Inner rotor magnetic suspension fan

Abstract

The utility model discloses an inner rotor magnetic suspension fan which comprises a tubular outer shell, a stator shell, a magnetic suspension stator and a rotor impeller assembly, the stator shell is arranged in the tubular outer shell, a rotor cavity is formed in the end, facing an air inlet, of the stator shell, the magnetic suspension stator is arranged in the stator shell in a sealed mode, and the rotor impeller assembly is arranged in the rotor cavity. The rotor impeller assembly comprises a rotor sheath, a magnetic suspension rotor, a connecting component and an impeller, the impeller comprises a cylindrical hub and a plurality of blades arranged on the peripheral side of the cylindrical hub, the cylindrical hub is arranged around the stator shell and fixedly connected with the rotor sheath through the connecting component, the magnetic suspension rotor is sealed in the rotor sheath, the rotor sheath is arranged in the rotor cavity, and the magnetic suspension rotor is arranged in the rotor cavity. The magnetic levitation stator is configured to drive the magnetic levitation rotor to rotate and magnetically levitate. According to the magnetic suspension fan, the axial flow type fluid characteristic with the large diameter is obtained in the form of the inner rotor, the structure is simple, the heat dissipation performance is good, and high-precision, high-sensitivity and good-stability rotor position detection can be achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of magnetic suspension, in particular to an inner rotor magnetic suspension fan. Background Art

[0002] A magnetic levitation motor is a magnetic levitation rotary drive that uses magnetic field force to suspend the rotor so that there is no mechanical contact between the rotor and the stator. The magnetic levitation motor can be a magnetic bearing motor, a bearingless motor, or a bearingless thin-film motor, etc.

[0003] A magnetic bearing motor, also known as a magnetic bearing, is a motor that combines a rotary drive motor with an axial magnetic bearing or / and a radial magnetic bearing or / and an axial-diameter hybrid magnetic bearing instead of integrating them together.

[0004] A bearingless motor is a motor that integrates motor rotation and suspension functions. A bearingless motor has an additional set of windings on top of the windings that generate a rotating drive magnetic field to generate an excitation magnetic field. The interaction between the two magnetic fields breaks the balanced distribution of the original drive magnetic field, thereby generating a radial force acting on the rotor. The rotor is suspended by controlling the radial force in the motor. Compared with a magnetic bearing motor, the magnetic suspension winding of a bearingless motor is wound on the stator and does not occupy additional radial space, which to a certain extent overcomes the shortcomings of large size and high cost of magnetic bearings. In order to achieve suspension of the motor rotor in five degrees of freedom, early bearingless motors generally required two bearingless motors and one axial magnetic bearing.

[0005] The bearingless thin-film motor is a special bearingless motor that inherits the advantages of bearingless motors. The axial length to diameter ratio of the rotor is very small and it is in the shape of a thin film, eliminating the axial magnetic bearing. The bearingless technology is used to realize the rotation of the rotor and the active suspension in the radial direction. The magnetic circuit formed by the mechanical structure is used to realize the passive suspension of the other three degrees of freedom except the radial and rotor rotation degrees of freedom. It has the characteristics of high cleanliness, no precipitation, no particles, no dynamic seal, and excellent performance. It has good application prospects in ultra-pure drive fields such as biochemistry, medical treatment, and semiconductor manufacturing.

[0006] Unless otherwise specified, the term magnetic levitation motor refers to a magnetic levitation rotary drive that uses magnetic field force to suspend the rotor so that there is no mechanical contact between the rotor and the stator.

[0007] The magnetic levitation motor can be equipped with different functional assemblies to become a magnetic levitation device for different application requirements. The magnetic levitation device can be configured as a magnetic levitation pump. In the application of the magnetic levitation pump, the magnetic levitation pump includes a magnetic levitation motor and a pump head. The pump head includes a pump housing and a rotor impeller arranged in the pump housing. The magnetic levitation rotor is both the rotor of the magnetic levitation motor and a part of the impeller of the pump. It can be, for example, a permanent magnet rotor, a short-circuit cage rotor, or a reluctance rotor.

[0008] The magnetic levitation device can also be configured as a magnetic levitation fan. For example, patent document CN112096632A discloses an outer rotor magnetic levitation fan, which includes a generally tubular housing having a suction opening configured to suck in a compressible fluid and a pressure opening configured to eject a compressible liquid; it also includes a stator and a rotor, and the stator and the rotor together form an electromagnetic rotary drive, that is, a magnetic levitation motor. Among them, the rotor is an outer rotor, and the rotor includes a magnetic core (permanent magnet) configured in an annular manner and an impeller. The impeller includes a hub, and a plurality of blades configured to generate a fluid flow are arranged on the hub, and the hub completely encloses the magnetic core. The stator is encapsulated in a stator housing and is formed of a low magnetic permeability material (such as plastic). The stator is a bearing and a driving stator, configured to magnetically drive the rotor without contact and magnetically levitate the rotor without contacting the stator, and the rotor can actively magnetically levitate in a radial plane perpendicular to the axial direction.

[0009] In the above structure, since the stator is encapsulated in the stator housing and is located at the center of the annular hub, and the eddy current sensor for detecting the displacement of the rotor also needs to be arranged in the stator housing, the stator housing is made of plastic and cannot use metal materials with better heat conduction effects (such as aluminum, copper, etc.) because metal materials will have an interference effect on the eddy current sensor. On the one hand, this limits the application of high-precision, high-sensitivity and good-stability eddy current sensors in magnetic levitation motors. On the other hand, it brings difficulties to the heat dissipation of the stator winding and the control unit in the stator housing. Summary of the Utility Model

[0010] In order to overcome the defects in the prior art, the embodiments of the present utility model provide an inner rotor magnetic levitation fan, which is used to solve at least one of the above problems.

[0011] The embodiments of the present disclosure disclose an inner rotor magnetic levitation fan, which includes a tubular outer shell, a stator housing, a magnetic levitation stator and a rotor impeller assembly. One end of the tubular outer shell is configured as an air inlet, and the other end is configured as an air outlet. The stator housing is arranged inside the tubular outer shell. One end of the stator housing facing the air inlet forms a rotor cavity. The magnetic levitation stator is hermetically arranged in the stator housing. The rotor impeller assembly includes a rotor sheath, a magnetic levitation rotor, a connecting member and an impeller. The impeller includes a cylindrical hub and a plurality of blades arranged on the outer peripheral side of the cylindrical hub. The cylindrical hub surrounds the stator housing and is fixedly connected to the rotor sheath through the connecting member. The magnetic levitation rotor is sealed in the rotor sheath. The rotor sheath is arranged in the rotor cavity. The magnetic levitation stator is configured to drive the magnetic levitation rotor to rotate and magnetically levitate.

[0012] Further, the stator housing includes an upper cover and a lower shell. The upper cover and the lower shell enclose a first accommodation space for accommodating the magnetic levitation stator, and the rotor cavity is configured as a part of the upper cover.

[0013] Furthermore, the upper cover is fixedly and sealingly connected to the lower housing, a heat-conducting potting material is filled in the first accommodation space, the upper cover is configured with a plastic material, and the lower housing is configured with a metal material.

[0014] Furthermore, the cylindrical hub surrounds the middle upper part of the lower housing, an air flow passage is formed between the outer peripheral side of the middle lower part of the lower housing and the inner wall of the tubular housing, and a plurality of heat dissipation fins are formed on the outer peripheral side of the lower housing.

[0015] Furthermore, the lower housing includes an outer cylinder part, an inner cylinder part, and a partition plate connected between the inner cylinder part and the outer cylinder part, and the upper cover, the inner cylinder part, the partition plate, and the outer cylinder part enclose the first accommodation space.

[0016] Furthermore, a second accommodation space is formed on a side of the partition plate facing away from the magnetic levitation stator, and a control unit for adjusting and controlling the magnetic levitation fan is provided in the second accommodation space.

[0017] Furthermore, the lower housing further includes a bottom cover, and the partition plate, the outer cylinder part, the inner cylinder part, and the bottom cover enclose the second accommodation space.

[0018] Furthermore, a protective coating is formed on the outer surface of the lower housing.

[0019] Furthermore, the magnetic levitation stator includes an annular magnetic yoke, a plurality of stator teeth, and a plurality of winding coils, the stator teeth are in a straight shape, the outer ends of the stator teeth are magnetically connected to the annular magnetic yoke, the winding coils are sleeved on the corresponding stator teeth, and the inner ends of the plurality of stator teeth are arranged around the magnetic levitation rotor.

[0020] Furthermore, the magnetic levitation stator includes an annular magnetic yoke, a plurality of stator teeth, and a plurality of winding coils, the stator teeth are in an L shape, the vertical portions of the stator teeth are magnetically connected to the annular magnetic yoke, the winding coils are sleeved on the vertical portions of the corresponding stator teeth, and the inner ends of the transverse portions of the plurality of stator teeth are arranged around the magnetic levitation rotor.

[0021] Furthermore, a chamfer is formed at the outer end of the transverse portion of the stator tooth.

[0022] Furthermore, the cylindrical hub surrounds the middle upper part of the lower housing, and the outer peripheral side of the middle lower part of the lower housing is fixedly connected to the inner wall of the tubular housing through a plurality of flow guiding pieces, and a blade flow passage is formed between two adjacent flow guiding pieces.

[0023] Furthermore, the connecting member includes a connecting plate and a support column, the support column is fixedly connected between the connecting plate and the rotor sheath, and the outer edge of the connecting plate is fixedly connected to the cylindrical hub.

[0024] Further, a plurality of hollow holes are formed on the connecting plate, or the connecting plate includes a central disc and a plurality of radially extending spokes extending outward from the central disc, and a spoke gap is formed between two adjacent spokes.

[0025] Further, the cylindrical hub includes a straight cylinder portion and a necking portion. The extending direction of the straight cylinder portion is parallel to the rotation axis of the magnetic levitation rotor. The necking portion extends obliquely from one end of the straight cylinder portion toward the rotation axis. The blade extends from the necking portion and the straight cylinder portion toward the tubular housing.

[0026] The beneficial effects of the present utility model are as follows: The present utility model provides an inner-rotor magnetic levitation fan. By arranging the rotor sheath in the rotor cavity formed by the stator housing and then realizing the fixed connection with the cylindrical hub of the impeller through the connecting member, an axial-flow magnetic levitation fan with an inner rotor but a relatively large diameter is formed. The structure is simple and the heat dissipation performance is good. On the one hand, this magnetic levitation fan can meet the hydrodynamic performance of an axial-flow fan with a relatively large diameter. On the other hand, it is not restricted by the material of the stator housing, which is convenient for using an eddy current sensor to realize the detection of the position of the magnetic levitation rotor with high precision, high sensitivity and good stability.

[0027] To make the above and other objects, features and advantages of the present utility model more obvious and understandable, the following specifically enumerates preferred embodiments and, in conjunction with the accompanying drawings, the detailed description is as follows. Description of the Drawings

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0029] Figure 1 It is a schematic structural diagram of an embodiment of an inner-rotor magnetic levitation fan in an embodiment of the present utility model;

[0030] Figure 2 It is a schematic structural diagram of another embodiment of an inner-rotor magnetic levitation fan in an embodiment of the present utility model;

[0031] Figure 3 It is a schematic structural diagram of an embodiment of an inner-rotor magnetic levitation fan (omitting the rotor impeller assembly) in an embodiment of the present utility model;

[0032] Figure 4 It is a schematic structural diagram of another embodiment of an inner-rotor magnetic levitation fan (omitting the rotor impeller assembly) in an embodiment of the present utility model;

[0033] Figure 5 It is a schematic structural diagram of an embodiment of the magnetic levitation stator in an embodiment of the present utility model;

[0034] Figure 6 It is a schematic structural diagram of another embodiment of the magnetic levitation stator in an embodiment of the present utility model;

[0035] Figure 7 It is a schematic structural diagram of yet another embodiment of the inner rotor magnetic levitation fan in an embodiment of the present utility model;

[0036] Figure 8 It is a schematic structural diagram of an embodiment of the rotor impeller assembly in an embodiment of the present utility model;

[0037] Figure 9 It is a three - dimensional view of an embodiment of the inner rotor magnetic levitation fan in an embodiment of the present utility model;

[0038] Figure 10 It is a top view of yet another embodiment of the inner rotor magnetic levitation fan in an embodiment of the present utility model; Detailed implementation manners

[0039] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present utility model.

[0040] In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation to the present utility model. The terms "include" and "are provided with" in the description and claims of the present utility model and any variations thereof are intended to cover non - exclusive inclusion. For example, a system, product or device including a series of units does not necessarily have to be limited to those units clearly listed, but may include other units not clearly listed or inherent to these products or devices.

[0041] In addition, the terms "first" and "second" are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present utility model, unless otherwise specified, the meaning of "a plurality" is two or more, unless otherwise clearly defined.

[0042] The drawings in the present disclosure are not strictly drawn to actual scale, and the specific dimensions and quantities of each structure can be determined according to actual needs. The drawings described in the present disclosure are only schematic diagrams.

[0043] See Figure 1 and Figure 2 According to an embodiment of the present disclosure, an inner-rotor magnetic levitation fan is provided, which includes a tubular housing 1, a stator housing 2, a magnetic levitation stator 3, and a rotor impeller assembly 4. One end of the tubular housing 1 is configured as an air inlet 11, and the other end is configured as an air outlet 12. The stator housing 2 is disposed inside the tubular housing 1. One end of the stator housing 2 facing the air inlet 11 forms a rotor cavity 21. The magnetic levitation stator 3 is hermetically disposed inside the stator housing 2. The rotor impeller assembly 4 includes a rotor sheath 41, a magnetic levitation rotor 42, a connecting member 43, and an impeller 44. The impeller 44 includes a cylindrical hub 441 and a plurality of blades 442 disposed on the outer peripheral side of the cylindrical hub 441. The cylindrical hub 441 is disposed around the stator housing 2 and is fixedly connected to the rotor sheath 41 through the connecting member 43. The magnetic levitation rotor 42 is hermetically sealed inside the rotor sheath 41. The rotor sheath 41 is disposed inside the rotor cavity 21. The magnetic levitation stator 3 is configured to drive the magnetic levitation rotor 42 to rotate and be magnetically levitated. In this way, by disposing the rotor sheath inside the rotor cavity formed by the stator housing and then realizing the fixed connection with the cylindrical hub of the impeller through the connecting member, an axial-flow magnetic levitation fan with an inner rotor but a relatively large diameter is formed, which has a simple structure and good heat dissipation performance. On the one hand, this magnetic levitation fan can meet the hydrodynamic performance of an axial-flow fan with a relatively large diameter. On the other hand, it is not restricted by the material of the stator housing, which is convenient for using an eddy current sensor to achieve high-precision, high-sensitivity, and good-stability detection of the position of the magnetic levitation rotor.

[0044] Among them, the tubular housing 41 is used to integrate the magnetic levitation fan into a pipeline or a pipeline system to generate, for example, a desired flow or pressure there. For this purpose, see Figure 9 The tubular housing may be provided with a first flange 13 and a second flange 14 at the air inlet and the air outlet to attach the magnetic levitation fan to the pipeline or the pipeline system. The present utility model does not limit the shape of the tubular housing. For example, see Figure 9 and Figure 10 The cross-section of the tubular housing is generally circular, while the first and second flanges are generally square.

[0045] Among them, the rotor sheath 41 is used to seal and protect the magnetic levitation rotor. The rotor sheath can be made of thermoplastic; for example, it can be made of fluorinated hydrocarbon plastic to resist the erosion of chemically corrosive substances. Preferably, the material of the rotor sheath can be perfluoroalkoxy polymer (PFA). In other embodiments, the material of the rotor sheath can also be ethylene chlorotrifluoroethylene (ECTFE) or polyvinylidene fluoride (PVDF).

[0046] Among them, the rotor sheath, as a rotating component, can be composed of a rotor body and a cover plate. The rotor body is generally cylindrical, and the cover plate is generally disc-shaped. The rotor body and the cover plate can be hermetically connected by welding. Among them, one side of the cover plate and the rotor body can be heated and melted first and then extrusion-welded together, that is, first heat one side of the cover plate and the end face of the rotor body, and then drive the two parts to move relative to each other so that the two end faces contact and produce extrusion, and finally the two parts are welded. Preferably, the heating method is non-contact heating, for example, an infrared heater for infrared welding is used for heating. Through infrared welding, the heating area can be precisely controlled, making the heating more uniform, avoiding local overheating, and not requiring contact with the material, reducing mechanical damage to the material surface. Through infrared welding, the cleanliness of the rotor body and the cover plate can also be ensured, ensuring that no other impurities are introduced during the manufacturing process of the inner rotor magnetic levitation fan. Furthermore, it meets the requirements for the inner rotor magnetic levitation fan to be applied in high-cleanliness fields.

[0047] Among them, the connecting member 43 is used to fixedly connect the rotor sheath of the magnetic levitation rotor and the rotor impeller assembly with a larger diameter. The structure of the connecting member is not limited as long as it can play a role in fixedly supporting the rotor impeller assembly. The connecting member and the rotor sheath and the rotor impeller assembly can be assembled and connected or welded through a split structure, and can also be integrally formed by injection molding or machining.

[0048] Among them, the impeller 44 includes a cylindrical hub 441 and a plurality of blades 442 provided on the outer peripheral side of the cylindrical hub 441. The rotation of the plurality of blades can drive the surrounding air to generate a continuous air flow. For example, through the rotation of the blades, a certain air volume is formed to realize the transportation of gas. The curvature and inclination angle of the blades determine the direction and speed of the air flow. The shape and number of the blades of the present utility model are not limited, and the blades can be designed according to the fluid characteristics of actual applications. Among them, the plurality of blades are arranged on the outer peripheral side of the cylindrical hub, which plays a role in increasing the diameter of the impeller. The cylindrical hub fits the stator housing on the one hand and is convenient for fixedly connecting or integrally forming with the connecting member on the other hand. Thus, the purpose of obtaining the axial flow fluid characteristics with a larger diameter in the form of an inner rotor is achieved. This design structure is simple and has good heat dissipation performance, and can also realize high-precision, high-sensitivity and good-stability rotor position detection.

[0049] Among them, the magnetic levitation rotor, also known as the magnetic action core, can be composed of only one or more permanent magnets, or can include one or more permanent magnets combined with soft magnetic components. Usually, the soft magnetic components are made of iron or nickel-iron or silicon-iron. Preferably, according to the embodiments of the present disclosure, refer to Figure 1 and Figure 2 , the magnetic levitation rotor is configured as a permanent magnet. The permanent magnet can be positioned within the rotor sheath by setting positioning pins in the stator holes, and the two stator pins can also prevent the permanent magnet from rotating relative to the rotor sheath. To prevent the magnetic levitation rotor from being corroded, a protective coating can be further coated outside the magnetic levitation rotor. For example, in order to resist the erosion of acidic or chemically corrosive substances, the magnetic levitation rotor is completely coated with a metal coating. To resist the erosion of small molecule substances, such as hydrochloric acid (HCl), hydrofluoric acid (HF), or ozone (O3), the magnetic levitation rotor is also coated with a plastic coating composed of a polymer belonging to the parylene class. Among them, the metal coating or the plastic coating can be one layer or multiple layers.

[0050] According to the embodiments of the present disclosure, refer to Figure 3 and Figure 4 , the stator housing 2 includes an upper cover 22 and a lower housing 23. The upper cover 22 and the lower housing 23 enclose a first accommodation space 24 for accommodating the magnetic levitation stator 3, and the rotor cavity 21 is configured as a part of the upper cover 22. In this way, the stator housing is designed as a split structure, which is convenient for accommodating the magnetic levitation stator and potting and fixing it in the lower housing. The heat generated by the magnetic levitation stator is transferred through the potting material, and the heat dissipation performance is good. Preferably, the upper cover 22 and the lower housing 23 are sealed and fixedly connected, the first accommodation space 24 is filled with a thermally conductive potting material, the upper cover 22 is configured with a plastic material, and the lower housing 23 is configured with a metal material. In this way, designing the upper cover with a plastic material will not interfere with the displacement sensor (eddy current sensor) arranged in the stator housing, and configuring the lower housing with a metal material facilitates the heat generated by the stator winding of the magnetic levitation stator to conduct outward, improving the heat dissipation performance. The first accommodation space is filled with a thermally conductive potting material such as epoxy resin, which on the one hand fixes the magnetic levitation stator and on the other hand plays a role in transferring heat. Among them, the metal material preferably uses metals with good thermal conductivity and easy to process and manufacture, such as aluminum and copper.

[0051] According to the embodiments of the present disclosure, refer to Figure 1 、 Figure 2 and Figure 7 , the cylindrical hub 441 surrounds the middle and upper part of the lower housing 23, and an air flow channel 7 is formed between the outer peripheral side of the middle and lower part of the lower housing 23 and the inner wall of the tubular housing 1. A plurality of heat dissipation fins (not shown) are formed on the outer peripheral side of the lower housing 23. In this way, by forming heat dissipation fins on the outer peripheral side of the lower housing, the heat dissipation fins can be in direct contact with the air flow in the air flow channel, further improving the heat dissipation performance.

[0052] According to the embodiments of the present disclosure, refer to Figure 1, Figure 2 and Figure 7 The cylindrical hub 441 surrounds the middle upper part of the lower housing 23. A plurality of flow guide vanes 6 are fixedly connected between the outer peripheral side of the middle lower part of the lower housing 23 and the inner wall of the tubular housing 1, and a blade flow passage 7 is formed between two adjacent flow guide vanes 6. In this way, by connecting the stator housing and the tubular housing with a plurality of flow guide vanes, while playing a role in fixed connection, it also plays the role of a fluid diffuser. By optimizing the curvature and inclination angle of the flow guide vanes, the air flow direction of the air outlet can be adjusted.

[0053] According to an embodiment of the present disclosure, referring to Figure 8 , the connecting member 43 includes a connecting plate 431 and a support column 432. The support column 432 is fixedly connected between the connecting plate 431 and the rotor sheath 41, and the outer edge of the connecting plate 431 is fixedly connected to the cylindrical hub 44. In this way, the connecting plate and the support column as a whole are in a T shape, which can play a role in stable support. Figure 8 The schematic diagram shows a single support column, but it is not limited thereto. In other embodiments, the support column can also be multiple. In other embodiments, the support column can also be a structure with a hollow interior.

[0054] According to an embodiment of the present disclosure, referring to Figure 10 , the connecting plate 431 includes a central circular plate 4311 and a plurality of radially extending spokes 4312 extending outward from the central circular plate 4311, and a spoke gap 4313 is formed between two adjacent spokes 4312. In other embodiments, a plurality of hollow holes can also be formed on the connecting plate. The air flow inside and outside the impeller can be connected through the holes or the spoke gaps between the spokes, thereby playing a role in balancing the axial force.

[0055] According to an embodiment of the present disclosure, referring to Figure 8 , the cylindrical hub 441 includes a straight cylinder part 4411 and a necked-down part 4412. The extending direction of the straight cylinder part 4411 is parallel to the rotation axis of the magnetic levitation rotor 42, and the necked-down part 4412 extends obliquely from one end of the straight cylinder part 4411 towards the rotation axis. The blades 442 extend from the necked-down part 4412 and the straight cylinder part 4411 towards the tubular housing 1. Among them, the cylindrical hub is composed of a necked-down part and a straight cylinder part, and the blades extend from the necked-down part and the straight cylinder part towards the tubular housing, that is, the blades are flared at the air inlet. The flared blades can provide a smooth transition area for the air flow to enter the fan from the external environment, which can play roles such as reducing air flow loss, increasing air intake, improving air flow distribution, reducing noise, improving efficiency, and improving thermal management.

[0056] According to an embodiment of the present disclosure, referring to Figure 3 and Figure 4, the lower housing 23 includes an outer cylinder portion 231, an inner cylinder portion 232, and a partition plate 233 connected between the inner cylinder portion 232 and the outer cylinder portion 231. The upper cover 22, the inner cylinder portion 231, the partition plate 233, and the outer cylinder portion 231 enclose a first accommodation space 24. In this way, the first accommodation space is formed between the inner cylinder portion and the outer cylinder portion, which can further increase the heat dissipation area and improve the heat dissipation performance. The partition plate bears the magnetic levitation stator, facilitating the potting of heat-conducting potting materials such as epoxy resin. Preferably, the outer cylinder portion 231, the inner cylinder portion 232, and the partition plate 233 connected between the inner cylinder portion 232 and the outer cylinder portion 231 are integrally formed by die casting. See Figure 3 and Figure 4 , the inner cylinder portion and the outer cylinder portion are coaxially arranged. The axial height of the inner cylinder portion is less than that of the outer cylinder portion, and the inner cylinder portion is located in the middle of the outer cylinder portion, that is, one end of the inner cylinder portion facing the air inlet is lower than one end of the outer cylinder portion facing the air inlet. One end of the inner cylinder portion facing the air outlet is higher than one end of the outer cylinder portion facing the air outlet. In this way, it is convenient to assemble the inner cylinder portion with the rotor cavity of the upper cover, and other accommodation spaces are formed below the inner cylinder portion. Preferably, a second accommodation space 25 is formed on the side of the partition plate 233 facing away from the magnetic levitation stator 3, and a control unit 5 for adjusting and controlling the magnetic levitation fan is provided in the second accommodation space 25. In this way, the control unit and the magnetic levitation fan are integrally arranged, which can control the magnetic levitation and rotation of the magnetic levitation fan, and can also condition the signals of the displacement sensors for detecting the magnetic levitation rotor. For example, the control unit includes at least one circuit board, and a processor, a power amplification circuit, a sensor conditioning circuit, etc. can be integrated on the circuit board. When necessary, it only needs to supply power to the magnetic levitation fan through a power cord. See Figure 9 and Figure 10 , a cable connector (gland) 15 is also provided on the tubular housing to play a role in introducing and fixing the power cord and waterproofing.

[0057] According to an embodiment of the present disclosure, see Figure 3 and Figure 4 , the lower housing 23 further includes a bottom cover 234, and the partition plate 233, the outer cylinder portion 231, the inner cylinder portion 232, and the bottom cover 234 enclose a second accommodation space 25. In this way, the inner cylinder portion, the partition plate, the outer cylinder portion, and the bottom cover enclose the second accommodation space, which has a simple structure, is convenient for airtight control of the unit and has good heat dissipation performance, and there is no need to configure other heat dissipation components therein. Preferably, the bottom cover is detachably and fixedly connected to the outer cylinder portion, and the bottom cover is flush with the bottom of the tubular housing or does not extend beyond the bottom (air outlet) of the tubular housing. Preferably, a protective coating is formed on the outer surface of the lower housing 23. In this way, a protective coating is provided outside the metal material to prevent it from being exposed to corrosive substances in the pipeline system and improve the service life.

[0058] The type of the magnetic levitation motor of the present utility model is not limited, and it can be generally summarized as a magnetic levitation rotary drive that uses magnetic force to levitate and rotate a magnetic levitation rotor, so that there is no mechanical contact between the magnetic levitation rotor and the magnetic levitation stator. Preferably, the magnetic levitation motor is a bearingless wafer motor.

[0059] The bearingless wafer motor is a special bearingless motor. It inherits the advantages of the bearingless motor, and the ratio of the axial length to the diameter of the rotor is very small, showing a wafer shape. The axial magnetic bearing is omitted, and the rotation and radial active suspension of the rotor are realized by using the bearingless technology. The passive suspension of the other three degrees of freedom except for the radial and rotor rotation degrees of freedom is realized by using the magnetic circuit composed of the mechanical structure. It has the characteristics of high cleanliness, no precipitation, no particles, no dynamic seal, and excellent performance, and has good application prospects in ultra-clean drive fields such as biochemistry, medical treatment, and semiconductor manufacturing.

[0060] According to the embodiments of the present disclosure, referring to Figure 1 and Figure 5 , the magnetic levitation stator 3 includes an annular yoke 33, a plurality of stator teeth 31 and a plurality of winding coils 32. The stator teeth 31 are in a straight shape. The outer ends of the stator teeth 31 are magnetically connected to the annular yoke 33. The winding coils 32 are sleeved on the corresponding stator teeth 31. The inner ends of the plurality of stator teeth 31 are arranged around the magnetic levitation rotor 42. Among them, for the magnetic levitation stator with straight stator teeth, the annular yoke is connected to the outer ends of the straight stator teeth. This structure will not cause the overall size to increase too much when increasing the height of the stator teeth, and the structure is compact. And it can reserve enough space for setting the control unit in the second accommodation space.

[0061] According to the embodiments of the present disclosure, referring to Figure 2 and Figure 6 , the magnetic levitation stator 3 includes an annular yoke 33, a plurality of stator teeth 31 and a plurality of winding coils 32. The stator teeth 31 are in an L shape. The vertical part of the stator teeth 31 is magnetically connected to the annular yoke 33. The winding coils 32 are sleeved on the vertical parts of the corresponding stator teeth 31. The inner ends of the horizontal parts of the plurality of stator teeth 31 are arranged around the magnetic levitation rotor 42. Among them, for the magnetic levitation stator with L-shaped stator teeth, the annular yoke is connected to the vertical part of the L-shaped stator teeth, and there is enough space for the winding to be arranged on the vertical part, and the influence of the winding heat on the magnetic levitation rotor is small.

[0062] According to the embodiments of the present disclosure, referring to Figure 7 , a chamfer 311 is formed at the outer end of the horizontal part of the stator tooth 31. For example, using chamfered silicon steel sheets laminated into stator teeth can adapt to the structure of a cylindrical hub with a necked-in opening, reasonably utilize the contraction space of the air inlet blades, and can extend the height of the horizontal part of the stator teeth, increasing the magnetic coupling between the magnetic levitation stator and the magnetic levitation rotor.

[0063] The number of stator teeth of the present utility model is not limited. Referring toFigure 5 and Figure 6 shows a case of eight stator teeth. In other embodiments, there may also be cases of six stator teeth or more stator teeth.

[0064] The bearingless wafer motor can be divided into a single-winding structure and a double-winding structure according to different winding structures. The present utility model does not limit the winding structure of the magnetic levitation stator, which can be a single-winding structure or a double-winding structure. In one embodiment, a winding coil is provided on each stator tooth of the magnetic levitation stator. The winding coil is a concentrated winding, and the winding coil is used for both rotation control and suspension control to form a single-winding structure of the magnetic levitation motor. In another embodiment, two winding coils are provided on each stator tooth of the magnetic levitation stator. The two winding coils can both be concentrated windings, or one winding coil can be a concentrated winding and the other winding coil can be a distributed winding. The two winding coils on the stator tooth are wound together. One winding coil is used for rotation control and the other winding coil is used for suspension control to form a double-winding structure of the magnetic levitation motor.

[0065] Specific embodiments are applied in the present utility model to elaborate on the principle and implementation manner of the present utility model. The description of the above embodiments is only used to help understand the technical solution and its core idea of the present utility model; at the same time, for those of ordinary skill in the art, according to the idea of the present utility model, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present utility model.

Claims

1. An internal rotor magnetic levitation fan, characterized in that, It includes a tubular housing (1), a stator housing (2), a magnetic levitation stator (3), and a rotor impeller assembly (4). One end of the tubular housing is configured as an air inlet (11), and the other end is configured as an air outlet (12). The stator housing is disposed inside the tubular housing. One end of the stator housing facing the air inlet forms a rotor cavity (21). The magnetic levitation stator is hermetically disposed inside the stator housing. The rotor impeller assembly includes a rotor sheath (41), a magnetic levitation rotor (42), a connecting member (43), and an impeller (44). The impeller includes a cylindrical hub (441) and a plurality of blades (442) disposed on the outer peripheral side of the cylindrical hub. The cylindrical hub surrounds the stator housing and is fixedly connected to the rotor sheath through the connecting member. The magnetic levitation rotor is sealed inside the rotor sheath. The rotor sheath is disposed inside the rotor cavity. The magnetic levitation stator is configured to drive the magnetic levitation rotor to rotate and be magnetically levitated.

2. The inner-rotor magnetic levitation fan according to claim 1, wherein The stator housing includes an upper cover (22) and a lower shell (23). The upper cover and the lower shell enclose a first accommodation space (24) for accommodating the magnetic levitation stator. The rotor cavity is configured as a part of the upper cover.

3. The inner-rotor magnetic levitation fan according to claim 2, wherein The upper cover and the lower shell are hermetically and fixedly connected. The first accommodation space is filled with a thermally conductive potting material. The upper cover is configured with a plastic material, and the lower shell is configured with a metal material.

4. The inner rotor magnetic levitation fan according to claim 2, characterized in that, The cylindrical hub surrounds the middle upper part of the lower shell. An air flow channel (7) is formed between the outer peripheral side of the middle lower part of the lower shell and the inner wall of the tubular housing. A plurality of heat dissipation fins are formed on the outer peripheral side of the lower shell.

5. The inner-rotor magnetic levitation fan according to claim 4, wherein The lower shell includes an outer cylinder part (231), an inner cylinder part (232), and a partition plate (233) connected between the inner cylinder part and the outer cylinder part. The upper cover, the inner cylinder part, the partition plate, and the outer cylinder part enclose the first accommodation space.

6. The inner rotor magnetic levitation fan according to claim 5, characterized in that, On the side of the partition plate facing away from the magnetic levitation stator, a second accommodation space (25) is formed. A control unit (5) for adjusting and controlling the magnetic levitation fan is disposed inside the second accommodation space.

7. The inner rotor magnetic levitation fan according to claim 6, wherein The lower shell further includes a bottom cover (234). The partition plate, the outer cylinder part, the inner cylinder part, and the bottom cover enclose the second accommodation space (25).

8. The inner rotor magnetic levitation fan according to claim 7, wherein, A protective coating is formed on the outer surface of the lower shell.

9. The inner-rotor magnetic levitation fan according to claim 1, wherein, The magnetic levitation stator includes an annular magnetic yoke (33), a plurality of stator teeth (31), and a plurality of winding coils (32). The stator teeth are in a straight shape. The outer ends of the stator teeth are magnetically connected to the annular magnetic yoke. The winding coils are sleeved on the corresponding stator teeth. The inner ends of the plurality of stator teeth surround the magnetic levitation rotor.

10. The inner-rotor magnetic levitation fan according to claim 1, wherein, The magnetic levitation stator includes an annular magnetic yoke (33), a plurality of stator teeth (31), and a plurality of winding coils (32). The stator teeth are in an L shape. The vertical part of the stator teeth is magnetically connected to the annular magnetic yoke. The winding coils are sleeved on the vertical parts of the corresponding stator teeth. The inner ends of the transverse parts of the plurality of stator teeth surround the magnetic levitation rotor.

11. The inner rotor magnetic levitation fan according to claim 10, wherein A chamfer (311) is formed at the outer end of the transverse part of the stator teeth.

12. The inner rotor magnetic levitation fan according to claim 2, characterized in that, The cylindrical hub surrounds the middle upper part of the lower housing, and the outer peripheral side of the middle lower part of the lower housing is fixedly connected to the inner wall of the tubular housing through a plurality of flow guiding vanes (6), and a blade flow channel is formed between two adjacent flow guiding vanes.

13. The inner rotor magnetic levitation fan according to claim 2, wherein The connecting member includes a connecting plate (431) and a support column (432), the support column is fixedly connected between the connecting plate and the rotor sheath, and the outer edge of the connecting plate is fixedly connected to the cylindrical hub.

14. The inner-rotor magnetic levitation fan according to claim 13, wherein A plurality of hollow holes are formed in the connecting plate or the connecting plate includes a central circular plate (4311) and a plurality of radially extending spokes (4312) extending outward from the central circular plate, and a spoke gap (4313) is formed between two adjacent spokes.

15. The inner rotor magnetic levitation fan according to claim 2, wherein, The cylindrical hub includes a straight cylinder part (4411) and a necking part (4412), the extending direction of the straight cylinder part is parallel to the rotation axis of the magnetic levitation rotor, the necking part extends obliquely from one end of the straight cylinder part towards the rotation axis, and the blades extend from the necking part and the straight cylinder part towards the tubular housing.

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