Magnetic suspension rotor impeller and magnetic suspension pump

Abstract

The magnetic suspension rotor impeller comprises a rotor main body, a magnetic body and a first cover plate, the rotor main body is provided with a first end face and a second end face which are oppositely arranged, a first cavity is formed in the first end face, one face of the first cover plate and the first end face are welded together, and the magnetic body is sealed in the first cavity; a plurality of blades are formed on the second end face of the rotor body, an exhaust hole is formed in at least one of the blades and penetrates through the rotor body to be communicated with the first cavity, or a plurality of blades are formed on the other face of the first cover plate, an exhaust hole is formed in at least one of the blades and penetrates through the first cover plate to be communicated with the first cavity. According to the utility model, the exhaust holes are formed in at least one of the plurality of blades, so that the arrangement is very ingenious, the appearance and the function of a product are not influenced, and the purposes of exhausting gas in a welding area and improving the welding quality and the sealing effect are achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of magnetic suspension, in particular to a magnetic suspension rotor impeller and a magnetic suspension pump. 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 assembled with fitting parts of different functions, thereby becoming 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 casing and a rotor impeller disposed within the pump casing. 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. Therefore, the impeller is also referred to as the magnetic levitation rotor impeller. The stator of the magnetic levitation motor is configured to drive the magnetic levitation rotor impeller to rotate and levitate.

[0008] Currently, the magnetic levitation rotor impeller generally includes a rotating body, magnetic bodies embedded within the rotating body, and a plurality of blades formed on one end face of the rotating body. A liquid passage (fluid passage) is formed between two adjacent blades. For a closed rotor, the magnetic levitation rotor impeller further includes a blade cover plate disposed on the side of the blade facing away from the rotating body, and a liquid inlet is formed in the middle of the blade cover plate. The rotating body is also referred to as a rotor sheath. For example, it can be made of fluorinated hydrocarbon plastic material to resist the erosion of chemically corrosive substances. The magnetic body is also referred to as a magnetic action core or a magnetic levitation rotor. It 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, nickel-iron, or silicon-iron. To prevent the magnetic body from being corroded, a protective coating is usually coated on the outside of the magnetic body. For example, to resist the erosion of acidic or chemically corrosive substances, the magnetic body 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 body 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.

[0009] Patent document CN109217507A discloses a rotor capable of magnetic levitation and a rotating machine having such a rotor. The rotor includes a cover plate, a plurality of blades, a sheath, permanent magnets, a metal coating, a plastic coating, etc. The sheath includes a cup-shaped housing portion for receiving the permanent magnet having a metal coating and a plastic coating, and a cover that seals the cup-shaped housing portion and is welded to the cup-shaped housing portion along the weld seam. An infrared welding process is preferably used to weld the cover to the housing portion. The permanent magnet in one of the embodiments is annular. When the permanent magnet is loaded into the cup-shaped housing portion for infrared welding, due to the action of high temperature, gas is likely to be generated inside the cup-shaped housing portion. If the gas cannot be discharged, it will cause welding difficulties, thereby affecting the welding quality and the sealing effect. In addition, the horizontal positioning accuracy of the magnetic body within the cup-shaped housing portion needs to be further improved. Summary of the Utility Model

[0010] In order to overcome the defects in the prior art, the embodiments of the present utility model provide a magnetic levitation rotor impeller and a magnetic levitation pump, which are used to solve at least one of the above problems.

[0011] An embodiment of the present disclosure discloses a magnetic levitation rotor impeller, which includes a rotor main body, a magnetic body, and a first cover plate. The rotor main body is cylindrical, and the rotor main body has a first end face and a second end face that are oppositely arranged. A first cavity is formed on the first end face. The first cover plate is disc-shaped, and one side of the first cover plate is welded to the first end face. The magnetic body is sealed in the first cavity. A plurality of blades are formed on the second end face of the rotor main body, and at least one of the plurality of blades is formed with an exhaust hole that penetrates the rotor main body to communicate with the first cavity, or a plurality of blades are formed on the other side of the first cover plate, and at least one of the plurality of blades is formed with an exhaust hole that penetrates the first cover plate to communicate with the first cavity.

[0012] Further, the blade includes a first guide portion, a second guide portion, and a third guide portion that enclose an accommodation space. The first guide portion of one blade is oppositely arranged with the second guide portion of an adjacent another blade and encloses a liquid flow path. The outer side surface of the third guide portion is flush with the outer side surface of the rotor main body or the first cover plate.

[0013] Further, the exhaust hole is arranged in the accommodation space of one of the blades.

[0014] Further, a convex column is formed in the accommodation space, and the exhaust hole is formed at the center of at least one of the convex columns.

[0015] Further, the first cavity is annular and is formed by enclosing a central cylinder and an annular outer wall. A first annular positioning surface or a plurality of first arc-shaped positioning surfaces that protrude toward the first cover plate are formed at the bottom of the first cavity.

[0016] Further, the magnetic body is configured as an annular permanent magnet, and at least two positioning pins are integrally injection-molded at the bottom of the first cavity. Positioning holes corresponding to the positioning pins are formed on the annular permanent magnet.

[0017] Further, a second annular positioning surface or a plurality of second arc-shaped positioning surfaces that protrude toward the annular permanent magnet are formed on one side of the first cover plate.

[0018] Further, the plurality of blades are arranged in an array around the rotation axis of the rotor main body, and the inner edges of the plurality of blades enclose a central cavity.

[0019] Further, the rotor main body and the plurality of blades or the first cover plate and the plurality of blades are integrally formed by injection molding.

[0020] Further, it further includes a second cover plate, which is welded to the top of the blade. The second cover plate closes the top of the liquid flow channel between two adjacent blades, and a liquid inlet communicating with the central cavity is formed in the middle of the second cover plate.

[0021] Further, a plurality of first through holes are formed in the central cylinder. The first through holes penetrate through the first end face and the second end face of the rotor main body. The plurality of first through holes are arranged in an array around the rotation axis of the rotor main body and are located in the central cavity; second through holes corresponding to the plurality of first through holes one by one are formed in the first cover plate.

[0022] Further, a third through hole is formed in the central cylinder. The third through hole penetrates through the second end face and the first end face of the rotor main body and is located in the central cavity. The rotation axis of the rotor main body passes through the second through hole; a fourth through hole corresponding to the third through hole is formed in the first cover plate.

[0023] Further, it further includes a partition plate. The partition plate is arranged in the central cavity and is welded to the inner side of the blade. The partition plate is at a first distance from the first end face or the first cover plate. The partition plate at least partially separates the main flow from the liquid inlet and the secondary flow from the first through holes.

[0024] Further, it further includes a partition plate. A central column is formed on the other side of the first cover plate or the second end face of the rotor main body. The central column is located in the central cavity. The partition plate is welded to the central column or the inner side of the partition plate blade and the central column. The partition plate is at a first distance from the first end face or the first cover plate. The partition plate at least partially separates the main flow from the liquid inlet and the secondary flow from the first through holes.

[0025] The embodiment of the present disclosure also provides a magnetic levitation pump, including the magnetic levitation rotor impeller described above.

[0026] The beneficial effects of the present utility model are as follows: The present utility model provides a magnetic levitation rotor impeller. By arranging the exhaust holes on at least one of the plurality of blades, the arrangement is very ingenious. Without affecting the appearance and function of the product, the gas in the welding area is exhausted, and the purpose of improving the welding quality and sealing effect is achieved.

[0027] To make the above and other purposes, 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, makes a detailed description as follows. Description of the Drawings

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. 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 the magnetic levitation rotor impeller in an embodiment of the present invention Figure 1 ;

[0030] Figure 2 It is a schematic structural diagram of an embodiment of the magnetic levitation rotor impeller in an embodiment of the present invention Figure 2 ;

[0031] Figure 3 It is a schematic structural diagram of an embodiment of the magnetic levitation rotor impeller in an embodiment of the present invention Figure 3 ;

[0032] Figure 4 It is a schematic structural diagram of an embodiment of the magnetic levitation rotor impeller in an embodiment of the present invention Figure 4 ;

[0033] Figure 5 It is a schematic structural diagram of an embodiment of the rotor main body in an embodiment of the present invention Figure 1 ;

[0034] Figure 6 It is a schematic structural diagram of an embodiment of the rotor main body in an embodiment of the present invention Figure 2 ;

[0035] Figure 7 is Figure 6 The sectional view in the A-A direction in

[0036] Figure 8 is Figure 6 The sectional view in the B-B direction in

[0037] Figure 9 It is a schematic structural diagram of an embodiment of the magnetic body in an embodiment of the present invention;

[0038] Figure 10 It is a schematic structural diagram of an embodiment of the first cover plate in an embodiment of the present invention;

[0039] Figure 11 It is a schematic structural diagram of another embodiment of the rotor main body in an embodiment of the present invention;

[0040] Figure 12 It is a schematic structural diagram of another embodiment of the first cover plate in an embodiment of the present invention;

[0041] Figure 13 It is a schematic structural diagram of a separately formed impeller (multiple blades) in an embodiment of the present utility model;

[0042] Figure 14 It is a schematic structural diagram of a magnetic levitation pump in an embodiment of the present utility model. Specific embodiments

[0043] 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 shall fall within the protection scope of the present utility model.

[0044] 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, and 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, and therefore should not be construed as a limitation of the present utility model. The terms "including" and "provided with" in the description and claims of the present utility model and any deformation 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.

[0045] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the 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 "multiple" is two or more, unless otherwise clearly defined.

[0046] The accompanying 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 accompanying drawings described in the present disclosure are only schematic diagrams.

[0047] See Figure 1 、 Figure 2 、 Figure 3 、 Figure 4, according to an embodiment of the present utility model, a magnetic levitation rotor impeller is provided, which includes a rotor main body 1, a magnetic body 2, and a first cover plate 3. The rotor main body 1 is cylindrical, and the rotor main body 1 has a first end face 11 and a second end face 12 arranged oppositely. A first cavity 13 is formed on the first end face 11. The first cover plate 3 is disc-shaped, and one side of the first cover plate 3 is welded to the first end face 11. The magnetic body 2 is sealed in the first cavity 13. A plurality of blades 14 are formed on the second end face 12 of the rotor main body 1, and an exhaust hole 15 is formed on at least one of the plurality of blades 14. The exhaust hole 15 penetrates the rotor main body 1 to communicate with the first cavity 13. In this way, the exhaust hole is arranged on at least one of the plurality of blades, and the layout is very ingenious. Without affecting the appearance and function of the product, the function of exhausting the gas in the welding area and improving the welding quality and sealing effect is realized.

[0048] Among them, the rotor main body 1 and the first cover plate 3 can be thermoplastic plastics; for example, they can be fluorinated hydrocarbon plastic materials to resist the erosion of chemically corrosive substances. Preferably, the materials of the rotor main body 1 and the first cover plate 3 can be perfluoroalkoxy polymer (PFA). In other embodiments, the materials of the rotor main body 1 and the first cover plate 3 can also be ethylene chlorotrifluoroethylene (ECTFE) or polyvinylidene fluoride (PVDF).

[0049] Among them, the rotor main body and the first cover plate are rotating components. The rotor main body is generally cylindrical, and the first cover plate 3 is generally disc-shaped, but it is not limited thereto. For example, the end face or side face of the first cover plate can also have other auxiliary convex parts 33 or concave part structures.

[0050] Among them, one side of the first cover plate 3 and the first end face 11 can be first heated and melted and then extruded and welded together, that is, first heat one side of the first cover plate and the first end face of the rotor main 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 weld the two parts. 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 needing to contact the material, reducing the mechanical damage to the material surface. Through infrared welding, the cleanliness of the rotor main body and the first cover plate can also be ensured, ensuring that no other impurities are introduced during the manufacturing process of the magnetic levitation rotor impeller. Furthermore, it meets the application of the magnetic levitation rotor impeller in high-cleanliness fields.

[0051] According to an embodiment of the present disclosure, refer to Figure 5 、 Figure 6 、 Figure 7 and Figure 8, the first cavity 13 of the rotor body 1 is annular and is formed by enclosing a central cylinder 131 and an annular outer wall 132; a plurality of blades 14 are integrally formed on the second end face 12 of the rotor body 1 by machining or injection molding. The plurality of blades 14 are arranged in an array around the rotation axis of the rotor body 1, and the inner edges of the plurality of blades 14 enclose a central cavity 140. In this way, the first cover plate 3 and the plurality of blades 14 are located on opposite sides of the rotor body 1. Since the hydrodynamic characteristics of the impeller depend on the blades, preferably, the blades are integrally injection-molded on the rotor body, which can ensure good product consistency while meeting mass production requirements. Preferably, a material storage cavity 1311 is formed on the central cylinder 131 of the rotor body 1. In this way, forming the material storage cavity 1311 on the end face of the central cylinder can receive the welding material when the first cover plate and the rotor body are extrusion-welded, improving the welding quality.

[0052] The structure of the plurality of blades is also called an impeller, which is integrally formed with the rotor body by injection molding, but is not limited to this. In another embodiment, see Figure 11 and Figure 12 , the first cavity 13 of the rotor body 1 is still annular and is formed by enclosing a central cylinder 131 and an annular outer wall 132. A plurality of blades 14 are integrally formed on the other side of the first cover plate 3 by injection molding. The plurality of blades 14 are arranged in an array around the rotation axis of the rotor body 1, and the inner edges of the plurality of blades 14 enclose a central cavity 140. In this embodiment, the first cover plate 3 and the plurality of blades 14 are integrally formed. The first cover plate 3 and the plurality of blades are located on the same side of the rotor body 1, and the positional relationship between the first cover plate and the rotor body is opposite to that of the above embodiment. Among them, one side and the other side of the first cover plate are two opposite end faces. See Figure 12 , a plurality of blades 14 are formed on the other side of the first cover plate 3, and at least one of the plurality of blades 14 is formed with an exhaust hole 15. The exhaust hole penetrates through the first cover plate 3 to communicate with the first cavity 13. Similarly, arranging the exhaust hole on at least one of the plurality of blades is very ingenious. While not affecting the appearance and function of the product, it realizes the function of exhausting the gas in the welding area, improving the welding quality and sealing effect.

[0053] In other embodiments, the plurality of impellers can also be separately injection-molded or machined. See Figure 13 , the magnetic levitation rotor impeller includes a blade plate 14', and a plurality of blades 14 are integrally formed on the circumferential side of the blade plate 14' by machining or injection molding. The plurality of blades 14 are fixedly welded to the second end face 12 of the rotor body 1. The plurality of blades 14 are arranged in an array around the rotation axis of the rotor body 1, and the inner edges of the plurality of blades 14 enclose a central cavity 140. In other embodiments, the welding can also be fixed by means such as snap-fitting, fasteners, bonding, etc.

[0054] The form of the blades in the above embodiments of the present utility model is not limited. Preferably, referring to Figure 6 and Figure 13 , the blade 14 includes a first flow guiding portion 142, a second flow guiding portion 143, and a third flow guiding portion 144 that enclose a receiving space 141. The first flow guiding portion 142 of one blade 14 is disposed opposite to the second flow guiding portion 143 of an adjacent other blade 14 and together encloses a liquid flow passage 145. The outer side surface of the third flow guiding portion 144 is flush with the outer side surface of the rotor main body 1 or the first cover plate 3. In this way, a receiving space is formed inside the blade, facilitating the setting of exhaust holes and the parts for injection molding ejection. The surface of the first flow guiding portion opposite to the second flow guiding portion constitutes the liquid flow passage, and the form of the liquid flow passage is designed according to the hydrodynamics of the magnetic levitation pump. For example, it is designed to meet the centrifugal flow passage of a centrifugal pump. At this time, the overall shape of the blade gradually thickens from the central inlet to the outer edge.

[0055] The form of the exhaust hole in the receiving space of the present utility model is not limited. In one embodiment, the exhaust hole 15 is provided in the receiving space 141 of one blade 14. In another embodiment, referring to Figure 3 , Figure 6 , Figure 7 and Figure 12 , a convex column 146 is formed in the receiving space 141, and the exhaust hole 15 is formed at the center of at least one convex column 146. In this way, on the one hand, the convex column is provided in the receiving space as an ejection part for injection molding ejection, and on the other hand, the exhaust hole can be arranged, with a simple structure. Among them, the exhaust hole is used to discharge gas during the infrared welding of the first cover plate and the rotor main body, and the exhaust hole needs to be sealed after the first cover plate and the rotor main body are welded.

[0056] According to an embodiment of the present disclosure, referring to Figure 4 , Figure 5 , Figure 6 , Figure 7 and Figure 11 , a plurality of first through holes 16 are integrally formed by injection molding on the central cylinder 131 of the rotor main body 1. The first through holes 16 penetrate the first end surface 11 and the second end surface 12 of the rotor main body 1, and the plurality of first through holes 16 are arranged in an array around the rotation axis of the rotor main body 1 and are located in the central cavity 140. In this way, by integrally forming a plurality of first through holes by injection molding, better product consistency can be ensured. Preferably, after the first cover plate 3 is welded to the rotor main body 1, second through holes 31 corresponding to the plurality of first through holes 16 one by one are machined on the first cover plate 3. Referring to Figure 6 and Figure 7, before the first cover plate is welded to the rotor body, the second through hole is not machined on the first cover plate. The second through hole corresponding to the first through hole one by one is machined on the first cover plate after welding. On the one hand, the overall penetration of the first and second through holes can be achieved, which can play a role in relieving the high-pressure liquid entering the bottom of the rotor and balancing the axial force. On the other hand, manufacturing the second through hole later instead of machining the second through hole on the first cover plate first can simplify the production process and avoid the problem of non-concentric through holes caused by misalignment of the two parts. In other embodiments, the second through holes corresponding to the plurality of first through holes 16 can also be machined on the first cover plate 3 in advance, and then the first cover plate 3 is welded to the rotor body 1. At this time, it is necessary to align the first through hole 16 with the second through hole through a tooling before welding. Preferably, after the first cover plate is welded to the rotor body, the first through hole and the second through hole are corrected by machining to remove the welding materials overflowing into the first through hole and the second through hole during the welding process, so as to form the pressure relief holes of the finished product of the magnetic levitation rotor impeller and make the size of the pressure relief holes consistent with the target size.

[0057] According to the embodiments of the present disclosure, a third through hole can also be integrally formed by injection molding on the central cylinder of the rotor body 1. The third through hole penetrates through the second end face and the first end face of the rotor body and is located in the central cavity. The rotation axis of the rotor body passes through the third through hole, that is, the third through hole is a central through hole. When designing a central through hole, the size of the central through hole is relatively large to play a role in relieving the high-pressure liquid entering the bottom of the rotor and balancing the axial force. Similarly, after the first cover plate is welded to the rotor body, a fourth through hole corresponding to the third through hole is machined on the first cover plate to simplify the production process and avoid the problem of non-concentric through holes caused by misalignment of the two parts. Preferably, after the first cover plate is welded to the rotor body, the third through hole and the fourth through hole are corrected by machining to remove the welding materials overflowing into the third through hole and the fourth through hole during the welding process and make the size of the through holes consistent with the target size.

[0058] The magnetic body, also known as the magnetic action core or the magnetic levitation rotor, 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 9, the magnetic body 2 is configured as an annular permanent magnet. A positioning pin 133 is integrally injection-molded at the bottom of the first cavity 13, and a positioning hole 21 corresponding to the positioning pin is formed on the annular permanent magnet. In this way, by setting the cooperation between the positioning pin and the stator hole, on the one hand, it can function as an annular permanent magnet, and on the other hand, the two stator pins can also prevent the annular permanent magnet from rotating relative to the first cavity. To prevent the magnetic body from being corroded, a protective coating can be coated outside the magnetic body. For example, to resist the erosion of acidic or chemically corrosive substances, the magnetic body 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 body 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.

[0059] According to an embodiment of the present disclosure, referring to Figure 10 , on one side of the first cover plate 3, a second annular positioning surface or a plurality of second arc-shaped positioning surfaces 32 protruding towards the annular permanent magnet are formed. The radial dimension of the second annular positioning surface or the second arc-shaped positioning surface 32 is smaller than the radial dimension of the first cavity. In this way, on the one hand, the smaller-sized annular or second arc-shaped positioning surface functions to support and position the annular permanent magnet, facilitating the horizontal positioning of the annular permanent magnet. On the other hand, an air gap can be formed to avoid some of the welding materials during welding, preventing the welded materials that have shifted during welding from damaging the protective coating of the annular permanent magnet. Moreover, there is sufficient flow space for the welding materials to enter the air gap, which can make the welding more sufficient and improve the welding quality. Based on the same principle of horizontal precise positioning, referring to Figure 7 and Figure 8 , on the bottom of the first cavity of the rotor body, a first annular positioning surface 134 or a plurality of first arc-shaped positioning surfaces protruding towards the first cover plate are formed. In this way, relative to the entire area of the bottom of the first cavity, the first annular positioning surface and the first arc-shaped positioning surface protrude a certain height and have a smaller area, facilitating the horizontal positioning (levelling) of the permanent magnet.

[0060] According to an embodiment of the present disclosure, referring to Figure 2 、 Figure 3 and Figure 4 , the magnetic levitation rotor impeller further includes a second cover plate 4. A liquid inlet 41 is formed in the middle of the second cover plate. One side of the second cover plate 4 is welded and fixed to the top of the blade 14, so that the second cover plate 4 closes the top of the liquid flow channel between two adjacent blades 14; referring to Figure 3 and Figure 4 , using the welding between the second cover plate and the top of the blade can, on the one hand, close the exhaust hole, and on the other hand, make the two parts fully welded, improving the stability of the connection of the second cover plate. Preferably, the welding is infrared welding.

[0061] According to an embodiment of the present disclosure, referring to Figure 2 、Figure 3 and Figure 4 , the magnetic levitation rotor impeller further includes a partition plate 5. One side of the partition plate 5 is welded to the inner side of the blade 14 or / and the central column 147 on the first end face 11, so that a first distance is formed between the partition plate 5 and the first end face 11. Through welding, the partition plate can be firmly fixed on the inner side of the blade or the central column, solving the problem that the partition plate is prone to falling off. The partition plate serves to separate the main flow at the impeller inlet and the secondary flow at the bottom of the rotor, avoiding the impact and collision between the main flow and the secondary flow, and balancing the axial force. In one embodiment, the partition plate 5 is arranged in the central cavity 140, and the partition plate 5 is welded to the inner side of the blade. A first distance is formed between the partition plate 5 and the first end face 11 or the first cover plate 3. The partition plate 5 at least partially separates the main flow from the liquid inlet and the secondary flow from the first through hole. In another embodiment, referring to Figure 3 and Figure 4 , a central column 147 is formed on the other side of the first cover plate 3 or the second end face 12 of the rotor body 1. The central column 147 is located in the central cavity 140. The partition plate 5 is welded to the central column or the partition plate is welded to the inner side of the blade 14 and the central column. A first distance is formed between the partition plate and the first end face or the first cover plate. The partition plate at least partially separates the main flow from the liquid inlet and the secondary flow from the first through hole. Preferably, the welding is configured as contact hot melt welding, which reduces the influence of welding heat on the structure of surrounding components while realizing the firm connection between the partition plate and the blade. Among them, the shape of the partition plate is not limited. Preferably, the partition plate is circular, and the outer edge of the partition plate may not contact the inner edge of the blade or the outer edge of the partition plate extends into the blade.

[0062] Based on the same inventive concept, referring to Figure 14 , the present utility model also proposes a magnetic levitation pump, including the magnetic levitation rotor impeller in each of the above embodiments. It further includes a pump head 100 and a magnetic levitation stator 200 of a magnetic levitation motor. In one embodiment, the pump head includes a pump housing 110. A rotor cavity and an impeller cavity are formed in the pump housing. An inlet 120 and an outlet 130 communicating with the impeller cavity are formed on the pump housing. The rotor cavity is arranged on one side of the impeller cavity, and the radial space of the rotor cavity is smaller than the radial space of the impeller cavity. The pump head further includes the magnetic levitation rotor impeller in each of the above embodiments, and the rotor body of the magnetic levitation rotor impeller is arranged in the rotor cavity.

[0063] The present utility model does not limit the type of the magnetic levitation motor, which can be generally summarized as a magnetic levitation rotary drive that uses magnetic force to levitate the rotor so that there is no mechanical contact between the rotor and the stator. Preferably, the magnetic levitation motor is a bearingless wafer motor.

[0064] 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. The rotation of the rotor and the active suspension in the radial direction are realized by the bearingless technology, and the passive suspension of the other three degrees of freedom except the radial and the rotor rotation degrees of freedom is realized by the magnetic circuit formed by 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-pure drive fields such as biochemistry, medical treatment, semiconductor manufacturing, etc.

[0065] According to different winding structures, the bearingless wafer motor can be divided into a single-winding structure and a double-winding structure. The present utility model does not limit the winding structure of the bearingless wafer motor, which can be a single-winding structure or a double-winding structure. In one embodiment, a winding coil is arranged 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 the single-winding structure of the magnetic levitation motor. In another embodiment, two winding coils are arranged 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 the double-winding structure of the magnetic levitation motor. Since the single-winding magnetic levitation motor can simultaneously realize the rotation and suspension of the motor rotor with only one set of winding coils, it has better performance advantages compared with the double-winding magnetic levitation motor.

[0066] Based on the principle of the bearingless wafer motor, the magnetic levitation pump of the present utility model can be configured as a magnetic levitation centrifugal pump. Among them, the pump head and the magnetic levitation rotor impeller configured therein can be separated from the housing of the magnetic levitation motor in an easier way. This will be another great advantage of the magnetic levitation centrifugal pump, because the pump housing and the impeller can thus be designed as, for example, disposable parts for single use. Due to the extremely high purity requirements, this kind of single-use application now often replaces the process in which all those components that come into contact with the fluid to be processed in the previous process must be cleaned and disinfected in a complex way (such as by steam sterilization). In the single-use design, those components that come into contact with the fluid to be processed are only used exactly once and then replaced by new (i.e., unused) disposable parts in the next application.

[0067] In the present utility model, specific embodiments are used 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. A magnetic levitation rotor impeller, comprising a rotor body (1), a magnetic body (2) and a first cover plate (3). The rotor body is cylindrical, and the rotor body has a first end face (11) and a second end face (12) arranged opposite to each other. A first cavity (13) is formed on the first end face, and it is characterized in that, The first cover plate is in a disc shape. One side of the first cover plate is welded to the first end face, and the magnetic body is sealed in the first cavity. The second end face (12) of the rotor body is formed with a plurality of blades (14), and at least one of the plurality of blades is formed with an exhaust hole (15) that penetrates the rotor body to communicate with the first cavity, or the other side of the first cover plate is formed with a plurality of blades (14), and at least one of the plurality of blades is formed with an exhaust hole (15) that penetrates the first cover plate to communicate with the first cavity.

2. The magnetic levitation rotor impeller according to claim 1, wherein The blade includes a first flow guiding portion (142), a second flow guiding portion (143) and a third flow guiding portion (144) that enclose an accommodation space (141). The first flow guiding portion of one blade is arranged opposite to the second flow guiding portion of an adjacent other blade and together form a liquid flow path (145). The outer side surface of the third flow guiding portion is flush with the outer side surface of the rotor body or the first cover plate.

3. The magnetic levitation rotor impeller according to claim 2, wherein, The exhaust hole is arranged in the accommodation space of one of the blades.

4. The magnetic levitation rotor impeller according to claim 2, characterized in that, A convex column (146) is formed in the accommodation space, and the exhaust hole is formed at the center of at least one of the convex columns.

5. The magnetic levitation rotor impeller according to claim 1, wherein, The first cavity is in an annular shape and is surrounded by a central cylinder (131) and an annular outer wall (132). The bottom of the first cavity is formed with a first annular positioning surface (134) or a plurality of first arc-shaped positioning surfaces that protrude towards the first cover plate.

6. The magnetic levitation rotor impeller according to claim 5, characterized in that, The magnetic body is configured as an annular permanent magnet. At least two positioning pins (133) are integrally injection-molded on the bottom of the first cavity, and positioning holes (21) corresponding to the positioning pins are formed on the annular permanent magnet.

7. The magnetic levitation rotor impeller according to claim 6, characterized in that, One side of the first cover plate is formed with a second annular positioning surface or a plurality of second arc-shaped positioning surfaces (32) that protrude towards the annular permanent magnet.

8. The magnetic levitation rotor impeller according to claim 5, characterized in that, The plurality of blades are arranged in an array around the rotation axis of the rotor body, and the inner edges of the plurality of blades enclose a central cavity (140).

9. The magnetic levitation rotor impeller according to claim 8, wherein, The rotor body and the plurality of blades or the first cover plate and the plurality of blades are integrally formed by injection molding.

10. The magnetic levitation rotor impeller according to claim 8, characterized in that, It further includes a second cover plate (4). The second cover plate is welded to the top of the blade. The second cover plate closes the top of the liquid flow path between two adjacent blades, and a liquid inlet (41) communicating with the central cavity is formed in the middle of the second cover plate.

11. The magnetic levitation rotor impeller according to claim 10, characterized in that, A plurality of first through holes (16) are formed on the central cylinder. The first through holes penetrate the first end face and the second end face of the rotor body. The plurality of first through holes are arranged in an array around the rotation axis of the rotor body and are located in the central cavity. Second through holes (31) corresponding to the plurality of first through holes are formed on the first cover plate.

12. The magnetic levitation rotor impeller according to claim 11, characterized in that, A third through hole is formed on the central cylinder. The third through hole penetrates the second end face and the first end face of the rotor body and is located in the central cavity. The rotation axis of the rotor body passes through the second through hole. A fourth through hole corresponding to the third through hole is formed on the first cover plate.

13. The magnetic levitation rotor impeller according to claim 11, wherein, It further includes a partition plate (5), which is arranged in the central cavity. The partition plate is welded to the inner side of the blade. There is a first distance between the partition plate and the first end face or the first cover plate. The partition plate at least partially separates the main flow from the liquid inlet and the secondary flow from the first through hole.

14. The magnetic levitation rotor impeller according to claim 11, characterized in that, It further includes a partition plate (5). A central column (147) is formed on the other side of the first cover plate or the second end face of the rotor body. The central column is located in the central cavity. The partition plate is welded to the central column or the inner side of the blade of the partition plate and the central column. There is a first distance between the partition plate and the first end face or the first cover plate. The partition plate at least partially separates the main flow from the liquid inlet and the secondary flow from the first through hole.

15. A magnetic levitation pump, characterized in that, It includes the magnetic levitation rotor impeller according to any one of claims 1-14.

Images