RU2449400C1 - Method of transformer winding preparation for pressing - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: method of transformer winding preparation for pressing includes fabrication of upper pressing plate by reeling metal band onto template after reeling transformer winding on one reeling machine, then joining turns of upper pressing plate, then removal of template with transformer winding and upper pressing plate from the machine and transferring them for tipping to carry out winding bracing and further processing.

EFFECT: reducing consumption of material for pressing plates fabrication and increasing productivity of labor by using horizontal reeling machine.

2 dwg

Description

The invention relates to electrical engineering and can be used in the manufacture of windings of power transformers and reactors, in particular in their preparation for pressing and further finishing.

The manufacture of transformer windings is one of the most critical types of work in the manufacture of transformers. Despite the wide variety of winding designs, the production sequence of many of them is not significantly different.

Before proceeding with the winding of a winding of a transformer (hereinafter simply windings), preparatory work is first carried out, including familiarization with the design note and the drawing of the winding. Then there is the preparation of the necessary devices, plates and studs for screed and pressing of the winding, wooden and metal supports necessary for screeding and pressing and other materials, devices and tools. After this, the entire installation for winding the winding is assembled, the winding machine with all the devices is adjusted and the winding is wound.

Under the operation of winding understand the complex of work performed at one workplace (Antonov MV, Gerasimova LS - Technology for the production of electric machines: Textbook for universities. - M .: Energoizdat, 1982., 408-411). Work on winding the winding includes both directly winding the turns of the winding on the bakelite cylinder or the template mandrel, and performing transitions, transpositions, loops of adjusting taps, installing and attaching capacitive rings, soldering or welding the ends of coils or conductors, isolating soldering places, installing insulation parts (rails, spacers, washers, boxes), installation of bandages and a number of other works.

For winding windings, horizontal-winding machines (GNS) and vertical-winding machines (ANS) are widely used. The type of machine and the optimal winding speed are selected in accordance with the type and size of the winding winding, its weight, shape and cross section of the winding wire.

After winding the winding, it needs additional processing: pressing, drying and finishing, during which all the geometric dimensions of the winding are brought to the required size, eliminate damage to insulation, bandages and other deviations

In order to impart a stable structural dimension to the winding in height, to avoid damage to the winding and insulation during pressing, to evenly distribute the compressive force, after winding, the winding is prepared for pressing and an intermediate operation is introduced to install special pressing plates tightened together by studs on the winding. This operation is called “winding screed”.

The preparation of windings of power transformers and reactors for pressing begins with the assembly of windings with terminal insulation (http://leg.co.ua/transformatori.html). Then, in accordance with the length and diameter of the winding being pulled together, the corresponding pressing plates and the studs pulling them from the previously manufactured plates for other types of windings are selected in size. The diameter of the axes of the holes for the studs in the plates should be approximately 200 mm larger than the outer diameter of the winding, and the length of the studs is equal to the estimated length of the winding and supports on both sides. Since the tool for pressing the windings is also a load-bearing structure, the calculation of the number of studs, their sizes and the design of the plates should be made taking into account two forces - pressing and the weight of the winding with the tool. If there are no plates with the required dimensions on the site, then their additional manufacture or purchase is necessary.

Using a bridge crane, the mandrel with the winding is removed from the winding machine and moved to the screed and pressing section, where the equipment (hydraulic installation, wrenches, canting device, pressing plates, studs, nuts) for carrying out the technological operation - winding screed is already prepared. On the tilting device, the mandrel with the winding is turned from a horizontal position to a vertical position and mounted on a prepared pressing unit. The upper pressing plate is laid so that the center of the plate coincides with the axis of the winding, the tie rods are inserted into the holes of the pressing plate and evenly tightened with a key on all nuts. At the same time, in the process of screeding, it is constantly supported by a crane. Windings pressed into the pressing plates are transferred for further processing.

A disadvantage of the known technical solutions is the use of individual pressing plates for each type of winding, which leads to additional technological operations for their manufacture and high material costs. After use - the plates must be stored, which requires additional space. Further use of such a plate is only possible with serial production of one type of transformer. When installing pressing plates, additional equipment is required.

In the known level of technology development close technical solutions that can be taken as a prototype of the invention have not been found.

The technical result of the claimed invention is to reduce the consumption of material for the manufacture of pressing plates and increase productivity by using a horizontal winding machine.

The technical result is achieved by the fact that the method of preparing the transformer winding for pressing includes manufacturing the upper pressing plate by winding a metal strip onto the template after winding the transformer winding on one winding machine, then fastening the turns of the upper pressing plate, then removing the template with the transformer winding and the upper pressing plate with the machine and moving them to tilting to conduct winding ties and further processing.

In the manufacture of a transformer winding, its inner and outer diameters are always known. Based on these sizes, the required size of the pressing plates is calculated in advance. Therefore, the length of the metal tape with its known thickness, necessary for the manufacture of the plate, for this particular winding is determined by the formula:

where L [mm] is the length of the metal tape;

π = 3.14 - Pi number

R _n [mm] is the outer radius of the pressing plate;

R _int [mm] - the inner radius of the pressing plate (equal to or less than the inner radius of the winding);

Δ [mm] is the thickness of the tape.

In the manufacture of a pressing plate for windings with other structural dimensions, the possibility of using a previously manufactured plate according to formula (2) is determined, since the internal radius of the manufactured winding and the length of the metal strip in a previously manufactured plate are always known:

The positive effect of the invention is:

- expanding the functionality of the winding machine without changing its design by using it immediately in two operations: winding the transformer winding and winding the pressing plate;

- repeated use of the upper pressing plate when tightening the windings leads to savings in materials during their manufacture and savings in production space during their storage, because a new pressing plate with other dimensions, if necessary, is made from an already used, but not necessary plate;

- increase in labor productivity in the manufacture of the pressing plate and in the areas of screed, pressing and finishing, because the transformer winding comes there assembled with the upper pressing plate;

- reducing the number of pressing plates of different sizes.

The invention is illustrated by drawings. Figure 1 graphically depicts the implementation of the proposed method using a horizontal winding machine. Figure 2 presents the design of the upper pressing plate.

The method of preparing the windings of power transformers for pressing is carried out on a horizontal winding machine 1. To do this, after the manufacture of the windings of the transformer 2 on this machine, first install the end insulation and finish the outer rails 3, then install a drum with a metal tape or previously used pressing plate of a given size on the carriage 4. Pass the end of the metal strip through the carriage of the radial tensioner 5 and fix it in a special device. On the internal rails installed on all the guide beams of the template 6, at a distance from the transformer winding, equal to the length of the prepared technological supports 7, a metal tape is wound on the transformer winding template. In this case, the carriage of the radial tensioner 5 and the axial pressing device 8 provide the density of the turns of the manufactured upper pressing plate 9. At the end of the winding of the upper pressing plate, the turns of the tape are fixed with clamps 10 (figure 2) and the template 6 with the transformer winding 2 and the upper pressing plate 9 is removed from the winding machine 1 and move to the next technological operation - tilting to conduct winding ties on a hydraulic press, the base of which serves as the lower pressing plate. After that, further technological processing of the transformer winding is carried out: pressing, drying, finishing.

According to the proposed method, the ring was wound from a metal tape 2 × 40 from spring steel 65 g (GOST 2283-79) on a horizontal winding machine "TUBOLY" using an expansion mandrel "Domieden" with dimensions: d _ext = 1200 mm; d _nar = 1400 mm, corresponding to the dimensions of the upper pressing plate of the high voltage winding of the transformer TRDTSN-100000/220.

The manufacturing time of the upper pressing plate was 0.5 hours. The manufactured plate corresponded to the geometrical dimensions and the planned parameters, while the density of the turns of the spiral satisfied the task. Technological tests carried out on a specially designed bench with alternate use of hydraulic cylinders with lower and upper arrangement in the amount of 8 pieces showed that when pressing with a force of 88 ton-force (155 bar with 8 cylinders RC506VE100) there are no structural and mechanical changes in the tested pressing plate made of metal tape was not observed.

The described method for preparing the windings of power transformers for pressing can be used at enterprises using both thermal vacuum processing of windings and mechanical screed. It allows you to reuse press plates for different types and types of transformer windings, reduces the cost of their manufacture, the purchase of additional devices, and also eliminates the use of intermediate plates. Reducing the manufacturing time of pressing plates using a winding machine increases labor productivity.

Claims (1)

The method of preparing the transformer winding for pressing, including the manufacture of the upper pressing plate by winding a metal strip onto the template after winding the transformer winding on one winding machine, then fastening the turns of the upper pressing plate, then removing the template with the transformer winding and the upper pressing plate from the machine and moving them to canting for winding ties and further processing.

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