Method for manufacturing magnetic suspension rotor impeller, magnetic suspension rotor impeller and magnetic suspension pump

Abstract

The invention discloses a method for manufacturing a magnetic suspension rotor impeller, the magnetic suspension rotor impeller and a magnetic suspension pump, and the method comprises the following steps: providing a rotor main body, a magnetic body and a first cover plate, and the rotor main body and the first cover plate are made of thermoplastic plastics; the magnetic body is positioned and arranged in the first cavity; one surface of the first cover plate and the first end surface of the rotor main body are firstly heated and fused and then are extruded and welded together, so that the magnetic body is sealed in the first cavity; wherein a first welding allowance is reserved before the first cover plate and the rotor main body are welded; and correcting the outer contour dimensions of the first cover plate and the rotor main body in a machining manner, so that the outer contour dimensions of the rotor main body and the first cover plate are the same as the first target dimension in an error range. The manufacturing process of the magnetic suspension rotor impeller is improved, the sealing performance of the rotor body is improved, and the requirement of the magnetic suspension rotor impeller for size precision is met.

Description

Technical Field

[0001] The invention relates to the technical field of magnetic suspension, and in particular to a method for manufacturing a magnetic suspension rotor impeller, 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 different functional parts 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 disposed 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 or a short-circuit cage rotor or a reluctance rotor. Therefore, the impeller is also called a 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] At present, the magnetic levitation rotor impeller generally includes a rotating body, a magnetic body embedded in the rotating body, and a plurality of blades formed on one end surface of the rotating body. A blade channel (liquid flow channel) is formed between two adjacent blades. For a closed rotor, the magnetic levitation rotor impeller also includes a blade cover plate, which is arranged 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 called a rotor sleeve, for example, it can be made of fluorinated hydrocarbon plastic material to resist corrosion by chemically corrosive substances. The magnetic body is also called a magnetic core or a magnetic levitation rotor, which can be composed of only one or more permanent magnets, or it can include one or more permanent magnets combined with soft magnetic components, usually made of iron or nickel-iron or silicon-iron. In order to prevent the magnetic body from being corroded, the magnetic body is usually coated with a protective coating. For example, in order to resist corrosion by acidic or chemically corrosive substances, the magnetic body is completely coated with a metal coating. In order to resist the corrosion of small molecules, such as hydrochloric acid (HCl) or hydrofluoric acid (HF) or ozone (O3), the magnetic body is also coated with a plastic coating composed of a polymer belonging to the polyparaxylene class. The metal coating or the plastic coating can be one or more layers.

[0009] Patent document CN109217507A discloses a rotor capable of magnetic levitation and a rotating machine having such a rotor, the rotor comprising a cover plate, a plurality of blades, a sheath, a permanent magnet, a metal coating and a plastic coating, etc. The sheath comprises a cup-shaped housing portion for receiving a permanent magnet having a metal coating and a plastic coating and a cover, the cover sealing the cup-shaped housing portion and being welded to the cup-shaped housing portion along a weld. The infrared welding process is preferably used to weld the cover to the housing portion. In the above patent document, it is not explained how the cover and the cup-shaped housing portion are infrared welded along the weld. Such a rotor impeller manufacturing process in the prior art cannot meet the requirements of high sealing performance and dimensional accuracy of the rotor impeller in the high clean field. In addition, when the permanent magnet is loaded into the cup-shaped housing portion for infrared welding, gas is easily generated in the cup-shaped housing portion due to the high temperature, and the inability of the gas to be discharged will cause welding difficulties, thereby affecting the welding quality and sealing effect. Summary of the invention

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

[0011] The present disclosure discloses a method for manufacturing a magnetically suspended rotor impeller, the method comprising the following steps:

[0012] A rotor body, a magnetic body and a first cover plate are provided, wherein the rotor body is cylindrical, has a first end face and a second end face which are arranged opposite to each other, the first end face forms a first cavity, the first cover plate is disc-shaped, and both the rotor body and the first cover plate are thermoplastic plastics;

[0013] Positioning the magnetic body into the first cavity;

[0014] One side of the first cover plate and the first end surface are first heated and melted and then extruded and welded together, so that the magnetic body is sealed in the first cavity; wherein a first welding margin is reserved between the first cover plate and the rotor body before welding;

[0015] The outer contour dimensions of the first cover plate and the rotor body are corrected by machining so that the outer contour dimensions of the rotor body and the first cover plate are the same as the first target dimensions within an error range.

[0016] Furthermore, the welding is infrared welding, the first welding allowance includes a first radial welding allowance and a first axial welding allowance, the first radial welding allowance ranges from 2 mm to 10 mm, and the first axial welding allowance ranges from 0.5 mm to 5 mm.

[0017] Furthermore, the first cavity is in a circular ring shape and is composed of a central cylinder and an annular outer wall; the second end face of the rotor body is integrally formed with a plurality of blades by injection molding, 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 form a central cavity.

[0018] Furthermore, when the rotor body is integrally injection molded, the injection gate is located on the central cylinder of the first end face, and the gate is removed by machining after injection molding to form a material cavity, or a material cavity is first molded on the central cylinder and then the gate is located in the material cavity.

[0019] Furthermore, the first cavity is in a circular shape and is composed of a central cylinder and an annular outer wall; a plurality of blades are integrally formed on the other side of the first cover plate by injection molding, 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 form a central cavity.

[0020] Furthermore, when the first cover plate is integrally injection molded, the injection gate is located on one surface of the first cover plate, the gate is removed by machining after injection molding, and a material holding cavity is formed at a position corresponding to the center cylinder and the gate.

[0021] Furthermore, at least one of the plurality of blades is formed with an exhaust hole, and the exhaust hole is connected to the first cavity.

[0022] Furthermore, the blade includes a first guide portion, a second guide portion and a third guide portion which enclose an accommodating space, and the first guide portion of one blade is arranged opposite to the second guide portion of another adjacent blade and encloses a liquid flow channel.

[0023] Furthermore, at least two protruding columns are formed in the accommodating space, and the exhaust hole is formed at the center of at least one of the protruding columns.

[0024] Furthermore, a plurality of first through holes are integrally formed on the central cylinder by injection molding, 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; after the first cover plate is welded to the rotor body, second through holes corresponding to the plurality of first through holes are processed and manufactured on the first cover plate.

[0025] Furthermore, a third through hole is formed on the central cylinder by injection molding, and the third through hole passes through the second end face and the first end face of the rotor body and is located in the central cavity, and the rotation axis of the rotor body passes through the third through hole; after the first cover plate is welded to the rotor body, a fourth through hole corresponding to the third through hole is processed and manufactured on the first cover plate.

[0026] Furthermore, the magnetic body is configured as an annular permanent magnet, the bottom of the first cavity is integrally injection-molded to form a positioning pin, and a positioning hole corresponding to the positioning pin is formed on the annular permanent magnet.

[0027] Furthermore, a second annular positioning surface or a plurality of second arcuate positioning surfaces protruding toward the annular permanent magnet is formed on one side of the first cover plate, and a radial dimension of the second annular positioning surface or the second arcuate positioning surface is smaller than a radial dimension of the first cavity.

[0028] Furthermore, the method also includes the step of welding a second cover plate before or after welding the first cover plate, and the step is as follows: one side of the second cover plate and the top of the blade are first melted and then extrusion welded together, so that the second cover plate closes the top of the liquid flow channel between two adjacent blades; a second welding margin is reserved between the second cover plate and the blade before welding.

[0029] Furthermore, the outer contour dimensions of the second cover plate and the blade are corrected by machining so that the outer contour dimensions of the blade and the second cover plate are the same as the second target dimension within an error range, and a liquid inlet is formed in the middle of the second cover plate.

[0030] Furthermore, the welding is infrared welding, the second welding allowance includes a second radial welding allowance and a second axial welding allowance, the second radial welding allowance ranges from 2 mm to 10 mm, and the second axial welding allowance ranges from 0.5 mm to 5 mm.

[0031] Furthermore, the first cover plate and / or the second cover plate are integrally formed into an injection molded part by injection molding, and the injection molded part includes a cover plate body, an annular side wall formed on one side of the cover plate body, and a plurality of radiating strips extending radially outward from a center column and connected to the annular side wall; the annular side wall and the radiating strips are removed by machining after the cover plate body is welded.

[0032] Furthermore, the method also includes the step of welding the partition plate, which is as follows: welding one side of the partition plate to the inner side of the blade or / and the central boss on the first end surface by contact hot melt welding, so that the partition plate is at a first distance from the first end surface.

[0033] Furthermore, the method also includes the step of welding the blades and the rotor body, which is as follows: providing a blade plate, the circumference of the blade plate is integrally formed with a plurality of blades by machining or injection molding, the plurality of blades are welded together with the second end face of the rotor body, 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 form a central cavity.

[0034] The disclosed embodiment also provides a magnetically suspended rotor impeller, which is manufactured by the above-mentioned method for manufacturing a magnetically suspended rotor impeller.

[0035] The disclosed embodiment also provides a magnetic levitation pump, comprising the above-mentioned magnetic levitation rotor impeller.

[0036] The beneficial effects of the present invention are as follows: The present invention proposes a method for manufacturing a magnetic levitation rotor impeller. Compared with the prior art welding process, the present invention reserves a welding margin, and then heats and melts one side of the first cover plate and the first end face of the rotor body and then extrude and welds them together, so that the two parts can be fully welded, there is no weld between the two parts, and the sealing performance of the magnetic body (such as an annular permanent magnet) in the first cavity is improved. After welding, the outer contour dimensions of the parts are corrected by machining technology, which solves the problems of bulges at the welding surface caused by extrusion welding deformation and large overall dimensional deviations of the magnetic levitation rotor impeller. At the same time, it meets the requirements of high sealing performance and dimensional accuracy of the rotor impeller in the high-clean field.

[0037] In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are specifically cited below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0039] Figure 1 The structure of the rotor body according to the present invention is shown in FIG. Figure 1 ;

[0040] Figure 2 The structure of the rotor body according to the present invention is shown in FIG. Figure 2 ;

[0041] Figure 3 yes Figure 2 Cross-section view in the AA direction;

[0042] Figure 4 yes Figure 2 Cross-section along the middle BB direction;

[0043] Figure 5 is a schematic structural diagram of an embodiment of a magnetic body provided in an embodiment of the present invention;

[0044] Figure 6 The structure of the first cover plate provided in the embodiment of the present invention is schematically shown in FIG. Figure 1 ;

[0045] Figure 7 The structure of the first cover plate provided in the embodiment of the present invention is schematically shown in FIG. Figure 2 ;

[0046] Figure 8 is a schematic diagram of welding and assembling a first cover plate and a rotor body provided in an embodiment of the present invention;

[0047] Fig. 9 is a schematic diagram of a first cover plate and a rotor body after being welded in an embodiment of the present invention;

[0048] Fig.10 is a structural schematic diagram of another embodiment of a rotor body provided in an embodiment of the present invention;

[0049] Fig.11 is a structural schematic diagram of another embodiment of the first cover plate provided in an embodiment of the present invention;

[0050] Fig.12 It is a schematic diagram of the structure of an impeller (multiple blades) formed separately provided in an embodiment of the present invention;

[0051] Fig.13 Schematic diagram of the structure of the second cover plate provided in an embodiment of the present invention Figure 1 ;

[0052] Fig.14 is a schematic diagram of welding and assembling the first cover plate, the second cover plate and the rotor body provided in an embodiment of the present invention;

[0053] Fig.15 is a schematic diagram of a first cover plate, a second cover plate and a rotor body after being welded in an embodiment of the present invention;

[0054] Fig.16 is a schematic structural diagram of an embodiment of an injection molded part provided in an embodiment of the present invention;

[0055] Fig.17 The structure of the magnetic suspension rotor impeller manufactured in the embodiment of the present invention is shown in FIG. Figure 1 ;

[0056] Fig.18 The structure of the magnetic suspension rotor impeller manufactured in the embodiment of the present invention is shown in FIG. Figure 2 ;

[0057] Fig.19 The structure of the magnetic suspension rotor impeller manufactured in the embodiment of the present invention is shown in FIG. Figure 3 ;

[0058] Fig. 20 The structure of the magnetic suspension rotor impeller manufactured in the embodiment of the present invention is shown in FIG. Figure 4 ;

[0059] Fig.21 Schematic diagram of the structure of the magnetic levitation pump in an embodiment of the present invention. DETAILED DESCRIPTION

[0060] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0061] In the description of the present invention, 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 drawings, and is only for the convenience of describing the present invention 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 cannot be understood as a limitation on the present invention. The terms "including" and "having" and any variations thereof in the specification and claims of the present invention and the above-mentioned drawings are intended to cover non-exclusive inclusions, for example, a system, product or device comprising a series of units is not necessarily limited to those units clearly listed, but may include other units that are not clearly listed or inherent to these products or devices.

[0062] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "plurality" means two or more, unless otherwise clearly specified.

[0063] The drawings in this disclosure are not drawn strictly according to the actual scale, and the specific size and quantity of each structure can be determined according to actual needs. The drawings described in this disclosure are only schematic diagrams.

[0064] According to an embodiment of the present invention, a method for manufacturing a magnetically suspended rotor impeller is provided, the method comprising the following steps:

[0065] See also Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 and Figure 8 , providing a rotor body 1, a magnetic body 2 and a first cover plate 3, the rotor body 1 is cylindrical, the rotor body 1 has a first end face 11 and a second end face 12 arranged opposite to each other, the first end face 11 forms a first cavity 13, the first cover plate 3 is disc-shaped, and the rotor body 1 and the first cover plate 3 are both thermoplastic plastics;

[0066] Position the magnetic body 2 and place it into the first cavity 13;

[0067] One side of the first cover plate 3 and the first end surface 11 are first heated and melted and then extruded and welded together, so that the magnetic body 2 is sealed in the first cavity 13; wherein, a first welding margin is reserved between the first cover plate 3 and the rotor body 1 before welding; Figure 8 The schematic diagram of welding and assembling the first cover plate 3 and the rotor body 1 is shown.

[0068] The outer contour dimensions of the first cover plate 3 and the rotor body 1 are corrected by machining, so that the outer contour dimensions of the rotor body 1 and the first cover plate 3 are the same as the first target dimensions within an error range.

[0069] In the above manufacturing method, by reserving the first welding margin, and then heating and melting one side of the first cover plate and the first end face of the rotor body and then extruding and welding them together, the two parts can be fully welded, there is no weld between the two parts, and the sealing performance of the magnetic body (such as an annular permanent magnet) in the first cavity is improved. After welding, the outer contour dimensions of the parts are corrected by machining technology, which solves the problems of bulges at the welding surface caused by extrusion welding deformation and large overall dimensional deviation of the magnetic suspension rotor impeller. At the same time, it meets the requirements of high sealing performance and dimensional accuracy of the rotor impeller in the high-clean field.

[0070] The rotor body 1 and the first cover plate 3 are both thermoplastics; for example, they can be made of fluorinated hydrocarbon plastics to resist corrosion by chemically aggressive substances. Preferably, the rotor body 1 and the first cover plate 3 can be made of perfluoroalkoxy polymer (PFA). In other embodiments, the rotor body 1 and the first cover plate 3 can also be made of ethylene chlorotrifluoroethylene (ECTFE) or polyvinylidene fluoride (PVDF).

[0071] Among them, the rotor body and the first cover plate serve as rotating parts. The rotor body is roughly cylindrical, and the first cover plate 3 is roughly disc-shaped, but not limited to this. For example, the end face or side face of the first cover plate may also have other auxiliary convex parts 33 or concave structures.

[0072] Among them, heating and melting one side of the first cover plate 3 and the first end face 11 and then extruding and welding them together means first heating one side of the first cover plate and the first end face of the rotor body, and then driving the two parts to move relative to each other so that the two end faces contact and extrude, and finally the two parts are completely welded. Preferably, in this process, the welding depth of the two parts is ensured by tooling according to the reserved first welding margin parameter, and the tooling is removed after the two parts are welded and cooled, and the welding is completed. Preferably, the heating method is non-contact heating, such as heating with an infrared heater for infrared welding. Infrared welding can accurately control the heating area, making the heating more uniform, avoiding local overheating, and does not require contact with the material, reducing mechanical damage to the surface of the material. Infrared welding can also ensure the cleanliness of the rotor body and the first cover plate, and ensure that no other impurities are introduced during the manufacturing process of the magnetic levitation rotor impeller. Thereby satisfying the application of magnetic levitation rotor impellers in high-cleanliness fields.

[0073] Since the first cover plate and the first end surface of the rotor body are extruded and welded together in a molten state, in order to ensure that the two are fully welded and the sealing performance is guaranteed, the welding material will bulge outward at the welding surface to form a weld bulge 6, see Fig. 9 , and will cause deformation of the middle part of the rotor body. This makes the rotor after direct welding deviate greatly from the design target size, especially unable to meet the dimensional accuracy requirements of the magnetic levitation rotor impeller as a magnetic levitation motor. Therefore, the present invention also includes an indispensable machining step after extrusion welding. The outer contour dimensions of the first cover plate 3 and the rotor body 1 can be corrected through machining, so that the outer contour dimensions of the rotor body 1 and the first cover plate 3 are the same as the first target dimension within the error range. Among them, the first target dimension is the design dimension, which is determined by the magnetic coupling ability between the magnetic levitation stator and the magnetic levitation rotor of the magnetic levitation motor. Among them, the outer contour dimensions of the first cover plate 3 and the rotor body 1 include but are not limited to the dimensions at the welding surface of the two, and also include the outer side surface dimensions of the rotor body outside the welding surface, and also include the dimensions of the other side of the first cover plate facing away from the magnetic body outside the welding surface.

[0074] Since the extrusion during welding is closely related to the welding allowance, the range of the first welding allowance becomes an important parameter of the manufacturing process. If the first welding allowance is too large, it will lead to low material utilization, increased machining efficiency and other problems. If the first welding allowance is too small, it will lead to insufficient welding and machining cannot meet the surface quality requirements. Therefore, it is necessary to repeatedly verify the relationship between the reserved welding allowance, heating temperature, pressure and time parameters through a large number of tests. The first welding allowance is the welding allowance of the first cover plate and the welding allowance of the rotor body, for example, the first radial welding allowance R1 (single side) in the outer diameter direction of the two or the first axial welding allowance Z1 (single side) in the thickness direction (axial direction). The first welding allowance includes the first radial welding allowance R1 and the first axial welding allowance Z1, the range of the first radial welding allowance is 2mm~10mm, and the range of the first axial welding allowance is 0.5mm~5mm. Preferably, according to the embodiment of the present disclosure, the range of the first axial welding allowance between the first cover plate 3 and the rotor body 1 is 0.5mm~2mm. The first radial welding margin between the first cover plate 3 and the rotor body 1 is in the range of 3 mm to 5 mm. It has been verified through experiments that by setting the first welding margin within this range, adjusting the pressure and time parameters according to the melting temperature of the material used, a magnetic suspension rotor impeller with good welding quality and an average wall thickness of 2 mm to 3 mm that meets the requirements of machining size correction can be obtained.

[0075] According to the embodiment of the present disclosure, see Figure 1 , Figure 2 , Figure 3 and Figure 4 In the above manufacturing method, the first cavity 13 of the rotor body 1 is in a circular shape and is surrounded by a central cylinder 131 and an annular outer wall 132; the second end face 12 of the rotor body 1 is integrally formed with a plurality of blades 14 by machining or injection molding, and 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 surround a central cavity 140. In this way, the first cover plate 3 and the plurality of blades are located on opposite sides of the rotor body 1. Since the fluid dynamic characteristics of the impeller depend on the blades, preferably, the blades are formed on the rotor body by integral injection molding, which can meet mass production while ensuring good product consistency. Preferably, when the rotor body 1 is integrally injection molded, the injection gate is located on the central cylinder 131 of the first end face 11, and the gate is removed by machining after injection molding to form a material cavity 1311, or the material cavity 1311 is first molded on the central cylinder 131 and then the gate is located in the material cavity 1311. By setting the injection molding gate on the central cylinder (internal structural part) of the first end face, the appearance of the product will not be affected, and a material holding cavity 1311 is formed at the gate, which can accommodate the welding material during extrusion welding and improve the welding quality.

[0076] In this embodiment, the plurality of blade structures are also referred to as impellers, which are integrally formed with the rotor body by injection molding, but are not limited thereto. Fig.10 and Fig.11 , the first cavity 13 of the rotor body 1 is still in the shape of a circular ring and is surrounded by a central cylinder 131 and an annular outer wall 132. The other side of the first cover plate 3 is integrally formed with a plurality of blades 14 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 surround 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. Preferably, when the first cover plate 3 is integrally injection molded, the injection gate is located on one side of the first cover plate 3, the gate is removed by machining after injection molding, and a material storage cavity 1311 is formed at a position corresponding to the central cylinder 131 and the gate. In this way, the injection gate is set on one side of the first cover plate, which will not affect the appearance of the product, and a material storage cavity is formed on the central cylinder corresponding to the gate, which can accommodate the welding material during extrusion welding and improve the welding quality. One side and the other side of the first cover plate are two opposite end surfaces.

[0077] In other embodiments, multiple impellers can also be individually injection molded or machined, see Fig.12 The manufacturing method further includes the step of welding the blades and the rotor body, which is as follows: providing a blade plate 14', forming a plurality of blades 14 on the circumferential side of the blade plate 14' by machining or injection molding, and welding the plurality of blades 14 to the second end surface 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 form a central cavity 140. In other embodiments, welding can also be a fixing method such as snaps, fasteners, and bonding.

[0078] According to the embodiment of the present disclosure, see Figure 1 , Figure 2 , Figure 3 , Figure 4 , Fig.11 and Fig.12 At least one of the plurality of blades 14 is formed with an exhaust hole 15, and the exhaust hole 15 is connected to the first cavity 13. In this way, the exhaust hole is arranged on at least one of the plurality of blades, and the arrangement is very clever. While not 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 achieved. For example, in one embodiment, see Figure 3The second end surface 12 of the rotor body 1 is formed with a plurality of blades 14, at least one of the plurality of blades 14 is formed with an exhaust hole 15, and the exhaust hole 15 penetrates the rotor body 1 (the portion carrying the plurality of blades) to communicate with the first cavity 13. In another embodiment, see Fig.11 A plurality of blades 14 are formed on the other side of the first cover plate 3 , and an exhaust hole 15 is formed on at least one of the plurality of blades 14 . The exhaust hole 15 penetrates the first cover plate 3 to communicate with the first cavity 13 .

[0079] The present invention is not limited to the form of the blades in the above embodiments. Preferably, see Figure 2 and Fig.12 The blade 14 includes a first guide portion 142, a second guide portion 143 and a third guide portion 144 which enclose an accommodation space 141. The first guide portion 142 of a blade 14 is arranged opposite to the second guide portion 143 of another adjacent blade 14 and encloses a liquid flow channel 145. The outer side surface of the third guide portion 144 after welding and machining is flush with the outer side surface of the rotor body 1 or the first cover plate 3. In this way, an accommodation space is formed in the blade, which is convenient for setting exhaust holes and a portion for injection molding ejection. The surface opposite to the first guide portion and the second guide portion constitutes a liquid flow channel. The form of the liquid flow channel is designed according to the fluid dynamics of the magnetic levitation pump, for example, it is designed to meet the centrifugal flow channel of a centrifugal pump. At this time, the overall performance of the blade is gradually thickened from the center inlet to the outer edge.

[0080] The present invention does not limit the form of the exhaust hole in the accommodation space. In one embodiment, the exhaust hole 15 is arranged in the accommodation space 141 of a blade 14. In another embodiment, see Figure 2 and Figure 3 A convex column 146 is formed in the accommodation space 141, and a vent hole 15 is formed at the center of at least one convex column 146. In this way, the convex column is provided in the accommodation space as an ejection part for injection molding ejection, and the vent hole can be arranged on the other hand, and the structure is simple. Among them, the vent hole is used to exhaust gas when the first cover plate and the rotor body are infrared welded, and the vent hole needs to be sealed after the first cover plate and the rotor body are welded.

[0081] According to the embodiment of the present disclosure, see Figure 1 , Figure 2 , Figure 3 , Figure 4 and Fig.10The central cylinder 131 of the rotor body 1 is integrally formed with a plurality of first through holes 16 by injection molding. The first through holes 16 penetrate the first end face 11 and the second end face 12 of the rotor body 1. The plurality of first through holes 16 are arranged in an array around the rotation axis of the rotor 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 body 1, second through holes corresponding to the plurality of first through holes 16 are processed and manufactured on the first cover plate 3. Figure 6 and Figure 7 Before the first cover plate is welded to the rotor body, the second through hole is not processed on the first cover plate. By machining the first cover plate after welding to make second through holes corresponding to the first through holes one by one, on the one hand, the first and second through holes can be connected as a whole, which can relieve the pressure of the high-pressure liquid entering the bottom of the rotor and balance the axial force. On the other hand, making the second through hole later instead of making the second through hole on the first cover plate first can simplify the production process and avoid the problem of eccentricity of the through holes caused by misalignment of the two parts. In other embodiments, second through holes corresponding to the multiple first through holes 16 can also be processed on the first cover plate 3 in advance, and then the first cover plate 3 and the rotor body 1 are welded. At this time, the first through hole 16 needs to be aligned with the second through hole by tooling before welding. Preferably, refer to Fig.17 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 fusion material overflowed into the first through hole and the second through hole during the welding process, so as to form the pressure relief hole of the finished magnetic suspension rotor impeller, and make the size of the pressure relief hole consistent with the target size.

[0082] According to the disclosed embodiment, a third through hole can also be integrally formed on the central cylinder of the rotor body 1 by injection molding. The third through hole passes 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 relieve the pressure of the high-pressure liquid entering the bottom of the rotor and balance 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 processed on the first cover plate to simplify the production process and avoid the problem of non-concentricity of the 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 fusion material overflowed into the third through hole and the fourth through hole during the welding process, and to make the size of the through hole consistent with the target size.

[0083] The magnetic body is also called a magnetic core or a magnetically suspended rotor, which may be composed of only one or more permanent magnets, or may include one or more permanent magnets combined with a soft magnetic component, which is usually made of iron or nickel-iron or silicon-iron. Figure 5 , the magnetic body 2 is configured as an annular permanent magnet, and the bottom of the first cavity 13 is integrally injection-molded to form a positioning pin 133, and a positioning hole 21 corresponding to the positioning pin is formed on the annular permanent magnet. In this way, by setting the coordination between the positioning pin and the stator hole, on the one hand, it can play the role of 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. In order to prevent the magnetic body from being corroded, the magnetic body can also be coated with a protective coating. For example, in order to resist the corrosion of acidic or chemically corrosive substances, the magnetic body is completely coated with a metal coating. In order to resist the corrosion of small molecules, such as hydrochloric acid (HCl) or hydrofluoric acid (HF) or ozone (O3), the magnetic body is also coated with a plastic coating composed of a polymer belonging to the polyparaxylene class. Among them, the metal coating or the plastic coating can be one or more layers.

[0084] According to the embodiment of the present disclosure, see Figure 6 and Figure 7 One side of the first cover plate 3 is formed with a second annular positioning surface or a plurality of second arc-shaped positioning surfaces 32 protruding toward the annular permanent magnet, and 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, the smaller annular or second arc-shaped positioning surface can, on the one hand, support and position the annular permanent magnet, thereby facilitating the horizontal positioning of the annular permanent magnet, and on the other hand, form an air gap to avoid part of the fusion material during welding, thereby preventing the fusion material displaced by welding from damaging the protective coating of the annular permanent magnet. Moreover, the fusion material has sufficient flow space to enter the air gap, which can make the fusion more complete and improve the fusion quality. Based on the same principle of horizontal precision positioning, see Figure 1 and Figure 3 A first annular positioning surface 134 or multiple first arc-shaped positioning surfaces protruding toward the first cover plate can also be formed at the bottom of the first cavity of the rotor body. 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 to a certain height and have a smaller area, which facilitates the horizontal positioning (leveling) of the permanent magnet.

[0085] According to the embodiment of the present disclosure, see Fig.13The manufacturing method further includes the step of welding the second cover plate 4 before or after welding the first cover plate, which is as follows: melting one side of the second cover plate 4 and the top of the blade 14 and then extruding and welding them together, so that the second cover plate 4 closes the top of the liquid flow channel between two adjacent blades 14; a second welding margin is reserved before welding the second cover plate 4 and the blade 14. The second cover plate is welded to the top of the blade to form a closed impeller structure, see Fig.17 and Fig.18 The welding of the second cover plate and the top of the blade can not only seal the exhaust hole, but also fully fuse the two parts, thereby improving the stability of the second cover plate connection. Similarly, by reserving a second welding margin, and then melting one side of the second cover plate and the top of the blade 14 before extrusion welding them together, the two parts can be fully welded, without a weld between the two parts, thereby improving the stability of the second cover plate connection. Since the second cover plate and the top of the blade are extrusion welded together in a molten state, in order to ensure that the two are fully welded and ensure the sealing performance, the welding material will bulge outward at the welding surface to form a weld bulge 6, see Fig.15 This makes the rotor after direct welding deviate greatly from the design target size, especially failing to meet the dimensional accuracy requirements of the magnetic levitation rotor impeller of the magnetic levitation motor. Therefore, the outer contour dimensions of the second cover plate and the blades are corrected by machining, so that the outer contour dimensions of the blades and the second cover plate are the same as the second target size within the error range, and a liquid inlet 41 is formed in the middle of the second cover plate, see Fig.18 . Similarly, after welding, the outer contour dimensions of the parts are corrected by machining technology, which solves the problems of bulges at the welding surface caused by extrusion welding deformation and large deviations in the overall size of the impeller, so as to meet the dimensional accuracy requirements of the magnetic levitation rotor impeller. In other embodiments, a liquid inlet may be first formed in the middle of the second cover plate, and then the second cover plate is welded to the top of the blade. Preferably, the welding is infrared welding, and the second weld allowance includes a second radial weld allowance R1 and a second axial weld allowance Z1. The range of the second radial weld allowance is 2mm to 10mm, and the range of the second axial weld allowance is 0.5mm to 5mm. Preferably, according to an embodiment of the present disclosure, the range of the second axial weld allowance is

[0086] 0.5mm~2.0mm, the second radial welding margin ranges from 3mm~5mm. Preferably, see FIG. Figure 3 and 13The second welding allowance is the welding allowance of the second cover plate and the welding allowance of the blade top, for example, the second radial welding allowance R2 in the outer diameter direction of the two or the second axial welding allowance Z2 in the thickness direction (axial direction). It has been verified through experiments that by setting the second welding allowance within this range, adjusting the pressure and time parameters according to the melting temperature of the material used, a magnetic suspension rotor impeller with good welding quality and meeting the requirements of machining size correction can be obtained.

[0087] The first cover plate and / or the second cover plate can be integrally formed into a molded part by machining or injection molding. The molded part here refers to a molded part that has the same structure as the final product but has a different size. Fig.17 and Fig.18 The first cover plate 3 includes a disc-shaped main body, a second through hole 31 formed on the main body, a plurality of second arc-shaped positioning surfaces and a convex portion 33. The difference between the molded part and the final product is only the size of the welding margin. In another embodiment, see Fig.14 , Fig.15 and Fig.16 , the first cover plate and / or the second cover plate are integrally formed into an injection molded part by injection molding. The injection molded part is a semi-molded part. The semi-molded part here refers to a structure and size of the final product that is different from the final shape of the product and is machined after welding. Preferably, the injection molded part includes a cover plate body 90, an annular side wall 91 formed on one side of the cover plate body 90, and a plurality of radial strips 92 extending radially outward from the center column 93 and connected to the annular side wall 91; the annular side wall 91, the radial strips 92 and the center column 93 are removed by machining after the cover plate body 90 is welded. When the injection molded part is thick, pores are easily formed inside, and the shrinkage of the pores after injection molding will cause surface defects. Injection molding the first cover plate and / or the second cover plate into a radial shape can reduce the use of injection molding materials on the one hand, and reduce the formation of pores on the other hand, ensuring that the surface quality of the second cover plate is excellent. The radial design also facilitates the gripping and fixing of the welding process. For example, see Fig.14 and Fig.16 When the top plane of the blade is a slope that gradually decreases from the center to the outer edge, the second cover plate is also a slope that gradually decreases from the center to the outer edge, and the cover plate body 90 of the second cover plate is in a raised state as a whole. At this time, the second cover plate is first formed into an injection molded part and then machined into the structure and size of the final product, which can better ensure the surface quality of the second cover plate.

[0088] According to the embodiment of the present disclosure, see Fig.18 , Fig.19 and Fig. 20, the manufacturing method also includes the step of welding the partition plate 5, which is as follows: weld one side of the partition plate 5 to the inner side of the blade 14 or / and the center boss 147 on the first end face 11, so that the partition plate 5 is at a first distance from the first end face 11. The partition plate can be firmly fixed to the inner side of the blade or the center boss by welding, which solves the problem of the partition plate easily falling off. The partition plate serves the purpose of separating the mainstream flow at the impeller inlet and the secondary flow at the bottom of the rotor, avoiding the impact and collision between the mainstream 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. The partition plate 5 is at a first distance from the first end face 11 or the first cover plate 3, and the partition plate 5 at least partially separates the mainstream flow from the liquid inlet and the secondary flow from the first through hole. In another embodiment, see Figure 3 and Figure 4 A central boss 147 is formed on the other side of the first cover plate 3 or the second end face 12 of the rotor body 1, and the central boss 147 is located in the central cavity 140. The partition plate 5 is welded to the central boss or the partition plate is welded to the inner side of the blade 14 and the central boss. The partition plate is at a first distance from the first end face or the first cover plate, and 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 configuration is contact hot melt welding, which can achieve a firm connection between the partition plate and the blade while reducing the influence of welding heat on the structure of surrounding components.

[0089] Based on the same inventive concept, the present invention also proposes a magnetically suspended rotor impeller, which is manufactured by the method for manufacturing a magnetically suspended rotor impeller in the above embodiments. Fig.17 , Fig.18 , Fig.19 and Fig. 20 The magnetic levitation rotor impeller includes a rotor body 1, a magnetic body 2, a first cover plate 3, a second cover plate 4 and a partition plate 5, and its structure has been described in detail in the above embodiments and will not be repeated here. The magnetic levitation rotor impeller manufactured by the above method for manufacturing a magnetic levitation rotor impeller improves the sealing performance of the magnetic body (such as an annular permanent magnet) in the first cavity because the two parts are fully fused and there is no weld between the two parts. After welding, the outer contour dimensions of the parts are corrected by machining technology, which solves the problems of bulges at the welding surface caused by extrusion welding deformation and large overall dimensional deviations of the magnetic levitation rotor impeller. At the same time, it meets the requirements of high sealing performance and dimensional accuracy of the rotor impeller in the high-cleanliness field.

[0090] Based on the same inventive concept, see Fig.21The present invention also proposes a magnetic levitation pump, including a magnetic levitation rotor impeller manufactured by the method for manufacturing a magnetic levitation rotor impeller in the above embodiments. It also 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 connected to 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 also includes the magnetic levitation rotor impeller in the above embodiments, and the rotor body of the impeller is arranged in the rotor cavity.

[0091] The present invention does not limit the type of magnetic levitation motor, which can be summarized as 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. Preferably, the magnetic levitation motor is a bearingless thin-film motor.

[0092] The bearingless thin-film motor is a special bearingless motor. It inherits the advantages of the bearingless motor, and the axial length to diameter ratio of the rotor is very small, 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 composed of 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.

[0093] The bearingless thin-film motor can be divided into a single winding structure and a double winding structure according to the different winding structures. The present invention does not limit the winding structure of the bearingless thin-film 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 suspension stator, and the winding coil is a concentrated winding. The winding coil is used for both rotation control and suspension control to form a single winding structure of the magnetic suspension motor. In another embodiment, two winding coils are arranged on each stator tooth of the magnetic suspension stator, and 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 teeth are stacked 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 suspension motor. Since the single-winding magnetic suspension motor can realize the rotation and suspension of the motor rotor at the same time with only one set of winding coils, it has better performance advantages than the double-winding magnetic suspension motor.

[0094] Based on the principle of bearingless thin-film motor, the magnetic levitation pump of the present invention can be configured as a magnetic levitation centrifugal pump, wherein the pump head and the magnetic levitation rotor impeller configured therein can be separated from the casing of the magnetic levitation motor in an easier way. This will be another great advantage of the magnetic levitation centrifugal pump, because the pump casing and the impeller can therefore be designed as disposable parts, such as disposable parts. Due to the extremely high purity requirements, such disposable applications now often replace the process in which all those parts in contact with the fluid to be treated must be cleaned and sterilized (for example, by steam sterilization) in a complex manner in the previous process. In the disposable design, those parts in contact with the fluid to be treated are used only once and then replaced by new (i.e., unused) disposable parts in the next application.

[0095] Specific embodiments are used in the present invention to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the technical solution and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A method for manufacturing a magnetically suspended rotor impeller, characterized in that: The method comprises the following steps: A rotor body (1), a magnetic body (2) and a first cover plate (3) are provided, wherein the rotor body is cylindrical, has a first end surface (11) and a second end surface (12) arranged opposite to each other, the first end surface forms a first cavity (13), the first cover plate is disc-shaped, and the rotor body and the first cover plate are both made of thermoplastic plastics; Positioning the magnetic body into the first cavity; One side of the first cover plate and the first end surface are first heated and melted and then extruded and welded together, so that the magnetic body is sealed in the first cavity; wherein a first welding margin is reserved between the first cover plate and the rotor body before welding; The outer contour dimensions of the first cover plate and the rotor body are corrected by machining so that the outer contour dimensions of the rotor body and the first cover plate are the same as the first target dimensions within an error range.

2. The method for manufacturing a magnetically suspended rotor impeller according to claim 1, characterized in that: The welding is infrared welding, the first welding margin includes a first radial welding margin and a first axial welding margin, the first radial welding margin ranges from 2 mm to 10 mm, and the first axial welding margin ranges from 0.5 mm to 5 mm.

3. The method for manufacturing a magnetically suspended rotor impeller according to claim 1, characterized in that: The first cavity is in the shape of a ring and is formed by a central cylinder (131) and an annular outer wall (132); a plurality of blades (14) are integrally formed on the second end surface (12) of the rotor body by injection molding, 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 form a central cavity (140).

4. The method for manufacturing a magnetically suspended rotor impeller according to claim 3, characterized in that: When the rotor body is integrally injection molded, the injection gate is located on the central cylinder of the first end face, and the gate is removed by machining after injection molding to form a material cavity (1311), or a material cavity is first molded on the central cylinder and then the gate is located in the material cavity.

5. The method for manufacturing a magnetically suspended rotor impeller according to claim 1, characterized in that: The first cavity is in the shape of a ring and is formed by 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 by injection molding, 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 form a central cavity (140).

6. The method for manufacturing a magnetically suspended rotor impeller according to claim 5, characterized in that: When the first cover plate is integrally injection molded, the injection gate is located on one surface of the first cover plate. The gate is removed by machining after injection molding, and a material holding cavity (1311) is formed at a position corresponding to the center cylinder and the gate.

7. The method for manufacturing a magnetically suspended rotor impeller according to claim 3 or 5, characterized in that: At least one of the plurality of blades is formed with an exhaust hole (15), and the exhaust hole is connected to the first cavity.

8. The method for manufacturing a magnetically suspended rotor impeller according to claim 7, characterized in that: The blade comprises a first flow guide portion (142), a second flow guide portion (143) and a third flow guide portion (144) which enclose an accommodating space (141); the first flow guide portion of one blade is arranged opposite to the second flow guide portion of another adjacent blade and encloses a liquid flow channel (145).

9. The magnetically suspended rotor impeller according to claim 8, characterized in that: At least two protruding columns (146) are formed in the accommodating space, and the exhaust hole is formed at the center of at least one of the protruding columns.

10. The method for manufacturing a magnetically suspended rotor impeller according to claim 3, characterized in that: A plurality of first through holes (16) are integrally formed on the central cylinder by injection molding, the first through holes passing through 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; after the first cover plate is welded to the rotor body, second through holes corresponding to the plurality of first through holes are processed and manufactured on the first cover plate.

11. The method for manufacturing a magnetically suspended rotor impeller according to claim 3, characterized in that: A third through hole is also formed on the central cylinder by injection molding, and the third through hole passes through the second end face and the first end face of the rotor body and is located in the central cavity, and the rotation axis of the rotor body passes through the third through hole; after the first cover plate is welded to the rotor body, a fourth through hole corresponding to the third through hole is processed and manufactured on the first cover plate.

12. The method for manufacturing a magnetically suspended rotor impeller according to claim 3, characterized in that: The magnetic body is configured as an annular permanent magnet, the bottom of the first cavity is integrally injection-molded to form a positioning pin (133), and a positioning hole (21) corresponding to the positioning pin is formed on the annular permanent magnet.

13. The method for manufacturing a magnetically suspended rotor impeller according to claim 12, characterized in that: A second annular positioning surface or a plurality of second arcuate positioning surfaces (32) protruding toward the annular permanent magnet is formed on one side of the first cover plate, and the radial dimension of the second annular positioning surface or the second arcuate positioning surface is smaller than the radial dimension of the first cavity.

14. The method for manufacturing a magnetically suspended rotor impeller according to claim 3, characterized in that: The method further comprises the step of welding a second cover plate (4) before or after welding the first cover plate, the step being as follows: melting one side of the second cover plate and the top of the blade and then extrusion welding them together, so that the second cover plate closes the top of the liquid flow channel between two adjacent blades; a second welding margin is reserved between the second cover plate and the blade before welding.

15. The method for manufacturing a magnetically suspended rotor impeller according to claim 14, characterized in that: The outer contour dimensions of the second cover plate and the blade are corrected by machining so that the outer contour dimensions of the blade and the second cover plate are the same as the second target dimension within an error range, and a liquid inlet (41) is formed in the middle of the second cover plate.

16. The method for manufacturing a magnetically suspended rotor impeller according to claim 14, characterized in that: The welding is infrared welding, the second welding margin includes a second radial welding margin and a second axial welding margin, the second radial welding margin ranges from 2 mm to 10 mm, and the second axial welding margin ranges from 0.5 mm to 5 mm.

17. The method for manufacturing a magnetically suspended rotor impeller according to claim 14, characterized in that: The first cover plate and / or the second cover plate are integrally formed into an injection molded part by injection molding, and the injection molded part comprises a cover plate body (90), an annular side wall (91) formed on one side of the cover plate body, and a plurality of radiating strips (92) extending radially outward from a center column (93) and connected to the annular side wall; the annular side wall and the radiating strips are removed by machining after the cover plate body is welded.

18. The method for manufacturing a magnetically suspended rotor impeller according to claim 3, characterized in that: The method further comprises the step of welding a partition plate (5), which step is as follows: one side of the partition plate is welded to the inner side of the blade or / and the central boss (147) on the first end surface by contact hot-melt welding, so that the partition plate is at a first distance from the first end surface.

19. The method for manufacturing a magnetically suspended rotor impeller according to claim 1, characterized in that: The method further comprises the step of welding the blades and the rotor body, which step is as follows: providing a blade plate (14'), the periphery of the blade plate being integrally formed with a plurality of blades (14) by machining or injection molding, the plurality of blades being welded together with the second end surface of the rotor body, the plurality of blades being arranged in an array around the rotation axis of the rotor body, and the inner edges of the plurality of blades forming a central cavity (140).

20. A magnetically suspended rotor impeller, characterized in that: The magnetic suspension rotor impeller is manufactured by the method for manufacturing a magnetic suspension rotor impeller according to any one of claims 1 to 19.

21. A magnetic levitation pump, characterized in that: Including a magnetically suspended rotor impeller as described in claim 20.

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