Method for Magnetic Isolation Assembly of Rotor During Submersible Permanent Magnet Motor Assembly

Abstract

This invention discloses a method for magnetically shielded assembly of a submersible permanent magnet motor rotor during casing assembly, which solves the problem of how to smoothly complete the casing assembly of a submersible permanent magnet motor rotor under magnetic shielding. On the assembly workbench (1), the motor base and stator (3) are placed vertically. An adsorption-type air gap magnetic shield (7) is made for rotor casing assembly. The air gap magnetic shield is adsorbed onto the motor rotor (4), covering the permanent magnet poles on the entire motor rotor (4). The motor rotor (4) with the adsorbed air gap magnetic shield (7) is lifted by the hoisting lifting equipment (5) and inserted into the vertically placed motor base and stator (3). The assembled motor rotor, motor base, and stator are changed from vertical to horizontal placement. A long screw (8) is inserted into the motor from the end before the motor end cover is installed, and the air gap magnetic shield (7) is pulled out from the air gap between the stator and the rotor. The casing assembly of the submersible permanent magnet motor is conveniently realized.

Description

Technical Field

[0001] This invention relates to an assembly method for a permanent magnet motor, and more particularly to an assembly method in which a magnetic isolation mechanism is set between the stator and the rotor when the rotor of a submersible permanent magnet motor is installed in the housing. Background Technology

[0002] In the assembly process of the rotor of a permanent magnet motor into the frame and stator, a vertical assembly method is usually adopted. This involves placing the already assembled stator motor frame vertically on the assembly table, and then using hoisting equipment to lift the rotor with permanent magnet poles and vertically insert it into the motor frame and stator. To overcome the attraction of the permanent magnet poles on the rotor, a magnetic shielding sleeve is generally installed between the stator and rotor to overcome the influence of the magnetic pole attraction on the rotor during installation. The magnetic shielding sleeve is made of non-magnetic stainless steel and can be installed and suspended on the observation hole of the motor end cover. It can be inserted through the air gap hole of the motor end cover during use and then removed from between the stator and rotor after the stator and rotor are assembled. Submersible motors are installed on the lower outer side of the vessel and are completely submerged in water. Therefore, the motor end cover is a completely closed end cover. This means that the magnetic shielding plate mechanism used in existing technology cannot be used during the assembly of the motor stator and rotor. How to complete the assembly of the submersible permanent magnet motor rotor under magnetic shielding has become a difficult problem to be solved on-site. Summary of the Invention

[0003] This invention provides a method for magnetically isolated assembly of the rotor during the assembly of a submersible permanent magnet motor, solving the technical problem of how to successfully complete the assembly of the submersible permanent magnet motor rotor under magnetic isolation.

[0004] The present invention solves the above technical problems through the following technical solutions: A method for magnetically isolated assembly of the rotor during the installation of the rotor into the housing in the assembly of a submersible permanent magnet motor includes an assembly workbench, hoisting equipment, a motor frame, stator, and motor rotor. The steps are as follows: Step 1: Place the motor base and stator vertically on the assembly workbench; The second step is to manufacture the adsorption-type air gap magnetic shielding plate for rotor housing. The specific process is as follows: According to the outer contour dimensions of the motor rotor, a stainless steel plate is rolled into a cylinder and spot-welded to fix it, so that the inner circle dimension of the cylinder is the same as the outer circle dimension of the magnetic pole on the motor rotor; then, the spot welds are removed, the cylinder is laid flat, and 5 mm wide rectangular grooves are machined at intervals on the flat stainless steel plate surface. The machined rectangular grooves should correspond to the magnetic poles on the motor rotor. Magnetizable carbon steel strips are embedded in the rectangular grooves, and the magnetizable carbon steel strips are welded to the stainless steel plate as a whole; the stainless steel plate with magnetizable carbon steel strips is annealed, then rolled and rounded again, so that the inner circle dimension of the re-rolled cylinder is the same as the outer circle dimension of the magnetic pole on the motor rotor; finally, the stainless steel plate with magnetizable carbon steel strips is cut into arc-shaped strips of air gap magnetic shielding plate according to the width of the motor rotor magnetic pole. A bending pull plate is set at the end of each air gap magnetic shielding plate, and a screw hole with internal thread is set on the bending pull plate; The third step is to attach the air gap magnetic shields processed in the second step to the outer surface of the magnetic poles of the motor rotor, covering the permanent magnet poles on the entire motor rotor, and then fix the end cap of the motor to one end of the motor rotor. The fourth step is to use hoisting equipment to lift the motor rotor with the air gap magnetic shielding plate, and then insert it into the vertically placed motor base and stator, and complete the centering and positioning work of the motor rotor center axis and the stator center axis. Step 5: Securely fix the assembly relationship between the motor rotor, motor frame, and stator after they are installed in the housing. Use hoisting equipment to change the assembled motor rotor, motor frame, and stator from a vertical position to a horizontal position. Step 6: Take the long screw and insert it into the motor from the end where the motor end cover is not yet installed. Screw the end of the long screw into the threaded hole on the bending plate. Then, pull the air gap magnetic shielding plate outward horizontally to pull it out of the air gap between the stator and the rotor. After pulling out all the air gap magnetic shielding plates, assemble the other end cover of the motor.

[0005] The assembly workbench is equipped with a tooling end cover for motor assembly, and the motor base and stator are placed vertically on the tooling end cover.

[0006] This invention changes the traditional practice of placing the magnetic shielding sleeve in the stator when the rotor is installed in the housing. Instead, the magnetic shielding plate is placed on the motor rotor in advance to isolate the magnetic poles on the motor rotor, thereby overcoming the magnetic attraction when the rotor is installed in the housing, thus facilitating the installation and assembly of the submersible permanent magnet motor. Attached Figure Description

[0007] Figure 1 This is a schematic diagram of the structure of the motor rotor 4 vertically inserted into the housing according to the present invention; Figure 2This is a schematic diagram of the structure of the motor rotor 4 after it is vertically installed in the housing according to the present invention; Figure 3 This is a schematic diagram of the structure of the air gap magnetic shielding plate 7 of the present invention when it is extracted; Figure 4 This is a schematic diagram of the structure of the air gap magnetic shielding plate 7 of the present invention; Figure 5 This is a schematic diagram of the structure of the bending plate 10 of the present invention. Implementation

[0008] The present invention will now be described in detail with reference to the accompanying drawings: A method for magnetically isolated assembly of a submersible permanent magnet motor during rotor insertion into the housing includes an assembly workbench 1, a hoisting lifting device 5, a motor base and stator 3 and a motor rotor 4. The motor base and stator 3 are assembled as one unit, and permanent magnet blocks are provided on the motor rotor 4. The rotor has been assembled. Step 1: On the assembly workbench 1, the motor base and stator 3 are placed vertically by hoisting, so that the motor rotor 4 can be lifted from the air and from top to bottom into the motor base and stator 3 by the hoisting equipment. The second step is to fabricate the adsorption-type air gap magnetic shield 7 for rotor housing. The specific process is as follows: Based on the outer contour dimensions of the motor rotor 4, a stainless steel plate is rolled into a cylinder and spot-welded to ensure that the inner diameter of the cylinder matches the outer diameter of the magnetic poles on the motor rotor 4. Then, the spot welds are removed, the cylinder is laid flat, and 5mm wide rectangular grooves are machined at intervals on the flattened stainless steel plate. These rectangular grooves must correspond to the magnetic poles on the motor rotor 4. Magnetizable carbon steel strips 9 are embedded within the rectangular grooves, and the magnetizable carbon steel strips 9 are welded to the stainless steel plate. The stainless steel plate with the magnetizable carbon steel strip 9 is annealed and then re-rolled and rounded so that the inner circle size of the re-rolled roll is the same as the outer circle size of the magnetic pole on the motor rotor 4. Finally, the stainless steel plate with the magnetizable carbon steel strip 9 is cut into arc-shaped strips of air gap magnetic shielding plate 7 according to the width of the magnetic pole of the motor rotor 4. A bending pull plate 10 is provided at the end of each air gap magnetic shielding plate. A screw hole 11 with internal thread is provided on the bending pull plate 10 to facilitate the subsequent connection of the air gap magnetic shielding plate 7 to the pulling long screw. The third step is to attach the air gap magnetic shielding plates 7 processed in the second step to the outer surface of the magnetic poles of the motor rotor 4, splice them into a cylindrical shape, cover the permanent magnet poles on the entire motor rotor 4, and fix the end cap 6 of the motor to one end of the motor rotor 4. Fourth step: Using hoisting equipment 5, lift the motor rotor 4 with the air gap magnetic plate 7 adsorbed, so that the motor rotor 4 is in a vertical state, and place the end cover 6 of the motor at the upper end of the vertically lifted motor rotor 4. Then, slowly insert the motor rotor 4 into the vertically placed motor base and stator 3, and complete the centering and positioning work of the motor rotor center axis and the stator center axis. Step 5: Securely fix the positional relationship between the motor rotor 4, motor frame and stator 3 after they are installed in the housing; then use the hoisting equipment 5 to change the assembled motor rotor 4, motor frame and stator 3 from a vertical position to a horizontal position. Step 6: Take the long screw 8 and insert it into the motor from the end where the motor end cover has not yet been installed. Screw the end of the long screw 8 into the threaded hole 11 on the bending pull plate 10. Then, pull the air gap magnetic shielding plate 7 outward horizontally to pull it out of the air gap between the stator and the rotor. After pulling out all the air gap magnetic shielding plates 7, assemble the other end cover of the motor.

[0009] A tooling end cover 2 for motor assembly is set on the assembly workbench 1. The motor base and stator 3 are placed vertically on the tooling end cover 2. In order to improve the assembly quality of the motor rotor into the housing, the tooling end cover 2 of the motor is generally used on the assembly site to simulate the condition of the motor after assembly. In this technical solution, a tooling end cover with the same size as the real end cover can be processed first, and the tooling end cover 2 is set on the assembly workbench 1. An annular through hole for the long screw 8 and the air gap magnetic plate 7 to enter and exit should be provided on the tooling end cover 2.

Claims

1. A method for magnetically isolated assembly of a submersible permanent magnet motor during rotor insertion into the housing, comprising an assembly workbench (1), a hoisting lifting device (5), a motor base and stator (3), and a motor rotor (4). Its characteristics include the following steps: Step 1: Place the motor base and stator (3) vertically on the assembly workbench (1); The second step is to manufacture the adsorption-type air gap magnetic shield (7) for rotor housing. The specific process is as follows: According to the outer contour dimensions of the motor rotor (4), a stainless steel plate is rolled into a cylinder and spot-welded to make the inner circle dimension of the cylinder equal to the outer circle dimension of the magnetic pole on the motor rotor (4); then, the spot welds are removed, the cylinder is laid flat, and 5 mm wide rectangular grooves are machined at intervals on the flat stainless steel plate surface. Magnetizable carbon steel strips (9) are embedded in the rectangular grooves, and the magnetizable carbon steel strips (9) are connected to the stainless steel plate. Welded together; the stainless steel plate with magnetizable carbon steel strip (9) is annealed and then re-rolled so that the inner circle size of the re-rolled plate is equal to the outer circle size of the magnetic pole on the motor rotor (4); finally, the stainless steel plate with magnetizable carbon steel strip (9) is cut into arc-shaped strip air gap magnetic shielding plates (7) according to the width of the magnetic pole on the motor rotor (4), and a bending pull plate (10) is provided at the end of each air gap magnetic shielding plate, and a screw hole (11) with internal thread is provided on the bending pull plate (10). The third step is to attach the air gap magnetic shields (7) processed in the second step to the motor rotor (4), cover the permanent magnet poles on the entire motor rotor (4), and fix the end cap (6) of the motor to one end of the motor rotor (4). The fourth step is to lift the motor rotor (4) with the air gap magnetic plate (7) adsorbed by the hoisting lifting equipment (5), and then put it into the vertically placed motor base and stator (3), and complete the center positioning work of the motor rotor center axis and the stator center axis. Step 5: Secure the assembly relationship between the motor rotor (4) after it is installed in the housing and the motor frame and stator (3). Use the hoisting equipment (5) to change the assembled motor rotor (4) and motor frame and stator (3) from vertical to horizontal. Step 6: Take the long screw (8), insert the long screw (8) into the motor from the end where the motor end cover has not yet been installed, screw the end of the long screw (8) into the threaded hole (11) on the bending pull plate (10), and then pull the air gap magnetic shield (7) outward horizontally to pull the air gap magnetic shield (7) out of the air gap between the stator and the rotor; after pulling out all the air gap magnetic shields (7), assemble the other end cover of the motor.

2. The method for magnetically isolating the rotor during installation in the housing of a submersible permanent magnet motor according to claim 1, characterized in that, A tooling end cover (2) for motor assembly is provided on the assembly workbench (1), and the motor base and stator (3) are placed vertically on the tooling end cover (2).

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