A method for replacing the main pole winding of a large or medium-sized DC motor and the tooling used therefor

Abstract

The present invention provides a method for replacing the main pole winding of a large and medium-sized DC motor and the tooling used therefor, belonging to the technical field of replacing the winding of large and medium-sized motors. Specifically, it includes: customizing tooling with a boss according to the stator size of the motor; lifting the motor stator by an external force, sleeving it onto the tooling, making the boss snap into the middle gap between adjacent compensating windings, and supporting the main pole iron core, removing the bolts connecting the motor frame and the main pole, separating the frame from the stator internal components, and then replacing the main pole winding in the exposed state; after replacement, reassembling the frame and the stator internal components, and then performing overall vacuum impregnation to complete the replacement of the main pole winding. The method provided by the present invention is simple and convenient to operate, can separate the stator winding without damage and take it out of the frame as a whole, will not damage the compensating winding, will neither cause waste of resources nor save the maintenance cost; the tooling used has a simple structure, is easy to operate, and is universal for different models of motors.

Description

Technical Field

[0001] The present invention relates to the technical field of replacing windings of large and medium-sized motors, and in particular to a method for replacing the main pole winding of a large and medium-sized DC motor and the tooling used therefor, which is particularly applicable to DC motors with a center height H of 315 to 560 mm. Background Art

[0002] DC motors are widely used in various fields of industrial production, and windings at various parts of DC motors will also be damaged due to various factors during use. Among them, if the armature winding, compensating winding and commutating pole winding are damaged and scrapped, they can be directly replaced without damaging other windings.

[0003] However, the main pole winding / field winding is different. The main pole winding of a DC motor is sleeved on the main pole core. If the main pole winding needs to be replaced, the main pole core needs to be removed from the machine base, but the compensating winding hinders the disassembly of the main pole core. The compensating winding of a DC motor with a center height H of 315 to 560 mm is generally made of electromagnetic wire or enameled wire and is embedded in the inner groove of the main pole core. After vacuum impregnation with varnish, it connects all the main poles in the machine base into one body. If the main pole winding needs to be replaced, it is necessary to first damage and cut the compensating winding, separate the connected main poles, remove them one by one and replace the main pole winding. Replacing the main pole winding also accompanies the damage of the compensating winding, resulting in waste of resources, increased cost, and complicated replacement procedures. Summary of the Invention

[0004] Aiming at the problems and deficiencies existing in the prior art, the present invention provides a method for replacing the main pole winding of a large and medium-sized DC motor and the tooling used therefor, which solves the above technical problems, can also simplify the process, is convenient to operate, saves maintenance costs, and the tooling used is applicable to motors of different models.

[0005] As the first aspect of the present invention, a method for replacing the main pole winding of a large and medium-sized DC motor is provided. The method uses a tooling provided with a boss. Without damaging the compensating winding, after the stator winding is taken out of the machine base as a whole, the main pole winding is then replaced.

[0006] The specific steps include:

[0007] (1) Customize a tooling provided with a boss according to the size of the motor stator;

[0008] (2) Remove the outlet box of the stator and separate or remove the commutating pole;

[0009] (3) Place the motor stator and the tooling vertically on a platform or a flat ground;

[0010] (4) Use a hoisting rope of a crane or a chain block to hook the machine base of the motor to lift the stator, and sleave it on the tooling. During the process of the stator falling, adjust the direction of the stator so that the middle gap between adjacent compensating windings catches on the boss of the tooling;

[0011] (5) The motor stator further descends, causing the tooling boss to fully bear the weight of the stator. At this time, the lifting rope is still in a taut state;

[0012] (6) Remove the bolts connecting the motor base and the main pole. At this time, the base is separated from the internal components of the stator, and the base descends until it lands on the platform or the ground, and then unhook the lifting rope;

[0013] (7) Hook the lifting rope to the upper center frame of the tooling, and lift the tooling together with the internal components of the stator until it is completely separated from the base. Then place the tooling together with the internal components of the stator at another position on the platform or the ground;

[0014] (8) Replace the main pole winding in the exposed state;

[0015] (9) After replacement, lift the base with the lifting rope, put it over the internal components of the stator, and complete the recombination of the stator;

[0016] (10) Vacuum impregnate the whole stator with paint to complete the replacement of the main pole winding.

[0017] As the second aspect of the present invention, a tooling is provided, specifically including: 2n columns, two layers of center frames, and 2n bosses; the two layers of center frames are welded parallel to each other between the 2n columns, so that the cross-section of the tooling surrounded by the 2n columns is a regular polygon. Each layer of the center frame is welded by n steel bars and intersects at the center point of the regular polygon; the 2n bosses are respectively welded on the outer surfaces of the 2n columns, and have the same angle with the outer surfaces of the columns, and are distributed on the same cross-section of the tooling; wherein, n is a positive integer satisfying 2 ≤ n ≤ 4.

[0018] Preferably, the steel bars used for the columns and the center frames are flat steel or channel steel.

[0019] Preferably, the length of the diagonal of the cross-section of the outer frame of the tooling is 3 - 5 mm smaller than the diameter of the inner circle of the stator.

[0020] Preferably, the height of the tooling is higher than the height of the base, and the distance from the boss to the bottom end of the column is greater than the distance from the main pole iron core to the bottom end of the base.

[0021] Preferably, the distance from the boss to the top end of the column is 50 - 100 mm greater than the distance from the main pole iron core to the top end of the base.

[0022] Preferably, it further includes 2n diagonal braces. The 2n diagonal braces are respectively welded at the intersection of the endpoints between adjacent two columns, so that the tooling is sufficient to bear the weight of the whole stator without deformation.

[0023] Preferably, the material used for the diagonal braces is flat steel or channel steel.

[0024] Preferably, the surface of the boss is coated with mica tape or silicone rubber tape to prevent the compensating winding from being damaged by subsequent pressure application.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0026] The method provided by the present invention is simple and convenient to operate. It can separate the stator winding without damage and take it out of the frame as a whole, without damaging the compensating winding, neither causing waste of resources nor saving the maintenance cost. The tooling used has a simple structure, is easy to operate, and is applicable to motors of different models. Description of the Drawings

[0027] The drawings are used to provide a further understanding of the present invention, and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present invention, but do not constitute a limitation to the present invention. In the drawings:

[0028] Figure 1 It is a schematic diagram of the distribution structure of the main poles, main pole windings, compensating windings and frame of the four-pole DC motor provided by the present invention;

[0029] Figure 2 is Figure 1 A-A sectional view of;

[0030] Figure 3 It is a schematic diagram of the structure of the four-pole motor tooling;

[0031] Figure 4 It is a top view of the four-pole motor tooling;

[0032] Figure 5 It is a sectional view of the four-pole motor tooling after being placed inside the stator components;

[0033] Figure 6 It is a schematic diagram of the structure of the six-pole motor tooling.

[0034] Reference numerals: 1 - main pole iron core, 2 - main pole winding, 3 - compensating winding, 4 - frame, 5 - commutating pole, 6 - lead wire, 7 - column, 8 - boss, 9 - cross, 10 - diagonal brace. Detailed Embodiments

[0035] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0036] Such as Figures 1 - 2As shown in the figure, in this embodiment, a four-pole motor is taken as an example, which includes a main pole core 1, a main pole winding 2, a compensating winding 3, a machine frame 4, a commutating pole 5, and a lead wire 6. The cross-section of the tooling is made into a regular quadrilateral. In addition, the principle of a six-pole motor is the same, and the cross-section of the tooling can be made into a regular hexagon. It should be noted that all the stator components inside the motor frame of the present invention (collectively referred to as the stator internal components) refer to the overall collection including the main pole core, the main pole winding, the compensating winding, and the commutating pole.

[0037] (1) Customize the tooling with bosses according to the stator size, specifically as follows:

[0038] As Figures 3 - 5 shown in the figure, the entire tooling includes: a center frame with two layers of cross-shaped frames 9, four columns 7, four diagonal braces 10, and four bosses 8. The columns 7 are made of flat steel, and the diagonal braces are made of channel steel. The two layers of cross-shaped frames 9 are welded parallel to each other between the 4 columns, so that the cross-section of the tooling surrounded by the four columns is a square; the four bosses are respectively welded on the outer surfaces of the four columns, and the angles with the outer surfaces of the columns are the same, distributed on the same cross-section of the tooling, and each connecting part is first spot-welded.

[0039] The length of the diagonal of the cross-section of the outer frame of the tooling (dimension a) should be slightly smaller than the diameter of the inner circle of the stator, generally 3 - 5 mm smaller, which is conducive to the loading and unloading of the tooling.

[0040] The height of the tooling should be slightly higher than the height of the machine frame. The bosses supporting the main pole core should be welded firmly, and the strength should be sufficient to support the weight of the entire stator. The distance from the boss to the top of the column (dimension b) should be greater than the distance from the main pole core to the end of the machine frame (dimension c), generally 50 - 100 mm greater.

[0041] After spot-welding at each part of the tooling, try to install it inside the stator, and observe whether the four bosses on the four columns of the tooling can be exactly placed in the middle gaps between each adjacent compensating winding, that is, the symmetry center of the main pole core, and will not squeeze and damage the coils. If there is a deviation after the trial installation, the position of the boss needs to be readjusted. The previous spot-welding is for adjusting the position after the trial installation; if there is no problem after the trial installation, weld all the solder joints firmly. After completion, the tooling should be able to withstand the weight of the entire stator without deformation.

[0042] Wrap two layers of mica tape or silicone rubber tape on the surface of the boss of the tooling to play a protective role and prevent subsequent extrusion and damage to the compensating winding;

[0043] (2) Refer to Figures 1 - 2 , remove the outlet box of the stator, separate or remove the commutating pole 5; if the main pole winding interferes with the commutating pole and causes the commutating pole to be unable to be removed, the commutating pole can be separated from the compensating winding 3 and then hoisted and tied to the compensating winding. If the commutating pole is heavy, it can be hoisted and tied to the tooling.

[0044] (3) Prepare the motor stator and the tooling, and place them vertically on a platform or a relatively flat ground;

[0045] (4) Use a crane or a chain block sling to hook the motor frame and lift the stator, then slip it onto the tooling. Refer to Figure 5 . During the process of the stator descending, adjust the direction of the stator, and carefully fit the middle gap between adjacent compensating windings onto the tooling boss 2. The centers of the four main pole cores are placed exactly on the four bosses of the tooling.

[0046] (5) Let the motor stator descend further until the tooling bosses completely bear the weight of the stator. At this time, the sling is still in a taut state.

[0047] (6) Remove the bolts connecting the motor frame and the main poles. At this time, the frame will be disengaged from the internal components as a whole. The frame will descend, and the sling will follow the frame down until the frame lands on the ground. Then unhook the sling.

[0048] (7) Hook the sling to the center of the upper cross of the tooling, and slowly lift the sling. The tooling together with the internal components of the stator will be separated from the frame. After they are completely separated, the frame remains in place. Additionally, if there are silicon steel sheets for adjusting the air gap between the main poles and the frame, pay attention to collecting them, making marks, cleaning them, and recycling them.

[0049] (8) Place the tooling and the internal components of the stator back on the ground. The supporting range of the legs of the tooling is relatively small, and it may not be stable when placed vertically. If transportation is required, the supporting range of the legs can be increased, such as welding steel plates with a larger area to the legs. In this state, the main pole coils are already exposed and can be freely removed and replaced with new coils.

[0050] (9) After the new coils are replaced, lift the frame with a sling, and reinstall the internal components of the stator into the frame to complete the recombination. Before installation, pay attention to cleaning the inner wall of the frame and the surface of the main pole core until they are smooth to prevent jamming during the installation process. If they are still too tight, the frame can be put into an oven and baked at a temperature of 180 °C for more than 4 hours. After the frame expands due to heat, then slip it on.

[0051] (10) Vacuum impregnate the stator together with the frame as a whole to complete the replacement of the main pole winding.

[0052] In addition, for some motor stators, the mounting stops at both ends of the end covers are relatively small, and the outer contour of the main pole winding is larger than this stop, resulting in a jamming phenomenon when the frame descends halfway. At this time, the jammed part of the stop can be marked, and the jammed part of the stop can be machined off on a boring machine. It is also possible to enlarge the inner circle of this stop on a vertical lathe or a boring machine and fabricate a matching end cover.

[0053] Refer to Figure 6 . The tooling structure of the six-pole motor is similar to that of the four-pole motor, and its usage method is the same as that of the four-pole motor tooling.

[0054] The above only introduces the technical solution of the present invention with preferred embodiments. However, for those of ordinary skill in the art, based on the idea of the embodiments of the present invention, changes should be made in the specific implementation manners and application scopes. Therefore, in summary, the content of this specification should not be construed as a limitation of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included within the scope of the claims of the present invention.

Claims

1. A method for replacing the main pole winding of a large or medium-sized DC motor, characterized in that, The method uses a tooling with bosses. Without damaging the compensating winding, after the stator winding is taken out of the frame as a whole, the main pole winding is replaced: (1) Customize a tooling with bosses according to the stator size of the motor; (2) Remove the outlet box of the stator and separate or remove the commutating poles; (3) Stand the motor stator and the tooling upright on a platform or a flat ground; (4) Use a hoist or a chain block sling to hook the frame of the motor to lift the stator, and put it on the tooling. During the process of the stator falling, adjust the direction of the stator so that the middle gap between adjacent compensating windings is stuck on the bosses of the tooling; (5) Let the motor stator fall further so that the bosses of the tooling completely bear the weight of the stator. At this time, the sling is still in a taut state; (6) Remove the bolts connecting the motor frame and the main poles. At this time, the frame is separated from the internal components of the stator, and the frame falls until it lands on the platform or the ground, and then unhook the sling; (7) Hook the sling to the upper center frame of the tooling, and lift the tooling together with the internal components of the stator until it is completely separated from the frame, and place the tooling together with the internal components of the stator at another position on the platform or the ground; (8) Replace the exposed main pole winding; (9) After the replacement is completed, lift the frame with a sling, put it into the internal components of the stator, and complete the recombination of the stator; (10) Vacuum impregnate the whole stator with varnish to complete the replacement of the main pole winding; The tooling includes 2n columns, two layers of center frames, and 2n bosses; the two layers of center frames are welded parallel to each other between the 2n columns, so that the cross-section of the tooling surrounded by the 2n columns is a regular polygon. Each layer of the center frame is welded by n steel bars, which intersect at the center point of the regular polygon; the 2n bosses are respectively welded on the outer surfaces of the 2n columns, and have the same angle with the outer surfaces of the columns, and are distributed on the same cross-section of the tooling; n is a positive integer satisfying 2 ≤ n ≤ 4; the distance from the boss to the top of the column is greater than the distance from the main pole core to the top of the frame; The height of the tooling is higher than the height of the frame. The distance from the boss to the top of the column is 50 - 100 mm greater than the distance from the main pole core to the bottom of the frame; it also includes 2n diagonal braces, and the endpoints of the 2n diagonal braces are respectively welded between adjacent two columns so that the tooling is sufficient to bear the weight of the whole stator without deformation; the surface of the boss is coated with mica tape or silicone rubber tape to prevent the compensating winding from being damaged by subsequent pressure.

2. A method for replacing the main pole winding of a large or medium-sized DC motor according to claim 1, characterized in that The steel bars used for the columns and the center frames are flat steel or channel steel.

3. A method for replacing the main pole winding of a large or medium-sized DC motor according to claim 2, characterized in that, The length of the diagonal of the cross-section of the outer frame of the tooling is 3 - 5 mm smaller than the diameter of the inner circle of the stator.

4. A method for replacing the main pole winding of a large or medium-sized DC motor according to claim 3, characterized in that, The material used for the diagonal braces is flat steel or channel steel.

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