JPH0435981B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method of manufacturing a rotating electrical machine that improves the method of fixing a stator core and a casing.

[Technical background of the invention and its problems]

Generally, the casing of a rotating electrical machine such as an induction motor holds a stator core, has bearing brackets attached to both ends of the casing to hold the shaft of the rotor, and has mounting legs for supporting the entire rotating electrical machine. In an induction motor with a relatively large capacity, the heat loss generated during operation is large, and a flat casing has insufficient heat dissipation area. For this reason, heat dissipation fins are arranged on the outer surface of the casing, and cooling fans are provided at the ends to increase the amount of heat dissipation. However, when the capacity is relatively small, there is less heat loss during operation, so the required heat dissipation area may also be smaller.
For this reason, the outer surface of the casing is generally flat and does not include a cooling fan. Therefore, the casing body of a small-capacity induction motor is made of a steel plate formed into a cylindrical shape, and the mounting legs for supporting the whole are also made of a stamped steel plate. The mounting legs may be attached to the casing shell in advance, or may be attached simultaneously to the stator core and the casing shell. In other words, in the former case, the stator core is inserted into the casing body where the overlapping part of the casing copper and the mounting leg is welded by spot welding, etc., and the stator core and casing are fixed with screws from the outside surface of the mounting leg. It's a method.
On the other hand, in the latter case, the stator core is inserted into a casing shell that has through holes provided at appropriate locations where the casing shell and the mounting legs overlap. Then, fusion welding is performed at the overlapping part of the pre-prepared through hole and the stator core, for example.
Attach the legs by spot welding using MIG welding etc.
This method simultaneously fixes the casing shell and stator core. The stator core fixed to the casing body in this manner is subjected to a rotational reaction force at the time of startup. In particular, standard small induction motors are used for an unspecified number of purposes, so they are generally started frequently, such as in forward and reverse rotations, and require strong fixing strength between the casing and the stator core. Therefore, in the former screw fixing method, many fixing locations are required, and the boss portion of the fixing screw must be made strong. That is, it is necessary to increase the thickness of the casing body or to provide a boss seat by welding or the like. On the other hand, when fixing the latter at the same time as the mounting legs, as in the case of the former, increase the number of welding points or enlarge the through holes previously provided in the casing body to improve penetration into the stator core. The core and casing are sufficiently welded by fillet welding to the stator core.This increase in the number of welding points is due to the fact that the casing body and mounting legs are made of relatively thin steel plate, which causes distortion due to welding heat, making it difficult to implement in practice. be restricted. Furthermore, there are also disadvantages in that the stator core side is affected by distortion due to welding heat, which significantly deteriorates the magnetic properties.

[Purpose of the invention]

An object of the present invention is to provide a method for manufacturing a rotating electric machine including a steel plate casing with high production efficiency and a stator core with excellent magnetic properties.

[Summary of the invention]

In the present invention, a through hole and a large through hole are provided at the overlapping portions of the casing body made of a cylindrical steel plate and the mounting leg made of a stamped steel plate, respectively. The molten metal between the casing shell and the mounting leg is welded by arc welding to the overlapping part of this through hole and the laminated guide groove provided on the outer periphery of the stator core inserted into the casing shell. By pouring the stator core into the laminated guide grooves and fixing the stator core and casing shell, the stator core can be made stronger and easier, and the magnetic properties of the stator core can be prevented from deteriorating. This also increases production efficiency.

[Embodiments of the invention]

This embodiment will be described below with reference to FIGS. 1 to 5. Although not shown, a steel plate or a hoop-shaped steel strip is cut to a predetermined size and formed into a cylindrical shape, and the abutting portions are welded to form the casing body 1. Several through holes 1a are provided in the body portion of the casing body 1 at the overlapped portions with the mounting legs described later and the overlapped portions with the stacking guide grooves of the stator core to be inserted. This through hole 1a is desirably smaller than the large through hole of the mounting leg, which will be described later. In other words, this is to ensure that the mounting leg and the casing are welded together. Stator core 4 is attached to casing shell 1 formed in this way.
is inserted so that the lamination guide groove on the outer periphery of the stator core, which will be described later, and the through hole 1a match. Reference numeral 3 denotes a mounting leg for supporting the entire body, which is made of the same steel plate as the casing body 1 described above or a steel strip wound into a hoop shape, cut into a shape with predetermined dimensions, and formed by stamping, and has the number of overlapping parts with the casing body 1. A large through hole 3a for welding connection to the casing shell 1 is provided at this location. Welding is performed by coated metal arc welding, MIG welding, carbon dioxide gas welding, etc. at the through hole 1a and the large through hole 3a, which are located at the overlapping part of the mounting leg 3 and the casing body 1 into which the stator core is inserted and fitted. . The stator core 4 is made by laminating a predetermined number of punched plates 4a punched from electric iron plates using the guide grooves 4b, and then using a conventional welding method such as TIG welding, laser welding, electron beam welding, plasma welding, etc. Weld the parts together in several places using a high energy density welding method. Fourth
The reference numeral 5 shown in the figure is a binding weld portion, which is provided on the outer periphery of the punched plate 4a at right angles to it. The penetration depth and number of binding welds 5 are determined from the viewpoint of magnetic properties.
Keep it to the minimum necessary. Molten metal from welding of the through hole 1a and the large through hole 3a, which are formed at the overlapping part of the casing body 1 and the mounting leg 3 into which the stator core 4 is inserted and fitted, is provided on the outer periphery of the stator core 4. It flows into the lamination guide groove 4b and solidifies, forming the casing body 1.
fixes the mounting leg 3 and stator core 4 together. At both ends of the casing body 1 are provided spigots 8 into which bearing brackets 7 for supporting the rotor 6 are fitted. 2 is a stator winding.

Next, the effect will be explained. In the rotating electric machine having the above configuration, heat loss generated from the rotor 6, stator core 4, stator winding 2, etc. during operation is dissipated from the outer surface of the casing shell 1 to the outside air. The casing body 1 and the stator core 4 are fixed through a through hole 1a and a large through hole 3 provided at the overlapping part of the casing body 1 and the mounting leg 3.
The production efficiency is high because the welding is simple as it is only necessary to perform high energy density spot welding of a, and from the viewpoint of the magnetic characteristics of the rotating electric machine, according to this embodiment, the casing shell 1 and the stator The casing shell 1 is fixed to the iron core 4 as shown in Figure 5.
and fillet welding 10 on the inner surface of the through hole 9 of the mounting leg 3
Compared to the conventional case, the casing body 1 mounting leg 3
The molten metal obtained by welding through the through hole 1a and the large through hole 3a in the overlapped portion with the stator core 4 is fixed to the lamination guide groove 4b of the stator core 4 by the flow solidified metal 11. Moreover, this is possible without increasing the welding heat input, so there is no thermal influence, that is, thermal shrinkage, and there is no distortion. Moreover, the deterioration of magnetic properties is reduced accordingly. As described above, in this embodiment, there is little deterioration in magnetic properties and no welding distortion occurs, so the operating characteristics of the entire rotating electrical system are improved, and good results are obtained in terms of bearing life and mechanical noise.

Note that the present invention is not limited to the embodiments described above and shown in the drawings; for example, the stator core 4 is fixed to the casing shell 1 by using the lamination guide groove 4.
It is needless to say that it is not necessary to be the shape shown in FIG. 1B, and that it can be implemented with various modifications, such as a recessed portion for the binding welded portion 5, without changing the gist thereof.

〔Effect of the invention〕

As explained above, according to the present invention, the through hole and the large through hole in the overlapping part of the casing body and the mounting leg are welded by arc welding or the like, and the molten metal is poured into the lamination guide groove of the stator core, and the molten metal is poured into the lamination guide groove of the stator core. To provide a method for manufacturing an inexpensive rotating electric machine that can reliably prevent rotation of a stator core at the same time as the installation, has excellent magnetic properties, operational performance, and noise characteristics, and provides high production efficiency.

[Brief explanation of drawings]

FIG. 1 is a vertical sectional view of the upper half of a rotating electric machine manufactured by an embodiment of the method of the present invention, FIG. 2 is a sectional view taken along the line - in FIG. 1, and FIG. Figure 4 is a perspective view showing the stator core in Figure 1, and Figure 5 is a cross-sectional view showing the main parts of a rotating electrical machine manufactured by the conventional method. be. 1...Casing body, 3...Mounting leg, 1a, 9
...Through hole, 3a... Large through hole, 4... Stator core, 4b... Guide groove for lamination, 10... Fillet welding, 11... Flow conduction solidified metal.

Claims (1)

[Claims] 1. A casing body made of a steel plate and formed into a cylindrical shape and having a plurality of through holes in the body, a mounting leg made of a steel plate having a diameter larger than the through hole and having a plurality of large through holes, and a mounting leg that is inserted into the casing body. A casing body having a stator core fitted therein and having a plurality of stacking guide grooves in the stacking direction on the outer periphery, and having a stator core inside which the stacking guide grooves and the through holes match and fit. The through holes and the large through holes are aligned with the body, the mounting legs are overlapped, and the welding is performed. At the same time, the molten metal is flowed into the stator core lamination guide groove in the casing body and solidified by main welding. A method of manufacturing a rotating electrical machine, which is characterized by fixing the machine.