RU1815748C - Process of formation of ends of stator winding of electric machine - Google Patents

Abstract

Usage: in electrical engineering, namely in the technology for manufacturing the stator windings of an electric machine. SUMMARY OF THE INVENTION: An installation implementing the method comprises a technological mandrel mounted in bearings with its axial shaft and connected through a coupling to the rotor of the engine. I install a wrapped stator on a technological mandrel that drives rotation through the shaft. New in the method is that the forming forces of the frontal parts of the winding create centrifugal forces acting on the frontal parts of the winding when the stator rotates. The residual deformation of the frontal parts is fixed by banding after the stator stops. 1 s.p. f-ly, 2 ill.

Description

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The invention relates to the field of electrical engineering, and in particular to a technology for manufacturing the stator windings of an electric machine.

The aim of the invention is to provide a method for forming the frontal parts of the stator winding of an electric machine, in which the insulation of the frontal parts is not subjected to impact and friction, is not damaged, as a result of which the winding is more reliable and durable; Another object of the invention is to increase the productivity of the frontal molding process.

In FIG. 1 shows a processing unit for implementing the method and forming forces acting on the frontal parts of a winding; in FIG. 2 - contours of the frontal part of the stator winding and different times of the molding process: before the stator rotates, during the stator rotation and after the stator stops.

To implement the proposed method of forming the frontal parts of the stator winding of an electric machine, an apparatus 1 is used (Fig. 1), containing a technological mandrel 4 installed in the bearings 2 by its axial shaft 3, which is connected through the coupling 5 to the rotor of the motor 6. The proposed method of forming the frontal parts of the winding of the winding as follows. A stator 7 with a winding is put on the outer surface of the mandrel 4, which, after laying and securing with slotted wedges 9, has not yet been impregnated. The stator package is fastened by one of the known methods, for example, brackets 10, or is pressed into the frame. The stator 7 is fixed on the mandrel 4 in any known manner, for example, by bolts 11, screwed into the mandrel holes to the stop with the stator (beam 00

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This fixation takes place if the bolts 11 are located in the slots of the stator grooves and abut against the groove wedges 9). Then, the engine 6 is turned on and the stator 7 is rotated at a frequency experimentally selected for a given design with specific values of the mass, outreach and stiffness of the frontal parts. When the stator rotates, radially directed centrifugal forces 12 and 13 arise, acting on cantilevered frontal windings 8 and moving these parts away from the axis of rotation. If the frontal parts 8 were located along the contour 14 (Fig. 2) before rotation of the stator, then during rotation they are moved apart under the influence of centrifugal forces and occupy a position corresponding to contour 15. This arrangement of the frontal part during rotation is due to the fact that the force 12 applied at a larger the shoulder 16 from the point of fastening by the wedge 9, creates a greater bending moment than the force 13 exerted on the smaller shoulder 17; therefore, the parts of the winding on the shoulder 16 move apart more than on the shoulder 17, and the surface of the frontal parts takes the form of a lateral surface of a truncated cone, which forms an angle of 18 with the direction of rotation of the stator.

The rotation time is held for 1-2 minutes, after which the engine is turned off and the stator is stopped. The release of centrifugal forces leads to a decrease in the angle between the surface of the frontal parts and the axial direction to a value of 19, which characterizes the residual deformation of the frontal part 8. The frontal part has the final contour 20. To apply the proposed method in serial production by selecting the frequency of rotation of the mandrel 4 on the reference a sample of the produced electric machine achieves a design angle of 19; according to these data, on all samples of serial production machines (taking into account permissible technological deviations), the frontal parts are formed by the described operation. After molding, the frontal parts are bandaged, thereby fixing the obtained bending angle 19 and the contour 20, and the stator is guided for impregnation.

In an embodiment of the proposed method, the intensity of the action of centrifugal forces is increased, auxiliary weights 21 are fixed to the winding sections in the frontal parts, for example by means of a tie. In this case, the rotation of the stator to achieve the desired angle 19 can be carried out with a lower frequency, which will protect the groove part of the winding from excessive mechanical stresses and possible shifts in the grooves of the stator. The use of auxiliary weights is advisable in windings with rigid sections having a large moment of resistance to bending (such as, for example, windings of electric machines with a large ratio of the height of the groove to its width). In this case, it is justified to increase the complexity of the molding process due to the attachment of auxiliary weights, since the presence of these weights makes it possible to easily obtain the necessary centrifugal forces for bending sections. Upon completion of molding, 5

powerful weights are loosened and the frontal parts are bandaged, after which the stator is directed to impregnation.

In those designs in which restrictive retaining rings are provided that cover the frontal parts on the outer surface, the angle 19 can be chosen so that after rotation of the stator the frontal parts abut against these

5 retaining rings fixed on the stator package with support brackets. In this case, upon completion, by the proposed method, the bending of the frontal parts, the latter are attached to the bandage

0 rings and thereby more clearly fixed in the desired position.

The proposed method for forming the frontal parts has significant advantages over the known ones. In known methods

5 molding forces are transmitted to the frontal parts through repeated impact or pressing actions, accompanied by friction of the working body of the technological device with frontal isolation

0 parts that can lead and in fact often lead to damage to the insulation of the frontal parts and to deterioration of the quality of the winding, to a reduction in its service life (especially during prolonged exposure to dust and moisture during operation). The presence of friction also leads to rapid wear of the surface of the working body of the technological molding device, therefore, in the known devices that implement

0 known moldings, it is necessary to periodically update the nozzles of the working body, which increases the cost of technological equipment. With shock or wringing, the winding

5 is deformed only in the local place of application of the impact, therefore, in order to achieve a predetermined frontal angle 19 by known methods when manually winding, the wrapper has to repeatedly upset all sections alternately around the grooves, gradually increasing the value of this angle to a predetermined one. Thus, the known HbiR methods of mechanized molding are associated with a deterioration in the quality of the insulation of the winding, and the known methods of manual molding of the frontal parts, with the aforementioned deterioration in the quality of the insulation, are also quite long in time, associated with noticeable labor costs that reduce productivity winding work.

In contrast, the molding of the stator frontal parts by the proposed method ensures the best quality of the winding due to shockless (non-contact) bending forces, which in this case arise simultaneously in all sections from centrifugal forces, with complete absence of friction and wear of the contacting parts. The simultaneous action of bending forces makes it possible to bend the frontal part with a smaller amount of force applied to each individual section, and therefore also leads to a significantly smaller influence of the molding process on the quality of insulation. Thus, when applying the proposed method of forming the frontal parts, there is no damage to the insulation and deterioration of the quality of the winding. On the other hand, the proposed method makes it possible to noticeably (approximately 1.5-2 times) reduce the time of frontal forming operations during manual winding and thereby reduce the laboriousness of winding operations.

Claims (2)

1. A method of forming the frontal parts of the stator winding of an electric machine, according to which the deposition forces in the radial direction are applied to the frontal parts of the stator windings before impregnation, they give the frontal parts of the winding the shape of a side surface of a truncated cone and fix this position of the frontal parts with a banding, o t is different. that, in order to increase the reliability and durability of the winding by eliminating damage to the insulation at the places of application of the upsetting force and increase productivity, the wound stator is mounted on a technological mandrel having an axial shaft and rotated through this shaft to create molding forces by centrifugal forces acting to the frontal parts of the winding during rotation of the stator, and their frontal parts are fixed after obtaining permanent deformation. 2. A method according to claim 1, characterized in that, in order to obtain large centrifugal molding forces, weights are fixed to the frontal parts of the winding before the stator rotates, which are removed after the stator stops.