Axial magnetic suspension bearing and magnetic suspension rotating machine

Abstract

The invention provides an axial magnetic suspension bearing and a magnetic suspension rotating machine, the axial magnetic suspension bearing comprises 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, the thrust disc is located between magnetic poles of the two stator iron cores, and the thrust disc is located between the first stator iron core and the second stator iron core. 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 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 invention belongs to the technical field of magnetic suspension bearing design, and in particular relates to an axial magnetic suspension bearing and a magnetic suspension rotating machine. Background Art

[0002] At present, the heat dissipation of magnetic levitation blowers is mainly achieved through external cooling equipment, such as external cooling fans, water cooling systems, and heat exchangers. The equipment has high maintenance costs, complex structural systems, and increased safety hazards. Alternatively, the heat is drawn out from the blower in the form of negative pressure, which cannot dissipate the heat of internal components more effectively. In particular, the heat dissipation of the axial magnetic bearings is not sufficient, affecting the stable operation of the magnetic levitation blower.

[0003] The axial magnetic bearing realizes the axial movement of the rotating shaft, and an axial force-bearing component is indispensable on the rotating shaft, which is the thrust plate. The axial magnetic bearing and the thrust plate are made of pure iron solid structure, which has relatively large self-loss, general thermal conductivity and small space. If it is 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 the heat of the magnetic bearing. The cooling air is input from the outside and dissipates the heat of the axial magnetic bearing through the gap between the bearing stator and the thrust plate, but the heat dissipation efficiency is not high. Summary of the invention

[0004] Therefore, the present invention provides an axial magnetic bearing and a magnetically suspended rotating machine, which can solve the technical problems of severe heating and low heat dissipation efficiency of the axial magnetic bearing in the magnetically suspended rotating machine in the prior art.

[0005] In order to solve the above problems, the present invention provides an axial magnetic suspension bearing, including an outer cylinder, a first axial stator assembly, a second axial stator assembly and a thrust plate 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 plate 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 ring grooves are formed on the surface areas where the first outer magnetic pole and the thrust plate are opposite to each other, and on the surface areas where the second outer magnetic pole and the thrust plate are opposite to each other, inner flow ring grooves are formed on the surface areas where the first inner magnetic pole and the thrust plate are opposite to each other, and on the surface areas where the second inner magnetic pole and the thrust plate are opposite to each other, the outer flow ring grooves and the inner flow ring grooves are both coaxially arranged with the thrust plate.

[0006] In some embodiments, the outer current ring groove includes a first current ring groove, which is formed on the magnetic end surfaces of the first outer magnetic pole and the second outer magnetic pole. Any radial plane perpendicular to the axis of the thrust plate is defined as a radial plane, and projected on the radial plane, the outer circular contour of the thrust plate is within the groove width range of the first current ring groove.

[0007] In some embodiments, the outer current ring groove also includes a second current ring groove, the second current ring groove is formed on the magnetic end surfaces of the first outer magnetic pole and the second outer magnetic pole, the first current ring groove is concentrically arranged with the second current ring groove, and the first current ring groove is located radially outside the second current ring groove.

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

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

[0010] In some embodiments, the inner flow ring groove includes a third flow ring groove and a fourth flow ring groove, and the third flow ring groove and the fourth flow ring groove are both formed on the magnetic end surfaces of the first inner magnetic pole and the second inner magnetic pole, the third flow ring groove is coaxial with the fourth flow ring groove and is located radially outward of the fourth flow ring groove, the third flow 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 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 plate and the magnetic pole 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 current ring groove, the second current ring groove, the third current ring groove, and the fourth current ring groove are all a, 2x≤a≤3x.

[0012] In some embodiments, the first stator core also includes a first stator yoke portion located between the first outer magnetic pole and the first inner magnetic pole, and the second stator core also includes a second stator yoke portion located 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 radial outer ring wall of the first outer magnetic pole, and the second stator yoke portion 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 a cooling cavity between the first outer magnetic pole and the outer cylinder and between the second outer magnetic pole and the outer cylinder, and the first current ring groove of the first axial stator assembly is connected to the first current ring groove of the second axial stator assembly through the cooling cavity.

[0013] In some embodiments, the outer cylinder has a bearing exhaust hole, and the bearing exhaust hole is connected to 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 a flow hole that penetrates along the axial direction thereof.

[0014] The present invention also provides a magnetic levitation rotating machine, comprising a rotating shaft and an axial magnetic levitation bearing for limiting the axial displacement of the rotating shaft, wherein the axial magnetic levitation bearing is the above-mentioned axial magnetic levitation bearing, wherein 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, and the cooling airflow introduced into the magnetic levitation rotating machine by the cooling impeller and / or part of the airflow at the blower turbine can enter the axial magnetic levitation bearing.

[0015] In some embodiments, the magnetic levitation rotating machine further includes a cylinder, in which a motor stator capable of driving the rotating shaft to rotate is assembled, and a stator cooling channel is formed in an area of ​​the cylinder corresponding to the position of the motor stator.

[0016] The axial magnetic suspension bearing and magnetic suspension rotating machine provided by the present invention have the following beneficial effects:

[0017] By arranging corresponding flow ring grooves (i.e., the aforementioned outer flow ring grooves and inner flow ring grooves) at the relative areas of the inner and outer magnetic poles and the thrust plate, the flow area of ​​the cooling air flow between the bearing stator and the thrust plate can be significantly increased, thereby significantly increasing the amount of cooling air flow entering the bearing from the outside, thereby achieving efficient cooling of the windings, stator core and thrust plate in the bearing; it is worth emphasizing that the flow ring groove in this technical solution is a circular groove coaxially arranged with the thrust plate, and when the thrust plate rotates, no circumferential magnetic field alternation will be formed, thereby preventing the occurrence of eddy current heating caused by the magnetic field alternation caused by the grooves forming a radial shape structure in the circumferential direction when the rotor rotates. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the implementation methods of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the implementation methods or the description of the prior art. The drawings described below are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

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

[0020] Figure 2 yes Figure 1 A schematic diagram of the internal structure of the axial magnetic bearing (half section), showing the relative position relationship between the magnetic pole and the thrust plate;

[0021] Figure 3 1 is a schematic diagram (half-section) of the internal structure of an axial magnetic bearing according to another embodiment of the present invention, wherein arrows in the figure indicate the flow direction of the cooling airflow;

[0022] Figure 4 yes Figure 3 A schematic diagram of the three-dimensional structure of the thrust plate;

[0023] Figure 5 Schematic diagram of the internal structure of the first embodiment of the magnetic suspension rotating machine of the present invention. The arrows in the figure show the flow path of the cooling airflow. The axial magnetic suspension bearing in the figure is Figure 1 Axial magnetic bearings in;

[0024] Figure 6 Schematic diagram of the internal structure of the second embodiment of the magnetic suspension rotating machine of the present invention. The arrows in the figure show the flow path of the cooling airflow. The axial magnetic suspension bearing in the figure is Figure 1 Axial magnetic bearings in;

[0025] Figure 7 Schematic diagram of the internal structure of the third embodiment of the magnetic suspension rotating machine of the present invention. The arrows in the figure show the flow path of the cooling airflow. The axial magnetic suspension bearing in the figure is Figure 1 Axial magnetic bearings in;

[0026] Figure 8 A schematic diagram of the internal structure of the fourth embodiment of the magnetic suspension rotating machine of the present invention, wherein the arrows in the figure indicate the flow path of the cooling airflow, and the axial magnetic suspension bearing in the figure is Figure 1 Axial magnetic bearings in.

[0027] The accompanying drawings are marked as follows:

[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 plate; 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 plate; 312. second inner magnetic pole; 313. second stator yoke; 32. second winding; 4. thrust plate; 41. fifth current ring groove; 42. sixth current ring groove; 43. seventh current ring Groove; 51, first flow ring groove; 52, flow hole; 53, second flow ring groove; 54, third flow ring groove; 55, fourth flow ring groove; 100, rotating shaft; 101, axial magnetic bearing; 102, blower turbine; 1021, turbine volute; 1022, front cover; 103, cooling impeller; 1031, rear cover; 1032, guide plate; 104, radial magnetic bearing; 1041, front casing; 1042, rear casing; 105, motor stator; 106, cylinder; 1061, exhaust hole; 1062, stator cooling channel. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only 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 is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the devices or elements referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention. The directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0031] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90° or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0032] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0033] See also Figures 1 to 8 As shown, according to an embodiment of the present invention, an axial magnetic bearing is provided, comprising an outer cylinder 1 (in some cases, the outer cylinder 1 may be, for example, a cylinder body 106 described later), wherein a first axial stator assembly 2, a second axial stator assembly 3 and a thrust plate 4 are assembled in a central through hole of the outer cylinder 1, wherein the first axial stator assembly 2 comprises a first stator core 21 and a first winding 22 assembled on the first stator core 21, wherein the second axial stator assembly 3 comprises a second stator core 31 and a second winding 32 assembled on the second stator core 31, wherein the thrust plate 4 is located between the magnetic poles of the first stator core 21 and the magnetic poles of the second stator core 31, and between the thrust plate 4 and the first stator core 21 and between the thrust plate 4 and the second stator core A corresponding air gap is formed between the first stator core 21 and the 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 ring grooves (not marked in the figure) are formed on the surface areas where the first outer magnetic pole 211 and the thrust plate 4 are opposite to each other, and on the surface areas where the second outer magnetic pole 311 and the thrust plate 4 are opposite to each other, inner current ring grooves (not marked in the figure) are formed on the surface areas where the first inner magnetic pole 212 and the thrust plate 4 are opposite to each other, and on the surface areas where the second inner magnetic pole 312 and the thrust plate 4 are opposite to each other, and the outer current ring grooves and the inner current ring grooves are both coaxially arranged with the thrust plate 4.

[0034] In this technical solution, by arranging corresponding flow ring grooves (i.e., the aforementioned outer flow ring grooves and inner flow ring grooves) at the relative areas of the inner and outer magnetic poles and the thrust plate 4, the flow area of ​​the cooling airflow between the bearing stator and the thrust plate 4 can be significantly increased, thereby significantly increasing the amount of cooling airflow entering the bearing from the outside, thereby achieving efficient cooling of the windings, stator core and thrust plate in the bearing; it is worth emphasizing that the flow ring groove in this technical solution is a circular groove coaxially arranged with the thrust plate 4. When the thrust plate 4 rotates, no circumferential magnetic field alternation will be formed, thereby preventing the occurrence of eddy current heating caused by the magnetic field alternation caused by the grooves forming a radial shape structure in the circumferential direction when the rotor rotates.

[0035] In a specific embodiment, the outer flow ring groove includes a first flow ring groove 51, which is formed on the magnetic end faces 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. Projected on the radial plane, the outer circular contour of the thrust disk 4 is within the groove width range of the first flow ring groove 51, so that the cooling airflow entering the bearing can flow out more smoothly through the first flow ring groove 51. In this technical solution, the flow ring groove is formed on the magnetic end face, and during the operation of the bearing, the position of the flow ring groove is relatively fixed, so the occurrence of eddy current heating can be effectively prevented.

[0036] In some embodiments, the outer flow ring groove also includes a second flow ring groove 53, which is formed on the magnetic end surfaces of the first outer magnetic pole 211 and the second outer magnetic pole 311, and the first flow ring groove 51 is concentrically arranged with the second flow ring groove 53, and the first flow ring groove 51 is located radially outside the second flow ring groove 53.

[0037] In this technical solution, by setting the second flow ring groove 53 on the radial inner side of the first flow ring groove 51, the flow area of ​​the cooling airflow into the bearing can be further increased, thereby further increasing the cooling air flow entering the bearing, 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 inward along the thrust plate 4, the second outer magnetic pole 311 includes a second cover plate portion 3111 extending radially inward along the thrust plate 4, and the first flow ring groove 51 and the second flow ring groove 53 are formed on the first cover plate portion 2111 and the second cover plate portion 3111.

[0039] The first cover plate portion 2111 and the second cover plate portion 3111 are specifically both an annular plate, which is a part of the stator core and is used to circulate the magnetic circuit formed by the corresponding winding. Since it extends radially inward along the thrust plate 4, the outer diameter of the corresponding thrust plate 4 can be designed to be smaller, thereby reducing the eccentric mass of the rotating shaft, which is beneficial to improving the dynamic balance performance of the rotating shaft. The first flow ring groove 51 and the second flow ring groove 53 are both formed on the first cover plate portion 2111 and the second cover plate portion 3111, and the adverse effect of the groove setting on the magnetic field can be minimized by adjusting the area of ​​the first cover plate portion 2111 and the second cover plate portion 3111.

[0040] In some embodiments, the second flow ring groove 53 passes through the radial inner ring wall of the first cover plate portion 2111 or the second cover plate portion 3111, ensuring that the cooling airflow entering the bearing through the flow hole on the inner magnetic pole can more smoothly enter the air gap between the outer magnetic pole and the thrust plate 4.

[0041] In some embodiments, the inner flow ring groove includes a third flow ring groove 54 and a fourth flow ring groove 55, and the third flow ring groove 54 and the fourth flow ring groove 55 are both formed on the magnetic end surfaces of the first inner magnetic pole 212 and the second inner magnetic pole 312, the third flow ring groove 54 is coaxial with the fourth flow ring groove 55 and is located radially outside the fourth flow ring groove 55, the third flow 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 ring groove 55 penetrates to 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 arranging corresponding third flow ring grooves 54 and fourth flow ring grooves 55 on the radial inner and outer sides of the inner magnetic pole, the effect of guiding the cooling air flow to the inside of the bearing can be further improved, further ensuring the cooling and heat dissipation effect of the internal structure of the bearing.

[0043] like Figure 2 As shown, when the annular grooves (i.e., the aforementioned first current annular grooves 51 and second current annular grooves 53) are set on the thrust plate or stator, they will objectively affect the magnetic circuit to a certain extent. In order to ensure that the output of the axial bearing is not affected, according to the magnetic circuit principle, when the magnetic circuit at other positions is large enough, the influence of the annular grooves on the magnetic circuit can be compensated. That is, the stator structure of the magnetic bearing or the coil excitation current can be appropriately increased to ensure that the output value of the magnetic bearing is not affected. The specific analysis is as follows:

[0044] exist Figure 2In the figure, assuming that no annular groove is provided on the thrust plate or the stator (operating condition 1), the axial bearing outputs of regions 1, 2, and 3 are F1, F2, and F3. The aforementioned region 1 is a circular region with a width of b1 between the outer circumferential wall of the thrust plate 4 and the inner annular groove wall of the first flow annular groove 51, and region 3 is a circular region with a width of b2 extending radially outward from the inner annular wall of the first cover plate portion 2111 or the second cover plate portion 3111, and region 3 is a circular region between the aforementioned regions 1 and 2. According to the Ampere loop law of the magnetic circuit, it can be obtained that:

[0045]

[0046] F 总 =F1+F2+F3

[0047] When an annular groove is provided on the thrust plate or stator (working condition 2), the air gap between the axial bearing stator and the thrust plate 4 in areas 1 and 3 becomes (x+a). For the convenience of subsequent calculation, let a=kx. Therefore, the axial bearing output in areas 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, F'3 are the axial bearing output values ​​in areas 1, 2, and 3 under two working conditions respectively; μ0 is the air magnetic permeability; N is the number of coil turns; A1, A2, A3 are the magnetic circuit areas of the magnetic bearing stator in areas 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 plate; a is the ring groove depth (also known as the aforementioned groove depth).

[0051] At this time, due to the influence of the ring groove, the axial bearing output value F 总 >>F′ 总 , if we want to ensure F 总 ′≥F 总 , the influence of the compensation ring groove on the magnetic circuit can increase the magnetic circuit area of ​​the magnetic bearing stator in area 1 and area 3 to (k+1) 2 A1, (k+1) 2 A3 or the coil excitation current increases to (k+1)i, where k is the ratio of the ring groove depth a to the air gap x between the axial bearing stator and the thrust plate.

[0052] In this regard, under the condition of taking into account the influence of the compensation ring groove on the magnetic circuit, considering the limitations of factors such as processing cost and control system performance, the ring groove depth a should be designed to be 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, 2x≤a≤3x.

[0053] In another embodiment, the aforementioned flow ring grooves can be formed on the left and right end surfaces of the thrust plate 4. Figure 3 and Figure 4 As shown, at this time, the outer flow ring groove can be specifically the fifth flow ring groove 41, and the inner flow ring groove can be the seventh flow ring groove 43. More preferably, it also includes a sixth flow ring groove 42. When projected on the aforementioned radial plane, the contours of the outer ring wall of the inner magnetic pole and the inner ring wall of the outer magnetic pole are both in the sixth flow ring groove 42, so that the cooling airflow can flow smoothly between the stator core and the thrust plate 4, and the flow area and flow rate of the cooling airflow can be ensured, thereby ensuring the cooling and heat dissipation effect inside the bearing. If the flow ring grooves formed on the magnetic pole end surface of the stator core are similar, the groove depths of the fifth flow ring groove 41, the sixth flow ring groove 42 and the seventh flow ring groove 43 are also a.

[0054] In some embodiments, the first stator core 21 further includes a first stator yoke 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 313 between the second outer magnetic pole 311 and the second inner magnetic pole 312, wherein the first stator yoke 213 has a first outer protruding ring (not marked in the figure) protruding from the radial outer ring wall of the first outer magnetic pole 211, and the second stator yoke 313 has a first outer protruding ring (not marked 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 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 a cooling cavity (not marked 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 flow ring groove 51 of the first axial stator assembly 2 is connected with the first flow ring groove 51 of the second axial stator assembly 3 through the cooling cavity.

[0055] In this technical solution, an outer convex ring is arranged radially outward on the stator yoke, so that 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 axial stator assemblies on both sides are connected to the cooling cavity, so that the stator core can be cooled more efficiently and fully, further preventing the temperature rise of the bearing from being too high.

[0056] In some embodiments, the outer cylinder 1 has a bearing exhaust hole 11, and the bearing exhaust hole 11 connects the cooling cavity and the external space of the outer cylinder 1, so that the cooling air flow entering the bearing can cool the inner magnetic pole, winding, thrust plate 4 and outer magnetic pole in turn and then be discharged to the external environment.

[0057] The first outer convex ring and / or the second outer convex ring have flow holes 52 extending axially therethrough. In another embodiment, flow holes 52 extending axially to the internal winding positions may also be constructed on the first stator yoke 213 and the second stator yoke 313, so that external cooling airflow can be introduced into the interior of the bearing through these flow holes 52, thereby 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 magnetically suspended rotating machine, such as a blower, an air compressor, etc., comprising a rotating shaft 100 and an axial magnetically suspended bearing 101 for limiting the axial displacement of the rotating shaft 100, wherein the axial magnetically suspended bearing 101 is the above-mentioned axial magnetically suspended bearing, wherein 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, wherein the cooling impeller 103 introduces a cooling airflow into the magnetically suspended rotating machine and / or part of the airflow at the blower turbine 102 can enter the axial magnetically suspended bearing, thereby the pressurized airflow generated by the cooling impeller 103 or the blower turbine 102 can be introduced into the axial magnetically suspended bearing to cool and dissipate heat of various components in the bearing, thereby 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 rotating shaft 100, when the magnetic levitation rotating machinery is running, the rotation of the cooling impeller 103 can be synchronously realized, and then the external air can be introduced into the magnetic levitation rotating machinery, that is, the cooling impeller 103 is directly driven by the rotating shaft 100, and there is no need to separately configure a corresponding cooling structure for cooling the bearing, and there is no need to set up 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 machinery also includes a cylinder 106, in which a motor stator 105 capable of driving the rotating shaft 100 to rotate is assembled, and a stator cooling channel 1062 is formed in the area corresponding to the position of the cylinder 106 and the motor stator 105. At this time, the cooling air flow driven by the cooling impeller 103 can flow through the air gap between the motor stator and rotor and the stator cooling channel 1062, so that the inside and outside of the motor stator 105 can be cooled and dissipated simultaneously.

[0060] Figure 6The figure shows the situation that each component in the magnetic levitation rotating machine is cooled only by the cooling airflow driven by the cooling impeller 103. The arrows in each figure indicate the flow path of the cooling airflow, and the aforementioned flow path is different depending on the setting position of the exhaust hole 1061. Figure 6 The aforementioned exhaust hole 1061 can be directly realized by using the aforementioned bearing exhaust hole 11. Figure 6 In the embodiment shown in , the cooling impeller 103 rotates to drive the external airflow into the cylinder 106 along the guide plate 1032. Figure 5 , Figure 7 and Figure 8 It also shows a way in which the cooling airflow is also partially led out from the blower turbine 102, that is, in a preferred embodiment, the cooling airflow is provided by the cooling impeller 103 and the blower turbine at the same time, so that the cooling airflow can be introduced from both axial ends of the magnetic levitation rotating machine, thereby ensuring comprehensive cooling of various components in 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 cooling airflow path of the magnetic levitation rotating machine of the present invention is further described below in conjunction with the respective figures:

[0062] First embodiment:

[0063] See also Figure 5As shown, an active pure air-cooling heat dissipation system is adopted, and the cold air is provided by the cooling impeller, and no additional heat dissipation drive motor is required. The cooling impeller 103 is assembled at the rear end of the rotor (that is, the second end of the rotating shaft 100, the same below), and the rear radial bearing (that is, the radial magnetic suspension bearing 104 near the second end position of the rotating shaft 100, the same below) is located between the cooling impeller 103 and the motor stator 105, the front radial bearing (that is, the radial magnetic suspension bearing 104 near the first end position of the rotating shaft 100, the same below) is placed at the front end of the rotor, and the axial bearing (that is, the axial magnetic suspension bearing 101, the same below) is located at the front radial Between the bearing and the front cover 1022, the rear housing 1042 is equipped with a guide plate 1032 and a rear cover 1031 for cooling the impeller to increase air flow conduction and reduce flow resistance, and the rear housing 1042, the cylinder (that is, the cylinder 106, the same below), the front housing 1041, the axial bearing and other parts are provided with a number of corresponding ventilation holes or ventilation grooves for air flow conduction. The cooling gas of the cooling impeller passes through the flow channel on the rear housing 1042 and the rotor flow channel (that is, the air gap between the stator and the rotor) to cool the motor rotor, and then is cooled in two ways at the front radial bearing: the first way: entering the inner circulation of the axial stator The second route: after passing through the flow channel of the motor stator (i.e. the flow hole and flow groove in the second axial stator assembly), the leakage gas of the main impeller (i.e. the blower turbine 102) merges with the leakage gas of the main impeller (30) after passing through the leakage channel of the main impeller (i.e. the blower turbine 102) → the inner flow channel hole of the axial stator and the left flow groove of the thrust plate or the upper magnetic pole of the stator (i.e. the flow hole and flow groove in the first axial stator assembly) and is discharged from the bearing exhaust hole 11; the second route: after passing through the motor stator flow channel (i.e. the stator cooling flow channel 1062, the same below) outside the motor stator to cool the motor stator The gas is discharged from the exhaust hole 1061 on the cylinder body through the cylinder 105. This flow channel structure arrangement can effectively cool 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 plate or the axial bearing stator, a ring groove structure is provided on the upper magnetic pole of the thrust plate or the axial bearing, and a flow channel hole is provided on the inner ring of the axial bearing stator. Under the high rotation speed of the rotor, the gas flow channel is enlarged, the cooling flow rate and speed are improved, and the cooling of the axial magnetic bearing and the thrust plate is accelerated. The whole heat dissipation system has a simple structure, the heat dissipation process is efficient and reliable, and the stability of the magnetic suspension system is improved.

[0064] Second embodiment:

[0065] See also Figure 6As shown, an active pure air cooling system is adopted. The cold air is provided by the cooling impeller. No additional heat dissipation drive motor is required. 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. The rear housing is equipped with a guide plate 1032 for guiding the cooling impeller and a rear end cover 1031 to increase air flow conduction and reduce flow resistance. The rear housing 1042, the cylinder, the front housing 1041, the axial bearing and other parts are Several corresponding ventilation holes or ventilation grooves are provided to facilitate air flow. The cooling gas for cooling the impeller is divided into three paths through the flow channel on the rear shell 1042. The first path: through the axial cooling flow channel in the cylinder (not marked in the figure) → axial bearing; the second path: through the motor stator flow channel on the cylinder → axial bearing; the third path: through the motor rotor flow channel (that is, the air gap between the motor stator and rotor) → axial bearing; the three cooling gases are discharged from the bearing exhaust hole 11 after passing through the inner ring flow channel holes of the axial stator and the magnetic poles or thrust plate ring grooves on the axial stator on both sides of the axial bearing. This flow channel structure arrangement can effectively cool heat-generating components such as stators, rotors, radial bearings, and axial bearings. At the same time, for high-heat-generating components such as thrust plates or axial bearing stators, an annular groove structure is provided on the upper magnetic pole of the thrust plates or axial bearings, and flow channel holes are provided on the inner ring of the axial bearing stator. Under high rotor speed, the gas flow channel is enlarged, the cooling flow rate and speed are increased, and the cooling of the axial magnetic bearings and thrust plates is accelerated. The entire heat dissipation system has a simple structure, the heat dissipation process is efficient and reliable, and the stability of the magnetic suspension system is improved.

[0066] Third embodiment:

[0067] See also Figure 7As shown, an active pure air-cooling heat dissipation system is adopted, and the cold air is provided by the cooling impeller, and no additional heat dissipation drive motor is required. The cooling impeller 103 is installed 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, and the axial bearing is located between the front radial bearing and the motor stator 105. The rear housing is equipped with a guide plate 1032 and a rear end cover 1031 for guiding the cooling impeller to increase air flow conduction and reduce flow resistance, and the rear housing 1042, the cylinder, the front housing 1041, the axial bearing and other parts are provided with a number of corresponding ventilation holes or ventilation slots to facilitate air flow conduction. The cooling gas of the cooling impeller is divided into two cooling paths after entering the motor rotor flow channel. The first path: the motor stator is cooled through the motor stator flow channel on the cylinder and then discharged through the exhaust hole 1061 ; The second route: after passing through the axial stator inner ring flow channel hole → the axial stator upper magnetic pole or thrust plate ring groove, it merges with the main impeller leakage gas that passes through the main impeller leakage flow channel → the axial stator inner ring flow channel hole and the axial stator upper magnetic pole or thrust plate ring groove and is discharged from the bearing exhaust hole 11. This flow channel structure arrangement can effectively cool 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 plate or axial bearing stator, a ring groove structure is provided on the upper magnetic pole of the thrust plate or axial bearing, and a flow channel hole is added on the inner ring of the axial bearing stator. Under the high rotation speed of the rotor, the gas flow channel is enlarged, the cooling flow rate and speed are increased, and the cooling of the axial magnetic bearing and the thrust plate is accelerated. The entire heat dissipation system has a simple structure, the heat dissipation process is efficient and reliable, and the stability of the magnetic suspension system is improved.

[0068] Fourth embodiment:

[0069] See also Figure 8As shown, an active pure air cooling system is adopted. The cold air is provided by the cooling impeller, and no additional heat dissipation drive motor is required. The cooling impeller 103 is installed 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, and the axial bearing is located between the front radial bearing and the motor stator 105. The rear housing is equipped with a guide plate 1032 for guiding the cooling impeller and a rear end cover 1031 to increase air flow conduction and reduce flow resistance, and the rear housing 1042, Several corresponding ventilation holes or ventilation grooves are provided on the cylinder, front shell 1041, axial bearing and other parts to facilitate air flow. The cooling gas of the cooling impeller passes through the rear shell 1042, through the motor stator flow channel and the motor rotor flow channel on the cylinder → the inner ring flow channel hole of the axial stator and the right side ring groove of the thrust plate or the stator magnetic pole, and then merges with the main impeller leakage gas passing through the main impeller leakage flow channel → the inner ring flow channel hole of the axial stator and the left side ring groove of the thrust plate or the axial stator magnetic pole, and is discharged from the bearing exhaust hole 11. This flow channel structure arrangement can effectively cool the stator, rotor, radial bearings, axial bearings and other heat-generating components separately, and can also effectively cool the stator, rotor, radial bearings, axial bearings and other heat-generating components at the same time. At the same time, for the high-heat-generating components such as the thrust plate or the axial bearing stator, an annular groove structure is provided on the upper magnetic pole of the thrust plate or the axial bearing, and a flow channel hole is provided on the inner ring of the axial bearing stator. Under the high rotation speed of the rotor, the gas flow channel is enlarged, the cooling flow rate and speed are increased, and the cooling of the axial magnetic bearing and the thrust plate is accelerated. The entire heat dissipation system has a simple structure, the heat dissipation process is efficient and reliable, and the stability of the magnetic suspension system is improved.

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

[0071] It is easy for those skilled in the art to understand that, without conflict, the advantageous technical features of the above-mentioned methods can be freely combined and superimposed.

[0072] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention. The above description is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and variations can be made without departing from the technical principles of the present invention. These improvements and variations should also be regarded as the protection scope of the present invention.

Claims

1. An axial magnetic bearing, comprising an outer cylinder (1), wherein a first axial stator assembly (2), a second axial stator assembly (3) and a thrust plate (4) are assembled in a central through hole of the outer cylinder (1), wherein the first axial stator assembly (2) comprises a first stator core (21), the second axial stator assembly (3) comprises a second stator core (31), the thrust plate (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) comprise a first outer magnetic pole (211) and a first inner magnetic pole (212), and the magnetic poles of the second stator core (31) comprise a second outer magnetic pole (311) and a second inner magnetic pole (312), characterized in that: An outer flow ring groove is formed on the surface area where the first outer magnetic pole (211) and the thrust disk (4) are opposite to each other, and an inner flow ring groove is formed on the surface area where the first inner magnetic pole (212) and the thrust disk (4) are opposite to each other, and an inner flow ring groove is formed on the surface area where the second inner magnetic pole (312) and the thrust disk (4) are opposite to each other. The outer flow ring groove and the inner flow ring groove are both coaxially arranged with the thrust disk (4).

2. The axial magnetic bearing according to claim 1, characterized in that: The outer flow ring groove comprises a first flow ring groove (51), the first flow ring groove (51) is formed on the magnetic end faces of the first outer magnetic pole (211) and the second outer magnetic pole (311), and any radial plane perpendicular to the axis of the thrust disk (4) is defined as a 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 ring groove (51).

3. The axial magnetic bearing according to claim 2, characterized in that: The outer flow ring groove also includes a second flow ring groove (53), the second flow ring groove (53) is formed on the magnetic end faces of the first outer magnetic pole (211) and the second outer magnetic pole (311), the first flow ring groove (51) and the second flow ring groove (53) are concentrically arranged, and the first flow ring groove (51) is located radially outside the second flow ring groove (53).

4. The axial magnetic bearing according to claim 3, characterized in that: The first outer magnetic pole (211) includes a first cover plate portion (2111) extending radially inward along the thrust plate (4), the second outer magnetic pole (311) includes a second cover plate portion (3111) extending radially inward along the thrust plate (4), and the first flow ring groove (51) and the second flow ring groove (53) are formed on the first cover plate portion (2111) and the second cover plate portion (3111).

5. The axial magnetic bearing according to claim 4, characterized in that: The second flow annular groove (53) passes through the radial inner annular wall of the first cover plate portion (2111) or the second cover plate portion (3111).

6. The axial magnetic bearing according to claim 3, characterized in that: The inner flow ring groove comprises a third flow ring groove (54) and a fourth flow ring groove (55), and the third flow ring groove (54) and the fourth flow ring groove (55) are both formed on the magnetic end faces of the first inner magnetic pole (212) and the second inner magnetic pole (312), the third flow ring groove (54) is coaxial with the fourth flow ring groove (55) and is located radially outside the fourth flow ring groove (55), the third flow 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 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 bearing according to claim 6, characterized in that: An air gap is formed between the thrust plate (4) and the magnetic pole of the first stator core (21) or the second stator core (31), the axial width of the air gap is x, the groove depths of the first current ring groove (51), the second current ring groove (53), the third current ring groove (54), and the fourth current ring groove (55) are all a, and 2x≤a≤3x.

8. The axial magnetic bearing according to claim 1, characterized in that: The first stator core (21) further comprises a first stator yoke (213) located between the first outer magnetic pole (211) and the first inner magnetic pole (212); the second stator core (31) further comprises a second stator yoke (313) located between the second outer magnetic pole (311) and the second inner magnetic pole (312); the first stator yoke (213) comprises a first outer protruding ring protruding from a radial outer ring wall of the first outer magnetic pole (211); and the second stator yoke (313) comprises a first outer protruding ring protruding from a radial outer ring wall of the second outer magnetic pole (311). A second outer convex ring of the radial outer ring wall, the first axial stator component (2) is assembled in the outer cylinder (1) via the first outer convex ring and the second axial stator component (3) is assembled in the outer cylinder (1) via the second outer convex ring to form a cooling cavity 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 flow ring groove (51) of the first axial stator component (2) and the first flow ring groove (51) of the second axial stator component (3) are connected through the cooling cavity.

9. The axial magnetic bearing according to claim 8, characterized in that: The outer cylinder (1) has a bearing exhaust hole (11), and the bearing exhaust hole (11) is connected to the cooling chamber and the external space of the outer cylinder (1); and / or the first outer convex ring and / or the second outer convex ring have a flow hole (52) that penetrates along the axial direction thereof.

10. A magnetically suspended rotating machine, characterized in that: The invention comprises a rotating shaft (100) and an axial magnetic bearing (101) for limiting the axial displacement of the rotating shaft (100), characterized in that the axial magnetic bearing (101) is the axial magnetic 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), the second end of the rotating shaft (100) is connected to a cooling impeller (103), and the cooling airflow introduced into the magnetically suspended rotating machinery by the cooling impeller (103) and / or part of the airflow at the blower turbine (102) can enter the axial magnetic bearing.

11. The magnetic levitation rotating machine according to claim 10, characterized in that: It also includes a cylinder (106), in which a motor stator (105) capable of driving the rotating shaft (100) to rotate is assembled, and a stator cooling channel (1062) is formed in an area of ​​the cylinder (106) corresponding to the position of the motor stator (105).

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