Metallic shield for canned pump

Abstract

The application provides a metal shielding sleeve for a canned pump, and belongs to the technical field of pumps.It solves the problems of high leakage risk and great processing difficulty of the existing welding structure of the shielding sleeve.The metal shielding sleeve for the canned pump comprises an inner support made of metal and an integrally formed rotor shielding cover, and the inner support and the rotor shielding cover enclose a rotor cavity.The rotor shielding cover comprises a first transverse circular ring part, a first vertical circular ring part and a second transverse circular ring part which are connected smoothly, the first transverse circular ring part abuts against the outer circumferential surface of the inner support, the first fixed part at the upper end of the inner support is fixed to the first transverse circular ring part through elastic sealing, and the second transverse circular ring part is fixed to the lower end of the inner support through welding.The application reduces the welding seam through the integrally formed structure, combines the upper end elastic sealing and the lower end welding, cooperates with multiple elastic sealing elements, effectively compensates for the welding deviation and uneven stress, significantly improves the sealing reliability, and ensures the stability of the electromagnetic performance and the manufacturing yield.

Description

Technical Field

[0001] This invention relates to the field of pump technology, specifically to a metal shielding sleeve for a canned pump. Background Technology

[0002] A canned motor pump is a seal-free pump that integrates the motor and pump body into one unit. The motor rotor and stator are isolated from the pumped medium by a shielding sleeve, thus achieving leak-free operation. In applications where corrosion resistance requirements are low, such as pumping clean water or sewage, the shielding sleeve is typically made of metal to ensure sufficient mechanical strength and corrosion resistance.

[0003] In existing technologies, such as the metal magnetic pump disclosed in Chinese Patent CN104235051A, the isolation sleeve is made of metal, and the inner magnetic rotor uses a structure in which a high-strength permanent magnet is embedded in the metal. This type of metal shielding sleeve or isolation sleeve typically adopts a cylindrical structure and is assembled and connected to related components through an embedded method. However, metal materials themselves are characterized by high hardness and difficulty in processing. The cylindrical embedded structure requires high dimensional accuracy and assembly technology during manufacturing, and is prone to deterioration of sealing performance due to processing errors or improper assembly, thus creating a risk of leakage. Furthermore, the embedded structure may experience loosening or seal failure due to factors such as temperature changes, pressure fluctuations, and vibration during long-term operation, affecting the pump's operational reliability and service life.

[0004] To address the aforementioned issues, existing technologies have improved the connection structure. For example, Chinese patent CN221009869U discloses a metal elastic expansion coupling sleeve for a shielded water pump motor rotor. This sleeve employs a straight tubular structure with a straight generatrix, and the outlines of the outer and inner walls are wavy lines connecting end to end, forming several axially convex and inner convex ridges. Elastic deformation enables the expansion connection between the ceramic shaft and the metal sealing sleeve. This structure improves coaxiality and assembly reliability to some extent. However, the metal sealing sleeve in this patent uses a split structure consisting of an inner sleeve, a cylindrical outer sleeve, and two annular end caps, which are welded together to achieve a seal. This welded structure has the following drawbacks: First, it involves numerous welds, requiring four annular welds, each a potential leakage channel, demanding extremely high welding precision; any minute defect can lead to media infiltration. Second, heat input during welding of thin-walled metal parts easily causes localized deformation, resulting in decreased coaxiality between the inner and outer sleeves and out-of-tolerance roundness of the central through hole, affecting subsequent assembly accuracy and rotor dynamic balance.

[0005] Therefore, it is necessary to further improve the shielding sleeve structure of existing canned pumps to overcome the defects of high leakage risk, high processing difficulty and insufficient reliability caused by welded structures, and to provide a metal shielding sleeve structure with higher sealing reliability and simpler manufacturing process. Summary of the Invention

[0006] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a metal shielding sleeve for a shielded pump.

[0007] The objective of this invention can be achieved through the following technical solution: a metal shielding sleeve for a shielded pump, comprising an inner support and a rotor shielding cover made of metal, wherein the inner support and the rotor shielding cover together enclose a rotor cavity; the rotor shielding cover is an integrally formed structure, including a first transverse annular portion, a first vertical annular portion, and a second transverse annular portion, wherein the two ends of the first vertical annular portion are smoothly connected to the first transverse annular portion and the second transverse annular portion, respectively; the inner circumferential surface of the first transverse annular portion abuts against the outer circumferential surface of the inner support; a first fixing portion is provided radially outwardly at the upper end of the inner support, the lower end surface of the first fixing portion abuts against the upper end surface of the first transverse annular portion and is fixed by elastic sealing; the upper end surface of the second transverse annular portion abuts against the lower end surface of the inner support and is fixed by welding. The rotor shielding cover is formed by stretching the first transverse annular portion, the first vertical annular portion, and the second transverse annular portion.

[0008] This solution achieves synergistic optimization of sealing and connection through a combination of axial elastic sealing at the upper end and welding at the lower end. The axial elastic sealing at the upper end actively absorbs axial dimensional deviations caused by thermal deformation, assembly errors, or structural asymmetry during the welding process at the lower end, while providing uniform preload to the lower weld. This effectively alleviates localized stress concentration or uneven stress distribution that may result from welding, reducing the risk of leakage. The welding at the lower end applies clamping force only along the axial direction and does not interfere with the radial fit between the inner support and the rotor shield, thus not affecting the radial air gap uniformity or electromagnetic performance between the rotor and stator assembly. The axial elastic sealing at the upper end is primarily responsible for maintaining the sealing contact pressure under dynamic operating conditions, complementing the welding at the lower end. Overall, this structure ensures sealing reliability while maintaining electromagnetic performance stability, reduces stringent requirements for welding process precision, and improves product manufacturing yield and long-term operational reliability.

[0009] Furthermore, the first vertical ring portion is perpendicular to both the first horizontal ring portion and the second horizontal ring portion.

[0010] Furthermore, the lower end face of the first fixing part abuts against the upper end face of the first transverse annular part, and the end of the first fixing part facing the first transverse annular part is recessed inward to form a first sealing groove. The inner sidewall of the first sealing groove is formed by the outer peripheral surface of the inner bracket. A first sealing element is fixedly provided between the first sealing groove and the first transverse annular part to achieve elastic sealing and fixing.

[0011] This solution achieves axial elastic sealing by setting a first sealing groove and a first sealing element between the first fixed part and the first transverse annular part. This effectively compensates for the axial dimensional deviation and uneven force caused by the welding and fixing at the lower end. At the same time, during the axial elastic compression process, the first sealing element expands radially due to the compression and fits tightly with the outer peripheral surface of the inner support and the side wall of the first sealing groove, thereby forming a reliable radial seal simultaneously and preventing the medium from seeping into the rotor cavity along the axial gap.

[0012] Furthermore, a rotor steel sleeve is fixedly installed inside the rotor cavity. The upper end face of the rotor steel sleeve abuts against the lower end face of the first transverse annular portion, and the lower end face of the rotor steel sleeve abuts against the upper end face of the second transverse annular portion. The inner circumferential surface of the rotor steel sleeve abuts against the inner support. A rotor groove is provided on the side of the rotor steel sleeve near the first vertical annular portion. A rotor magnet is fixedly installed between the rotor groove and the first vertical annular portion. The upper and lower end faces of the rotor steel sleeve abut against the lower end face of the first transverse annular portion and the upper end face of the second transverse annular portion, respectively, and the inner circumferential surface abuts against the inner support. This achieves bidirectional positioning of the rotor steel sleeve in both the axial and radial directions, ensuring a uniform gap between the rotor magnet and the first vertical annular portion. Moreover, the rigid support of the rotor steel sleeve is independent of the first sealing element at the upper end, so that the compression of the first sealing element is not affected by the positioning accuracy of the rotor steel sleeve. This maintains effective axial elastic compensation capability and ensures stable operation of the rotor assembly and consistency of electromagnetic performance.

[0013] Furthermore, a second sealing groove is formed in the recess at one end of the rotor steel sleeve near the first transverse annular portion. The second sealing groove and the outer peripheral surface of the inner support form a concave groove with one end open. A second sealing element is fixedly provided between the second sealing groove and the first transverse annular portion to achieve elastic sealing and fixation.

[0014] This design incorporates a second sealing groove at one end of the rotor steel sleeve near the first transverse annulus, forming a concave groove with one open end together with the outer circumferential surface of the inner support. A second sealing element is fixedly installed between the second sealing groove and the first transverse annulus. When the upper axial elastic seal is compressed, the second sealing element undergoes elastic deformation under axial compression. On one hand, it maintains a continuous elastic preload in the axial direction, effectively compensating for axial dimensional deviations and stress unevenness caused by the lower end welding fixation, thus preventing seal failure due to rigid contact. On the other hand, during axial compression, the second sealing element expands radially and towards the opening of the concave groove, tightly fitting against the outer circumferential surface of the inner support, thereby achieving a reliable radial seal and preventing the medium from seeping into the rotor cavity along the gap between the rotor steel sleeve and the inner support. This second sealing element, in conjunction with the first sealing element, forms a double elastic sealing barrier, enhancing the overall sealing reliability while maintaining axial elastic compensation capability, and without affecting the radial electromagnetic air gap between the rotor and stator assembly. Overall, this structure achieves both radial and axial elastic sealing functions, further improving the long-term operational stability of the shielding sleeve.

[0015] Furthermore, it also includes a stator shield, a pump shaft, and a pump housing. The stator shield is made of metal and is sealed and fixed to the pump shaft and pump housing respectively by a first sealing gasket and a second sealing gasket.

[0016] Furthermore, the stator shield is integrally formed with a first sealing part, a recessed cavity, and a second sealing part. The rotor shield is located inside the recessed cavity. The first sealing gasket is fixed between the first sealing part and the pump housing, and the second sealing gasket is fixed between the second sealing part and the pump shaft.

[0017] Furthermore, a housing is provided outside the stator shield, and a stator assembly is fixedly disposed between the housing and the stator shield. The stator assembly has a primary stator step surface and a secondary stator step surface at one end near the first sealing part. The height of the secondary stator step surface is higher than that of the primary stator step surface. The first sealing part includes a first sealing step part, a second sealing step part, and a third sealing step part that rise sequentially from the outside to the inside. The third sealing step part is the highest and is smoothly connected to the upper end of the cavity. The second sealing step part abuts against the secondary stator step surface, and there is a gap between the third sealing step part and the secondary stator step surface. The pump housing has a first pump housing step surface and a second pump housing step surface at one end near the first sealing part. The first sealing step part is pressed against and pressed between the first pump housing step surface and the primary stator step surface. The first sealing gasket is fixed between the second pump housing step surface and the second sealing step part. The second pump housing step surface also abuts against the third sealing step part.

[0018] This design utilizes an integrally molded stator shield, with its stepped first sealing part, recessed cavity, and second sealing part forming a multi-stage stepped surface mating structure with the pump casing, pump shaft, and stator assembly, respectively. Specifically, the first sealing gasket is fixed between the second pump casing stepped surface and the second sealing stepped part, while the second sealing gasket is fixed between the second sealing part and the pump shaft, achieving a double elastic seal between the stator shield and the pump casing and shaft, effectively preventing media leakage along the pump shaft and pump casing mating surface. Simultaneously, the first sealing stepped part is pressed between the first pump casing stepped surface and the first-stage stator stepped surface, the second sealing stepped part abuts against the second-stage stator stepped surface, and a pre-existing gap is left between the third sealing stepped part and the second-stage stator stepped surface, with the second pump casing stepped surface abutting against the third sealing stepped part. This multi-stage stepped surface mating design ensures controllable axial compression of the sealing gasket, avoids over-positioning, and achieves precise radial and axial positioning of the stator shield with the pump casing and stator assembly. The rotor shield is located within the recessed cavity and is concentric with the stator shield, ensuring uniform air gap between the rotor assembly and the stator assembly. Overall, this structure simplifies the assembly process while significantly improving sealing reliability and electromagnetic performance stability.

[0019] Furthermore, a ceramic shaft is fixedly connected to the outer periphery of the pump shaft, a bushing is slidably connected to the outer periphery of the ceramic shaft, the bushing is fixed inside the inner bracket, the second sealing gasket is axially fixed between the second sealing part and the ceramic shaft, and the second sealing gasket radially abuts against the outer periphery of the pump shaft.

[0020] Furthermore, a first bearing and a second bearing are fixedly connected to the outer periphery of the pump shaft. The outer peripheries of the first bearing and the second bearing are fixedly connected to the inner support. A pressure plate is abutted against the lower part of the second bearing. The second sealing gasket is axially fixed between the second sealing part and the pressure plate. The second sealing gasket abuts radially against the outer periphery of the pump shaft.

[0021] Compared with existing technologies, the technical advantages of this invention are as follows: 1. By designing the rotor shield as an integrally formed structure with a smooth connection between the first transverse ring, the first vertical ring, and the second transverse ring, the number of welds is significantly reduced, fundamentally lowering the risk of leakage caused by welding defects. Simultaneously, the upper end employs a combination of axial elastic sealing and lower end welding fixation. The axial elastic sealing compensates for dimensional deviations and stress unevenness caused by welding, and the first sealing element expands radially during axial compression to form a radial seal. A second sealing element is added at the rotor steel sleeve, forming a double elastic sealing barrier with the first sealing element, further preventing media from seeping into the rotor cavity. The stator shield adopts an integrally formed stepped structure, and achieves multiple elastic seals with the pump casing and pump shaft through the first and second sealing gaskets, forming a full-path sealing protection, significantly improving the sealing reliability of the canned pump during long-term operation. 2. The lower end welding fixation only applies clamping force along the axial direction, without interfering with the radial fit between the inner support and the rotor shield, thus not affecting the uniformity of the radial air gap between the rotor and stator assembly. The upper and lower end faces of the rotor steel sleeve abut against the lower end face of the first transverse ring and the upper end face of the second transverse ring, respectively, while the inner circumferential surface abuts against the inner support, achieving bidirectional axial and radial positioning and ensuring uniform gap between the rotor magnet and the first vertical ring. The concave cavity of the stator shield is concentric with the rotor shield, and the multi-stage stepped surface ensures precise alignment between the stator assembly and the pump casing, thereby guaranteeing the stability of the motor's electromagnetic performance and the smoothness of rotor operation, reducing vibration and noise. Thirdly, the axial elastic seals of the first and second sealing components at the upper end actively absorb the axial dimensional tolerances and thermal deformation deviations caused by the welding and fixing at the lower end, reducing the stringent requirements for welding process precision and improving product manufacturing yield. Attached Figure Description

[0022] Figure 1 This is a cross-sectional view of the entire invention. Figure 1 .

[0023] Figure 2 This is an overall cross-sectional view of the inner support and rotor shield of the present invention after assembly.

[0024] Figure 3 This is an enlarged view of point A in the present invention.

[0025] Figure 4 This is a perspective view of the stator shield of the present invention.

[0026] Figure 5 This is a cross-sectional view of the entire invention. Figure 2 .

[0027] Figure 6 This is a perspective view of another stator shield structure of the present invention.

[0028] Figure number markings: 1. Inner support; 11. First fixing part; 111. First sealing groove; 2. Rotor shield; 21. First transverse annular part; 22. First vertical annular part; 23. Second transverse annular part; 31. First sealing element; 32. Second sealing element; 33. First sealing gasket; 34. Second sealing gasket; 4. Rotor steel sleeve; 41. Rotor groove; 42. Second sealing groove; 5. Rotor magnet; 6. Stator shield; 61. First sealing part; 611. First sealing 612. Second sealing step; 613. Third sealing step; 62. Cavity; 63. Second sealing part; 7. Pump shaft; 71. Ceramic shaft; 72. Shaft sleeve; 73. First bearing; 74. Second bearing; 75. Pressure plate; 8. Housing; 9. Pump housing; 91. First pump housing step surface; 92. Second pump housing step surface; 10. Rotor cavity; 100. Stator assembly; 101. First-stage stator step surface; 102. Second-stage stator step surface; 200. Impeller. Detailed Implementation

[0029] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0030] It should be noted that the descriptions of directions such as "upper," "lower," "left," "right," "top," and "bottom" in this invention are defined based on the orientation or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, not to indicate or imply that the device must be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Figures 1 to 5 As shown in the figure, this embodiment provides a metal shielding sleeve for a shielded pump, including an inner support 1 and a rotor shielding cover 2. Both the inner support 1 and the rotor shielding cover 2 are made of metal, preferably a non-magnetic metal, such as stainless steel, non-magnetic steel, or alloy. The inner support 1 and the rotor shielding cover 2 together form a rotor cavity 10. The rotor shielding cover 2 is an integrally formed structure, manufactured by a stretch forming process, including a first transverse annular portion 21, a first vertical annular portion 22, and a second transverse annular portion 23. The two ends of the first vertical annular portion 22 are smoothly connected to the first transverse annular portion 21 and the second transverse annular portion 23, respectively. Preferably, the first vertical annular portion 22 is perpendicular to the first transverse annular portion 21 and the second transverse annular portion 23, forming an approximately "U"-shaped cross-sectional profile.

[0031] The inner support 1 is generally a hollow cylindrical structure, with its outer circumferential surface abutting against the inner circumferential surface of the first transverse annular portion 21. A first fixing portion 11 protrudes radially outward from the upper end of the inner support 1, and an impeller 200 is threadedly connected to the upper end of the first fixing portion 11. The lower end surface of the first fixing portion 11 abuts against the upper end surface of the first transverse annular portion 21 and is fixed by an elastic seal. The upper end surface of the second transverse annular portion 23 abuts against the lower end surface of the inner support 1 and is fixed by welding. The welding point is at the annular gap where the second transverse annular portion 23 and the lower end surface of the inner support 1 abut. Thus, the upper end of the rotor shield 2 is connected to the inner support 1 by an elastic seal, and the lower end is fixed to the inner support 1 by welding, forming a hybrid connection structure with one end being elastic and the other rigid.

[0032] To achieve elastic sealing, the first fixing part 11 is recessed inward at one end facing the first transverse annular part 21 to form a first sealing groove 111. The inner sidewall of the first sealing groove 111 is formed by the outer peripheral surface of the inner bracket 1. A first sealing element 31 is fixedly disposed between the first sealing groove 111 and the first transverse annular part 21. The first sealing element 31 is preferably an O-ring or a rectangular cross-section elastic sealing ring, made of rubber or fluororubber material resistant to media corrosion. When the first fixing part 11 and the first transverse annular part 21 are axially pressed together, the first sealing element 31 is axially compressed, generating an axial elastic preload to compensate for possible axial dimensional deviations caused by welding at the lower end. On the other hand, it expands radially due to pressure, tightly fitting against the outer peripheral surface of the inner bracket 1 and the sidewall of the first sealing groove 111 to form a radial seal.

[0033] A rotor sleeve 4 is also fixedly installed inside the rotor cavity 10. The upper end face of the rotor sleeve 4 abuts against the lower end face of the first transverse annular portion 21, the lower end face of the rotor sleeve 4 abuts against the upper end face of the second transverse annular portion 23, and the inner circumferential surface of the rotor sleeve 4 abuts against the outer circumferential surface of the inner support 1, thereby achieving bidirectional positioning of the rotor sleeve 4 in both the axial and radial directions. The inner support 1 has several weight-reducing grooves formed by an inward recess on the side near the rotor sleeve 4. A rotor groove 41 is provided on the side of the rotor sleeve 4 near the first vertical annular portion 22, and a rotor magnet 5 is fixedly installed between the rotor groove 41 and the first vertical annular portion 22. The rotor magnet 5 is preferably a permanent magnet, which is fixed in the rotor groove 41 by bonding or pressing.

[0034] To further improve sealing performance, a second sealing groove 42 is recessed at one end of the rotor steel sleeve 4 near the first transverse annular portion 21. The second sealing groove 42 and the outer peripheral surface of the inner support 1 together form a concave groove with one open end. A second sealing element 32 is fixedly disposed between the second sealing groove 42 and the first transverse annular portion 21. The second sealing element 32 is preferably an O-ring or a rectangular cross-section elastic sealing ring. When the first fixing part 11 is axially pressed against the first transverse annular portion 21, the second sealing element 32 is subjected to axial compression. On the one hand, it maintains a continuous elastic preload in the axial direction; on the other hand, it expands in the direction of the opening of the concave groove and radially during the compression process, tightly fitting against the outer peripheral surface of the inner support 1 to form a reliable radial seal. The first sealing element 31 and the second sealing element 32 work together to form a double elastic sealing barrier.

[0035] This embodiment also includes a stator shield 6, a pump shaft 7, and a pump housing 9. The stator shield 6 is made of metal, preferably a non-magnetic metal, such as stainless steel, non-magnetic steel, or an alloy. The stator shield 6 is preferably integrally formed by stretching or stamping. The structure of the stator shield 6 includes a first sealing part 61, a recessed cavity 62, and a second sealing part 63. Depending on the operating conditions, the bottom of the recessed cavity 62 and the second sealing part 63 can be made as one, that is, the bottom of the recessed cavity 62 is the second sealing part 63. The rotor shield 2 is located inside the recessed cavity 62 and is concentric with the stator shield 6. The stator shield 6 is sealed and fixed to the pump shaft 7 and the pump housing 9 by a first sealing gasket 33 and a second sealing gasket 34, respectively. Specifically, the first sealing gasket 33 is fixed between the first sealing part 61 and the pump housing 9, and the second sealing gasket 34 is fixed between the second sealing part 63 and the pump shaft 7.

[0036] A housing 8 is disposed outside the stator shield 6, and a stator assembly 100 is fixedly disposed between the housing 8 and the stator shield 6. The stator assembly 100 has a primary stator step surface 101 and a secondary stator step surface 102 at the end near the first sealing part 61, with the height of the secondary stator step surface 102 being higher than that of the primary stator step surface 101. The first sealing part 61 includes a first sealing step part 611, a second sealing step part 612, and a third sealing step part 613 that rise sequentially from the outside to the inside, with the third sealing step part 613 being the highest and smoothly connected to the upper end of the cavity part 62. The second sealing step part 612 abuts against the secondary stator step surface 102, and a gap exists between the third sealing step part 613 and the secondary stator step surface 102. A pump housing 9 has a first pump housing step surface 91 and a second pump housing step surface 92 at the end near the first sealing part 61. The first sealing step 611 is pressed against and squeezed between the first pump housing step surface 91 and the first stator step surface 101. The first sealing gasket 33 is fixed between the second pump housing step surface 92 and the second sealing step 612. The second pump housing step surface 92 also abuts against the third sealing step 613. Through the above-mentioned multi-stage step surface cooperation, the stator shield 6 is accurately positioned axially and radially with the pump housing 9 and the stator assembly 100, while ensuring that the compression of the first sealing gasket 33 is controllable.

[0037] Two preferred support structures can be used between the pump shaft 7 and the inner support 1. First, a ceramic shaft 71 is fixedly connected to the outer periphery of the pump shaft 7, and a bushing 72 is slidably connected to the outer periphery of the ceramic shaft 71. The bushing 72 is fixed inside the inner support 1, and a second sealing gasket 34 is axially fixed between the second sealing part 63 and the ceramic shaft 71, with the second sealing gasket 34 radially abutting against the outer periphery of the pump shaft 7. Second, a first bearing 73 and a second bearing 74 are fixedly connected to the outer periphery of the pump shaft 7. The outer peripheries of the first bearing 73 and the second bearing 74 are fixedly connected to the inner support 1. A pressure plate 75 is abutting against the lower part of the second bearing 74, and the second sealing gasket 34 is axially fixed between the second sealing part 63 and the pressure plate 75, with the second sealing gasket 34 radially abutting against the outer periphery of the pump shaft 7.

[0038] During assembly, the rotor magnet 5 is first placed in the rotor slot 41. The rotor sleeve 4 and rotor magnet 5 are then assembled into the rotor shield 2 to form a whole. The rotor shield 2 can be pre-formed and then assembled with the rotor sleeve 4, or it can be directly formed using the rotor sleeve 4 as a positioning fixture. After assembly, the upper and lower end faces of the rotor sleeve 4 abut against the lower end face of the first transverse ring portion 21 and the upper end face of the second transverse ring portion 23, respectively. Then, the inner bracket 1 is inserted from the upper end of the rotor shield 2, so that the inner circumferential surface of the first transverse ring portion 21 abuts against the outer circumferential surface of the inner bracket 1, and the upper end face of the second transverse ring portion 23 abuts against the lower end face of the inner bracket 1, and is welded and fixed at this point. Before the inner bracket 1 is inserted, the first sealing element 31 and the second sealing element 32 are placed in the first sealing groove 111 and the second sealing groove 42, respectively, so that the first sealing element 31 and the second sealing element 32 undergo axial compression and radial expansion, completing the elastic sealing fixation at the upper end. Subsequently, the stator shield 6 is fitted over the rotor shield 2, with its recessed portion 62 concentric with the rotor shield 2. Sealing and positioning with the pump housing 9 and pump shaft 7 are achieved through the mating of the first sealing gasket 33, the second sealing gasket 34, and the multi-stage stepped surface. Finally, depending on the selected bearing structure, the ceramic shaft 71 and bushing 72 are installed, or the first bearing 73, the second bearing 74, and the pressure plate 75 are installed to complete the overall assembly.

[0039] This embodiment achieves the following technical effects through the above structure: First, the rotor shield 2 is integrally formed, which greatly reduces the number of welds. Combined with the hybrid connection of the upper double elastic seal and the lower weld, it forms a full-path sealing protection, which significantly improves the sealing reliability. Second, the lower weld only applies axial force and does not interfere with the radial air gap. Combined with the bidirectional positioning of the rotor steel sleeve 4 and the concentric cavity design of the stator shield 6, it ensures the stability of electromagnetic performance and the smooth operation of the rotor. Third, the upper axial elastic seal can absorb the tolerance and thermal deformation of the lower weld, reduce the welding process requirements, and improve the manufacturing yield and assembly fault tolerance.

[0040] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications, equivalent variations, and alterations made based on the technical solution of the present invention shall fall within the protection scope of the present invention.

Claims

1. A metal shield sleeve for a canned pump, characterized by: An inner support (1) and a rotor shield (2) made of metal are provided together to form a rotor cavity (10). The rotor shield (2) is an integrally formed structure, including a first transverse ring (21), a first vertical ring (22), and a second transverse ring (23). The two ends of the first vertical ring (22) are smoothly connected to the first transverse ring (21) and the second transverse ring (23), respectively. The inner circumferential surface of the first transverse ring (21) abuts against the outer circumferential surface of the inner support (1). The upper end of the inner support (1) is provided with a first fixing part (11) that protrudes radially outward. The lower end surface of the first fixing part (11) abuts against the upper end surface of the first transverse ring (21) and is fixed by elastic sealing. The upper end face of the second transverse annular portion (23) abuts against the lower end face of the inner support (1) and is fixed by welding; the welding point is the annular gap after the second transverse annular portion (23) abuts against the lower end face of the inner support (1); the welding fixation only applies clamping force along the axial direction and does not interfere with the radial fit between the inner support and the rotor shield. The lower end face of the first fixing part (11) abuts against the upper end face of the first transverse ring part (21). The first fixing part (11) is recessed inward at one end facing the first transverse ring part (21) to form a first sealing groove (111). The inner sidewall of the first sealing groove (111) is formed by the outer peripheral surface of the inner bracket (1). A first sealing member (31) is fixedly provided between the first sealing groove (111) and the first transverse ring part (21) to achieve elastic sealing and fixing. The first seal (31) can generate radial expansion when the first fixing part (11) and the first transverse annular part are axially pressed together to compensate for the axial dimension deviation caused by welding.

2. The metal shield sleeve for a canned pump according to claim 1, characterized by: The first vertical ring portion (22) is perpendicular to the first horizontal ring portion (21) and the second horizontal ring portion (23), respectively.

3. The metal shielding sleeve for a shielded pump according to claim 2, characterized in that: A rotor steel sleeve (4) is fixedly installed inside the rotor cavity (10). The upper end face of the rotor steel sleeve (4) abuts against the lower end face of the first transverse ring (21). The lower end face of the rotor steel sleeve (4) abuts against the upper end face of the second transverse ring (23). The inner circumferential surface of the rotor steel sleeve (4) abuts against the inner support (1). A rotor groove (41) is provided on the side of the rotor steel sleeve (4) near the first vertical ring (22). A rotor magnet (5) is fixedly installed between the rotor groove (41) and the first vertical ring (22).

4. The metal shielding sleeve for a shielded pump according to claim 3, characterized in that: The rotor steel sleeve (4) has a second sealing groove (42) recessed at one end near the first transverse annular portion (21). The second sealing groove (42) and the outer peripheral surface of the inner support (1) form a concave groove with one end open. A second sealing element (32) is fixedly provided between the second sealing groove (42) and the first transverse annular portion (21) to achieve elastic sealing and fixation.

5. A metal shielding sleeve for a shielded pump according to any one of claims 1 to 4, characterized in that: It also includes a stator shield (6), a pump shaft (7) and a pump housing (9). The stator shield (6) is made of metal and is sealed and fixed to the pump shaft (7) and the pump housing (9) by a first sealing gasket (33) and a second sealing gasket (34), respectively.

6. A metal shielding sleeve for a shielded pump according to claim 5, characterized in that: The stator shield (6) is integrally formed with a first sealing part (61), a cavity part (62) and a second sealing part (63). The rotor shield (2) is located in the cavity part (62). The first sealing gasket (33) is fixed between the first sealing part (61) and the pump housing (9). The second sealing gasket (34) is fixed between the second sealing part (63) and the pump shaft (7).

7. A metal shielding sleeve for a shielded pump according to claim 6, characterized in that: An outer casing (8) is provided outside the stator shield (6). A stator assembly (100) is fixedly disposed between the casing (8) and the stator shield (6). The stator assembly (100) has a primary stator step surface (101) and a secondary stator step surface (102) at one end near the first sealing part (61). The height of the secondary stator step surface (102) is higher than the height of the primary stator step surface (101). The first sealing part (61) includes a first sealing step part (611), a second sealing step part (612), and a third sealing step part (613) that rise sequentially from the outside to the inside. The third sealing step part (613) is the highest and is smoothly connected to the upper end of the cavity part (62). The second sealing step (612) abuts against the secondary stator step surface (102), and the third sealing step (613) has a gap with the secondary stator step surface (102). The pump housing (9) is provided with a first pump housing step surface (91) and a second pump housing step surface (92) at one end near the first sealing part (61). The first sealing step (611) is pressed against and squeezed between the first pump housing step surface (91) and the primary stator step surface (101). The first sealing gasket (33) is fixed between the second pump housing step surface (92) and the second sealing step (612). The second pump housing step surface (92) also abuts against the third sealing step (613).

8. A metal shielding sleeve for a shielded pump according to claim 7, characterized in that: The pump shaft (7) is fixedly connected to the ceramic shaft (71) on its outer periphery, and the ceramic shaft (71) is slidably connected to the bushing (72) on its outer periphery. The bushing (72) is fixed inside the inner bracket (1). The second sealing gasket (34) is axially fixed between the second sealing part (63) and the ceramic shaft (71). The second sealing gasket (34) is radially abutted against the outer periphery of the pump shaft (7).

9. A metal shielding sleeve for a shielded pump according to claim 7, characterized in that: The pump shaft (7) is fixedly connected to a first bearing (73) and a second bearing (74) on its outer periphery. The outer periphery of the first bearing (73) and the second bearing (74) is fixedly connected to the inner bracket (1). A pressure plate (75) is abutted against the lower part of the second bearing (74). The second sealing gasket (34) is axially fixed between the second sealing part (63) and the pressure plate (75). The second sealing gasket (34) abuts radially against the outer periphery of the pump shaft (7).

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