Magnetic suspension bearing structure

Abstract

The invention provides a magnetic suspension bearing structure which comprises a rotating shaft, a protrusion is arranged on the rotating shaft, grooves are formed in the two sides of the protrusion in the axial direction of the rotating shaft, iron core assemblies are arranged on the two sides of the protrusion, the iron core assemblies and the protrusion are arranged at intervals, and the iron core assemblies and the rotating shaft are arranged at intervals; the iron core assembly comprises a first iron core, a part of the first iron core extends into the groove, a first permanent magnet is arranged on the part, extending into the first groove, of the first iron core, a second permanent magnet is arranged on the inner side wall of the groove, the first permanent magnet and the second permanent magnet are oppositely arranged, and a first coil is arranged on the part, located outside the groove, of the first iron core. In the radial direction of the rotating shaft, the first coil is located between the first permanent magnet and the second permanent magnet, and the first permanent magnet and the second permanent magnet have the same magnetic poles facing each other. According to the invention, the technical problems of complex structure and high cost of the magnetic suspension bearing in the prior art are solved.

Description

Technical Field

[0001] This invention belongs to the field of magnetic levitation bearing technology, and specifically relates to a magnetic levitation bearing structure. Background Technology

[0002] As a high-tech product, magnetic levitation bearings have significant advantages such as non-contact operation, wear-free operation, high speed, high precision, and no need for lubrication or sealing. Their working principle integrates knowledge from multiple disciplines such as electromagnetics, electronic technology, control engineering, and signal processing.

[0003] Magnetic levitation bearings can be classified into three types: active, passive, and hybrid. Active magnetic levitation bearings offer high stiffness and precise control, but suffer from limitations such as large size and high power consumption. Passive magnetic levitation bearings achieve levitation through the interaction between magnetic materials, but their stiffness and damping characteristics are relatively low. Hybrid magnetic levitation bearings use permanent magnets to generate a bias magnetic field, replacing the static magnetic field of electromagnets in active bearings. This significantly reduces the ampere-turns of the control windings, achieving a reduction in bearing size and an increase in load-bearing capacity. This hybrid design exhibits unique advantages in applications where size and power consumption are limited, while the main application areas of magnetic levitation bearings are concentrated in high-speed and ultra-high-speed conditions. Therefore, the integration and miniaturization of magnetic levitation systems, as well as the improvement of the stability and reliability of control systems, have become key research directions.

[0004] The related technology discloses a five-degree-of-freedom magnetic bearing, including a rotor, a rotor body, and a thrust disk arranged circumferentially around the rotor body; a stator, including a first stator core, a second stator core, a third stator core, and a fourth stator core arranged sequentially along the axis of the rotor, the thrust disk being located between the second stator core and the third stator core, the first stator core and the fourth stator core being wound with a first radial winding, the second stator core and the third stator core being wound with an axial winding and a second radial winding, and consisting of three magnetic bearings, namely two radial magnetic bearings and one axial magnetic bearing. However, it suffers from several drawbacks, including numerous control parameters, poor control accuracy due to motion coupling between them, complex structure, high cost, long axial dimension, and low critical speed.

[0005] Because existing magnetic levitation bearings have technical problems such as complex structure, high cost and long axial dimension, this invention studies and designs a magnetic levitation bearing structure. Summary of the Invention

[0006] Therefore, the present invention provides a magnetic levitation bearing structure that can solve the technical problems of complex structure and high cost of existing magnetic levitation bearings.

[0007] To solve the above problems, the present invention provides a magnetic levitation bearing structure, comprising: a rotating shaft, a protrusion provided on the rotating shaft, grooves on both sides of the protrusion along the axial direction of the rotating shaft, and iron core assemblies on both sides of the protrusion, the iron core assemblies being arranged at a distance from the protrusion and the rotating shaft.

[0008] The core assembly includes a first core, a portion of which extends into the groove. A first permanent magnet is disposed on the portion of the first core extending into the groove. A second permanent magnet is disposed on the inner wall of the groove. The first and second permanent magnets are arranged opposite to each other. A first coil is disposed on the portion of the first core outside the groove. Along the radial direction of the rotating shaft, the first coil is located between the first and second permanent magnets. The first and second permanent magnets have the same magnetic poles facing each other.

[0009] In some embodiments, the protrusion and the first iron core are annular. With the axial section of the rotating shaft as the projection plane, the protrusion is T-shaped. The protrusion has a first side and a second side. A groove is formed between the first side, the second side and the rotating shaft. The second permanent magnet is embedded in the side of the first side and the second side facing the rotating shaft.

[0010] In some embodiments, the first core is L-shaped and has a first segment and a second segment, the first segment extending axially along the shaft and the first permanent magnet being embedded in the side of the first segment facing away from the shaft.

[0011] In some embodiments, a magnetic ring is provided at one end of the second segment facing away from the rotating shaft. The magnetic ring extends toward the protrusion along the axial direction of the rotating shaft, and the magnetic ring is at least partially opposite to the protrusion. A second iron core is provided on the side of the magnetic ring facing the protrusion, and a second coil is provided on the second iron core.

[0012] In some embodiments, the second iron core is arranged at a distance from the first iron core along the axial direction of the rotating shaft, and the second iron core is arranged opposite to the first permanent magnet.

[0013] In some embodiments, a magnetic shielding ring is provided on the side of the first segment facing the rotating shaft.

[0014] In some embodiments, the second segment extends radially along the axis of rotation, and the second segment is embedded in the first coil on the side facing the protrusion.

[0015] In some embodiments, a permanent magnet magnetic circuit is formed between the first permanent magnet and the second permanent magnet, and the magnetic poles of the permanent magnet magnetic circuit on both sides of the protrusion are opposite in direction.

[0016] In some embodiments, the first coil forms an axial control magnetic circuit, and the magnetic circuit directions of the axial control magnetic circuits on both sides of the protrusion are opposite.

[0017] In some embodiments, the two core assemblies are arranged mirror images of each other about the center point of the protrusion along the axial direction of the shaft.

[0018] The magnetic levitation bearing structure provided by this invention has the following beneficial effects:

[0019] The first and second permanent magnets have the same magnetic poles facing each other, and a repulsive force is generated between them. The first and second permanent magnets provide radial levitation force. The magnetic field between the first and second permanent magnets also provides an axial bias magnetic field for the first coil. The bottom of the groove serves as the axial magnetic pole, which improves the utilization rate of the permanent magnets. Both sides of the protrusion have iron core assemblies. The symmetrical distribution of the iron core assemblies provides more constraints, improves the overall rigidity of the system, increases the radial anti-interference capability of the bearing, and makes the magnetic bearing structure more compact and lower in cost. Attached Figure Description

[0020] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. The drawings described below are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the magnetic levitation bearing structure of the present invention. Figure 1 ;

[0022] Figure 2 This is a schematic diagram of the magnetic levitation bearing structure of the present invention. Figure 2 ;

[0023] Figure 3 This is a magnetic circuit diagram of the magnetic levitation bearing structure of the present invention.

[0024] The attached figures are labeled as follows:

[0025] 1. First iron core; 2. Magnetic ring; 3. First coil; 4. First permanent magnet; 5. Second permanent magnet; 6. Second iron core; 7. Second coil; 8. Magnetic isolation ring; 9. Shaft; 10. Protrusion; 11. First side; 12. Second side; 13. First section; 14. Second section; 15. Axial control magnetic circuit; 16. Permanent magnet magnetic circuit; 17. Radial control magnetic circuit. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0028] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0029] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0030] See also Figure 1-3As shown, according to an embodiment of the present invention, a magnetic levitation bearing structure is provided, including: a rotating shaft 9, a protrusion 10 provided on the rotating shaft 9, grooves on both sides of the protrusion 10 along the axial direction of the rotating shaft 9, and iron core assemblies on both sides of the protrusion 10, the iron core assemblies being arranged at a distance from the protrusion 10 and the rotating shaft 9 being arranged at a distance from the iron core assemblies.

[0031] The core assembly includes a first core 1, a portion of which extends into the groove. A first permanent magnet 4 is disposed on the portion of the first core 1 extending into the groove. A second permanent magnet 5 is disposed on the inner sidewall of the groove. The first permanent magnet 4 and the second permanent magnet 5 are arranged opposite to each other. A first coil 3 is disposed on the portion of the first core 1 located outside the groove. Along the radial direction of the rotating shaft 9, the first coil 3 is located between the first permanent magnet 4 and the second permanent magnet 5. The first permanent magnet 4 and the second permanent magnet 5 have the same magnetic poles facing each other.

[0032] In this technical solution, the first permanent magnet 4 and the second permanent magnet 5 have the same magnetic poles facing each other, and a repulsive force is generated between the first permanent magnet 4 and the second permanent magnet 5. The first permanent magnet 4 and the second permanent magnet 5 provide radial levitation force. The magnetic field between the first permanent magnet 4 and the second permanent magnet 5 also provides an axial bias magnetic field for the first coil 3. The bottom of the groove serves as the axial magnetic pole, which improves the utilization rate of the permanent magnets. Both sides of the protrusion 10 have iron core assemblies. The symmetrical distribution of the iron core assemblies provides more constraints, improves the overall rigidity of the system, increases the radial anti-interference capability of the bearing, and makes the magnetic bearing structure more compact and lower in cost.

[0033] In some embodiments, the protrusion 10 and the first iron core 1 are annular. With the axial section of the rotating shaft 9 as the projection plane, the protrusion 10 is T-shaped. The protrusion has a first side 11 and a second side 12. A groove is formed between the first side 11, the second side 12 and the rotating shaft 9. The second permanent magnet 5 is embedded in the side of the first side 11 and the second side 12 facing the rotating shaft 9.

[0034] In this technical solution, see [reference] Figure 2 As shown, the cross-section of the protrusion 10 is T-shaped, and a groove is formed between the first side 11, the second side 12 and the rotating shaft 9. The second permanent magnet 5 is embedded in the side of the first side 11 and the second side 12 facing the rotating shaft 9, thereby embedding the second permanent magnet 5 into the protrusion and fixing the second permanent magnet 5.

[0035] In some embodiments, the first iron core 1 is L-shaped and has a first segment 13 and a second segment 14. The first segment 13 extends along the axial direction of the rotating shaft 9, and the first permanent magnet 4 is embedded in the side of the first segment 13 facing away from the rotating shaft 9.

[0036] In this technical solution, see [reference] Figure 2 As shown, the first iron core 1 is L-shaped, and part of the first section 13 extends into the groove. The side of the first section 13 that extends into the groove facing away from the rotating shaft 9 is embedded in the first permanent magnet 4, thereby fixing the first permanent magnet 4.

[0037] In some embodiments, the first coil 3 is located at the opening of the groove, and along the radial direction of the rotating shaft 9, the first coil 3 is located between the first permanent magnet 4 and the second permanent magnet 5.

[0038] In some embodiments, a magnetic ring 2 is provided at one end of the second segment 14 facing away from the rotating shaft 9. The magnetic ring 2 extends toward the protrusion 10 along the axial direction of the rotating shaft 9, and the magnetic ring 2 is at least partially opposite to the protrusion 10. A second iron core 6 is provided on the side of the magnetic ring 2 facing the protrusion 10, and a second coil 7 is provided on the second iron core 6.

[0039] In this technical solution, a radial control magnetic field is formed by the second iron core 6 and the second coil 7. A magnetic ring 2 is provided at the end of the second segment 14 facing away from the rotating shaft 9, and the second iron core 6 is provided on the side of the magnetic ring 2 facing the protrusion 10. The first permanent magnet 4 and the second permanent magnet 5 provide passive levitation force radially and bias magnetic field axially, improving the utilization rate of permanent magnets. Radial and axial forces do not interfere with each other, avoiding coupling of radial and axial magnetic flux and improving the control accuracy of the bearing.

[0040] In some embodiments, along the axial direction of the rotating shaft 9, the second iron core 6 is arranged at a distance from the first iron core 1, and the second iron core 6 is arranged opposite to the first permanent magnet 4.

[0041] In this technical solution, the second iron core 6 is arranged at intervals with the first iron core 1, and the second iron core 6 is arranged opposite to the first permanent magnet 4. The active radial magnetic levitation bearing is combined with the passive magnet by using the first permanent magnet 4 and the second permanent magnet 5, so that the radial magnetic bearing has fewer windings, lower bearing inductance, and lower cost.

[0042] In some embodiments, a magnetic shielding ring 8 is provided on the side of the first segment 13 facing the rotating shaft 9.

[0043] In this technical solution, a magnetic shielding ring 8 is provided on the side of the first segment 13 facing the rotating shaft 9 to avoid magnetic leakage of the magnetic field on the first iron core, the magnetic field between the first permanent magnet 4 and the second permanent magnet 5, and the magnetic induction intensity of the coil.

[0044] In some embodiments, the second segment 14 extends radially along the shaft 9 and is embedded in the first coil 3 on the side of the second segment 14 toward the protrusion 10.

[0045] In this technical solution, an axial control magnetic field is formed between the first coil 3 and the bottom of the groove, and the rotor end face is used as the axial magnetic pole. There is no need for a thrust disk structure, thereby reducing the air friction loss of the rotor. The axial length of the magnetic levitation bearing is greatly shortened, which can break through the limitations of high power and ultra-high speed, and can achieve miniaturization.

[0046] In some embodiments, a permanent magnet magnetic circuit 16 is formed between the first permanent magnet 4 and the second permanent magnet 5, and the magnetic poles of the permanent magnet magnetic circuit 16 on both sides of the protrusion 10 are opposite in direction.

[0047] In this technical solution, the magnetic poles of the permanent magnet magnetic circuit 16 on both sides of the protrusion 10 are opposite. The passive same polarity permanent magnets provide a bias magnetic field for the axial bearing at the same time, providing both radial levitation force and axial bias magnetic field, thereby improving the utilization rate of the permanent magnets.

[0048] In some embodiments, the first coil forms an axial control magnetic circuit 15, and the magnetic circuit directions of the axial control magnetic circuit 15 on both sides of the protrusion 10 are opposite.

[0049] In this technical solution, the magnetic circuit directions of the axial control magnetic circuits 15 on both sides of the protrusion 10 are opposite. The radial first permanent magnet 4 and the second permanent magnet 5 provide both passive levitation force in the radial direction and bias magnetic field in the axial direction, improving the utilization rate of the permanent magnets. The radial and axial directions do not interfere with each other, avoiding coupling of radial and axial magnetic flux and improving the control accuracy of the bearing.

[0050] In some embodiments, the two core assemblies are arranged in a mirror image about the center point of the protrusion 10 along the axial direction of the shaft 9.

[0051] In this technical solution, the two core components are mirror-symmetrically distributed about the center point of the protrusion 10, which provides more constraints, improves the overall stiffness of the system, increases the radial anti-interference capability of the bearing, and makes the magnetic bearing structure more compact and lower in cost.

[0052] The suspension bearing structure of the present invention combines an active radial magnetic suspension bearing with a passive magnet, resulting in fewer radial magnetic bearing windings, lower bearing inductance, and lower cost.

[0053] In some embodiments, along the axial direction of the rotating shaft 9, see [reference needed]. Figure 1 As shown, the left side of protrusion 10 is the front side, and the right side of protrusion 10 is the rear side. There is a front radial air gap g1 between the front second iron core 6 and protrusion 10, and a rear radial air gap g2 between the rear second iron core 6 and protrusion 10. Along the axial direction of the rotating shaft 9, there is a front axial air gap g3 between the front iron core 1 and the end of the first segment 13, a front axial air gap g4 between the part of the front first iron core 1 extending into the groove and the bottom of the groove, a rear axial air gap g5 between the rear first iron core 1 and the end of the second segment 14, and a rear axial air gap g6 between the part of the rear first iron core 1 extending into the groove and the bottom of the groove.

[0054] The radial bearing control logic of the suspension bearing structure of this invention is as follows, in conjunction with [see reference 1] Figure 3 As shown, in the radial control magnetic circuit 17, the permanent magnet provides a constant radial levitation force. When the radial air gaps g1 and g2 are larger than the radial air gap on the symmetrical side, the current of the radial control second coil 7 increases, the magnetic flux density of air gaps g1 and g2 increases, and the magnetic pole attraction at this point is greater than that on the opposite side. The rotor shifts towards this magnetic pole side, and the radial air gap is rebalanced. Conversely, when the radial air gaps g1 and g2 are smaller than the radial air gap on the symmetrical side, the current of the radial control second coil 7 decreases, the magnetic flux density of air gaps g1 and g2 decreases, and the magnetic pole attraction at this point is less than that on the opposite side. The rotor shifts towards the opposite side of this magnetic pole, and the radial air gap is rebalanced.

[0055] The axial bearing control logic is as follows, see reference. Figure 3 As shown, the axial permanent magnet circuit 16 and the axial control magnetic circuit 15 are configured such that when the sensor detects that the axial air gap (g3, g4) > (g5, g6), current is supplied to the first coil 3 of the front axial control circuit. This increases the superimposed magnetic flux density of air gaps g3 and g4, making the front axial magnetic pole attraction greater than the rear axial attraction. The rotor then shifts forward axially, and the axial air gap rebalances. Conversely, when the sensor detects that the axial air gap (g3, g4) < (g5, g6), current is supplied to the first coil 3 of the rear axial control circuit. This increases the magnetic flux density of air gaps g5 and g6, making the front axial magnetic pole attraction less than the rear axial attraction. The rotor then shifts backward axially, and the axial air gap rebalances. This includes:

[0056] It will be readily understood by those skilled in the art that, without conflict, the advantageous technical features of the above-mentioned methods can be freely combined and superimposed.

[0057] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention. The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the protection scope of the present invention.

Claims

1. A magnetic levitation bearing structure, characterized in that: include: A rotating shaft (9) is provided with a protrusion (10). Along the axial direction of the rotating shaft (9), both sides of the protrusion (10) have grooves. Both sides of the protrusion (10) have iron core assemblies. The iron core assemblies are arranged at intervals from the protrusion (10) and the iron core assemblies are arranged at intervals from the rotating shaft (9). The core assembly includes a first core (1), a portion of which extends into the groove. A first permanent magnet (4) is provided on the portion of the first core (1) extending into the first groove. A second permanent magnet (5) is provided on the inner wall of the groove. The first permanent magnet (4) and the second permanent magnet (5) are arranged opposite to each other. A first coil (3) is provided on the portion of the first core (1) located outside the groove. Along the radial direction of the rotating shaft (9), the first coil (3) is located between the first permanent magnet (4) and the second permanent magnet (5). The first permanent magnet (4) and the second permanent magnet (5) have the same magnetic poles facing each other.

2. The magnetic levitation bearing structure according to claim 1, characterized in that: The protrusion (10) and the first iron core (1) are annular. With the axial section of the rotating shaft (9) as the projection plane, the protrusion (10) is T-shaped. The protrusion has a first side (11) and a second side (12). A groove is formed between the first side (11), the second side (12) and the rotating shaft (9). The second permanent magnet (5) is embedded on the side of the first side (11) and the second side (12) facing the rotating shaft (9).

3. The magnetic levitation bearing structure according to claim 1, characterized in that: The first iron core (1) is L-shaped and has a first segment (13) and a second segment (14). The first segment (13) extends along the axial direction of the rotating shaft (9) and the first permanent magnet (4) is embedded on the side of the first segment (13) facing away from the rotating shaft (9).

4. The magnetic levitation bearing structure according to claim 3, characterized in that: The second segment (14) is provided with a magnetic ring (2) at one end facing away from the rotating shaft (9). Along the axial direction of the rotating shaft (9), the magnetic ring (2) extends toward the protrusion (10), and the magnetic ring (2) is at least partially opposite to the protrusion (10). A second iron core (6) is provided on the side of the magnetic ring (2) facing the protrusion (10), and a second coil (7) is provided on the second iron core (6).

5. The magnetic levitation bearing structure according to claim 4, characterized in that: Along the axial direction of the rotating shaft (9), the second iron core (6) is arranged at a distance from the first iron core (1), and the second iron core (6) is arranged opposite to the first permanent magnet (4).

6. The magnetic levitation bearing structure according to claim 3, characterized in that: A magnetic shielding ring (8) is provided on the side of the first segment (13) facing the rotating shaft (9).

7. The magnetic levitation bearing structure according to claim 3, characterized in that: The second segment (14) extends radially along the shaft (9) and is embedded in the first coil (3) on the side of the protrusion (10).

8. The magnetic levitation bearing structure according to claim 1, characterized in that: A permanent magnet magnetic circuit (16) is formed between the first permanent magnet (4) and the second permanent magnet (5), and the magnetic poles of the permanent magnet magnetic circuit (16) on both sides of the protrusion (10) are opposite.

9. The magnetic levitation bearing structure according to claim 1, characterized in that: The first coil forms an axial control magnetic circuit (15), and the magnetic circuit directions of the axial control magnetic circuit (15) on both sides of the protrusion (10) are opposite.

10. The magnetic levitation bearing structure according to claim 1, characterized in that: Along the axial direction of the shaft (9), the two core assemblies are arranged in a mirror image about the center point of the protrusion (10).

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