Method for manufacturing magnetically levitated rotor impeller, magnetically levitated rotor impeller, and magnetically levitated pump

Abstract

Disclosed in embodiments of the present disclosure are a method for manufacturing a magnetically levitated rotor impeller, a magnetically levitated rotor impeller, and a magnetically levitated pump. The method comprises the following steps: providing a rotor body, a magnetic body and a first cover plate, wherein the rotor body and the first cover plate are both made of thermoplastic; positioning and mounting the magnetic body into a first cavity; heating and melting a surface of the first cover plate and a first end face of the rotor body, and then press-welding the two together, so that the magnetic body is sealed in the first cavity, wherein a first welding allowance is reserved between the first cover plate and the rotor body before welding; and correcting the outer contour dimensions of the first cover plate and the rotor body by means of machining, so that the outer contour dimensions of the rotor body and the first cover plate are the same as first target dimensions within an error range. The present disclosure improves the process of manufacturing a magnetically levitated rotor impeller, thereby not only improving the sealing performance of the rotor body, but also meeting the requirements of the magnetically levitated rotor impeller for dimensional accuracy.

Description

Method for manufacturing a magnetic levitation rotor impeller, magnetic levitation rotor impeller and magnetic levitation pump

[0001] Cross-reference to related applications

[0002] The present disclosure claims priority to the Chinese patent application No. 202411266343.2, filed on September 10, 2024, and entitled “Method for manufacturing a magnetic levitation rotor impeller, magnetic levitation rotor impeller and magnetic levitation pump”, the entire content of which is incorporated herein by reference. TECHNICAL FIELD

[0003] The present disclosure relates to the technical field of magnetic levitation, in particular to a method for manufacturing a magnetic levitation rotor impeller, a magnetic levitation rotor impeller and a magnetic levitation pump. BACKGROUND

[0004] A magnetic levitation motor is a magnetic levitation rotary driver that uses magnetic field force to levitate 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 sheet motor, etc.

[0005] A magnetic bearing motor, also known as a magnetic bearing, is a motor that combines a rotary driving motor with an axial magnetic bearing or / and a radial magnetic bearing or / and an axial-radial hybrid magnetic bearing, rather than integrating them together.

[0006] A bearingless motor is a motor that integrates the functions of motor rotation and levitation. The bearingless motor has a set of windings on the windings that generate the rotary driving magnetic field, which generates an excitation magnetic field. The interaction of the two magnetic fields breaks the balance distribution of the original driving magnetic field, thereby generating a radial force acting on the rotor. The suspension of the rotor is achieved by controlling the radial force in the motor. Compared with the magnetic bearing motor, the magnetic suspension winding of the bearingless motor is wound on the stator, which does not occupy additional radial space, and to some extent overcomes the disadvantages of large size and high cost of the magnetic bearing. In order to achieve the suspension of the motor rotor in five degrees of freedom, early bearingless motors generally need two bearingless motors and an axial magnetic bearing.

[0007] A bearingless sheet motor is a special bearingless motor that inherits the advantages of the bearingless motor, and the axial length to diameter ratio of the rotor is very small, showing a sheet shape. The axial magnetic bearing is omitted, and the rotation and active suspension of the rotor in the radial direction are achieved by using bearingless technology. The passive suspension of the other three degrees of freedom except the radial and rotor rotation degrees of freedom is achieved by using a magnetic circuit composed of a mechanical structure, which has the characteristics of high cleanliness, no precipitation, no particles, no dynamic seal and superior performance, and has good application prospects in the fields of ultra-clean driving such as biochemistry, medical treatment and semiconductor manufacturing.

[0008] Unless otherwise specified, the term magnetic levitation motor refers to a magnetic levitation rotary driver that uses magnetic force to suspend the rotor, so that there is no mechanical contact between the rotor and the stator.

[0009] The magnetic levitation motor can be assembled with different functional assemblies to become a magnetic levitation device for different application requirements. The magnetic levitation device can be configured as a magnetic levitation pump, in the application of the magnetic levitation pump, the magnetic levitation pump comprises a magnetic levitation motor and a pump head, the pump head comprises a pump shell and a rotor impeller arranged in the pump shell, the magnetic levitation rotor is both the rotor of the magnetic levitation motor and part of the impeller of the pump, which can be, for example, a permanent magnet rotor or a short-circuit cage rotor or a magnetor, therefore, the impeller is also called a magnetic levitation rotor impeller, and the stator of the magnetic levitation motor is configured to drive the magnetic levitation rotor impeller to rotate and levitate.

[0010] At present, the magnetic levitation rotor impeller generally comprises a rotary body, a magnetic body embedded in the rotary body, and a plurality of blades formed on one end surface of the rotary body, a blade channel (liquid flow channel) is formed between adjacent two blades, for a closed rotor, the magnetic levitation rotor impeller further comprises a blade cover plate arranged on the side of the blades away from the rotary body, and a liquid inlet is formed in the middle of the blade cover plate. The rotary body is also called a rotor sheath, which can be made of fluorinated hydrocarbon plastic material to resist the corrosion of chemically aggressive substances. The magnetic body is also called a magnetic action core or a magnetic levitation rotor, which can be composed of one or more permanent magnets, or can comprise one or more permanent magnets combined with a soft magnetic component, which is usually made of iron or nickel-iron or silicon-iron. In order to prevent the magnetic body from being corroded, a protective coating is usually coated outside the magnetic body, for example, in order to resist the corrosion of acidic or chemically aggressive substances, the magnetic body is completely coated with a metal coating. In order to resist the corrosion of small molecule substances such as hydrochloric acid (HCl) or hydrofluoric acid (HF) or ozone (O3), the magnetic body is also coated with a plastic coating composed of polymers belonging to the poly-p-xylylene class. Among them, the metal coating or the plastic coating can be one or more layers.

[0011] Patent document CN109217507A discloses a rotor capable of magnetic levitation and a rotary machine having such a rotor, which comprises 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 configured to receive the permanent magnet having the metal coating and the plastic coating, and a cover sealing the cup-shaped housing portion and welded to the cup-shaped housing portion along a weld seam. An 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 seam, and the manufacturing process of such a rotor impeller in the prior art cannot meet the requirements of high sealing performance and dimensional accuracy of the rotor impeller in the high-cleanliness field. In addition, when the permanent magnet is loaded into the cup-shaped housing portion for infrared welding, due to the high temperature, gas is easily generated in the cup-shaped housing portion, and the gas cannot be discharged, which will cause welding difficulty, and further affect the welding quality and sealing effect.

[0012] DISCLOSURE

[0013] To overcome the defects in the prior art, the embodiments of the disclosure provide a method for manufacturing a magnetic suspension rotor impeller, a magnetic suspension rotor impeller and a magnetic suspension pump, which are used to solve at least one of the above problems.

[0014] The embodiments of the disclosure disclose a method for manufacturing a magnetic suspension rotor impeller, the method comprising the following steps:

[0015] A rotor body, a magnetic body and a first cover plate are provided, the rotor body is cylindrical, the rotor body has oppositely arranged first and second end faces, the first end face is formed with a first cavity, the first cover plate is disc-shaped, and the rotor body and the first cover plate are both thermoplastic plastics;

[0016] The magnetic body is positioned and fitted into the first cavity;

[0017] One side of the first cover plate is first heated and fused and then extrusion welded to the first end face, so that the magnetic body is sealed in the first cavity; wherein the first cover plate and the rotor body are provided with a first fusion allowance before welding;

[0018] 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 size within an error range.

[0019] Optionally, the welding is infrared welding, the first fusion allowance includes a first radial fusion allowance and a first axial fusion allowance, the first radial fusion allowance ranges from 2 mm to 10 mm, and the first axial fusion allowance ranges from 0.5 mm to 5 mm.

[0020] Optionally, the first cavity is annular and is surrounded by a central cylinder and an annular outer wall; the second end face of the rotor body is integrally formed by injection molding a plurality of blades, the plurality of blades are arranged around the rotation axis of the rotor body, and the inner edges of the plurality of blades surround a central cavity.

[0021] Optionally, when the rotor body is integrally injection molded, a sprue of injection molding is located on the central cylinder of the first end face, the sprue is removed by machining after injection molding and forms a material containing cavity, or a material containing cavity is first formed on the central cylinder and then the sprue is located in the material containing cavity.

[0022] Optionally, the first cavity is annular and is formed by a center cylinder and an annular outer wall; the other side of the first cover plate is integrally formed by injection molding with a plurality of blades, the plurality of blades are arranged around the rotation axis of the rotor body, and the inner edges of the plurality of blades enclose a center cavity.

[0023] Optionally, when the first cover plate is integrally injection molded, a gate of injection molding is located on one side of the first cover plate, the gate is removed by machining after injection molding, and the center cylinder is formed with a material containing cavity at a position corresponding to the gate.

[0024] Optionally, at least one of the plurality of blades is formed with an exhaust hole, and the exhaust hole communicates with the first cavity.

[0025] Optionally, the blade includes a first flow guide part, a second flow guide part and a third flow guide part enclosing a containing space, the first flow guide part of one blade is arranged opposite to the second flow guide part of an adjacent another blade and encloses a liquid flow channel.

[0026] Optionally, at least two convex columns are formed in the containing space, and the center of at least one of the convex columns forms the exhaust hole.

[0027] Optionally, a plurality of first through holes are integrally formed on the center cylinder by injection molding, the first through holes penetrate the first end surface and the second end surface of the rotor body, the plurality of first through holes are arranged around the rotation axis of the rotor body and are located in the center cavity; after the first cover plate is welded to the rotor body, a second through hole corresponding to each of the plurality of first through holes is machined on the first cover plate.

[0028] Optionally, a third through hole is also integrally formed on the center cylinder by injection molding, the third through hole penetrates the second end surface and the first end surface of the rotor body and is located in the center 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 machined on the first cover plate.

[0029] Optionally, the magnetic body is configured as an annular permanent magnet, a positioning pin is integrally injection molded at the bottom of the first cavity, and the annular permanent magnet is formed with a positioning hole corresponding to the positioning pin.

[0030] Optionally, one side of the first cover plate is formed with a second annular positioning surface or a plurality of second arc-shaped positioning surfaces protruding towards the annular permanent magnet, and the radial dimension of the second annular positioning surface or the second arc-shaped positioning surface is smaller than the radial dimension of the first cavity.

[0031] Optionally, the method further comprises a step of welding a second cover plate before or after welding the first cover plate, which is as follows: one side of the second cover plate is firstly fused and then extrusion welded with the top of the vane, so as to seal the top of the flow channel between two adjacent vanes; and the second cover plate and the vane are provided with a second fusion allowance before welding.

[0032] Optionally, the outer contour size of the second cover plate and the vane is corrected by machining, so that the outer contour size of the vane and the second cover plate is the same as the second target size within an error range, and a liquid inlet is formed in the middle of the second cover plate.

[0033] Optionally, the welding is infrared welding, and the second fusion allowance comprises a second radial fusion allowance and a second axial fusion allowance, the second radial fusion allowance ranges from 2 mm to 10 mm, and the second axial fusion allowance ranges from 0.5 mm to 5 mm.

[0034] Optionally, the first cover plate or / and the second cover plate is integrally formed by injection molding into an injection molded part, the injection molded part comprises a cover plate body, an annular side wall formed on one side of the cover plate body, and a plurality of radial strips extending radially outward from a central column and connected with the annular side wall; and the annular side wall and the radial strips are removed by machining after the cover plate body is welded.

[0035] Optionally, the method further comprises a step of welding a partition plate, which is as follows: one side of the partition plate is welded with the inner side of the vane or / and the central convex column on the first end face by contact type hot melt welding, so as to keep a first distance between the partition plate and the first end face.

[0036] Optionally, the method further comprises a step of welding a vane and a rotor body, which is as follows: a vane plate is provided, the circumference of the vane plate is integrally formed with a plurality of vanes by machining or injection molding, the plurality of vanes are welded with the second end face of the rotor body, the plurality of vanes are arranged in an array around the rotation axis of the rotor body, and the inner edges of the plurality of vanes enclose a central cavity.

[0037] The embodiments of the present disclosure further provide a magnetic suspension rotor impeller manufactured by the method for manufacturing a magnetic suspension rotor impeller.

[0038] The embodiments of the present disclosure further provide a magnetic suspension pump comprising the magnetic suspension rotor impeller.

[0039] The beneficial effects of the embodiments of the present disclosure are as follows: the present disclosure proposes a method for manufacturing a magnetic suspension rotor impeller. Compared with the welding process in the prior art, the present disclosure can make the two parts fully welded by reserving a welding allowance, then heating and melting one side of the first cover plate and the first end face of the rotor body, and then extrusion welding them together, so that there is no welding seam between the two parts, and the sealing performance of the magnetic body (for example, an annular permanent magnet) in the first cavity is improved. After welding, the machining process is used to correct the outer contour size of the part, solving the problems of bulging at the welding surface and large overall size deviation of the magnetic suspension rotor impeller caused by extrusion welding deformation. At the same time, the requirements of high sealing performance and size accuracy of the rotor impeller in the high-cleanliness field are met.

[0040] In order to make the above and other objects, features and advantages of the present disclosure more apparent, more easily understood, the following will specifically describe a preferred embodiment, and combine with the attached drawings, make a detailed description as follows. BRIEF DESCRIPTION OF DRAWINGS

[0041] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the present disclosure, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0042] Fig. 1 is a structural schematic diagram of a rotor body provided in the embodiments of the present disclosure;

[0043] Fig. 2 is a structural schematic diagram of a rotor body provided in the embodiments of the present disclosure;

[0044] Fig. 3 is a sectional view in the direction of A-A in Fig. 2;

[0045] Fig. 4 is a sectional view in the direction of B-B in Fig. 2;

[0046] Fig. 5 is a structural schematic diagram of a magnetic body provided in the embodiments of the present disclosure;

[0047] Fig. 6 is a structural schematic diagram of a first cover plate provided in the embodiments of the present disclosure;

[0048] Fig. 7 is a structural schematic diagram of a first cover plate provided in the embodiments of the present disclosure;

[0049] Fig. 8 is a schematic diagram of the welding assembly of the first cover plate and the rotor body provided in the embodiments of the present disclosure;

[0050] Fig. 9 is a schematic diagram of the first cover plate and the rotor body after welding in the embodiments of the present disclosure;

[0051] Fig. 10 is a structural schematic diagram of a rotor body provided in the embodiments of the present disclosure;

[0052] Fig. 11 is a structural schematic diagram of a first cover plate provided in the embodiments of the present disclosure;

[0053] Fig. 12 is a structural schematic diagram of an impeller (a plurality of blades) separately formed in the embodiments of the present disclosure;

[0054] Fig. 13 is a structural schematic diagram of a second cover plate provided in the embodiments of the present disclosure;

[0055] Fig. 14 is a schematic diagram of the first cover plate, the second cover plate and the rotor body welded together in the embodiments of the present disclosure;

[0056] Fig. 15 is a schematic diagram of the first cover plate, the second cover plate and the rotor body after welding in the embodiments of the present disclosure;

[0057] Fig. 16 is a structural schematic diagram of an injection molded part provided in the embodiments of the present disclosure;

[0058] Fig. 17 is a structural schematic diagram of a magnetic levitation rotor impeller manufactured in the embodiments of the present disclosure;

[0059] Fig. 18 is a structural schematic diagram of a magnetic levitation rotor impeller manufactured in the embodiments of the present disclosure;

[0060] Fig. 19 is a structural schematic diagram of a magnetic levitation rotor impeller manufactured in the embodiments of the present disclosure;

[0061] Fig. 20 is a structural schematic diagram of a magnetic levitation rotor impeller manufactured in the embodiments of the present disclosure;

[0062] Fig. 21 is a structural schematic diagram of a magnetic levitation pump in the embodiments of the present disclosure. DETAILED DESCRIPTION

[0063] The technical solutions in the embodiments of the present disclosure will be described clearly and completely below in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, rather than all the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present disclosure.

[0064] In the description of the disclosure, it should be explained that the terms "upper", "lower", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the disclosure and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the disclosure. The terms "including", "provided with" and their any variants in the specification and claims of the disclosure and the above-mentioned drawings are intended to cover non-exclusive inclusion, for example, a system, product or device including a series of units does not have to be limited to those units clearly listed, but can include other units not clearly listed or inherent to these products or devices.

[0065] In addition, the terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the disclosure, unless otherwise stated, the meaning of "a plurality of" is two or more, unless otherwise explicitly limited.

[0066] The drawings in the disclosure are not strictly drawn to scale, and the specific size and quantity of each structure can be determined according to actual needs. The drawings described in the disclosure are only schematic diagrams.

[0067] According to the embodiments of the disclosure, a method for manufacturing a magnetic suspension rotor impeller is provided, the method comprising the following steps:

[0068] Referring to FIG. 1, FIG. 2, FIG. 3, FIG. 4, FIG. 5, FIG. 6, FIG. 7 and FIG. 8, a rotor body 1, a magnetic body 2 and a first cover plate 3 are provided, the rotor body 1 is cylindrical, the rotor body 1 has oppositely arranged first and second end faces 11 and 12, the first end face 11 is formed with 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;

[0069] The magnetic body 2 is positioned and fitted into the first cavity 13;

[0070] One side of the first cover plate 3 is first heated and fused and then extrusion welded with the first end face 11, so that the magnetic body 2 is sealed in the first cavity 13; wherein the first cover plate 3 and the rotor body 1 are pre-reserved with a first fusion allowance before welding; FIG. 8 shows a schematic view of the welding assembly of the first cover plate 3 and the rotor body 1.

[0071] The outer contour size of the first cover plate 3 and the rotor body 1 is corrected by machining, so that the outer contour size of the rotor body 1 and the first cover plate 3 is the same as the first target size within the error range.

[0072] In the manufacturing method, the first cover plate is first heated and melted and then extrusion welded to the first end face of the rotor body by reserving a first welding allowance, so that the two parts are fully welded, there is no weld between the two parts, and the sealing performance of the magnetic body (e.g. annular permanent magnet) in the first cavity is improved. After welding, the outer contour size of the part is corrected by machining process, which solves the problems of bulging at the welding surface and large overall size deviation of the magnetic suspension rotor impeller caused by extrusion welding deformation. At the same time, the requirements of high sealing performance and size accuracy of the rotor impeller in the high-cleanliness field are met.

[0073] The rotor body 1 and the first cover plate 3 are both thermoplastic plastics, for example, fluorinated hydrocarbon plastic material, which can resist chemical erosion of corrosive substances. Alternatively, the materials of the rotor body 1 and the first cover plate 3 can be perfluoroalkoxy polymer (PFA). Alternatively, the materials of the rotor body 1 and the first cover plate 3 can also be ethylene chlorotrifluoroethylene (ECTFE) or polyvinylidene fluoride (PVDF).

[0074] The rotor body and the first cover plate are rotary parts, the rotor body is generally cylindrical, and the first cover plate 3 is generally disc-shaped, but not limited thereto, for example, the end face or side face of the first cover plate can also have other auxiliary convex or concave structures.

[0075] The first cover plate 3 is first heated and melted and then extrusion welded to the first end face 11, which means that the first cover plate and the first end face of the rotor body are first heated, and then the two parts are driven to move relative to each other to make the two end faces contact and extrusion, and finally the two parts are completely welded. Alternatively, in this process, the welding depth of the two parts is ensured by the tooling according to the first welding allowance parameter, and the tooling is removed after the two parts are welded and cooled, i.e. the welding is completed. Alternatively, the heating method is non-contact heating, for example, using an infrared heater for infrared welding to heat. Through infrared welding, the heating area can be accurately controlled, so that the heating is more uniform, local overheating is avoided, and there is no need to contact the material, reducing mechanical damage to the surface of the material. Through infrared welding, the cleanliness of the rotor body and the first cover plate can be ensured, and no other impurities are introduced during the manufacturing process of the magnetic suspension rotor impeller. Further, the magnetic suspension rotor impeller is applied to the high-cleanliness field.

[0076] Since the first cover plate and the first end surface of the rotor body are extruded and fused together in a molten state, in order to ensure sufficient fusion of the two to guarantee sealing performance, the fused material will bulge outward at the welding surface to form a welding protrusion 6, as shown in FIG. 9, and will cause the middle portion of the rotor body to deform. This makes the rotor after direct welding deviate greatly from the target design size, especially unable to meet the dimensional accuracy requirements of the magnetic suspension rotor impeller of the magnetic suspension motor. Therefore, the present disclosure further includes an indispensable machining step after extrusion welding, which can correct the outer contour dimensions of the first cover plate 3 and the rotor body 1, so that the outer contour dimensions of the rotor body 1 and the first cover plate 3 are the same as the first target size within the error range. The first target size is the design size, which is determined by the magnetic coupling capacity between the magnetic suspension stator and the magnetic suspension rotor of the magnetic suspension motor. 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, also include the outer side surface dimensions of the rotor body outside the welding surface, and also include the dimensions of the other surface of the first cover plate away from the magnetic body outside the welding surface.

[0077] Since the extrusion and fusion allowance in the welding process are closely related, the range of the first fusion allowance becomes an important parameter of the manufacturing process. If the first fusion allowance is too large, it will lead to low material utilization and increased machining processing efficiency. If the first fusion allowance is too small, it will lead to insufficient fusion and the machining cannot meet the surface quality requirements. Therefore, it is necessary to verify the relationship between the reserved fusion allowance, heating temperature, pressure and time parameters through a large number of experiments. The first fusion allowance is the fusion allowance of the first cover plate and the rotor body, for example, the first radial fusion allowance R1 (single side) in the outer diameter direction or the first axial fusion allowance Z1 (single side) in the thickness direction (axial direction). The first fusion allowance includes the first radial fusion allowance R1 and the first axial fusion allowance Z1. The range of the first radial fusion allowance is 2mm-10mm, and the range of the first axial fusion allowance is 0.5mm-5mm. Alternatively, according to the embodiment of the present disclosure, the range of the first axial fusion allowance of the first cover plate 3 and the rotor body 1 is 0.5mm-2mm. The range of the first radial fusion allowance of the first cover plate 3 and the rotor body 1 is 3mm-5mm. It has been verified through experiments that setting the first fusion allowance in this range, adjusting the pressure and time parameters according to the melting temperature of the used material, can obtain a magnetic suspension rotor impeller with good fusion quality and an average wall thickness of 2mm-3mm that meets the size correction needs of machining.

[0078] According to the embodiments of the present disclosure, referring to FIG. 1, FIG. 2, FIG. 3 and FIG. 4, in the manufacturing method, the first cavity 13 of the rotor body 1 is annular and surrounded by the center cylinder 131 and the annular outer wall 132; the second end surface 12 of the rotor body 1 is machined or integrally formed with a plurality of blades 14 by injection molding, the plurality of blades 14 are arranged around the rotation axis of the rotor body 1, and the inner edges of the plurality of blades 14 surround a center 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 dynamics of the impeller depends on the blades, integrally injection molding the blades on the rotor body can ensure good product consistency while meeting mass production. Alternatively, when the rotor body 1 is integrally injection molded, the injection gate is located on the center cylinder 131 of the first end surface 11. The injection gate is removed by machining after injection molding and forms a material containing cavity 1311, or the injection gate is located in the material containing cavity 1311 after the material containing cavity 1311 is formed on the center cylinder 131. By setting the injection gate on the center cylinder (internal structure) of the first end surface, the appearance of the product is not affected, and the material containing cavity 1311 is formed at the injection gate to accommodate the welding material during extrusion welding, improving the welding quality.

[0079] In the present embodiment, the plurality of blade structures are also called impellers and are integrally formed with the rotor body by injection molding, but are not limited thereto. In another embodiment, referring to FIG. 10 and FIG. 11, the first cavity 13 of the rotor body 1 is still annular and surrounded by the center cylinder 131 and the 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 around the rotation axis of the rotor body 1, and the inner edges of the plurality of blades 14 surround a center cavity 140. In the present 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-mentioned embodiment. Alternatively, when the first cover plate 3 is integrally injection molded, the injection gate is located on one side of the first cover plate 3, and the injection gate is removed by machining after injection molding. The center cylinder 131 has a material containing cavity 1311 corresponding to the injection gate. In this way, the injection gate is set on one side of the first cover plate, which does not affect the appearance of the product, and the material containing cavity is formed on the center cylinder corresponding to the injection gate, which can accommodate the welding material during extrusion welding, improving the welding quality. The one side and the other side of the first cover plate are two opposite end surfaces.

[0080] Optionally, the plurality of blades can also be separately injection molded or machined, as shown in FIG. 12, and the above manufacturing method further comprises the step of welding the blades and the rotor body, which is as follows: providing a blade plate 14', integrally 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 and the second end surface 12 of the rotor body 1 together. 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. Optionally, the welding can also be a fixing method such as buckling, fastening, bonding, etc.

[0081] According to the embodiments of the present disclosure, as shown in FIGS. 1, 2, 3, 4, 11 and 12, at least one of the plurality of blades 14 is formed with an exhaust hole 15 that communicates with the first cavity 13. In this way, the exhaust hole is arranged on at least one of the plurality of blades, which is very ingenious in arrangement, does not affect the appearance and function of the product, and realizes the functions of exhausting gas in the welding area and improving the welding quality and sealing effect. For example, in one embodiment, as shown in FIG. 3, the 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 bearing the plurality of blades) to communicate with the first cavity 13. In another embodiment, as shown in FIG. 11, the other face of the first cover plate 3 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 first cover plate 3 to communicate with the first cavity 13.

[0082] The present disclosure is not limited to the form of the blades in the above embodiments, and optionally, as shown in FIGS. 2 and 12, the blade 14 comprises a first flow guide portion 142, a second flow guide portion 143 and a third flow guide portion 144 that enclose a receiving space 141, the first flow guide portion 142 of one blade 14 is arranged opposite to the second flow guide portion 143 of the adjacent other blade 14 and encloses a liquid flow channel 145, and the outer side surface of the third flow 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, the receiving space is formed in the blade, which facilitates the arrangement of the exhaust hole and the configuration of the injection ejection position. The opposite faces of the first flow guide portion and the second flow guide portion constitute the liquid flow channel, and the form of the liquid flow channel is designed according to the fluid dynamics of the magnetic suspension pump, for example, designed to meet the centrifugal flow channel of the centrifugal pump, at this time, the whole blade gradually thickens from the center inlet to the outer edge.

[0083] The form of the exhaust hole in the accommodation space is not limited in the present disclosure. Optionally, the exhaust hole 15 is arranged in the accommodation space 141 of one blade 14. In addition, referring to FIGS. 2 and 3, optionally, a convex column 146 is formed in the accommodation space 141 in the embodiment, and the center of at least one convex column 146 forms the exhaust hole 15. In this way, the convex column is arranged in the accommodation space, which serves as an ejection position for injection molding ejection on one hand, and the exhaust hole can be arranged on the other hand, and the structure is simple. The exhaust hole is configured to exhaust gas when the first cover plate is infrared welded with the rotor body, and the exhaust hole needs to be sealed after the first cover plate is welded with the rotor body.

[0084] According to the embodiment of the present disclosure, referring to FIGS. 1, 2, 3, 4 and 10, a plurality of first through holes 16 are integrally formed on the central cylinder 131 of the rotor body 1 by injection molding, the first through holes 16 pass through 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 around the rotation axis of the rotor body 1 and located in the central cavity 140. In this way, the plurality of first through holes are integrally formed by injection molding, which can ensure good product consistency. Optionally, after the first cover plate 3 is welded with the rotor body 1, a second through hole corresponding to each first through hole 16 is machined on the first cover plate 3. Referring to FIGS. 6 and 7, the second through hole is not machined on the first cover plate before the first cover plate is welded with the rotor body. The second through hole corresponding to the first through hole is machined on the first cover plate after welding, which can realize the overall penetration of the first and second through holes, balance the axial force, and balance the axial force. On the other hand, the second through hole is machined after the first cover plate is welded with the rotor body, which can simplify the production process and avoid the problem of different through holes caused by misalignment of two parts. Optionally, the second through hole corresponding to each first through hole 16 can be machined on the first cover plate 3 in advance, and then the first cover plate 3 is welded with the rotor body 1. At this time, the first through hole 16 and the second through hole need to be aligned by a tool before welding. Optionally, referring to FIG. 17, the first through hole and the second through hole are corrected by machining after the first cover plate is welded with the rotor body, the welding material overflowed in the first through hole and the second through hole in the welding process is removed, and the pressure relief hole of the finished product of the magnetic levitation rotor impeller is formed, so that the size of the pressure relief hole is consistent with the target size.

[0085] According to the embodiment of the present disclosure, a third through hole can also be integrally formed on the center cylinder of the rotor body 1 by injection molding, 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 third through hole, that is, the third through hole is a center through hole, when designing a center through hole, the size of the center through hole is correspondingly larger, so as to play the role of relieving the high-pressure liquid entering the bottom of the rotor and balancing the axial force; similarly, after the first cover plate is welded with the rotor body, a fourth through hole corresponding to the third through hole is processed on the first cover plate, so as to simplify the production process and avoid the problem of eccentric through holes caused by misalignment of two parts. Optionally, after the first cover plate is welded with the rotor body, the third through hole and the fourth through hole are modified by machining, the welding materials overflowing in the welding process are removed, and the size of the through hole is consistent with the target size.

[0086] The magnetic body, also known as a magnetic action core or a magnetic levitation rotor, can be composed of one or more permanent magnets, or can include one or more permanent magnets combined with a soft magnetic component, which is usually made of iron or nickel-iron or silicon-iron. Optionally, according to the embodiment of the present disclosure, referring to FIG. 5, the magnetic body 2 is configured as a ring-shaped permanent magnet, the bottom of the first cavity 13 is integrally injection molded to form a positioning pin 133, and the ring-shaped permanent magnet is formed with a positioning hole 21 corresponding to the positioning pin. In this way, by setting the cooperation of the positioning pin and the stator hole, on the one hand, the ring-shaped permanent magnet can play a role, and on the other hand, the two stator pins can also play a role of preventing the ring-shaped permanent magnet from rotating relative to the first cavity. In order to prevent the magnetic body from being corroded, the magnetic body can be coated with a protective coating outside, for example, in order to resist the corrosion of acidic or chemically aggressive substances, the magnetic body is completely coated with a metal coating. In order to resist the corrosion of small molecule substances, such as hydrochloric acid (HCl) or hydrofluoric acid (HF) or ozone (O3), the magnetic body is also coated with a plastic coating composed of polymers belonging to the poly-p-xylylene class. Among them, the metal coating or the plastic coating can be one or more layers.

[0087] According to the embodiment of the present disclosure, referring to FIG. 6 and FIG. 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 towards 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 annular positioning surface or the second arc-shaped positioning surface with a smaller dimension can support and position the annular permanent magnet on one hand, and facilitate the horizontal positioning of the annular permanent magnet on the other hand, and can form an air gap to avoid partial welding of the welding material, preventing the welded material from damaging the protective coating of the annular permanent magnet. Moreover, the welding material has sufficient space to flow into 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 FIG. 1 and FIG. 3, a first annular positioning surface 134 or a plurality of first arc-shaped positioning surfaces protruding towards 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 a certain height and have a small area, which facilitates the horizontal positioning (leveling) of the permanent magnet.

[0088] According to the embodiment of the present disclosure, referring to FIG. 13, the above 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: one side of the second cover plate 4 is first melted and then extrusion welded with the top of the blade 14, so that the second cover plate 4 closes the top of the liquid flow channel between the adjacent two blades 14; the second cover plate 4 and the blade 14 are pre-arranged with a second welding allowance before welding. The welding of the second cover plate and the top of the blade forms a closed impeller structure, referring to FIG. 17 and FIG. 18, which can close the exhaust hole on one hand and fully weld the two parts on the other hand, thereby improving the stability of the connection of the second cover plate. Similarly, by pre-arranging the second welding allowance and then first melting and then extrusion welding one side of the second cover plate with the top of the blade 14, the two parts can be fully welded, and there is no welding seam between the two parts, thereby improving the stability of the connection of the second cover plate. Since the second cover plate and the top of the blade are extrusion welded together in a molten state, in order to ensure the full welding of the two parts and guarantee the sealing performance, the welding material will protrude outward at the welding surface to form a welding seam protrusion 6, referring to FIG. 15. This makes the rotor after direct welding have a large deviation from the design target size, especially cannot meet the size precision requirements of the magnetic suspension rotor impeller of the magnetic suspension motor. Therefore, the outer contour size of the second cover plate and the blade is corrected by machining, so that the outer contour size of the blade and the second cover plate is 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, referring to FIG. 18. Similarly, the outer contour size of the part is corrected by machining after welding, which solves the problems of protrusion at the welding surface due to extrusion welding deformation and large deviation of the overall size of the impeller, thereby meeting the size precision requirements of the magnetic suspension rotor impeller.

[0089] Optionally, the liquid inlet can be formed in the middle of the second cover plate first, and then the second cover plate is welded with the top of the blade. Optionally, the welding is infrared welding, the second welding allowance includes a second radial welding allowance R1 and a second axial welding allowance Z1, the second radial welding allowance ranges from 2mm to 10mm, and the second axial welding allowance ranges from 0.5mm to 5mm. Optionally, according to the embodiment of the present disclosure, the second axial welding allowance ranges from 0.5mm to 2.0mm, and the second radial welding allowance ranges from 3mm to 5mm. Optionally, referring to FIGS. 3 and 13, the second welding allowance is the welding allowance of the second cover plate and the welding allowance of the top of the blade, for example, the second radial welding allowance R2 in the outer diameter direction or the second axial welding allowance Z2 in the thickness direction (axial direction). It has been verified through experiments that the second welding allowance is set in this range, and according to the melting temperature of the used material, the pressure and time parameters are adjusted, so that the magnetic suspension rotor impeller with good welding quality and meeting the needs of machining size correction can be obtained.

[0090] The first cover plate or / and the second cover plate can be machined or integrally formed by injection molding into a shaped piece. The shaped piece here refers to the same structure as the final product but with different sizes, referring to FIGS. 17 and 18, the first cover plate 3 includes a disc-shaped body part and a second through hole 31, a plurality of second arc-shaped positioning surfaces and a convex part 33 formed on the body part. The difference between the shaped piece and the final product is only the size of the welding allowance.

[0091] In addition, referring to FIG. 14, FIG. 15 and FIG. 16, the first cover plate or / and the second cover plate in the embodiment is integrally formed by injection molding as an injection molded part, which is a semi-formed part, meaning that the structure and size of the final product is formed by machining after welding. Alternatively, 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 with the annular side wall 91; the annular side wall 91, the radial strips 92 and the center column 93 are removed by machining after welding of the cover plate body 90. When the injection molded part is thick, it is easy to form pores inside, and the shrinkage of the pores after injection molding will cause surface defects. The first cover plate or / and the second cover plate is molded in a radial shape, which on the one hand reduces the use of injection molding material, and on the other hand can reduce the formation of pores, ensuring that the surface quality of the second cover plate is excellent. And the design in a radial shape also facilitates the grabbing and fixing position in the welding process. For example, referring to 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 also has a slope that gradually decreases from the center to the outer edge, and the cover plate body 90 of the second cover plate as a whole is in a raised state. At this time, the second cover plate is first formed into an injection molded part and then formed into the structure and size of the final product by machining, which can better ensure the surface quality of the second cover plate.

[0092] According to the embodiment of the present disclosure, referring to FIG. 18, FIG. 19 and FIG. 20, the manufacturing method further includes the step of welding the partition plate 5, which is as follows: one side of the partition plate 5 is welded with the inner side of the blade 14 or / and the center protruding column 147 on the first end face 11, so that the partition plate 5 is spaced apart from the first end face 11 by a first distance. By welding, the partition plate can be firmly fixed on the inner side of the blade or the center protruding column, solving the problem of easy falling off of the partition plate, and the partition plate plays a role in separating the main flow from the inlet and the secondary flow from the bottom of the rotor, avoiding the impact and collision of the main flow and the secondary flow, and balancing the axial force. Alternatively, the partition plate 5 is arranged in the center cavity 140, the partition plate 5 is welded with the inner side of the blade, and the partition plate 5 is spaced apart from the first end face 11 or the first cover plate 3 by a first distance, and the partition plate 5 at least partially separates the main flow from the inlet and the secondary flow from the first through hole. In addition, referring to FIG. 3 and FIG. 4, alternatively, the other side of the first cover plate 3 or the second end face 12 of the rotor body 1 is formed with a center protruding column 147, the center protruding column 147 is located in the center cavity 140, the partition plate 5 is welded with the center protruding column or the inner side of the blade 14 and the center protruding column, the partition plate is spaced apart from the first end face or the first cover plate by a first distance, and the partition plate at least partially separates the main flow from the inlet and the secondary flow from the first through hole. Alternatively, the welding is configured as a contact type hot melting welding, which can realize the firm connection of the partition plate and the blade while reducing the influence of welding heat on the structure of the surrounding components.

[0093] Based on the same inventive concept, the magnetic levitation rotor impeller is manufactured by the method for manufacturing the magnetic levitation rotor impeller in the above embodiments. For example, referring to FIGS. 17, 18, 19 and 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, a partition plate 5 and the like, the structure of which has been described in detail in the above embodiments and will not be repeated here. The magnetic levitation rotor impeller manufactured by the method for manufacturing the magnetic levitation rotor impeller has sufficient fusion between the two parts and no welding seam between the two parts, thereby improving the sealing performance of the magnetic body (e.g., annular permanent magnet) in the first cavity. After welding, the outer contour size of the part is corrected by machining process, thereby solving the problems of bulging at the welding surface and large overall size deviation of the magnetic levitation rotor impeller caused by extrusion welding deformation. At the same time, the requirements of high sealing performance and size precision of the rotor impeller in the high-cleanliness field are met.

[0094] Based on the same inventive concept, referring to FIG. 21, the disclosure further provides a magnetic levitation pump including the magnetic levitation rotor impeller manufactured by the method for manufacturing the magnetic levitation rotor impeller in the above embodiments. The magnetic levitation pump 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 shell 110, a rotor cavity and an impeller cavity are formed in the pump shell, an inlet 120 and an outlet 130 communicating with the impeller cavity are formed on the pump shell, the rotor cavity is arranged at one side of the impeller cavity, and the radial space of the rotor cavity is smaller than that of the impeller cavity. The pump head further includes the magnetic levitation rotor impeller in the above embodiments, and the rotor body of the impeller is arranged in the rotor cavity.

[0095] The type of the magnetic levitation motor is not limited in the disclosure, which can be summarized as a magnetic levitation rotary driver that suspends a rotor by magnetic force and has no mechanical contact between the rotor and the stator. Optionally, the magnetic levitation motor is a bearingless sheet motor.

[0096] The bearingless sheet motor is a special bearingless motor that inherits the advantages of the bearingless motor and has a very small axial length to diameter ratio of the rotor, i.e., in a sheet shape, and eliminates the axial magnetic bearing. The bearingless technology is used to realize the rotation and active suspension of the rotor in the radial direction, and 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 rotational degrees of freedom of the rotor. The bearingless sheet motor has the characteristics of high cleanliness, no precipitation, no particles, no dynamic seal and superior performance, and has good application prospects in the fields of ultrapure driving such as biochemistry, medical treatment and semiconductor manufacturing.

[0097] The bearingless sheet motor can be divided into single-winding structure and double-winding structure according to the winding structure, and the winding structure of the bearingless sheet motor is not limited in the disclosure, which can be single-winding structure or double-winding structure. In an embodiment, one winding coil is arranged on each stator tooth of the magnetic suspension stator, the winding coil is a concentrated winding, and the winding coil is used for both rotation control and suspension control to form a single-winding structure of the magnetic 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 is a concentrated winding and the other winding coil is a distributed winding. The two winding coils on the stator tooth 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 both rotation and suspension of the motor rotor by using one set of winding coils, it has better performance advantage than the double-winding magnetic suspension motor.

[0098] Based on the principle of the bearingless sheet motor, the magnetic suspension pump in the disclosure can be configured as a magnetic suspension centrifugal pump, wherein the pump head and the magnetic suspension rotor impeller arranged therein can be separated from the casing of the magnetic suspension motor in a relatively easy manner. This will be another big advantage of the magnetic suspension centrifugal pump, because the pump casing and the impeller can thus be designed as, for example, single-use parts. Due to the extremely high purity requirements, such single-use applications often replace processes in which all those components that come into contact with the fluid to be treated have to be cleaned and disinfected in a complex manner (for example by steam sterilization) in previous processes. In the single-use design, those components that come into contact with the fluid to be treated are used only once and then replaced by new (i.e. unused) single-use parts in the next application.

[0099] The principles and implementation manners of the disclosure are described in the specific embodiments in the disclosure, and the above embodiment descriptions are only used to help understand the technical solutions and core ideas of the disclosure; meanwhile, for those skilled in the art, according to the idea of the disclosure, the specific implementation manners and application ranges will be changed, and the above description of the specification should not be understood as a limitation of the disclosure. Industrial applicability

[0100] In summary, the method for manufacturing the magnetic suspension rotor impeller, the magnetic suspension rotor impeller and the magnetic suspension pump provided by the embodiments of the present disclosure can make the two parts fully welded and have no welding seam between the two parts, and improve the sealing performance of the magnetic body in the first cavity. After welding, the machining process is used to correct the outer contour size of the part, solving the problems of bulging at the welding surface and large overall size deviation of the magnetic suspension rotor impeller caused by the extrusion welding deformation. At the same time, the requirements of high sealing performance and size precision of the rotor impeller in the high-cleanliness field are met.

Claims

1. A method of manufacturing a magnetic levitation rotor impeller, characterized by, The method comprises the following steps: Providing a rotor body (1), a magnetic body (2) and a first cover plate (3), the rotor body is cylindrical, the rotor body has oppositely arranged first and second end faces (11, 12), the first end face is formed with 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 plastic; Positioning and loading the magnetic body into the first cavity; After heating and melting, the one side of the first cover plate is extrusion welded with the first end face, so that the magnetic body is sealed in the first cavity; wherein the first cover plate and the rotor body are provided with a first fusion allowance before welding; The outer contour size of the first cover plate and the rotor body is corrected by machining, so that the outer contour size of the rotor body and the first cover plate is the same as the first target size within the error range.

2. The method of manufacturing a magnetic levitation rotor impeller according to claim 1, characterized in that, The welding is infrared welding, the first fusion allowance includes a first radial fusion allowance and a first axial fusion allowance, the first radial fusion allowance ranges from 2 mm to 10 mm, and the first axial fusion allowance ranges from 0.5 mm to 5 mm.

3. The method of manufacturing a magnetic levitation rotor impeller according to claim 1 or 2, characterized in that, The first cavity is annular and surrounded by a central cylinder (131) and an annular outer wall (132); the second end face (12) of the rotor body is integrally formed by injection molding with a plurality of blades (14), the plurality of blades are arranged around the rotation axis of the rotor body, and the inner edges of the plurality of blades surround a central cavity (140).

4. The method of manufacturing a magnetic levitation 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, the gate is removed by machining after injection molding and forms a material containing cavity (1311), or the gate is located in the material containing cavity after the material containing cavity is formed on the central cylinder.

5. The method of manufacturing a magnetic levitation rotor impeller according to claim 1 or 2, characterized in that, The first cavity is annular and surrounded by a central cylinder (131) and an annular outer wall (132); the other side of the first cover plate is integrally formed by injection molding with a plurality of blades (14), the plurality of blades are arranged around the rotation axis of the rotor body, and the inner edges of the plurality of blades surround a central cavity (140).

6. The method of manufacturing a magnetic levitation 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 side of the first cover plate, the gate is removed by machining after injection molding, and the central cylinder and the corresponding position of the gate form a material containing cavity (1311).

7. The method of manufacturing a magnetic levitation rotor impeller according to any one of claims 3-6, characterized in that, At least one of the plurality of blades is formed with an exhaust hole (15) which communicates with the first cavity.

8. The method of manufacturing a magnetic levitation rotor impeller according to claim 7, characterized in that The blade comprises a first flow guide part (142), a second flow guide part (143) and a third flow guide part (144) which surround a containing space (141), the first flow guide part of one blade is arranged opposite to the second flow guide part of an adjacent blade and surrounds a liquid flow channel (145).

9. The magnetic levitation rotor impeller of claim 8, wherein, At least two protruding columns (146) are formed in the containing space, and the center of at least one of the protruding columns forms the exhaust hole.

10. The method of manufacturing a magnetic levitation rotor impeller according to claim 3 or 4, characterized in that, A plurality of first through holes (16) are integrally formed on the center cylinder by injection molding, the first through holes penetrating the first end face and the second end face of the rotor body, the plurality of first through holes being arrayed around the rotation axis of the rotor body and 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 machined on the first cover plate.

11. The method of manufacturing a magnetic levitation rotor impeller according to claim 3 or 4, characterized in that, A third through hole is also integrally formed on the center cylinder by injection molding, the third through hole penetrating the second end face and the first end face of the rotor body and located in the central cavity, the rotation axis of the rotor body passing 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 machined on the first cover plate.

12. The method of manufacturing a magnetic levitation rotor impeller according to any one of claims 2-11, characterized in that, The magnetic body is configured as a ring-shaped permanent magnet, a positioning pin (133) is integrally formed at the bottom of the first cavity by injection molding, and a positioning hole (21) corresponding to the positioning pin is formed on the ring-shaped permanent magnet.

13. The method of manufacturing a magnetic levitation rotor impeller according to claim 12, characterized in that One side of the first cover plate is formed with a second annular positioning face or a plurality of second arc-shaped positioning faces (32) protruding towards the ring-shaped permanent magnet, the radial dimension of the second annular positioning face or the second arc-shaped positioning face being smaller than the radial dimension of the first cavity.

14. The method of manufacturing a magnetic levitation rotor impeller according to claim 3 or 4, characterized in that, The method further comprises the step of welding a second cover plate (4) before or after welding the first cover plate, which is as follows: one side of the second cover plate is first fused and then extrusion welded to the top of the blades, so that the second cover plate closes the top of the liquid flow channel between adjacent two blades; the second cover plate and the blades are provided with a second fusion allowance before welding.

15. The method of manufacturing a magnetic levitation rotor impeller according to claim 14, characterized in that 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 dimensions within an error range, and a liquid inlet (41) is formed in the middle of the second cover plate.

16. The method of manufacturing a magnetic levitation rotor impeller according to claim 14 or 15, characterized in that The welding is infrared welding, and the second fusion allowance includes a second radial fusion allowance and a second axial fusion allowance, the range of the second radial fusion allowance being 2mm-10mm, and the range of the second axial fusion allowance being 0.5mm-5mm.

17. The method of claim 14-16, wherein the method further comprises: The first cover plate and / or the second cover plate are integrally formed by injection molding as injection molded parts, the injection molded part comprising a cover plate body (90), an annular side wall (91) formed on one side of the cover plate body, and a plurality of radial strips (92) extending radially outward from a center column (93) and connected to the annular side wall; the annular side wall and the radial strips are removed by machining after the cover plate body is welded.

18. The method of manufacturing a magnetic levitation rotor impeller according to claim 3 or 4, characterized in that, The method further comprises the step of welding a partition plate (5), which is as follows: one side of the partition plate is welded to the inner side of the blades and / or the center convex column (147) on the first end face by contact type hot melt welding, so that the partition plate is spaced apart from the first end face by a first distance.

19. The method of manufacturing a magnetic levitation rotor impeller according to any one of claims 1-18, wherein, The method further comprises the step of welding the vanes and the rotor body by providing a vane plate (14') having a periphery with a plurality of vanes (14) integrally formed by machining or injection molding, the plurality of vanes being welded to the second end face of the rotor body, the plurality of vanes being arranged in an array about the axis of rotation of the rotor body, and the inner edges of the plurality of vanes bounding a central cavity (140).

20. A magnetic levitation rotor impeller characterized by, A magnetic levitation rotor impeller manufactured by the method of any one of claims 1-19.

21. A magnetic levitation pump characterized by, A magnetic levitation rotor impeller comprising the rotor impeller of claim 20.

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