provide a static bias magnetic field. Description of the Drawings

[0020] Figure 1 This is a perspective view of the first embodiment of the five-degree-of-freedom permanent-magnet biased magnetic suspension bearing of the present utility model;

[0021] Figure 2 This is a sectional view of the first embodiment of the five-degree-of-freedom permanent-magnet biased magnetic suspension bearing of the present utility model;

[0022] Figure 3 This is a perspective view of the stator core of the first embodiment of the five-degree-of-freedom permanent-magnet biased magnetic suspension bearing of the present utility model;

[0023] Figure 4 This is a schematic diagram of the magnetic circuit of the first embodiment of the five-degree-of-freedom permanent-magnet biased magnetic suspension bearing of the present utility model;

[0024] Figure 5 This is a schematic diagram of the axial offset of the inner rotor group of the first embodiment of the five-degree-of-freedom permanent-magnet biased magnetic suspension bearing of the present utility model;

[0025] Figure 6 This is a schematic diagram of the radial offset of the inner rotor group of the first embodiment of the five-degree-of-freedom permanent-magnet biased magnetic suspension bearing of the present utility model;

[0026] Figure 7 This is a top view of the second embodiment of the five-degree-of-freedom permanent-magnet biased magnetic suspension bearing of the present utility model;

[0027] Figure 8 This is a sectional view of the third embodiment of the five-degree-of-freedom permanent-magnet biased magnetic suspension bearing of the present utility model;

[0028] Figure 9 This is a schematic diagram of the radial deflection of the inner rotor group of the third embodiment of the five-degree-of-freedom permanent-magnet biased magnetic suspension bearing of the present utility model;

[0029] Figure 10 This is a perspective view of the third embodiment of the five-degree-of-freedom permanent-magnet biased magnetic suspension bearing of the present utility model;

[0030] Figure 11 This is a sectional view of the third embodiment of the five-degree-of-freedom permanent-magnet biased magnetic suspension bearing of the present utility model;

[0031] Figure 12 This is a sectional view of the fourth embodiment of the five-degree-of-freedom permanent-magnet biased magnetic suspension bearing of the present utility model.

[0032] The following description is made in conjunction with the accompanying drawings:

[0033] 1. Stator core; 101. Stator teeth; 1011. Convex teeth; 102. Stator ring;

[0034] 2. Stator magnetic ring; 3. Coil; 4. Rotor core; 401. Convex ring; 5. Rotor permanent magnet; 6. Non-magnetic washer; 7. Stator yoke; 701. Inner flange; 8. Rotor yoke; 801. Outer flange. Detailed implementation mode

[0035] The following will combine with the attached drawings to make a detailed description of the preferred embodiments of the present utility model.

[0036] Embodiment 1

[0037] Refer to Figures 1 to 6 , the present utility model provides a five-degree-of-freedom permanent magnet biased magnetic bearing, including: an outer stator group and an inner rotor group. The outer stator group is cylindrical, and the inner rotor group is arranged in the outer stator group and is in clearance fit with the outer stator group.

[0038] Among them, the outer stator group includes an annular stator core 1 and two stator magnetic rings 2 respectively arranged at the upper and lower ends of the stator core 1. The two stator magnetic rings 2 are both fixedly connected to the stator core 1, and the fixing method can be but not limited to bonding, etc., and the two stator magnetic rings 2 are both coaxially distributed with the stator core 1.

[0039] Furthermore, the stator core 1 includes a stator ring 102 and a plurality of stator teeth 101. The plurality of stator teeth 101 are integrally arranged on the inner wall of the stator ring 102 along the radial direction of the stator ring 102, and the plurality of stator teeth 101 are evenly distributed in a ring shape at equal intervals. A coil 3 is wound around the outer circumference of each stator tooth 101 for one circle.

[0040] In this embodiment, the thicknesses of the plurality of stator teeth 101 are the same as the thickness of the stator ring 102, that is, the upper and lower end faces of the plurality of stator teeth 101 are flush with the upper and lower end faces of the stator ring 102. The outer diameter and ring width of the stator ring 102 are the same as the outer diameter and ring width of the two stator magnetic rings 2.

[0041] Refer to Figure 2 , the inner rotor group includes a rotor core 4 and two rotor permanent magnets 5 respectively arranged at the upper and lower ends of the rotor core 4. The rotor core 4 is arranged radially opposite to the plurality of stator teeth 101 and is in clearance fit. When the coil 3 on any one stator tooth 101 is energized, a radial suction force can be generated between the magnetized stator tooth 101 and the rotor core 4.

[0042] In this embodiment, the two rotor permanent magnets 5 are both fixedly connected to the rotor core 4, and the fixing method can be but not limited to bonding, etc., and the two rotor permanent magnets 5 are both coaxially distributed with the rotor core 4. Among them, the stator magnetic ring 2 and the rotor permanent magnet 5 located on the same axial side (taking Figure 2 as a reference, that is, located on the upper side or the lower side) are radially opposite to each other.

[0043] In the present utility model, the two stator magnetic rings 2 and the two rotor permanent magnets 5 are both axially magnetized, that is, their two magnetic polarities are distributed on the corresponding upper and lower ends respectively, and the magnetization directions of the two stator magnetic rings 2 are opposite to each other, and the magnetization directions of the two rotor permanent magnets 5 are also opposite to each other. At the same time, the magnetization direction of any one stator magnetic ring 2 is also opposite to the magnetization direction of a rotor permanent magnet 5 radially opposite thereto.

[0044] The axial force of the five-degree-of-freedom permanent-magnet biased magnetic suspension bearing of the present utility model is controlled by the permanent-magnet force between the stator magnetic ring 2 and the rotor permanent magnet 5. Since both the stator magnetic ring 2 and the rotor permanent magnet 5 adopt axial magnetization and the magnetization directions of the stator magnetic ring 2 and the rotor permanent magnet 5 on the same side are opposite, once the inner rotor group axially deviates from the origin, due to the interaction force between the stator magnetic ring 2 and the rotor permanent magnet 5, a restoring force that makes the inner rotor group return to the origin will be generated axially. This structure will generate a restoring force towards the origin axially whether the inner rotor group is axially upward or axially downward, enabling the axial suspension of the inner rotor group.

[0045] The radial force of the five-degree-of-freedom permanent-magnet biased magnetic suspension bearing of the present utility model is mainly controlled by the permanent-magnet force between the stator magnetic ring 2 and the rotor permanent magnet 5. The permanent-magnet forces generated by the two stator magnetic rings 2 at the upper and lower ends of the stator iron core 1 converge into the stator iron core 1 to form a main magnetic path. The main magnetic flux path is transmitted from the stator teeth 101 on the stator iron core 1 through the air gap between the stator iron core 1 and the rotor iron core 4 to the rotor iron core 4, and then transmitted to the rotor permanent magnet 5, so that a closed magnetic circuit can be jointly formed between the stator magnetic rings 2 and the rotor permanent magnets 5 on the upper and lower sides, the stator iron core 1, and the rotor iron core 4, driving the radial suspension of the inner rotor group; at the same time, by controlling the current direction and magnitude of the control coil 3, the attraction force of the stator teeth 101 on the rotor iron core 4 is controlled as an auxiliary control force. When the inner rotor group is disturbed and radially deviates, the Hall sensor detects the deviation amount and feeds it back to the control system. The control system controls the current of one or more coils 3 closer to the inner rotor group to decrease, so as to reduce the attraction force of the stator teeth 101 on the rotor iron core 4, or changes the current direction of the coil 3 to generate a magnetic field opposite to the direction of the main magnetic path, further reducing the attraction force of the stator teeth 101 on the rotor iron core 4. At the same time, it is also possible to control the current direction and increase the current of one or more coils 3 farther away to generate a magnetic field in the same direction as the main magnetic path to increase the attraction force of the stator teeth 101 on the rotor iron core 4 until the Hall sensor detects that the inner rotor group is in the radially centered position, the current directions of the coils 3 are consistent, and the current decreases to a continuous current that can keep the inner rotor group stable.

[0046] It can be seen that the five-degree-of-freedom permanent magnet biased magnetic suspension bearing of the present utility model adopts a form of combination of permanent magnet and electromagnetism, and uses the permanent magnet force between the stator magnetic ring 2 and the rotor permanent magnet 5 to provide a static bias magnetic field. At the same time, an electromagnet composed of the stator teeth 101 and the coil 3 of the stator is used as a dynamic suspension auxiliary adjustment, which not only maintains the low power consumption characteristic of the permanent magnet bearing, but also realizes high-precision suspension and adjustment through electromagnetic control, and realizes five-degree-of-freedom suspension. It can not only reduce the bias current required for electromagnetic control, significantly reduce the power consumption of the system, making the bearing more advantageous in application scenarios that require long-term operation or limited energy supply, but also enable the bearing to have higher load-carrying capacity and better stability, and can adapt to various complex working conditions.

[0047] In addition, there has always been a contradiction between the power consumption and volume of magnetic suspension bearings at present, that is, when the power is low, the volume must be made very large; while when the volume is small, higher power is required to maintain stable suspension, and the heat generation will increase accordingly.

[0048] To solve the above technical problems, the present utility model is provided with permanent magnets at both the upper and lower ends of the stator core 1 and the rotor core 4, and the permanent magnets on the upper and lower sides can form two closed magnetic circuits through the stator teeth 101 of the middle stator core 1 and the rotor core 4, so that the magnetic force utilization rate is higher. Under the same magnetic force requirement, the volume can be made smaller, the structure is more compact, and a stable static bias magnetic field can be provided. At the same time, the bias current required for electromagnetic control is small, thus realizing a five-degree-of-freedom permanent magnet biased magnetic bearing with low power consumption, small volume and light weight. For example, when the five-degree-of-freedom permanent magnet biased magnetic suspension bearing of the present utility model is used in a blood pump, on the premise of ensuring blood compatibility and long-term reliability, it can realize more efficient energy utilization and a more compact structural design to improve the overall performance and clinical applicability of the blood pump.

[0049] In the present utility model, the rotor core 4 and the two upper and lower rotor permanent magnets 5 can be annular or cylindrical, and the former is adopted in this embodiment.

[0050] Preferably, the stator magnetic ring 2 and the rotor permanent magnet 5 located on the same axial side (i.e., located on the upper side or the lower side) have the same thickness and the same height, that is to say, the upper and lower end faces of the stator magnetic ring 2 located on the upper and lower same sides are flush with the upper and lower end faces of the rotor permanent magnet 5 to provide a more stable axial suspension effect.

[0051] Among them, the number of stator teeth 101 is more than three, preferably three to twelve, and specifically four in this embodiment. The coils 3 wound on the four stator teeth 101 all work independently. Therefore, when the inner rotor group has a radial offset, the current direction and magnitude of the corresponding coil 3 can be independently controlled.

[0052] Such as Figure 4As shown, in this embodiment, the upper end of the stator magnetic ring 2 on the upper side is the S pole and the lower end is the N pole; the upper end of the stator magnetic ring 2 on the lower side is the N pole and the lower end is the S pole; the upper end of the rotor permanent magnet 5 on the upper side is the N pole and the lower end is the S pole; the upper end of the rotor permanent magnet 5 on the lower side is the S pole and the lower end is the N pole. The permanent magnetic forces generated by the stator magnetic rings 2 on the upper and lower sides converge into the stator iron core 1 to form the main magnetic path. The main magnetic flux path is transmitted from the stator teeth 101 on the stator iron core 1 through the air gap between the stator iron core 1 and the rotor iron core 4 to the rotor iron core 4, then to the rotor permanent magnet 5, and finally back to the stator magnetic ring 2, so that a closed magnetic circuit can be jointly formed between the stator magnetic rings 2 and the rotor permanent magnets 5 on the upper and lower sides and the middle stator iron core 1 and rotor iron core 4 (as Figure 4 indicated by the arrow direction in

[0053] ). Without external force interference, the permanent magnetic forces of the two stator magnetic rings 2 and the two rotor permanent magnets 5 are relied on to provide a static bias magnetic field, so that the inner rotor group is in an absolutely dynamically suspended state in the axial and radial directions.

[0054] Of course, in other embodiments of the present invention, the pole directions of all the stator magnetic rings 2 and the rotor permanent magnets 5 can also be opposite. Figure 5 As shown, when the inner rotor group is axially upwardly offset due to external force interference, the stator magnetic rings 2 on the upper and lower sides respectively generate an axially downward attractive force on the two rotor permanent magnets 5, causing the inner rotor group to recover to the origin.

[0055] As shown in Figure 6 , when the inner rotor group is radially rightwardly offset due to external force interference, the Hall sensor detects the offset amount and feeds it back to the control system. The control system controls the current of one coil 3 on the right side to decrease, so as to reduce the attractive force of the stator teeth 101 on the rotor iron core 4. If the current of one coil 3 on the right side decreases to 0 and the inner rotor group is still offset to the right, then the current direction of one coil 3 on the right side is changed to generate a magnetic field opposite to the direction of the main magnetic path, further reducing the attractive force of the stator teeth 101 on the rotor iron core 4. At the same time, the current direction of one coil 3 on the left side can also be controlled and the current increased to generate a magnetic field in the same direction as the main magnetic path, so as to increase the attractive force of the stator teeth 101 on the rotor iron core 4, until the Hall sensor detects that the inner rotor group is in the radially centered position, the current directions of the coils 3 are the same, and the current decreases to a continuous current that can keep the inner rotor group stable.

[0056] It can be seen that while the five-degree-of-freedom permanent magnet biased magnetic suspension bearing of the present invention realizes stable suspension control in the radial direction, it has good axial suspension stiffness and suspension stability, improves the flexibility and stability of the system, and has the advantages of no mechanical wear, no need for lubrication, no pollution, etc., and is particularly suitable for high-speed application occasions.

[0057] Embodiment 2

[0058] Refer to Figure 7 , the difference between this embodiment and Embodiment 1 is that: on the inner wall of the stator ring 102, the stator core 1 is provided with eight stator teeth 101 that are evenly distributed in a ring shape along the radial direction, and each of the eight stator teeth 101 is wound with an independently controllable coil 3. By independently controlling the eight coils 3, a more stable auxiliary control radial suspension effect can be provided.

[0059] Embodiment 3

[0060] Refer to Figure 8 , the difference between this embodiment and Embodiment 1 or Embodiment 2 is that: both the outer stator group and the inner rotor group are provided with two groups. The two outer stator groups are arranged and distributed along the axial direction, and the two inner rotor groups are also arranged and distributed along the axial direction, and the two inner rotor groups are correspondingly arranged in the two outer stator groups.

[0061] By providing two outer stator groups and two inner rotor groups, the present utility model relies on the permanent magnetic force between four pairs of stator magnetic rings 2 and rotor permanent magnets 5 (each pair is composed of a stator magnetic ring 2 and a rotor permanent magnet 5 in each layer) to provide a static bias magnetic field, further improving the suspension stability of the inner rotor group in the axial and radial directions, and having a better constraint effect on the axial and radial degrees of freedom.

[0062] When there is an axial offset, at the same time, relying on the attractive force generated by the four pairs of stator magnetic rings 2 and rotor permanent magnets 5 in the axial direction, the inner rotor group is restored to the origin.

[0063] When there is a radial offset, the current directions and magnitudes of the corresponding multiple coils 3 can be controlled simultaneously to adjust the electromagnetic force to restore the inner rotor group to the radially centered position.

[0064] When there is a radial deflection, such as Figure 9As shown, the inner rotor group deflects clockwise by a certain angle. The upper end of the inner rotor group is closer to a stator tooth 101 in the upper right, and the lower end of the inner rotor group is closer to a stator tooth 101 in the lower left. The Hall sensor detects the offset of the inner rotor group and feeds it back to the control system. The control system controls the current of a coil 3 in the upper right to decrease, so as to reduce the attraction of the stator tooth 101 in the upper right to the rotor core 4. If the current of a coil 3 in the upper right decreases to 0 and the inner rotor group is still deflecting clockwise, then change the current direction of a coil 3 in the upper right to generate a magnetic field opposite to the direction of the main magnetic path, further reducing the attraction of the stator tooth 101 in the upper right to the rotor core 4. At the same time, the control system controls the current of a coil 3 in the lower left to decrease, so as to reduce the attraction of the stator tooth 101 in the lower left to the rotor core 4. If the current of a coil 3 in the lower left decreases to 0 and the inner rotor group is still deflecting clockwise, then change the current direction of a coil 3 in the lower left to generate a magnetic field opposite to the direction of the main magnetic path, further reducing the attraction of the stator tooth 101 in the lower left to the rotor core 4. Meanwhile, the current directions of the coils 3 in the upper left and lower right can also be controlled and the current increased to generate a magnetic field in the same direction as the main magnetic path, so as to increase the attraction of the stator teeth 101 in the upper left and lower right to the rotor core 4 until the Hall sensor detects that the inner rotor group is in the radially centered position, the current directions of the coils 3 are the same, and the current decreases to a continuous current that can keep the inner rotor group stable.

[0065] It can be seen that the present utility model adopting two sets of outer stator groups and two sets of inner rotor groups can further improve the restraint effect on the radial deflection freedom degree of the inner rotor group.

[0066] It is worth mentioning that non-magnetic washers 6 are fixedly installed between the two sets of outer stator groups and the two sets of inner rotor groups. Through the non-magnetic washers 6, mutual interference between the two sets of outer stator groups and the two sets of inner rotor groups can be effectively prevented.

[0067] Embodiment 4

[0068] Referring to Figure 10 and Figure 11 , the difference between this embodiment and Embodiment 1 is that: the outer stator group in this embodiment further includes two stator yokes 7, and the two stator yokes 7 are respectively fixedly arranged at one end of the two stator magnetic rings 2 facing away from each other. The inner rotor group further includes two rotor yokes 8, and the two rotor yokes 8 are respectively fixedly arranged at one end of the two rotor permanent magnets 5 facing away from each other. The two rotor yokes 8 are respectively located in the middle of the two stator yokes 7 and are distributed radially opposite to each other one by one.

[0069] The permanent magnetic forces generated by the two stator magnetic rings 2 at the upper and lower ends of the stator core 1 converge into the stator core 1 to form a main magnetic path. The main magnetic flux path is transmitted from the stator teeth 101 on the stator core 1 through the air gap between the stator core 1 and the rotor core 4 to the rotor core 4, and then transmitted to the upper and lower rotor yokes 8 through the upper and lower rotor permanent magnets 5 respectively. Finally, it returns to the two stator magnetic rings 2 through the upper and lower stator yokes 7 respectively. Thus, a closed magnetic circuit can be jointly formed between the stator magnetic rings 2, rotor permanent magnets 5, stator yokes 7 and rotor yokes 8 located on the same axial side, as well as the stator core 1 and the rotor core 4. By providing the stator yoke 7 and the rotor yoke 8, the present utility model can enhance the magnetic circuit structure, improve the magnetic force conduction efficiency, reduce the magnetic force loss, enhance the static bias magnetic field provided by the stator magnetic ring 2 and the rotor permanent magnet 5, improve the suspension stability effect, and simultaneously achieve a better effect of reducing power.

[0070] Wherein, the stator yoke 7 extends radially inward with an annular inner flange 701, and the rotor yoke 8 extends radially outward with an annular outer flange 801. The inner flange 701 of the stator yoke 7 and the outer flange 801 of the rotor yoke 8 located on the same axial side are distributed radially opposite and in clearance fit to reduce the magnetic field air gap between the stator yoke 7 and the rotor yoke 8 and improve the magnetic force conduction efficiency.

[0071] It is worth mentioning that a plurality of convex rings 401 arranged at intervals along the axial direction are provided on the outer circumferential surface of the rotor core 4. In this embodiment, the convex rings 401 are specifically arranged as three; three convex teeth 1011 are correspondingly provided on the inner side surface of each stator tooth 101, and the three convex teeth 1011 on each stator tooth 101 are distributed radially opposite to the three convex rings 401 one by one. In this way, the pole facing area between the stator tooth 101 and the rotor core 4 can be reduced, the magnetic flux density can be increased, and thus the magnetic force can be greater; at the same time, through the cooperation of the convex teeth 1011 and the convex rings 401, a plurality of branch magnetic paths can also be formed to further enhance the magnetic circuit structure.

[0072] Embodiment Five

[0073] Refer to Figure 12 , the difference between this embodiment and Embodiment Four is that: both the outer stator group and the inner rotor group are provided with two groups. The two outer stator groups are arranged and distributed along the axial direction, and the two inner rotor groups are also arranged and distributed along the axial direction, and the two inner rotor groups are correspondingly arranged in the two outer stator groups one by one. Non-magnetic gaskets 6 are fixedly installed between the two outer stator groups and the two inner rotor groups. Through the non-magnetic gaskets 6, the mutual interference between the two outer stator groups and the two inner rotor groups can be effectively prevented.

[0074] It can be seen that the five-degree-of-freedom permanent magnet biased magnetic suspension bearing of the present utility model adopts a form of combination of permanent magnet and electromagnetic, and uses the permanent magnet force between the stator magnetic ring 2 and the rotor permanent magnet 5 to provide a static bias magnetic field. At the same time, the electromagnet composed of the stator teeth 101 and the coil 3 is used as a dynamic suspension auxiliary adjustment, which not only maintains the low power consumption characteristics of the permanent magnet bearing, but also realizes high-precision suspension and adjustment through electromagnetic control, achieving five-degree-of-freedom suspension. It can not only reduce the bias current required for electromagnetic control, significantly reduce the power consumption of the system, making the bearing more advantageous in application scenarios that require long-term operation or limited energy supply, but also enables the bearing to have higher load-carrying capacity and better stability, and can adapt to various complex working conditions. The present utility model is provided with permanent magnets at both the upper and lower ends of the stator core 1 and the rotor core 4, and the permanent magnets on the upper and lower sides can form two closed magnetic circuits through the stator teeth 101 of the middle stator core 1 and the rotor core 4, so that the magnetic force utilization rate is higher. Under the same magnetic force requirement, the volume can be made smaller, the structure is more compact, a stable static bias magnetic field can be provided, and the bias current required for electromagnetic control is small, thus realizing a five-degree-of-freedom permanent magnet biased magnetic bearing with low power consumption, small volume and light weight. Further, the present utility model can enhance the magnetic circuit structure, improve the magnetic force conduction efficiency, reduce the magnetic force loss, and enhance the static bias magnetic field provided by the stator magnetic ring 2 and the rotor permanent magnet 5 by arranging the stator yoke 7 on the outer rotor group and the rotor yoke 8 on the inner rotor group, so as to improve the suspension stability effect and better reduce the power. In addition, the present utility model is provided with two groups of outer stator groups and two groups of inner rotor groups, and relies on the permanent magnet forces between the four pairs of stator magnetic rings 2 and rotor permanent magnets 5 to provide a static bias magnetic field, further improving the suspension stability of the inner rotor group in the axial and radial directions, and having a better constraint effect on the axial and radial degrees of freedom, especially on the radial deflection degree of freedom of the inner rotor group.

[0075] Many specific details are set forth in the above description to facilitate a full understanding of the present utility model. However, the above description is only a preferred embodiment of the present utility model, and the present utility model can be implemented in many other ways different from those described herein. Therefore, the present utility model is not limited by the specific implementations disclosed above. At the same time, any person skilled in the art can make many possible changes and modifications to the technical solution of the present utility model by using the methods and technical contents disclosed above without departing from the scope of the technical solution of the present utility model, or modify it into an equivalent embodiment with equivalent changes. All simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present utility model without departing from the content of the technical solution of the present utility model still fall within the scope of protection of the technical solution of the present utility model.

Claims

1. A five-degree-of-freedom permanent magnet biased magnetic bearing, comprising an outer stator group and an inner rotor group, the inner rotor group being arranged in the outer stator group, characterized in that: The outer stator assembly includes an annular stator core (1) and two stator magnetic rings (2) respectively provided at two end portions of the stator core (1). A plurality of stator teeth (101) are radially provided on the inner wall of the stator core (1) and are distributed at equal intervals in a ring shape, and a coil (3) is wound around each stator tooth (101); the inner rotor assembly includes a rotor core (4) and two rotor permanent magnets (5) respectively provided at two end portions of the rotor core (4), and the rotor core (4) is radially opposed to the plurality of stator teeth (101) and is in clearance fit; wherein, the two stator magnetic rings (2) and the two rotor permanent magnets (5) are all magnetized axially, and the magnetization directions of the two stator magnetic rings (2) are opposite to each other, and at the same time, the magnetization direction of any one of the stator magnetic rings (2) is also opposite to the magnetization direction of a rotor permanent magnet (5) radially opposed to it.

2. The five-degree-of-freedom permanent magnet biased magnetic bearing according to claim 1, wherein: The stator magnetic ring (2) and the rotor permanent magnet (5) located on the same axial side are radially opposed to each other and can jointly form a closed magnetic circuit with the stator core (1) and the rotor core (4).

3. The five-degree-of-freedom permanent magnet biased magnetic suspension bearing according to claim 1, wherein: The stator magnetic ring (2) and the rotor permanent magnet (5) located on the same axial side have the same thickness and the same height.

4. The five-degree-of-freedom permanent magnet biased magnetic suspension bearing according to claim 1, wherein: The coils (3) wound around each stator tooth (101) work independently of each other.

5. The five-degree-of-freedom permanent magnet biased magnetic bearing according to claim 1, characterized in that: The number of the stator teeth (101) is more than three.

6. The five-degree-of-freedom permanent magnet biased magnetic bearing according to claim 1, characterized in that: Both the outer stator assembly and the inner rotor assembly are provided with two sets arranged axially, and a non-magnetic washer (6) is installed between the two outer stator assemblies and between the two inner rotor assemblies.

7. The five-degree-of-freedom permanent magnet biased magnetic suspension bearing according to claim 1, wherein: A plurality of convex rings (401) are provided on the outer circumferential surface of the rotor core (4) and are arranged at intervals axially, and a plurality of convex teeth (1011) are provided on the inner side surface of each stator tooth (101), and the plurality of convex teeth (1011) are distributed in one-to-one correspondence with the plurality of convex rings (401).

8. The five-degree-of-freedom permanent magnet biased magnetic suspension bearing according to claim 1, characterized in that: The outer stator assembly further includes two stator yokes (7), and the two stator yokes (7) are respectively provided at one end of the two stator magnetic rings (2) facing away from each other; the inner rotor assembly further includes two rotor yokes (8), and the two rotor yokes (8) are respectively provided at one end of the two rotor permanent magnets (5) facing away from each other; the stator magnetic ring (2) and the rotor permanent magnet (5) located on the same axial side can jointly form a closed magnetic circuit with the stator core (1), the rotor core (4), the stator yoke (7) and the rotor yoke (8).

9. The five-degree-of-freedom permanent magnet biased magnetic suspension bearing according to claim 8, wherein: The stator yoke (7) extends radially inward with an annular inner flange (701), and the rotor yoke (8) extends radially outward with an annular outer flange (801), and the inner flange (701) of the stator yoke (7) and the outer flange (801) of the rotor yoke (8) located on the same axial side are radially opposed to each other and are in clearance fit.

10. The five-degree-of-freedom permanent magnet biased magnetic suspension bearing according to claim 8, characterized in that: Both the outer stator assembly and the inner rotor assembly are provided with two sets arranged axially, and a non-magnetic washer (6) is installed between the two outer stator assemblies and between the two inner rotor assemblies.

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