JP4859357B2 - Method for manufacturing stator core of rotating electric machine - Google Patents

Description

  The present invention relates to a method for manufacturing a stator core of a rotating electrical machine, in which a large number of annular cores made of electromagnetic steel sheets are laminated and a plurality of outer peripheral portions are welded along the axial direction to manufacture a stator core. is there.

The stator core of a rotating electrical machine is formed by punching electromagnetic steel sheets in an annular shape to form an iron core material, laminating a large number of this iron core material, and welding a plurality of locations on the outer periphery of this laminated iron core material along the axial direction. They are manufactured by being united together (for example, see Patent Document 1).
Japanese Patent Publication No. 3-68624 (FIGS. 15 and 16)

  In the above conventional manufacturing method, when the outer periphery of the laminated iron core material is welded, the radius of the welded part (welded part) shrinks due to the thermal effect, and conversely, the reaction between the welded part and the welded part occurs. As the radius expands, a stator core having irregularities formed on the outer periphery is formed, and dimensional accuracy cannot be ensured. For this reason, when the stator core is fitted into the inner periphery of the frame of the rotating electrical machine and incorporated, the contact area between the stator core and the frame is not as set, and the planned heat dissipation performance cannot be obtained. was there.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to manufacture a stator core capable of ensuring a contact area with a frame as set and obtaining a predetermined heat dissipation performance. It is providing the manufacturing method of the stator core of a rotary electric machine.

According to the first aspect of the present invention, there is provided a stator core for a rotating electrical machine in which a large number of annular cores made of electromagnetic steel sheets are laminated and a plurality of outer peripheral parts are welded along the axial direction to manufacture a stator core. In the manufacturing method, on the outer periphery of the iron core before welding, the radius of the welded part equivalent part is larger than the target radius, and the radius of the intermediate point between the welded part equivalent part and the adjacent welded part equivalent part is smaller than the target radius. It is formed so that it may change like this.

  According to such a configuration, when the outer periphery of the laminated core is welded at a plurality of locations, the radius of the welded portion of the outer periphery of the stator core contracts and the radius of the portion between the welded locations expands. The radius of the outer periphery of the stator core is corrected so as to become the target radius as a whole. Therefore, when the stator core is fitted and incorporated in the frame of the rotating electrical machine, the contact area between the stator core and the frame can be ensured as set, and the planned heat dissipation performance can be obtained.

The invention described in claim 2 is characterized in that the core material before welding is formed such that the inner periphery of the stator core has an arbitrary shape after welding.
According to this configuration, the air gap between the rotor becomes uneven, vibrations with the rotation of the rotor is adapted to generate, for example, it is possible to easily configure the vibration motor .

  When manufacturing a stator core by welding a plurality of locations on the outer periphery of a laminated core material along the axial direction, the present invention can ensure the contact area with the frame as set, and has a planned heat dissipation performance. Can be obtained.

(First embodiment)
A first embodiment of the present invention will be described below with reference to FIGS.
FIG. 4 is a radial cross-sectional view of an induction motor as a rotating electric machine. The induction motor 1 is formed by laminating a stator 5 in which a stator winding 4 is housed in a slot 3 of a stator core 2 manufactured as described later, and a large number of annular electromagnetic steel plates. And a rotor 8 in which a large number of conductors 7 are embedded in the outer peripheral portion of the rotor core 6. The induction motor 1 includes a stator 5 in which the outer periphery of the stator core 2 is fitted and incorporated in the inner periphery of the frame of the induction motor 1, and the rotor 8 is disposed in the inner periphery of the stator core 2. The rotor shaft of the rotor 8 is supported by a bracket bearing. In FIG. 4, the frame, bracket, bearings of the induction motor 1 and the rotor shaft of the rotor 8 are not shown.

Next, a method for manufacturing the stator core 2 will be described with reference to FIGS.
As shown in FIG. 1 and FIG. 2, the stator core 2 is formed by laminating a large number of iron core materials punched from electromagnetic steel sheets. Here, for convenience, the iron core material before welding is 2a. And the iron core material after welding is 2b. On the outer periphery of the iron core material 2a before welding, a plurality of, for example, six welded groove portions 9 corresponding to the weld locations are formed at equal intervals (equal angle of 60 degrees). It has a three-stage structure of valley, mountain, and valley in the direction.

  And the outer periphery and inner periphery of the iron core material 2b after welding are set so that each radius has the target perfect circle radius Ro which is a target radius, and the target perfect circle radius Ri which is a target radius. In this case, the target perfect circle radii Ro and Ri include an allowable error. On the other hand, at the outer periphery of the iron core material 2a before welding, the radius Roa of the weld groove 9 is larger than the target perfect circle radius Ro, and the intermediate point between the weld groove 9 and the adjacent weld groove 9 is provided. The radius Rob is changed so as to be smaller than the target perfect circle radius Ro (Roa> Ro> Rob).

Moreover, in the inner periphery of the iron core material 2a before welding, the radius Ria of the weld groove 9 is larger than the target perfect circle radius Ri, and the radius of the intermediate point between the weld groove 9 and the adjacent weld groove 9 Rib is formed so as to be larger than the target perfect circle radius Ri and smaller than the radius Ria (Ria>Rib> Ri).
The iron core material 2a before welding has a large number of slots 3. As shown in FIG. 3, the iron core material 2a is fitted into a mandrel 10 and laminated. The mandrel 10 is formed with a flange 111 having six notches 11a at equal intervals, and a key 10a that engages with one slot 3 of the laminated core material 2c. With this key 10a, the laminated iron core material 2c is positioned so as to prevent rotation, and each notch 11a of the flange 11 corresponds to each weld groove 9 of the laminated iron core material 2c. The presser plate 12 is fitted to the mandrel 10 from above the laminated core material 2c, and the laminated iron core material 2c is sandwiched and fixed between the flange portion 11 and the presser plate 12. In this case, the presser plate 12 has a notch 12 a corresponding to the notch 11 a of the flange 11.

Thus, as described above, the laminated core material 2c set on the mandrel 10 is integrally bundled by welding the six welding grooves 9 by the TIG welding machine, and the stator core 2 is manufactured. . In addition, the notch part 11a of the collar part 11 and the notch part 12a of the pressing plate 12 are for escape of the welding torch when welding the welding groove part 9.
Here, when the welding groove portion 9 of the laminated core material 2c is welded, the outer periphery of the portion (radius Roa portion) contracts to become a welding location 9a (see FIG. 4) having the target perfect circle radius Ro, and the welding location 9a. And the outer circumference of the intermediate point portion (the portion of radius Rob) between the adjacent welding point 9a expands to have the target perfect circle radius Ro.

  Further, when the welding groove 9 of the laminated iron core material 2c is welded, the inner circumference of the portion (radius Ria portion) contracts to have the target perfect circle radius Ri, and between the welding location 9a and the adjacent welding location 9a. The inner circumference of the intermediate point portion (radius Rib portion) is slightly contracted to have the target perfect circle radius Ro.

  As described above, according to the present embodiment, the outer periphery of the iron core material 2a before welding is such that the radius Roa of the weld groove 9 that shrinks during welding is larger than the target perfect circle radius Ro and the weld groove 9 that expands during welding. Since the radius Rob of the intermediate point between the adjacent weld groove 9 is smaller than the target perfect circle radius Ro (Roa> Ro> Rob), there are many iron core materials 2a. The stator core 2 manufactured by being laminated and bundled together by welding has an outer periphery having a target perfect circle radius Ro. Therefore, the conventional unevenness is formed on the outer periphery of the stator core 2. No, the contact area set when the outer periphery of the stator core 2 is fitted into the inner periphery of the frame (not shown) of the induction motor 1 can be ensured, and a predetermined heat dissipation performance can be obtained. be able to.

  Further, the inner circumference of the iron core material 2a before welding is such that the radius Ria of the weld groove 9 that shrinks during welding is larger than the target perfect circle radius Ri, and the weld groove 9 adjacent to the weld groove 9 that slightly shrinks during welding. Since the radius Rib of the intermediate point between them is larger than the target perfect circle radius Ri and smaller than the radius Ria (Ria> Rib> Ri), the inner radius of the stator core 2 is increased. The circumference has a target perfect circle radius Ri. Therefore, when the rotor 8 is disposed in the stator core 2, the air gap can be made uniform, and the occurrence of vibration can be prevented.

(Second embodiment)
FIG. 5 shows a second embodiment of the present invention. In FIG. 5, the same parts as those in FIG. 4 are denoted by the same reference numerals.
Like the stator core 2, the stator core 13 is formed by laminating a large number of iron cores formed by punching electromagnetic steel plates in an annular shape and welding welding groove portions corresponding to six weld locations. And a welding portion 14 corresponding to the welding groove. As for the outer periphery of the iron core before welding, the maximum radius part 15 having a radius Rb larger than the radius Ra of the other part is equidistant (center-to-center) at three parts, which are a plurality of parts excluding the weld part equivalent part (weld part 14). Is formed with an angle of 120 degrees).

  In this case, in the iron core material before welding, if the dimensional control of the maximum radius portion 15 is strict in consideration of the thermal expansion coefficient at the time of manufacture, the radius Rb of the maximum radius portion 15 is maintained even if it is affected by heat during welding. can do. The inner circumference of the stator core 13 is formed in the same manner as the stator core 2 and has a target perfect circle radius Ri. The stator winding 4 is housed in the slot 3 of the stator core 13 to form a stator 16. The stator 16 is fitted into the inner periphery of the frame 17 so that the maximum radius portion 15 is in pressure contact with small diameter portions 18 formed at three locations on the inner periphery of the frame 17.

  As described above, according to the second embodiment, the maximum radius portion 15 can be maintained at the radius Rb even if a large number of core members are stacked and bundled together by welding to form the stator core 13. Since it can be pressed against the small-diameter portion 18 of the frame 17, the contact area of the stator core 13 with respect to the frame 17 can be set as set, and thus the same effect as in the first embodiment can be obtained. be able to. Since the object can be achieved only by strictly controlling the size of the maximum radius portion 15 of the iron core material, the price does not increase so much as compared with the case where the entire size control is strictly controlled.

(Other examples)
In the first and second embodiments, the inner circumferences of the stator cores 2 and 13 are formed so as to have the target perfect circle radius Ri. However, the present invention is not limited to a perfect circle, and may have any shape. . In this way, the air gap with the rotor becomes non-uniform and vibrations are generated. By using this, for example, a vibration motor can be easily configured.

  In addition, the present invention is not limited to the above-described embodiments, and it goes without saying that the present invention can be carried out by being appropriately modified within the scope without departing from the gist.

The partial expanded front view of the iron core material before welding which shows the 1st example of the present invention Front view of iron core before welding Exploded perspective view of mandrel and laminated iron core when welding Radial cross section of induction motor Radial sectional view of a stator core and a frame showing a second embodiment of the present invention

Explanation of symbols

In the drawings, 1 is an induction motor (rotary electric machine), 2 is a stator core, 2a is a core material before welding, 2b is a core material after welding, 2c is a laminated core material, 5 is a stator, 8 is a rotor, 9 is a weld groove (corresponding to a weld location), 9a is a weld location, 10 is a mandrel, 13 is a rotor core, 14 is a weld location, 15 is a maximum radius portion, 16 is a stator, 17 is a frame, and 18 is a small diameter portion. Indicates.

Claims (2)

In a manufacturing method of a stator core of a rotating electrical machine, a plurality of annular cores made of electromagnetic steel plates are laminated, and a plurality of outer peripheral portions are welded along the axial direction to manufacture a stator core.
The outer periphery of the iron core before welding changes so that the radius of the welded part equivalent part is larger than the target radius and the radius of the intermediate point between the welded part equivalent part and the adjacent welded part equivalent part is smaller than the target radius. A method for manufacturing a stator core of a rotating electrical machine, wherein the stator core is formed as described above. The method for manufacturing a stator core of a rotating electrical machine according to claim 1, wherein the core material before welding is formed so that the inner periphery of the stator core has an arbitrary shape after welding .

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