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, and the magnetic poles of the second stator iron core comprise a second outer magnetic pole and a second inner magnetic pole. Outer side overflowing annular grooves are formed in the surface area, opposite to the thrust disc, of the first outer magnetic pole and the surface area, opposite to the thrust disc, of the second outer magnetic pole. Inner side overflowing ring grooves are formed in the surface area, opposite to the thrust disc, of the first inner magnetic pole and the surface area, opposite to the thrust disc, of the second inner magnetic pole, and the outer side overflowing ring grooves and the inner side overflowing ring grooves are coaxial with the thrust disc. The internal structure of the bearing can be effectively cooled.

Description

Technical Field

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

[0002] At present, the heat dissipation of magnetic suspension 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 structural system is complex, and potential safety hazards are increased. Or in the form of negative pressure, air is sucked from the blower to guide heat out, which cannot more effectively achieve the heat dissipation of internal components, especially the heat dissipation of axial magnetic bearings is insufficient, affecting the stable operation of magnetic suspension 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 materials of the axial magnetic bearing and the thrust disk are pure iron solid structures, with relatively large self-loss, general thermal conductivity, and narrow space. If not effectively cooled, they 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 suspension bearing and a magnetic suspension rotating machine, which can solve the technical problems of serious heat generation and low heat dissipation efficiency of the axial magnetic bearing in the existing magnetic suspension rotating machine.

[0005] To solve the above problems, the utility model provides an axial magnetic suspension bearing, including 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. Outer flow-through annular grooves are formed on the surface areas of the first outer magnetic pole and the thrust disk facing each other and on the surface areas of the second outer magnetic pole and the thrust disk facing each other. Inner flow-through annular grooves are formed on the surface areas of the first inner magnetic pole and the thrust disk facing each other and on the surface areas of the second inner magnetic pole and the thrust disk facing each other. The outer flow-through annular grooves and the inner flow-through annular grooves are coaxially arranged with the thrust disk.

[0006] In some embodiments, the outer flow-through ring groove includes a first flow-through ring groove 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 flow-through ring groove.

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

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

[0009] In some embodiments, the second flow-through ring groove penetrates to the radial inner ring wall of the first cover plate portion or the second cover plate portion.

[0010] In some embodiments, the inner flow-through ring groove includes a third flow-through ring groove and a fourth flow-through ring groove, both of which are formed on the magnetic pole end faces of the first inner magnetic pole and the second inner magnetic pole. The third flow-through ring groove and the fourth flow-through ring groove are coaxial and the third flow-through ring groove is radially outside the fourth flow-through ring groove. The third flow-through ring groove penetrates to the radial outer ring wall of the first inner magnetic pole or the second inner magnetic pole, and the fourth flow-through ring groove penetrates to the radial inner ring wall of the first inner magnetic pole or the second inner magnetic pole.

[0011] In some embodiments, an air gap is formed between the thrust disk and the magnetic poles of the first stator core or the second stator core. The axial width of the air gap is x, and the groove depths of the first flow-through ring groove, the second flow-through ring groove, the third flow-through ring groove, and the fourth flow-through ring groove are all a, where 2x ≤ a ≤ 3x.

[0012] In some embodiments, the first stator core further includes a first stator yoke between the first outer magnetic pole and the first inner magnetic pole, and the second stator core further includes a second stator yoke between the second outer magnetic pole and the second inner magnetic pole. The first stator yoke has a first outer convex ring protruding from the radial outer ring wall of the first outer magnetic pole, and the second stator yoke has a second outer convex ring protruding from the radial outer ring wall of the second outer magnetic pole. The first axial stator assembly is assembled in the outer cylinder via the first outer convex ring, and the second axial stator assembly is assembled in the outer cylinder via the second outer convex ring to form cooling cavities between the first outer magnetic pole and the outer cylinder and between the second outer magnetic pole and the outer cylinder. The first flow-through ring groove of the first axial stator assembly communicates with the first flow-through ring groove of the second axial stator assembly through the cooling cavity.

[0013] In some embodiments, the outer cylinder has bearing exhaust holes that communicate the cooling cavity and the external space of the outer cylinder; and / or, the first outer convex ring and / or the second outer convex ring have through-flow holes extending axially therethrough.

[0014] The present utility model also provides a magnetic levitation rotating machine, including 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 above-mentioned 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 part of the air flow at the blower turbine can enter the axial magnetic levitation bearing.

[0015] 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.

[0016] The axial magnetic levitation bearing and the magnetic levitation rotating machine provided by the present utility model have the following beneficial effects:

[0017] By providing corresponding flow-through ring grooves (i.e., the aforementioned outer flow-through ring groove and inner flow-through ring groove) at the relative regions between the inner and outer magnetic poles and the thrust disk respectively, 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 improved, so as to achieve efficient cooling of the windings, stator core and thrust disk in the bearing. It should be emphasized that the flow-through ring groove in this technical solution is an annular groove coaxially arranged with the thrust disk. When the thrust disk rotates, no magnetic field alternation occurs in the circumferential direction, thereby preventing 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. Brief Description of the Drawings

[0018] In order to more clearly illustrate the embodiments of the present invention 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 by extending the provided drawings.

[0019] Figure 1 It is a schematic internal structure diagram (half-section) of an axial magnetic levitation bearing according to an embodiment of the present invention, and the arrows in the figure indicate the flow direction of the cooling air flow;

[0020] Figure 2 is Figure 1 A schematic internal structure diagram (half-section) of the axial magnetic levitation bearing in

[0021] Figure 3 It is a schematic internal structure diagram (half-section) of an axial magnetic levitation bearing according to another embodiment of the present invention, and the arrows in the figure indicate the flow direction of the cooling air flow;

[0022] Figure 4 is Figure 3 A three-dimensional structure diagram of the thrust disk in

[0023] Figure 5 It is a schematic internal structure diagram of the first embodiment of the magnetic levitation rotating machine of the present invention. The arrows in the figure show the flow path of the cooling air flow, and the axial magnetic levitation bearing in the figure is Figure 1 The axial magnetic levitation bearing in

[0024] Figure 6 It is a schematic internal structure diagram of the second embodiment of the magnetic levitation rotating machine of the present invention. The arrows in the figure show the flow path of the cooling air flow, and the axial magnetic levitation bearing in the figure is Figure 1 The axial magnetic levitation bearing in

[0025] Figure 7 It is a schematic internal structure diagram of the third embodiment of the magnetic levitation rotating machine of the present invention. The arrows in the figure show the flow path of the cooling air flow, and the axial magnetic levitation bearing in the figure is Figure 1 The axial magnetic levitation bearing in

[0026] Figure 8 A schematic internal structure diagram of the fourth embodiment of the magnetic levitation rotating machine of the present invention. The arrows in the figure show the flow path of the cooling air flow, and the axial magnetic levitation bearing in the figure is Figure 1 The axial magnetic levitation bearing in

[0027] The reference numerals are:

[0028] 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 part; 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 part; 32. Second winding; 4. Thrust disk; 41. Fifth overflow ring groove; 42. Sixth overflow ring groove; 43. Seventh overflow ring groove; 51. First overflow ring groove; 52. Through-flow hole; 53. Second overflow ring groove; 54. Third overflow ring groove; 55. Fourth overflow ring groove; 100. Rotating shaft; 101. Axial magnetic suspension bearing; 102. Blowing turbine; 1021. Turbine volute; 1022. Front end cover; 103. Cooling impeller; 1031. Rear end cover; 1032. Deflector; 104. Radial magnetic suspension bearing; 1041. Front housing; 1042. Rear housing; 105. Motor stator; 106. Cylinder; 1061. Exhaust hole; 1062. Stator cooling flow channel. Detailed implementation manners

[0029] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and in no way constitutes a limitation to the present invention and its application or use. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0030] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the orientation words such as "front, rear, upper, lower, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" is usually based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description. Without contrary explanation, these orientation words 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, and therefore cannot be understood as a limitation to the protection scope of the present invention; the orientation words "inner, outer" refer to the inside and outside relative to the contour of each component itself.

[0031] For ease of description, spatial relative terms such as "above", "over", "on the upper surface", "upper", etc. can be used here to describe the spatial positional relationship of a device or feature shown in the figure with other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation in addition to the orientation depicted in the figure for the device. For example, if the device in the attached drawing is inverted, a device described as "above" or "over" other devices or structures will then be positioned "below" 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 are made for the spatial relative descriptions used here.

[0032] In addition, it should be noted that the use of terms such as "first" and "second" to define components is only for the convenience of differentiating the corresponding components. Without additional statements, the above terms have no special meanings, and thus should not be construed as limiting the protection scope of the present utility model.

[0033] Referring to Figures 1 to 8 As 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 disk 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 disk 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 formed respectively between the thrust disk 4 and the first stator core 21 and between the thrust disk 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. Outer current-carrying ring grooves (not labeled in the figure) are formed on the surface areas of the first outer magnetic pole 211 and the thrust disk 4 facing each other and on the surface areas of the second outer magnetic pole 311 and the thrust disk 4 facing each other. Inner current-carrying ring grooves (not labeled in the figure) are formed on the surface areas of the first inner magnetic pole 212 and the thrust disk 4 facing each other and on the surface areas of the second inner magnetic pole 312 and the thrust disk 4 facing each other. The outer current-carrying ring grooves and the inner current-carrying ring grooves are coaxially arranged with the thrust disk 4.

[0034] In this technical solution, by providing corresponding overflow annular grooves (i.e., the aforementioned outer overflow annular groove and inner overflow annular groove) at the relative regions between the inner and outer magnetic poles and the thrust disk 4 respectively, the flow area of the cooling air flow between the bearing stator and the thrust disk 4 can be significantly increased, thereby significantly enhancing the cooling air flow rate entering the bearing interior from the outside of the bearing, so as to achieve efficient cooling of the windings, stator core and thrust disk inside the bearing. It should be emphasized that the overflow annular groove in this technical solution is an annular groove coaxially arranged with the thrust disk 4. When the thrust disk 4 rotates, there will be no magnetic field alternation in the circumferential direction, thus preventing the occurrence of eddy current heating phenomenon caused by the magnetic field alternation during the rotation of the rotor due to the formation of a radially shaped groove in the circumferential direction.

[0035] In a specific embodiment, the outer overflow annular groove includes a first overflow annular groove 51, and the first overflow annular 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 annular groove 51, so that the cooling air flow entering the bearing interior can flow out more smoothly through the first overflow annular groove 51. In this technical solution, the overflow annular groove is formed on the magnetic pole end face. During the operation of the bearing, the position of its overflow annular groove remains relatively stationary, so the occurrence of eddy current heating phenomenon can be effectively prevented.

[0036] In some embodiments, the outer overflow annular groove further includes a second overflow annular groove 53, and the second overflow annular groove 53 is formed on the magnetic pole end faces of the first outer magnetic pole 211 and the second outer magnetic pole 311. The first overflow annular groove 51 and the second overflow annular groove 53 are concentrically arranged, and the first overflow annular groove 51 is radially outside the second overflow annular groove 53.

[0037] In this technical solution, by providing the second overflow annular groove 53 radially inside the first overflow annular groove 51, the flow area of the cooling air flow flowing into the bearing interior can be further increased, thereby further increasing the cooling air flow rate entering the bearing interior, and the cooling and heat dissipation effect is better.

[0038] In some embodiments, the first outer magnetic pole 211 includes a first cover plate portion 2111 extending radially inwards along the thrust disk 4, and the second outer magnetic pole 311 includes a second cover plate portion 3111 extending radially inwards along the thrust disk 4. The first overflow annular groove 51 and the second overflow annular groove 53 are formed on the first cover plate portion 2111 and the second cover plate portion 3111.

[0039] The foregoing first cover plate portion 2111 and second cover plate portion 3111 are specifically both an annular plate, which, as a part of the stator core, is used 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. Forming the foregoing first overflow ring groove 51 and second overflow ring groove 53 on the first cover plate portion 2111 and second cover plate portion 3111 can minimize the adverse effect of the groove on the magnetic field by adjusting the areas of the first cover plate portion 2111 and second cover plate portion 3111 to the greatest extent.

[0040] In some embodiments, the second overflow ring groove 53 penetrates through the radial inner 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 overflow holes on the inner magnetic pole can more smoothly enter the air gap between the outer magnetic pole and the thrust disk 4.

[0041] In some embodiments, the inner overflow ring groove includes a third overflow ring groove 54 and a fourth overflow ring groove 55. The third overflow ring groove 54 and the fourth overflow ring groove 55 are both formed on the magnetic pole end faces of the first inner magnetic pole 212 and the second inner magnetic pole 312. The third overflow ring groove 54 and the fourth overflow ring groove 55 are coaxial and the third overflow ring groove 54 is radially outside the fourth overflow ring groove 55. The third overflow ring groove 54 penetrates through the radial outer ring wall of the first inner magnetic pole 212 or the second inner magnetic pole 312, and the fourth overflow ring groove 55 penetrates through the radial inner ring wall of the first inner magnetic pole 212 or the second inner magnetic pole 312.

[0042] In this technical solution, by providing the corresponding third overflow ring groove 54 and fourth overflow ring groove 55 on the radial inner and outer sides of the inner magnetic pole, the effect of guiding the cooling air flow into the bearing can be further improved, and the cooling and heat dissipation effect of the internal structure of the bearing can be further ensured.

[0043] As Figure 2 shown, when the ring grooves provided on the thrust disk or the stator (i.e., the foregoing first overflow ring groove 51 and second overflow ring groove 53) objectively have a certain impact on the magnetic circuit to a certain extent. To ensure that the output force of the axial bearing is not affected, according to the magnetic circuit principle, when the magnetic circuit at other positions is large enough, the impact 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 to be unaffected. The specific analysis is as follows:

[0044] In Figure 2In the case where no annular grooves are provided on the thrust disk or the stator (operating condition 1), the axial bearing forces of regions 1, 2, and 3 are F1, F2, and F3. Region 1 mentioned above is an annular region with a width of b1 between the outer circumferential wall of the thrust disk 4 and the inner annular groove wall of the first flow-through annular groove 51. Region 3 is an annular region extending radially outward by a width of b2 from the inner wall of the first cover part 2111 or the second cover part 3111. Region 3 is the annular region between the aforementioned regions 1 and 2. According to Ampere's circuital law of magnetic circuits, we can obtain:

[0045]

[0046] F 总 = F1 + F2 + F3

[0047] When annular grooves are provided on the thrust disk or the stator (operating condition 2), the air gap between the axial bearing stator of regions 1 and 3 and the thrust disk 4 becomes (x + a). For the convenience of subsequent calculation, let a = kx. Therefore, the axial bearing forces of regions 1 and 3 can be expressed as:

[0048]

[0049] F 总 ' = F1' + F2' + F3'

[0050] Explanation of formula symbols: F1, F2, F3, F'1, F'2, and F'3 are the axial bearing force values of regions 1, 2, and 3 in the two operating conditions respectively; μ0 is the magnetic permeability of air; N is the number of turns of the coil; A1, A2, and A3 are the magnetic circuit areas of the magnetic bearing stator of 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 depth of the annular groove (i.e., the aforementioned groove depth).

[0051] At this time, due to the influence of the annular groove, the axial bearing force value F 总 >> F' 总 , if we want to ensure that F' 总 ≥ F 总 , to compensate for the influence of the annular groove on the magnetic circuit, the magnetic circuit areas of the magnetic bearing stator of regions 1 and 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.

[0052] In this regard, under the condition of taking into account the influence of the compensation ring groove on the magnetic circuit, considering factors such as processing cost and control system performance, the depth a of the ring groove 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 overflow ring groove 51 and the second overflow ring groove 53 are both a, where 2x ≤ a ≤ 3x.

[0053] In another embodiment, the aforementioned overflow ring groove can specifically be formed on the left and right end faces of the thrust disk 4. For specific reference, see Figure 3 and Figure 4 As shown, at this time, the outer overflow ring groove can specifically be the fifth overflow ring groove 41, and the inner overflow ring groove can be the seventh overflow ring groove 43. More preferably, a sixth overflow ring groove 42 is further included. When projected onto the aforementioned radial plane, the outlines of the outer ring wall of the inner magnetic pole and the inner ring wall of the outer magnetic pole are both within the sixth overflow ring groove 42. In this way, it can ensure the smooth flow of the cooling air flow between the stator core and the thrust disk 4, ensure the flow area and flow rate of the cooling air flow, and further ensure the cooling and heat dissipation effect inside the bearing. Similar to the various overflow ring grooves formed on the magnetic pole end faces of the stator core, the groove depths of the fifth overflow ring groove 41, the sixth overflow ring groove 42, and the seventh overflow ring groove 43 are also a.

[0054] 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, and 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, and 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. The first overflow ring groove 51 of the first axial stator assembly 2 communicates with the first overflow ring groove 51 of the second axial stator assembly 3 through the cooling cavity.

[0055] 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 temperature rise of the bearing from being too high.

[0056] In some embodiments, the outer cylinder 1 is provided with a bearing exhaust hole 11 which communicates the cooling chamber with 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, the winding, the thrust disk 4 and the outer magnetic pole in sequence and then be discharged to the external environment.

[0057] The first outer convex ring and / or the second outer convex ring are / is provided with a through-flow hole 52 penetrating axially therethrough. In another embodiment, the first stator yoke portion 213 and the second stator yoke portion 313 may also be provided with through-flow holes 52 penetrating axially to the position of the internal winding, so that the external cooling air flow can be introduced into the bearing through these through-flow holes 52, further improving the cooling and heat dissipation effect on the internal structure of the bearing.

[0058] According to an embodiment of the present invention, there is also provided a magnetic levitation rotating machine, such as a blower, an air compressor, etc., including 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 above-mentioned 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 invention, since the cooling impeller 103 and the blower turbine share the same rotating shaft 100, when the magnetic levitation rotating machine is running, 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, without separately configuring a corresponding cooling structure for the cooling of the bearing, and without separately setting a special controller for the cooling impeller 103, the control logic is simple, and the heat dissipation reliability is high.

[0059] In some embodiments, the magnetic levitation rotating machine 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 the area corresponding to the electric machine stator 105 in the cylinder body 106. 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 cool and dissipate heat from the inner and outer sides of the electric machine stator 105 simultaneously.

[0060] Figure 6shows a case where only the cooling air flow driven by the cooling impeller 103 is used to cool each component inside the magnetic levitation rotating machine. 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 Figure 6 the aforementioned exhaust hole 1061 can be directly implemented by using the aforementioned bearing exhaust hole 11. In Figure 6 in the illustrated embodiment, the cooling impeller 103 rotates to drive the external air flow to enter the cylinder 106 along the guide plate 1032. And Figure 5 、 Figure 7 and Figure 8 also show a way that part of the cooling air flow is led out from the blower turbine 102. That is, in a preferred embodiment, the cooling air flow is provided by the simultaneous 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 the comprehensive cooling of each component inside the magnetic levitation rotating machine, such as the aforementioned axial magnetic levitation bearing 101, radial magnetic levitation bearing 104, and motor stator 105.

[0061] The following further elaborates on the flow path of the cooling air flow of the magnetic levitation rotating machine of the present invention in combination with each figure respectively:

[0062] First Embodiment:

[0063] See Figure 5As 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 (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), the front housing 1041, and the axial bearing 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-side annular groove of the thrust disc or the magnetic pole on the stator (i.e., the through-flow holes and through-flow annular grooves in the second axial stator assembly), it converges with the leakage gas of the main impeller (i.e., the blower turbine 102) that passes through the leakage flow channel of the main impeller (i.e., the cooling air flow diverted by the blower turbine) → the axial stator inner circulation channel hole and the left-side annular groove of the thrust disc or the magnetic pole on the stator (i.e., the through-flow holes and through-flow annular grooves 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 outside the motor stator (i.e., the stator cooling flow channel 1062, the same below) and is discharged from the exhaust hole 1061 opened on the cylinder. 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 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 stator, 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] Second Embodiment:

[0065] See Figure 6As 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. 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 vane 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 provided on parts such as the rear housing 1042, the cylinder, the front housing 1041, and the axial bearing to facilitate 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 labeled in the figure) in the cylinder → the axial bearing; the second path: through the motor stator flow channel on the cylinder → 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 annular flow channel holes and the magnetic poles or thrust disc ring grooves on the axial stator on both sides of the axial bearing and then are 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 stator, 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 inlet 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.

[0066] Third Embodiment:

[0067] See Figure 7As 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. A plurality of corresponding ventilation holes or ventilation grooves are provided on parts such as the rear housing 1042, the cylinder body, the front housing 1041, and the axial bearing 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 ring flow channel hole → the magnetic pole or thrust disk 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 ring flow channel hole and the magnetic pole or thrust disk 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-heating 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, 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.

[0068] Fourth Embodiment:

[0069] See Figure 8As shown, an active pure air-cooled heat dissipation system is adopted. The cold air is provided by a 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. Moreover, several corresponding ventilation holes or ventilation grooves are provided on parts such as the rear housing 1042, the cylinder, the front housing 1041, and the axial bearing to facilitate the air flow conduction. The cooling gas of the cooling impeller passes through the rear housing 1042, via the motor stator flow channel and the motor rotor flow channel on the cylinder, to the axial stator inner circulation channel hole and the right annular groove of the thrust disc or the magnetic pole on the stator, and then converges with the main impeller leakage gas passing through the main impeller leakage flow channel to the axial stator inner circulation channel hole and the left annular 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-heating 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.

[0070] It should be noted that, due to the through-flow holes 52 on the yoke part of the stator core of the axial bearing or the outer convex ring of the yoke part in the present utility model, the contact area between the cooling air flow and the stator core or the winding can be further increased, and the cooling and heat dissipation effect on the inside of the bearing can be further improved. It can be understood that, due to the arrangement of the aforementioned through-flow holes 52, the flow path of the cooling air flow is different. Please refer to the arrows shown in the corresponding drawings.

[0071] 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-mentioned various methods can be freely combined and superimposed.

[0072] The above are only the preferred embodiments of the present utility model, and are not intended to limit the present utility model. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present utility model shall be included in the protection scope of the present utility model. The above is only the preferred implementation manner of the present utility model. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present utility model, several improvements and modifications can still be made, and these improvements and modifications should also be regarded as the protection scope of the present utility model.

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 a 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), 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), the magnetic poles of the second stator core (31) include a second outer magnetic pole (311) and a second inner magnetic pole (312), characterized in that, On the surface areas of the first outer magnetic pole (211) and the thrust disk (4) facing each other, as well as on the surface areas of the second outer magnetic pole (311) and the thrust disk (4) facing each other, outer flow-through ring grooves are formed. On the surface areas of the first inner magnetic pole (212) and the thrust disk (4) facing each other, as well as on the surface areas of the second inner magnetic pole (312) and the thrust disk (4) facing each other, inner flow-through ring grooves are formed. The outer flow-through ring grooves and the inner flow-through ring grooves are coaxially arranged with the thrust disk (4).

2. The axial magnetic suspension bearing according to claim 1, wherein The outer flow-through ring groove includes a first flow-through ring groove (51). The first flow-through 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 flow-through ring groove (51).

3. The axial magnetic suspension bearing according to claim 2, characterized in that, The outer flow-through ring groove further includes a second flow-through ring groove (53). The second flow-through ring groove (53) is formed on the magnetic pole end faces of the first outer magnetic pole (211) and the second outer magnetic pole (311). The first flow-through ring groove (51) and the second flow-through ring groove (53) are concentrically arranged, and the first flow-through ring groove (51) is radially outside the second flow-through ring 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). The second outer magnetic pole (311) includes a second cover plate portion (3111) extending radially inward along the thrust disk (4). The first flow-through ring groove (51) and the second flow-through ring 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, characterized in that, The second flow-through ring groove (53) penetrates to the radial inner 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, wherein The inner flow-through ring groove includes a third flow-through ring groove (54) and a fourth flow-through ring groove (55). The third flow-through ring groove (54) and the fourth flow-through ring groove (55) are both formed on the magnetic pole end faces of the first inner magnetic pole (212) and the second inner magnetic pole (312). The third flow-through ring groove (54) and the fourth flow-through ring groove (55) are coaxial and the third flow-through ring groove (54) is radially outside the fourth flow-through ring groove (55). The third flow-through ring groove (54) penetrates to the radial outer ring wall of the first inner magnetic pole (212) or the second inner magnetic pole (312), and the fourth flow-through ring groove (55) penetrates to the radial inner ring wall of the first inner magnetic pole (212) or the second inner magnetic pole (312).

7. The axial magnetic suspension bearing according to claim 6, wherein, An air gap is formed between the thrust disk (4) and the magnetic poles of the first stator core (21) or the second stator core (31). The axial width of the air gap is x, and the groove depths of the first flow-through ring groove (51), the second flow-through ring groove (53), the third flow-through ring groove (54), and the fourth flow-through ring groove (55) are all a, where 2x ≤ a ≤ 3x.

8. 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), and 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), and 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 in the outer cylinder (1) via the first outer convex ring, and the second axial stator assembly (3) is assembled in 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.

9. The axial magnetic suspension bearing according to claim 8, 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); and / or, the first outer convex ring and / or the second outer convex ring are / is provided with a through-flow hole (52) axially penetrating therethrough.

10. 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 9. 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.

11. The magnetic levitation rotating machine according to claim 10, characterized in that, It further includes a cylinder body (106), and a motor 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 corresponding to the motor stator (105) of the cylinder body (106).

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