Axial magnetic suspension bearing and magnetic suspension rotating machine

Abstract

The utility model provides an axial magnetic suspension bearing and a magnetic suspension rotating machine, which comprise an outer cylinder, a first axial stator assembly, a second axial stator assembly and a thrust disc are assembled in the outer cylinder, the first axial stator assembly comprises a first stator iron core, the second axial stator assembly comprises a second stator iron core, and the thrust disc is assembled in the outer cylinder. The thrust disc is located between the magnetic poles of the two stator iron cores, the magnetic poles of the first stator iron core comprise a first outer magnetic pole and a first inner magnetic pole, the magnetic poles of the second stator iron core comprise a second outer magnetic pole and a second inner magnetic pole, and first overflowing ring grooves are formed in the opposite surface areas of the first outer magnetic pole and the thrust disc and the second outer magnetic pole and the thrust disc; the first overflowing ring groove and the thrust disc are coaxially arranged, overflowing through holes are formed in the first inner magnetic pole and the second inner magnetic pole, the overflowing through holes extend in the radial direction of the thrust disc, and the overflowing through holes and the first overflowing ring groove are communicated through an air gap between the outer magnetic pole and the thrust disc, and the position of the air gap corresponds to the position of the first overflowing ring groove. The internal structure of the bearing can be effectively cooled.

Description

Technical Field

[0001] The utility model belongs to the technical field of magnetic levitation bearing design, and particularly relates to an axial magnetic levitation bearing and a magnetic levitation rotating machine. Background Technique

[0002] At present, the heat dissipation of magnetic levitation blowers mainly relies on external cooling equipment, such as external cooling fans, water cooling systems, and heat exchangers, etc. The equipment maintenance cost is high, the structure system is complex, and potential safety hazards are increased. Or in the form of negative pressure, air is sucked from the blower to guide the heat out, but it cannot more effectively achieve the heat dissipation of internal components, especially the heat dissipation of axial magnetic bearings is insufficient, which affects the stable operation of magnetic levitation blowers.

[0003] The axial magnetic bearing realizes the axial movement of the rotating shaft. It is necessary to have an axial force-bearing component on the rotating shaft, which is the thrust disk. The axial magnetic bearing and the thrust disk are made of a pure iron solid structure, with relatively large self-loss, general thermal conductivity, and small space. If not effectively cooled, it will generate serious heat. Usually, in order to avoid excessive temperature rise of the axial magnetic bearing, forced air cooling is often applied externally to dissipate heat from the magnetic bearing. The cooling air is input from the outside and passes through the gap between the bearing stator and the thrust disk to dissipate heat from the axial magnetic bearing, but the heat dissipation efficiency is not high. Summary of the Utility Model

[0004] Therefore, the utility model provides an axial magnetic levitation bearing and a magnetic levitation rotating machine, which can solve the technical problems of serious heating and low heat dissipation efficiency of the axial magnetic bearing in the existing magnetic levitation rotating machine.

[0005] To solve the above problems, the utility model provides an axial magnetic levitation bearing, which includes an outer cylinder. A first axial stator assembly, a second axial stator assembly, and a thrust disk are assembled in the central through hole of the outer cylinder. The first axial stator assembly includes a first stator core, the second axial stator assembly includes a second stator core, the thrust disk is located between the magnetic poles of the first stator core and the magnetic poles of the second stator core. The magnetic poles of the first stator core include a first outer magnetic pole and a first inner magnetic pole, the magnetic poles of the second stator core include a second outer magnetic pole and a second inner magnetic pole. A first flow-through ring groove is formed on the surface area of the first outer magnetic pole opposite to the thrust disk, and a first flow-through ring groove is also formed on the surface area of the second outer magnetic pole opposite to the thrust disk, and the first flow-through ring groove is coaxially arranged with the thrust disk. A flow-through hole is formed on the first inner magnetic pole and the second inner magnetic pole, the flow-through hole extends along the radial direction of the thrust disk, and the flow-through hole is communicated with the first flow-through ring groove through the air gap between the corresponding outer magnetic pole and the thrust disk.

[0006] In some embodiments, the first overflow ring groove is formed on the magnetic pole end faces of the first outer magnetic pole and the second outer magnetic pole. Any radial plane perpendicular to the axis of the thrust disk is defined as a radial plane. When projected onto the radial plane, the outer circular contour of the thrust disk is within the groove width range of the first overflow ring groove; and / or, there are a plurality of flow-through holes, and the plurality of flow-through holes are arranged at intervals along the circumferential direction of the thrust disk.

[0007] In some embodiments, a second overflow ring groove is further formed on the magnetic pole end faces of the first outer magnetic pole and the second outer magnetic pole. The first overflow ring groove and the second overflow ring groove are concentrically arranged, and the first overflow ring groove is radially outside the second overflow ring groove.

[0008] In some embodiments, the first outer magnetic pole includes a first cover plate portion extending radially inwards along the thrust disk, the second outer magnetic pole includes a second cover plate portion extending radially inwards along the thrust disk, and the first overflow ring groove and the second overflow ring groove are formed on the first cover plate portion and the second cover plate portion.

[0009] In some embodiments, the second overflow ring groove penetrates through to the radially outer ring wall of the first cover plate portion or the second cover plate portion.

[0010] In some embodiments, the axial width of the air gap is x, and the groove depths of the first overflow ring groove and the second overflow ring groove are both a, and 2x ≤ a ≤ 3x.

[0011] In some embodiments, the first stator core further includes a first stator yoke portion between the first outer magnetic pole and the first inner magnetic pole, the second stator core further includes a second stator yoke portion between the second outer magnetic pole and the second inner magnetic pole. The first stator yoke portion has a first outer convex ring protruding from the radially outer ring wall of the first outer magnetic pole, the second stator yoke portion has a second outer convex ring protruding from the radially outer ring wall of the second outer magnetic pole. The first axial stator assembly is assembled into the outer cylinder via the first outer convex ring, and the second axial stator assembly is assembled into the outer cylinder via the second outer convex ring to form a cooling cavity between the first outer magnetic pole and the outer cylinder and between the second outer magnetic pole and the outer cylinder. The first overflow ring groove of the first axial stator assembly and the first overflow ring groove of the second axial stator assembly are communicated through the cooling cavity.

[0012] In some embodiments, the outer cylinder has a bearing exhaust hole, and the bearing exhaust hole communicates the cooling cavity and the external space of the outer cylinder.

[0013] The present utility model also provides a magnetic levitation rotating machine, which includes a rotating shaft and an axial magnetic levitation bearing for defining the axial displacement of the rotating shaft. The axial magnetic levitation bearing is the aforementioned axial magnetic levitation bearing. The first end of the rotating shaft is connected to a blower turbine, and the second end of the rotating shaft is connected to a cooling impeller. The cooling air flow introduced into the magnetic levitation rotating machine by the cooling impeller and / or a part of the air flow at the blower turbine can enter the axial magnetic levitation bearing.

[0014] In some embodiments, the magnetic levitation rotating machine further includes a cylinder body, and a motor stator capable of driving the rotating shaft to rotate is assembled in the cylinder body. A stator cooling flow channel is formed in a region corresponding to the motor stator in the cylinder body.

[0015] An axial magnetic levitation bearing and a magnetic levitation rotating machine provided by the present utility model have the following beneficial effects:

[0016] By providing radially communicating flow-through holes on the inner magnetic pole and corresponding flow-through annular grooves at the relative region between the outer magnetic pole and the thrust disk, the flow-through area of the cooling air flow between the bearing stator and the thrust disk can be significantly increased, and further, the cooling air flow rate entering from the outside of the bearing into the inside of the bearing can be significantly increased, so as to realize efficient cooling of the windings, stator iron cores and thrust disks in the bearing. The flow-through annular groove in this technical solution is a circular annular groove coaxially arranged with the thrust disk. When the thrust disk rotates, no magnetic field alternation in the circumferential direction will be formed, and further, the occurrence of eddy current heating phenomenon caused by the magnetic field alternation when the rotor rotates due to the formation of a radially shaped groove in the circumferential direction can be avoided. Description of the Drawings

[0017] In order to more clearly illustrate the embodiments of the present utility model or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. The drawings in the following description are only exemplary. For those of ordinary skill in the art, without creative efforts, other implementation drawings can also be obtained according to the provided drawings.

[0018] Figure 1 It is a schematic internal structure diagram (half-section) of an axial magnetic levitation bearing according to an embodiment of the present utility model. The arrows in the figure indicate the flow direction of the cooling air flow;

[0019] Figure 2 It is a schematic internal structure diagram (half-section) of an axial magnetic levitation bearing according to an embodiment of the present utility model. The relative position relationship between the magnetic pole and the thrust disk is shown in the figure;

[0020] Figure 3 It is a schematic internal structure diagram of a first embodiment of the magnetic levitation rotating machine of the present utility model. The arrows in the figure show the flow path of the cooling air flow;

[0021] Figure 4 It is a schematic diagram of the internal structure of the second embodiment of the magnetic levitation rotating machine of the present utility model. The arrows in the figure show the flow path of the cooling air flow;

[0022] Figure 5 It is a schematic diagram of the internal structure of the third embodiment of the magnetic levitation rotating machine of the present utility model. The arrows in the figure show the flow path of the cooling air flow;

[0023] Figure 6 Schematic diagram of the internal structure of the fourth embodiment of the magnetic levitation rotating machine of the present utility model. The arrows in the figure show the flow path of the cooling air flow.

[0024] Reference numerals are:

[0025] 1. Outer cylinder; 11. Bearing exhaust hole; 2. First axial stator assembly; 21. First stator core; 211. First outer magnetic pole; 2111. First cover part; 212. First inner magnetic pole; 213. First stator yoke; 22. First winding; 3. Second axial stator assembly; 31. Second stator core; 311. Second outer magnetic pole; 3111. Second cover part; 312. Second inner magnetic pole; 313. Second stator yoke; 32. Second winding; 4. Thrust disc; 51. First overflow ring groove; 52. Through-flow hole; 53. Second overflow ring groove; 100. Rotating shaft; 101. Axial magnetic levitation bearing; 102. Blower turbine; 1021. Turbine volute; 1022. Front end cover; 103. Cooling impeller; 1031. Rear end cover; 1032. Deflector; 104. Radial magnetic levitation bearing; 1041. Front housing; 1042. Rear housing; 105. Motor stator; 106. Cylinder; 1061. Exhaust hole; 1062. Stator cooling flow channel. Detailed implementation manners

[0026] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and in no way limits the present utility model and its application or use. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present utility model.

[0027] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by orientation terms such as "front, rear, upper, lower, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom", etc. is usually based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description. Without contrary description, these orientation terms do not indicate and imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation on the protection scope of the present utility model; the orientation terms "inside, outside" refer to the inside and outside relative to the contour of each component itself.

[0028] For the convenience of description, spatial relative terms such as "above...", "over...", "on the upper surface of...", "upper" etc. can be used here to describe the spatial positional relationship between a device or feature shown in the drawings and other devices or features. It should be understood that the spatial relative terms are intended to cover different orientations in use or operation in addition to the orientation described in the drawings for the device. For example, if the device in the drawing is inverted, the device described as "above other devices or structures" or "over other devices or structures" will then be positioned as "below other devices or structures" or "under other devices or structures". Thus, the exemplary term "above..." can include both the orientations of "above..." and "below...". The device can also be positioned in other different ways (rotated 90° or in other orientations), and corresponding interpretations should be made for the spatial relative descriptions used here.

[0029] In addition, it should be noted that the use of words such as "first", "second", etc. to limit components is only for the convenience of distinguishing the corresponding components. Without additional statement, the above words have no special meaning. Therefore, it should not be construed as a limitation on the protection scope of the present utility model.

[0030] See in conjunction with Figures 1 to 6As shown, according to an embodiment of the present utility model, an axial magnetic levitation bearing is provided, which includes an outer cylinder 1. In some cases, the outer cylinder 1 can be, for example, the cylinder 106 hereinafter. A first axial stator assembly 2, a second axial stator assembly 3 and a thrust disc 4 are assembled in the central through hole of the outer cylinder 1. The first axial stator assembly 2 includes a first stator core 21 and a first winding 22 assembled on the first stator core 21. The second axial stator assembly 3 includes a second stator core 31 and a second winding 32 assembled on the second stator core 31. The thrust disc 4 is located between the magnetic poles of the first stator core 21 and the magnetic poles of the second stator core 31, and corresponding air gaps are respectively formed between the thrust disc 4 and the first stator core 21 and between the thrust disc 4 and the second stator core 31. The magnetic poles of the first stator core 21 include a first outer magnetic pole 211 and a first inner magnetic pole 212. The magnetic poles of the second stator core 31 include a second outer magnetic pole 311 and a second inner magnetic pole 312. A first overcurrent ring groove 51 is formed on the surface area of the first outer magnetic pole 211 opposite to the thrust disc 4. A first overcurrent ring groove 51 is also formed on the surface area of the second outer magnetic pole 311 opposite to the thrust disc 4. And the first overcurrent ring groove 51 is coaxially arranged with the thrust disc 4. Through holes 52 for current passage are formed on both the first inner magnetic pole 212 and the second inner magnetic pole 312. The through holes 52 extend along the radial direction of the thrust disc 4. The through holes 52 are communicated with the first overcurrent ring groove 51 through the air gap between the corresponding outer magnetic pole and the thrust disc 4. The so-called corresponding position means that, with respect to the first axial stator assembly 2, the first overcurrent ring groove 51 and the through holes 52 therein are communicated through the air gap between it and the thrust disc 4. Similarly, with respect to the second axial stator assembly 3, the first overcurrent ring groove 51 and the through holes 52 therein are communicated through the air gap between it and the thrust disc 4.

[0031] In this technical solution, by providing radially communicated through holes 52 on the inner magnetic poles and corresponding overcurrent ring grooves in the relative areas between the outer magnetic poles and the thrust disc 4, the flow area of the cooling air flow between the bearing stator and the thrust disc 4 can be significantly increased, and further the cooling air flow entering from the outside of the bearing into the inside of the bearing can be significantly increased, so as to realize the efficient cooling of the windings, stator cores and thrust disc inside the bearing. It should be emphasized that the overcurrent ring groove in this technical solution is an annular groove coaxially arranged with the thrust disc 4. When the thrust disc 4 rotates, there will be no magnetic field alternation in the circumferential direction, and thus the occurrence of eddy current heating caused by the magnetic field alternation when the rotor rotates due to the formation of a radially shaped groove in the circumferential direction can be avoided.

[0032] It can be understood that the foregoing overcurrent ring groove 51 can specifically be formed on the left and right end faces of the thrust disc 4. In a specific embodiment, specifically refer to Figure 1and Figure 2 As shown in Figure 2 , the first overflow ring groove 51 is formed on the magnetic pole end faces of the first outer magnetic pole 211 and the second outer magnetic pole 311. Define any radial plane perpendicular to the axis of the thrust disk 4 as the radial plane. When projected on the radial plane, the outer circular contour of the thrust disk 4 is within the groove width range of the first overflow ring groove 51, so that the cooling air flow entering the bearing can flow out more smoothly through the first overflow ring groove 51.

[0033] In a preferred embodiment, there are multiple through holes 52, and the multiple through holes 52 are arranged at intervals along the circumferential direction of the thrust disk 4, so as to realize uniform cooling and heat dissipation of the inside of the bearing in the circumferential direction.

[0034] In some embodiments, a second overflow ring groove 53 is further formed on the magnetic pole end faces of the first outer magnetic pole 211 and the second outer magnetic pole 311. The first overflow ring groove 51 and the second overflow ring groove 53 are concentrically arranged, and the first overflow ring groove 51 is located radially outside the second overflow ring groove 53.

[0035] In this technical solution, by arranging the second overflow ring groove 53 on the radial inner side of the first overflow ring groove 51, the flow area of the cooling air flow flowing into the bearing can be further increased, and then the cooling air flow entering the bearing can be further increased, and the cooling and heat dissipation effect is better.

[0036] In some embodiments, the first outer magnetic pole 211 includes a first cover plate portion 2111 extending radially inward along the thrust disk 4, the second outer magnetic pole 311 includes a second cover plate portion 3111 extending radially inward along the thrust disk 4, and the first overflow ring groove 51 and the second overflow ring groove 53 are formed on the first cover plate portion 2111 and the second cover plate portion 3111.

[0037] The aforementioned first cover plate portion 2111 and second cover plate portion 3111 are specifically both an annular plate, which is used as a part of the stator core to conduct the magnetic circuit formed by the corresponding windings. Since it extends radially inward along the thrust disk 4, the outer diameter of the corresponding thrust disk 4 can be designed to be smaller, thereby reducing the eccentric mass of the rotating shaft and being beneficial to improving the dynamic balance performance of the rotating shaft. And forming the aforementioned first overflow ring groove 51 and second overflow ring groove 53 on the first cover plate portion 2111 and the second cover plate portion 3111 can minimize the adverse influence on the magnetic field due to the setting of the grooves by adjusting the areas of the first cover plate portion 2111 and the second cover plate portion 3111.

[0038] Specifically refer to Figure 1As shown, in some embodiments, the second overcurrent ring groove 53 penetrates through the radial outer ring wall of the first cover plate portion 2111 or the second cover plate portion 3111, ensuring that the cooling air flow entering the bearing through the overcurrent holes on the inner magnetic pole can more smoothly enter the air gap between the outer magnetic pole and the thrust disk 4.

[0039] As Figure 2 shown, when ring grooves (i.e., the aforementioned first overcurrent ring groove 51 and second overcurrent ring groove 53) are provided on the thrust disk or the stator, objectively, to a certain extent, it will affect the magnetic circuit. To ensure that the output force of the axial bearing is not affected, according to the magnetic circuit principle, when the magnetic circuit in other positions is large enough, the influence of the ring groove on the magnetic circuit can be compensated. That is, by appropriately increasing the magnetic bearing stator structure or the coil excitation current, the output force value of the magnetic bearing can be ensured not to be affected. The specific analysis is as follows:

[0040] In Figure 2 , assuming that no ring groove is opened on the thrust disk or the stator (working condition 1), the axial bearing output forces in regions 1, 2, and 3 are F1, F2, and F3. The aforementioned region 1 is a circular ring region with a width of b1 between the outer circumferential wall of the thrust disk 4 and the inner ring groove wall of the first overcurrent ring groove 51. Region 3 is a circular ring region with a width of b2 extending radially outward along the inner ring wall of the first cover plate portion 2111 or the second cover plate portion 3111. Region 3 is the circular ring region between the aforementioned regions 1 and 2. According to the magnetic circuit Ampere's circuital law, we can obtain:

[0041]

[0042] F 总 = F1 + F2 + F3

[0043] When a ring groove is opened on the thrust disk or the stator (working condition 2), the air gap between the axial bearing stator in regions 1 and 3 and the thrust disk 4 becomes (x + a). For subsequent calculation convenience, let a = kx. Therefore, the axial bearing output forces in regions 1 and 3 can be expressed as:

[0044]

[0045] F 总 ' = F1' + F2' + F3'

[0046] Explanation of formula symbols: F1, F2, F3, F'1, F'2, and F'3 are the axial bearing output force values in regions 1, 2, and 3 under the two working conditions respectively; μ0 is the air magnetic permeability; N is the number of coil turns; A1, A2, and A3 are the magnetic circuit areas of the magnetic bearing stator in regions 1, 2, and 3 respectively; i is the coil excitation current; x is the axial width of the air gap between the axial bearing stator and the thrust disk; a is the ring groove depth (i.e., the aforementioned groove depth).

[0047] At this time, due to the influence of the annular groove, the axial bearing output value F 总 >> F' 总 . If it is necessary to ensure that F' 总 ≥ F 总 , and compensate for the influence of the annular groove on the magnetic circuit, the magnetic bearing stator magnetic circuit areas in Region 1 and Region 3 can be increased to (k + 1) 2 A1, (k + 1) 2 A3, or the coil excitation current can be increased to (k + 1)i, where k is the ratio of the annular groove depth a to the air gap x between the axial bearing stator and the thrust disk.

[0048] In this regard, while taking into account the influence of the annular groove on the magnetic circuit, considering factors such as processing cost and control system performance limitations, the annular groove depth a should be designed in the range of (2 - 3)x, that is, the axial width of the air gap is x, and the groove depths of the first overcurrent annular groove 51 and the second overcurrent annular groove 53 are both a, 2x ≤ a ≤ 3x.

[0049] In some embodiments, the first stator core 21 further includes a first stator yoke portion 213 between the first outer magnetic pole 211 and the first inner magnetic pole 212, the second stator core 31 further includes a second stator yoke portion 313 between the second outer magnetic pole 311 and the second inner magnetic pole 312, the first stator yoke portion 213 has a first outer convex ring (not labeled in the figure) protruding from the radial outer ring wall of the first outer magnetic pole 211, the second stator yoke portion 313 has a second outer convex ring (not labeled in the figure) protruding from the radial outer ring wall of the second outer magnetic pole 311, the first axial stator assembly 2 is assembled into the outer cylinder 1 via the first outer convex ring, and the second axial stator assembly 3 is assembled into the outer cylinder 1 via the second outer convex ring to form a cooling cavity (not labeled in the figure) between the first outer magnetic pole 211 and the outer cylinder 1 and between the second outer magnetic pole 311 and the outer cylinder 1, and the first overcurrent annular groove 51 of the first axial stator assembly 2 communicates with the first overcurrent annular groove 51 of the second axial stator assembly 3 through the cooling cavity.

[0050] In this technical solution, by providing an outer convex ring radially outward along the stator yoke portion, a corresponding cooling cavity is formed between the stator core and the outer cylinder 1. At the same time, the winding cooling channels in the two axial stator assemblies on both sides communicate with this cooling cavity, so that more efficient and sufficient cooling of the stator core can be achieved, and further prevent the bearing temperature from rising too high.

[0051] In some embodiments, the outer cylinder 1 has a bearing exhaust hole 11, and the bearing exhaust hole 11 communicates the cooling cavity and the external space of the outer cylinder 1, so that the cooling air flow entering the bearing can cool and dissipate heat from the inner magnetic pole, winding, thrust disk 4, and outer magnetic pole in sequence and then be discharged to the external environment.

[0052] According to an embodiment of the present utility model, there is also provided a magnetic levitation rotating machine, such as a blower, an air compressor, etc., which includes a rotating shaft 100 and an axial magnetic levitation bearing 101 for defining the axial displacement of the rotating shaft 100. The axial magnetic levitation bearing 101 is the aforementioned axial magnetic levitation bearing. The first end of the rotating shaft 100 is connected to a blower turbine 102, and the second end of the rotating shaft 100 is connected to a cooling impeller 103. The cooling air flow introduced into the magnetic levitation rotating machine by the cooling impeller 103 and / or part of the air flow at the blower turbine 102 can enter the axial magnetic levitation bearing, so that the pressure air flow generated by the cooling impeller 103 or the blower turbine 102 can be introduced into the axial magnetic levitation bearing to cool and dissipate heat from the components inside the bearing, effectively preventing the bearing temperature from rising too high. It should be noted that in the present utility model, since the cooling impeller 103 and the blower turbine share the same rotating shaft 100, when the magnetic levitation rotating machine is operating, the rotation of the cooling impeller 103 can be realized synchronously, and then the external air can be introduced into the magnetic levitation rotating machine, that is, the direct drive of the cooling impeller 103 by the rotating shaft 100 is realized. There is no need to separately configure a corresponding cooling structure for the cooling of the bearing, and there is no need to separately set a special controller for the cooling impeller 103. The control logic is simple and the heat dissipation reliability is high.

[0053] In some embodiments, the magnetic levitation rotating machine further includes a cylinder 106. An electric machine stator 105 capable of driving the rotating shaft 100 to rotate is assembled inside the cylinder 106. A stator cooling flow channel 1062 is formed in the area of the cylinder 106 corresponding to the electric machine stator 105. At this time, the cooling air flow driven by the cooling impeller 103 can flow through the air gap between the electric machine stator and rotor and the stator cooling flow channel 1062, so as to be able to cool and dissipate heat from the inner and outer sides of the electric machine stator 105 at the same time.

[0054] Figures 3 to 6 The situation of cooling only the components inside the magnetic levitation rotating machine with the cooling air flow driven by the cooling impeller 103 is shown. The arrows in each figure indicate the flow path of the cooling air flow, and the aforementioned flow path varies according to the setting position of the exhaust hole 1061. In Figures 3 to 6 the embodiments shown in each figure, the cooling impeller 103 rotates to drive the external air flow to enter the cylinder 106 along the guide plate 1032. And Figure 3 、 Figure 4 and Figure 6Also shown is the manner in which a part of the cooling air flow is also led out from the blower turbine 102. That is, in a preferred embodiment, the cooling air flow is provided by the combined action of the cooling impeller 103 and the blower turbine. In this way, the introduction of the cooling air flow can be achieved from both axial ends of the magnetic levitation rotating machine, so as to ensure comprehensive cooling of various components within the magnetic levitation rotating machine, such as the aforementioned axial magnetic levitation bearing 101, radial magnetic levitation bearing 104, and motor stator 105. In this structural form, it is preferred to set the exhaust hole 1061 in the axially centered area of the cylinder 106, specifically in the area between the axial magnetic levitation bearing 101 and the motor stator 105.

[0055] The path of the cooling air flow of the magnetic levitation rotating machine of the present invention will be further described below with reference to the respective figures:

[0056] First Embodiment:

[0057] See Figure 3As shown in the figure, an active pure air-cooling system is adopted. The cold air is provided by the cooling impeller without an additional heat dissipation drive motor. The cooling impeller 103 is assembled at the rear end of the rotor (i.e., the second end of the rotating shaft 100, the same below). The rear radial bearing (i.e., the radial magnetic levitation bearing 104 near the second end of the rotating shaft 100, the same below) is located between the cooling impeller 103 and the motor stator 105. The front radial bearing (i.e., the radial magnetic levitation bearing 104 near the first end of the rotating shaft 100, the same below) is placed at the front end of the rotor. The axial bearing (i.e., the axial magnetic levitation bearing 101, the same below) is located between the front radial bearing and the front end cover 1022. A deflector 1032 for guiding the cooling impeller and a rear end cover 1031 are assembled on the rear housing 1042 to increase the air flow conduction and reduce the flow resistance. A plurality of corresponding ventilation holes or ventilation grooves are provided on parts such as the rear housing 1042, the cylinder (i.e., the cylinder 106, the same below), and the front housing 1041 to facilitate the air flow conduction. The cooling gas of the cooling impeller passes through the flow channel on the rear housing 1042, passes through the rotor flow channel (i.e., the air gap between the stator and the rotor), cools the motor rotor, and then is divided into two paths for cooling at the front radial bearing: The first path: After entering the axial stator inner circulation channel hole and the right annular groove of the thrust disk or the magnetic pole on the stator (i.e., the through-flow hole and the through-flow annular groove in the second axial stator assembly), it converges with the main impeller leakage gas that has passed through the main impeller (i.e., the blower turbine 102) leakage channel (i.e., the cooling air flow diverted by the blower turbine) → the axial stator inner circulation channel hole and the left annular groove of the thrust disk or the magnetic pole on the stator (i.e., the through-flow hole and the through-flow annular groove in the first axial stator assembly), and then is discharged from the bearing exhaust hole 11; The second path: It cools the motor stator 105 through the motor stator flow channel (i.e., the stator cooling flow channel 1062, the same below) outside the motor stator and is discharged from the exhaust hole 1061 opened on the cylinder. This flow channel structure arrangement effectively cools the heating components such as the stator, rotor, radial bearing, and axial bearing. At the same time, for the high-heating components such as the thrust disk or the axial bearing stator, a ring groove structure is provided on the upper magnetic pole of the thrust disk or the axial bearing, and a flow channel hole is added to the inner ring of the axial bearing stator. At the high rotational speed of the rotor, the gas flow channel is increased, the cooling flow rate and speed are increased, and the cooling of the axial magnetic bearing and the thrust disk is accelerated. The entire heat dissipation system has a simple structure, an efficient and reliable heat dissipation process, and improves the stability of the magnetic levitation system.

[0058] Second Embodiment:

[0059] See Figure 4As shown in the figure, an active pure air-cooled heat dissipation system is adopted. The cold air is provided by the cooling impeller without an additional heat dissipation drive motor. The cooling impeller 103 is assembled at the rear end of the rotor. The rear radial bearing is located between the cooling impeller 103 and the motor stator 105. The front radial bearing is placed at the front end of the rotor. The axial bearing is located between the front radial bearing and the motor stator 105. A guide plate 1032 for guiding the cooling impeller and a rear end cover 1031 are assembled on the rear housing to increase the air flow conduction and reduce the flow resistance. A plurality of corresponding ventilation holes or ventilation grooves are provided on parts such as the rear housing 1042, the cylinder body, and the front housing 1041 to facilitate the air flow conduction. The cooling gas of the cooling impeller is divided into three paths through the flow channel on the rear housing 1042. The first path: through the axial cooling flow channel (not marked in the figure) in the cylinder body → the axial bearing; the second path: through the motor stator flow channel on the cylinder body → the axial bearing; the third path: through the motor rotor flow channel (i.e., the air gap between the motor stator and rotor) → the axial bearing; the three paths of cooling gas pass through the axial stator inner circulation channel holes and the ring grooves of the magnetic poles or thrust disks on the axial stator on both sides of the axial bearing and are discharged from the bearing exhaust holes 11. This flow channel structure arrangement effectively cools the heat-generating components such as the stator, rotor, radial bearing, and axial bearing. At the same time, for the high-heat-generating components such as the thrust disk or the axial bearing stator, a ring groove structure is provided on the magnetic pole of the thrust disk or the axial bearing. Flow channel holes are added to the inner ring of the axial bearing stator. At the high rotational speed of the rotor, the gas flow channel is increased, the cooling flow rate and speed are increased, and the cooling of the axial magnetic bearing and the thrust disk is accelerated. The entire heat dissipation system has a simple structure, an efficient and reliable heat dissipation process, and improves the stability of the magnetic levitation system.

[0060] Third Embodiment:

[0061] See Figure 5As shown, an active pure air-cooled heat dissipation system is adopted. The cold air is provided by the cooling impeller without an additional heat dissipation drive motor. The cooling impeller 103 is assembled at the rear end of the rotor. The rear radial bearing is located between the cooling impeller 103 and the motor stator 105. The front radial bearing is placed at the front end of the rotor. The axial bearing is located between the front radial bearing and the motor stator 105. A deflector 1032 for guiding the flow of the cooling impeller and a rear end cover 1031 are assembled on the rear housing to increase the air flow conduction and reduce the flow resistance. A plurality of corresponding ventilation holes or ventilation grooves are provided on parts such as the rear housing 1042, the cylinder body, and the front housing 1041 to facilitate the air flow conduction. The cooling gas of the cooling impeller is divided into two paths for cooling when entering the motor rotor flow channel. The first path: After cooling the motor stator through the motor stator flow channel on the cylinder body, it is discharged through the exhaust hole 1061. The second path: After passing through the axial stator inner circulation channel hole → the magnetic pole or thrust disc ring groove on the axial stator, it converges with the main impeller leakage gas passing through the main impeller leakage flow channel → the axial stator inner circulation channel hole and the magnetic pole or thrust disc ring groove on the axial stator and is discharged from the bearing exhaust hole 11. This flow channel structure layout effectively cools the heating components such as the stator, rotor, radial bearing, and axial bearing. At the same time, for the high-heat-generating components such as the thrust disc or the axial bearing stator, a ring groove structure is provided on the magnetic pole of the thrust disc or the axial bearing, and a flow channel hole is added to the inner ring of the axial bearing stator. At the high rotational speed of the rotor, the gas flow channel is increased, the cooling flow rate and speed of the inflow are increased, and the cooling of the axial magnetic bearing and the thrust disc is accelerated. The entire heat dissipation system has a simple structure, an efficient and reliable heat dissipation process, and improves the stability of the magnetic levitation system.

[0062] Fourth Embodiment:

[0063] See Figure 6As shown in the figure, an active pure air-cooled heat dissipation system is adopted. The cold air is provided by the cooling impeller without an additional heat dissipation drive motor. The cooling impeller 103 is assembled at the rear end of the rotor. The rear radial bearing is located between the cooling impeller 103 and the motor stator 105. The front radial bearing is placed at the front end of the rotor. The axial bearing is located between the front radial bearing and the motor stator 105. A deflector 1032 for guiding the cooling impeller and a rear end cover 1031 are assembled on the rear housing to increase the air flow conduction and reduce the flow resistance. Several corresponding ventilation holes or ventilation grooves are opened on parts such as the rear housing 1042, the cylinder body, and the front housing 1041 to facilitate the air flow conduction. The cooling gas of the cooling impeller passes through the rear housing 1042, through the motor stator flow channel and the motor rotor flow channel on the cylinder body → the axial stator inner circulation channel hole and the right ring groove of the thrust disc or the magnetic pole on the stator, and then merges with the main impeller leakage gas passing through the main impeller leakage flow channel → the axial stator inner circulation channel hole and the left ring groove of the thrust disc or the magnetic pole on the axial stator, and then is discharged from the bearing exhaust hole 11. This flow channel structure arrangement effectively cools the stator, rotor, radial bearings, axial bearings and other heating components. At the same time, for the high-heat-generating components such as the thrust disc or the axial bearing stator, a ring groove structure is provided on the upper magnetic pole of the thrust disc or the axial bearing, and a flow channel hole is added to the inner ring of the axial bearing stator. At the high rotational speed of the rotor, the gas flow channel is increased, the cooling flow rate and speed are increased, and the cooling of the axial magnetic bearing and the thrust disc is accelerated. The entire heat dissipation system has a simple structure, an efficient and reliable heat dissipation process, and improves the stability of the magnetic levitation system.

[0064] It is easy for those skilled in the art to understand that, on the premise of no conflict, the advantageous technical features of the above various methods can be freely combined and superimposed.

[0065] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention. The above is only the preferred implementation manner of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. An axial magnetic levitation bearing, comprising an outer cylinder (1). A first axial stator assembly (2), a second axial stator assembly (3) and a thrust disc (4) are assembled in the central through hole of the outer cylinder (1). The first axial stator assembly (2) includes a first stator core (21), the second axial stator assembly (3) includes a second stator core (31), and the thrust disc (4) is located between the magnetic poles of the first stator core (21) and the magnetic poles of the second stator core (31). The magnetic poles of the first stator core (21) include a first outer magnetic pole (211) and a first inner magnetic pole (212), and the magnetic poles of the second stator core (31) include a second outer magnetic pole (311) and a second inner magnetic pole (312). It is characterized in that, A first current-carrying annular groove (51) is formed in a surface area of the first outer magnetic pole (211) and the thrust disk (4) facing each other, and a first current-carrying annular groove (51) is also formed in a surface area of the second outer magnetic pole (311) and the thrust disk (4) facing each other. The first current-carrying annular groove (51) is coaxially arranged with the thrust disk (4). A current-carrying through hole (52) is formed in the first inner magnetic pole (212) and the second inner magnetic pole (312). The current-carrying through hole (52) extends along the radial direction of the thrust disk (4). The current-carrying through hole (52) communicates with the first current-carrying annular groove (51) through an air gap between the outer magnetic pole and the thrust disk (4) at corresponding positions.

2. The axial magnetic suspension bearing according to claim 1, characterized in that, The first current-carrying annular groove (51) is formed on the magnetic pole end surfaces of the first outer magnetic pole (211) and the second outer magnetic pole (311). Any radial plane perpendicular to the axis of the thrust disk (4) is defined as a radial plane. When projected onto the radial plane, the outer circular contour of the thrust disk (4) is within the groove width range of the first current-carrying annular groove (51); and / or, there are a plurality of the current-carrying through holes (52), and the plurality of current-carrying through holes (52) are arranged at intervals along the circumferential direction of the thrust disk (4).

3. The axial magnetic suspension bearing according to claim 2, wherein, A second current-carrying annular groove (53) is further formed on the magnetic pole end surfaces of the first outer magnetic pole (211) and the second outer magnetic pole (311). The first current-carrying annular groove (51) and the second current-carrying annular groove (53) are concentrically arranged, and the first current-carrying annular groove (51) is radially outside the second current-carrying annular groove (53).

4. The axial magnetic suspension bearing according to claim 3, wherein, The first outer magnetic pole (211) includes a first cover plate portion (2111) extending radially inward along the thrust disk (4), and the second outer magnetic pole (311) includes a second cover plate portion (3111) extending radially inward along the thrust disk (4). The first current-carrying annular groove (51) and the second current-carrying annular groove (53) are formed on the first cover plate portion (2111) and the second cover plate portion (3111).

5. The axial magnetic suspension bearing according to claim 4, wherein The second current-carrying annular groove (53) penetrates through the radially outer ring wall of the first cover plate portion (2111) or the second cover plate portion (3111).

6. The axial magnetic suspension bearing according to claim 3, characterized in that, The axial width of the air gap is x, and the groove depths of the first current-carrying annular groove (51) and the second current-carrying annular groove (53) are both a, and 2x ≤ a ≤ 3x.

7. The axial magnetic suspension bearing according to claim 1, characterized in that, The first stator core (21) further includes a first stator yoke portion (213) between the first outer magnetic pole (211) and the first inner magnetic pole (212). The second stator core (31) further includes a second stator yoke portion (313) between the second outer magnetic pole (311) and the second inner magnetic pole (312). The first stator yoke portion (213) has a first outer convex ring protruding from the radial outer ring wall of the first outer magnetic pole (211). The second stator yoke portion (313) has a second outer convex ring protruding from the radial outer ring wall of the second outer magnetic pole (311). The first axial stator assembly (2) is assembled into the outer cylinder (1) via the first outer convex ring, and the second axial stator assembly (3) is assembled into the outer cylinder (1) via the second outer convex ring to form cooling cavities between the first outer magnetic pole (211) and the outer cylinder (1) and between the second outer magnetic pole (311) and the outer cylinder (1). The first flow-through ring groove (51) of the first axial stator assembly (2) communicates with the first flow-through ring groove (51) of the second axial stator assembly (3) through the cooling cavities.

8. The axial magnetic suspension bearing according to claim 7, wherein The outer cylinder (1) is provided with a bearing exhaust hole (11), and the bearing exhaust hole (11) communicates the cooling cavity and the external space of the outer cylinder (1).

9. A magnetic levitation rotating machine, characterized in that, It includes a rotating shaft (100) and an axial magnetic suspension bearing (101) for defining the axial displacement of the rotating shaft (100). The axial magnetic suspension bearing (101) is the axial magnetic suspension bearing according to any one of claims 1 to 8. The first end of the rotating shaft (100) is connected to a blower turbine (102), and the second end of the rotating shaft (100) is connected to a cooling impeller (103). The cooling air flow introduced into the magnetic suspension rotating machine by the cooling impeller (103) and / or a part of the air flow at the blower turbine (102) can enter the axial magnetic suspension bearing.

10. The magnetic levitation rotating machine according to claim 9, characterized in that, It further includes a cylinder body (106). An electric machine stator (105) capable of driving the rotating shaft (100) to rotate is assembled in the cylinder body (106). A stator cooling flow channel (1062) is formed in a region of the cylinder body (106) corresponding to the electric machine stator (105).

Images