Vacuum impregnation method for permanent magnet motor rotor

Abstract

The application discloses a vacuum paint dipping method for a permanent magnet motor rotor, which comprises the following steps: coating release agent on the outer surfaces of two shaft extensions of a rotor rotating shaft, the outer surface of an upper pressing plate and the outer surface of a lower pressing plate; installing protective sleeves on the upward shaft extensions of the rotating shaft; entering a vacuum tank for paint dipping; leaving the tank; first cleaning: removing the protective sleeves, cleaning the outer surfaces of the upward shaft extensions, the surface of the upper pressing plate and the root of a groove on the upper pressing plate, and the outer surface of the rotor iron core; drying; and second cleaning: cleaning the outer surfaces of the downward shaft extensions and the surface of the lower pressing plate. The application has the advantages of obviously shortening the paint dipping and cleaning operation time, improving the paint dipping and cleaning efficiency and cleaning quality.

Description

Technical Field

[0001] This invention relates to the field of vacuum impregnation of permanent magnet motor rotors, and more particularly to a method for vacuum impregnation of permanent magnet motor rotors. Background Technology

[0002] Permanent magnet rotors typically employ a vacuum vertical impregnation and vertical static baking method with the drive end facing upwards. Before impregnation, a masking agent is applied to the unimpregnated surface. After impregnation, the ventilation holes (holes penetrating the rotor) and the outer surface of the iron core are cleaned of any remaining paint. After baking and drying, the masking agent, paint film, and paint nodules on the rotor core surface, shaft extension surface, and upper and lower pressure plate surfaces are cleaned. The disadvantages of this method are: 1) Paint nodules or films frequently form on the shaft extension surface and unimpregnated surfaces (especially at the root of the groove on the upper pressure plate) due to incomplete masking, making cleaning difficult; 2) The boiling during vacuum impregnation causes paint to splash onto the drive end shaft extension surface and the top threaded hole, making cleaning difficult. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a vacuum impregnation method for permanent magnet motor rotors that significantly shortens the impregnation and cleaning operation time and improves the impregnation and cleaning efficiency and cleaning quality.

[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0005] A method for vacuum impregnation of a permanent magnet motor rotor includes the following steps:

[0006] S1. Apply release agent to the outer surfaces of the two shaft extensions of the rotor shaft, the outer surface of the upper pressure plate, and the outer surface of the lower pressure plate;

[0007] S2. Install a protective sleeve on the shaft extension facing upwards;

[0008] S3. Enter the vacuum tank for impregnation;

[0009] S4, Discharge from tank;

[0010] S5. First cleaning: Remove the protective sleeve, clean the outer surface of the upward-facing shaft extension, clean the surface of the upper pressure plate and the root of the groove thereon, and clean the outer circular surface of the rotor core.

[0011] S6. Drying;

[0012] S7. Secondary cleaning: Clean the outer surface of the downward-facing shaft extension and the surface of the lower pressure plate.

[0013] As a further improvement to the above technical solution, after step S1 and before step S2, the rotor is pre-baked.

[0014] As a further improvement to the above technical solution, the protective sleeve is a polytetrafluoroethylene sleeve.

[0015] As a further improvement to the above technical solution, the top of the protective sleeve is provided with a hoisting hole for hoisting the rotor.

[0016] As a further improvement to the above technical solution, the outer circumference of the protective sleeve is provided with ventilation holes.

[0017] As a further improvement to the above technical solution, multiple vent holes are provided.

[0018] As a further improvement to the above technical solution, the inner diameter of the protective sleeve is larger than the outer diameter of the shaft extension, and the difference between the two is 1-2 mm.

[0019] As a further improvement to the above technical solution, in step S5, before cleaning, the residual paint in the ventilation holes and grooves is blown away with high-pressure air, and then all the residual paint on each surface is cleaned with a cleaning agent. Finally, the residual paint and residual cleaning agent on the outer surface of the iron core are wiped clean with a clean cloth.

[0020] As a further improvement to the above technical solution, in step S5, the time for one cleaning session does not exceed the set time for dripping paint.

[0021] As a further improvement to the above technical solution, there is a distance h between the lower end of the protective sleeve and the transmission end step on the shaft extension, where h > 0.

[0022] Compared with the prior art, the advantages of the present invention are as follows:

[0023] The vacuum impregnation method for permanent magnet motor rotors of this invention involves placing a protective sleeve on the upward-facing shaft extension of the rotor before impregnation. This sleeve protects the exposed outer surface of the shaft extension and the threaded hole at the shaft end, preventing impregnation paint from splashing onto these surfaces during vacuum splashing, thus reducing cleaning difficulties and time. This ultimately improves the efficiency of vacuum impregnation cleaning. Before drying after removal from the tank, a thorough cleaning of the upward-facing surface is performed simultaneously with paint dripping. Cleaning while the paint is still wet yields better results, significantly reducing the cleaning time of the paint film after baking and drying. This allows the rotor to basically meet production capacity requirements. Furthermore, since the paint film on the shaft extension is essentially cleaned after baking, the product qualification rate is greatly improved. Additionally, a release agent is applied to the unimpregnated surfaces before impregnation. After impregnation, the release agent forms a transparent protective film that does not require cleaning, further reducing cleaning workload and time. This invention significantly shortens the impregnation cleaning operation time, improves impregnation cleaning efficiency and quality, and thus meets production capacity requirements. Attached Figure Description

[0024] Figure 1 This is a schematic flowchart of the vacuum impregnation method for the permanent magnet motor rotor of the present invention.

[0025] Figure 2 This is a schematic diagram of the protective sleeve in this invention.

[0026] Figure 3 This is a schematic diagram of the cooperation between the protective sleeve and the rotating shaft extension in this invention.

[0027] Figure 4 This is a schematic diagram of the cleaning surface of the rotor after it has been immersed in paint and removed from the tank in this invention.

[0028] Figure 5 This is a shaft end view of the permanent magnet motor rotor in this invention.

[0029] The labels in the diagram represent:

[0030] 1. Shaft; 11. Shaft extension; 12. Transmission end step; 13. Shaft end threaded hole; 2. Upper pressure plate; 21. Groove; 3. Iron core; 4. Lower pressure plate; 5. Protective sleeve; 51. Lifting hole; 52. Ventilation hole; 6. Ventilation hole. Detailed Implementation

[0031] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] like Figures 1 to 5 As shown, the vacuum impregnation method for a permanent magnet motor rotor in this embodiment includes the following steps:

[0033] S1. Apply a release agent to the outer surfaces of the two shaft extensions 11 of the rotor shaft 1, the outer surface of the upper pressure plate 2, and the outer surface of the lower pressure plate 4.

[0034] S2. Install a protective sleeve 5 on the shaft extension 11 facing upwards from the shaft 1;

[0035] S3. Enter the vacuum tank for impregnation;

[0036] S4, Discharge from tank;

[0037] S5. First cleaning: Remove the protective sleeve 5, clean the outer surface of the upward-facing shaft extension 11, clean the surface of the upper pressure plate 2 and the root of the groove 21 thereon, and clean the outer circular surface of the rotor core 3.

[0038] S6. Drying;

[0039] S7. Secondary cleaning: Clean the outer surface of the downward-facing shaft extension 11 and the surface of the lower pressure plate 4.

[0040] All non-painted surfaces need to be coated with a release agent. After impregnation, the release agent forms a transparent protective film on the outer surface of the shaft extension 11, the outer surface of the upper pressure plate 2, and the outer surface of the lower pressure plate 4, which does not require cleaning.

[0041] The rotor shaft extension 11 is a non-painted surface. Paint cannot be applied to the upper end of the shaft extension 11, and paint application is difficult to clean and leaves marks. Therefore, in step S2, a protective sleeve is placed on the rotor shaft extension 11 facing upward before paint application to protect the exposed outer surface of the transmission end (upward) shaft extension 11 and the threaded hole 13 at the shaft end. This prevents the paint from splashing onto the outer surface of the transmission end shaft extension 11 and into the threaded hole 13 at the shaft end during vacuum splashing, which would cause cleaning difficulties. This reduces the cleaning difficulty and time of the surface of the transmission end shaft extension 11, and ultimately improves the efficiency of vacuum paint application cleaning.

[0042] Step S5 is a newly added cleaning step. After exiting the can, the rotor needs to be dripped with paint. At the same time as dripping paint, the surface facing upwards of the rotor is cleaned. Figure 4 The area indicated by the double-dotted line M is the cleaning surface for the first cleaning. A thorough cleaning is performed while the paint is still wet, which significantly reduces the time needed to clean the paint film after baking and drying. This allows the rotor to basically meet production capacity requirements, and since the drive shaft extension requires minimal paint film cleaning after baking, the product qualification rate is greatly improved. This thorough first cleaning reduces the workload of post-drying cleaning by two-thirds, shortening the second cleaning time to one-third of the original time, and the cleaning process is also simpler.

[0043] This invention can significantly shorten the time for impregnation and cleaning operations, improve the efficiency and quality of impregnation and cleaning, thereby meeting production capacity requirements.

[0044] It should be noted that in step S5, the cleaning time for one cleaning session shall not exceed the paint dripping time set.

[0045] In this embodiment, after step S1 and before step S2, the rotor is pre-baked. The purpose of pre-baking is to (1) remove moisture from the product and improve the quality of the impregnation; and (2) allow the release agent to dry and solidify to form a protective film.

[0046] In this embodiment, the protective sleeve 5 is made of polytetrafluoroethylene (PTFE), a material that is not paint-repellent and is easy to demold after impregnation and drying. The top of the protective sleeve 5 has a lifting hole 51 for hoisting the rotor, as hoisting the rotor is required both when entering and exiting the vacuum tank. A vent hole 52 is provided on the outer circumference of the protective sleeve 5. This hole can balance the pressure difference between the inside and outside of the cavity after the protective sleeve 5 is fitted onto the shaft extension 11 of the rotating shaft 1. Preferably, four vent holes 52 are provided.

[0047] In this embodiment, the inner diameter of the protective sleeve 5 is larger than the outer diameter of the shaft extension 11, with a difference of 1-2 mm, which facilitates disassembly and assembly. The lower end of the protective sleeve 5 has a distance h between it and the transmission end step 12 on the shaft extension 11, where h > 0.

[0048] In this embodiment, in step S5, before cleaning, high-pressure air is used to blow away the residual paint in the ventilation hole 6 and the groove 21. Then, a cleaning agent is used to clean the outer surface of the upward-facing shaft extension 11 (including the threaded hole 13 at the shaft end), the surface of the upper pressure plate 2, and the root of the groove 21 thereon. Finally, the residual paint and cleaning agent on the outer surface of the iron core 3 are wiped clean with a clean cloth. The ventilation hole 6 is a hole that passes through the upper pressure plate 2, the iron core 3, and the lower pressure plate 4.

[0049] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Any person skilled in the art can make many possible variations and modifications to the technical solutions of the present invention, or modify them into equivalent embodiments, without departing from the scope of the present invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention, without departing from the scope of the present invention, should fall within the protection scope of the present invention.

Claims

1. A method for vacuum impregnation of a permanent magnet motor rotor, characterized in that, Includes the following steps: S1. Apply release agent to the outer surfaces of the two shaft extensions (11) of the rotor shaft (1), the outer surface of the upper pressure plate (2), and the outer surface of the lower pressure plate (4); S2. Install a protective sleeve (5) on the shaft extension (11) facing upwards; the inner diameter of the protective sleeve (5) is larger than the outer diameter of the shaft extension (11), and the difference between the two is 1 to 2 mm; there is a distance h between the lower end of the protective sleeve (5) and the transmission end step (12) on the shaft extension (11), where h > 0; S3. Enter the vacuum tank for impregnation; S4, Discharge from tank; S5. First cleaning: Remove the protective sleeve (5), clean the outer surface of the upward-facing shaft extension (11), clean the surface of the upper pressure plate (2) and the root of the groove (21) thereon, and clean the outer surface of the rotor core (3); wherein the time for the first cleaning shall not exceed the paint dripping time. S6. Drying; S7. Secondary cleaning: Clean the outer surface of the downward-facing shaft extension (11) and the surface of the lower pressure plate (4).

2. The vacuum impregnation method for a permanent magnet motor rotor according to claim 1, characterized in that: After step S1 and before step S2, the rotor is pre-baked.

3. The vacuum impregnation method for a permanent magnet motor rotor according to claim 1, characterized in that: The protective sleeve (5) is a polytetrafluoroethylene sleeve.

4. The vacuum impregnation method for a permanent magnet motor rotor according to any one of claims 1 to 3, characterized in that: The top of the protective sleeve (5) is provided with a hoisting hole (51) for hoisting the rotor.

5. The vacuum impregnation method for a permanent magnet motor rotor according to any one of claims 1 to 3, characterized in that: The outer circumference of the protective sleeve (5) is provided with a vent (52).

6. The vacuum impregnation method for a permanent magnet motor rotor according to claim 5, characterized in that: Multiple vents (52) are provided.

7. The vacuum impregnation method for a permanent magnet motor rotor according to any one of claims 1 to 3, characterized in that: In step S5, before cleaning, use high-pressure air to blow away the residual paint in the ventilation holes (6) and grooves (21), then use a cleaning agent to clean all the residual paint on each surface, and finally wipe the residual paint and residual cleaning agent on the outer surface of the iron core (3) with a clean cloth.

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