RU2072108C1 - Transformer - Google Patents

Abstract

FIELD: electrical engineering; heavy-current equipment, resistance-welding apparatuses, feeding induction furnaces, etc. SUBSTANCE: transformer has primary winding 2 wound on toroidal core 1 and secondary winding 3 wound around primary one and made of bundles of noninsulated flexible conductors building up insulated coils 4, 5, 6 and fan-shaped in transitions from hole to outer surface of toroidal core 1 and back to hole. EFFECT: facilitated manufacture, reduced size and loss. 3 cl, 1 dwg

Description

 The invention relates to electrical engineering and can be used in high-current equipment, for example, in resistance welding devices, for checking current releases, for supplying induction furnaces, as well as in EDM installations, etc.

 Known transformer containing the primary winding and the secondary winding, which is made in the form of a composite container consisting of cylinders and disks (see AS USSR N 431561, class N 01 F 27/26 from 1972).

 However, the known device has a complex structure, requiring reliable electrical connection between the components of the container and tap current leads. The need for a welding joint complicates the manufacturing technology, and the welding process must be performed already after winding the primary winding, which in this case can greatly overheat.

 By technical nature, the closest to the proposed one is a transformer containing a primary winding located on a toroidal core and covering the secondary winding (see French patent N 2323215, CL H 01 F 31/06 from 1976).

 However, the design of the known device is cumbersome, relatively low efficiency due to the presence of significant losses from eddy currents and difficulties in assembling the secondary winding.

 The technical task is to increase manufacturability, reduce the size and reduce losses.

 To do this, in the transformer containing the primary winding located on the toroidal core and covering the secondary winding, the secondary winding is made of n bundles of uninsulated flexible conductors (where n is an integer) laid in insulated sections, and at the transitions from the hole to the outside and back to the hole of the toroidal The core beams are fan-shaped, in addition, the thickness of each bundle on the outer side of the toroidal core is equal to h, and h is equal to the thickness of the flexible conductor, while the coefficient filling the hole of the toroidal core is not less than 0.8.

 The essence of the invention lies in the fact that the implementation of the secondary winding with bundles of uninsulated flexible conductors made it possible to facilitate the winding of the secondary winding, to reduce dimensions due to the lack of insulation, to reduce the length of the coil, and the implementation of the isolated sections made it possible to organize the turns, isolating the beams from each other. In addition, in this design of the winding, eddy currents are significantly reduced, and consequently, losses are reduced, which also contributes to the organization of the fan-shaped shape of the secondary winding bundles.

 Comparison of the proposed device with the closest analogue allows us to judge the fulfillment of the criterion of "novelty", and the lack of distinctive features of the analogues of the proposed device indicates the fulfillment of the criterion of "inventive step". Dummy tests confirm the possibility of industrial use.

 The drawing shows the design of the proposed transformer.

 The transformer contains a toroidal core 1, a primary winding 2 placed on it and a secondary winding 3 covering it, made by n bundles (in figure 1 n1) of uninsulated flexible conductors from a brush wire of the ПЩ type. The bundles of the secondary winding 3 of the transformer are laid in the hole and on the outside of the toroidal core 1 with insulated sections 4,5,6 and, when switching from the hole to the outside of the toroidal core 1, have a fan-shaped shape. The primary and secondary windings 2 and 3 are separated by insulating tape 7 and impregnated with varnish. The thickness of the beam on the outside of the toroidal core 1 is equal to h, the value of which with a single-row secondary winding is equal to the thickness of the flexible conductor.

 Fan-shaped construction of the beam of the secondary winding 3 is necessary for organizing uniform coverage of the magnetic circuit to increase magneto-coupling and reduce power dissipation.

 The optimal value of the "fill factor" of the hole of the toroidal core should be at least 0.8. In this case, the remaining free space can be used to organize forced cooling of the device.

 The manufacturing process of the transformer is as follows. After winding onto the toroidal core 1 by a known method of primary winding 2 and applying an insulation tape 7 to it and impregnating it with varnish (or compound), a bundle of uninsulated flexible wires, for example, ПЩ type, is taken, one end of it is fixed on the outside of the toroidal core 1, straightening the wires in in the form of a fan for a more complete and tight coverage of the magnetic circuit in the form of a fan for a more complete and tight coverage of the magnetic circuit from the outside, and the first turn is made, and when changing from the hole to the outside, it is straightened again dissolved in a fan beam. The formed first section 4 is isolated, and when passing from the outside of the toroidal core 1, the wires are again collected in the form of a fan in a bundle. Next, a second turn is made with the formation of the corresponding second section 5 and its isolation from the subsequent third section 6, the end of which on the outside of the toroidal core 1 is also laid in the form of a fan and strengthened in the usual way.

 The result is a secondary winding having three turns and, accordingly, three sections.

 Similarly, additional secondary windings can be arranged, having their own isolated sections, respectively, if the transformer parameters are previously calculated.

 In this case, there may be various combinations of connections of the ends of the bundles of the secondary windings 3, depending on the required tasks.

 The sections of the secondary winding 3 are also impregnated with varnish or compound to increase strength and heat dissipation.

 Thus, the implementation of the secondary winding by 3 bundles of uninsulated flexible conductors made it possible to facilitate winding, reduce dimensions due to the use of conductors without insulation and denser winding, reduce the length of each turn and, accordingly, reduce active and eddy current losses, which also contributed to the organization of the fan-shaped shape of the secondary bundles windings.

Claims (3)

 1. A transformer containing a primary winding located on a toroidal core and enveloping its secondary winding, characterized in that the secondary winding is made of n bundles of uninsulated flexible conductors, where n is an integer laid in insulated sections, and at the transitions from the hole to the outside of the toroidal core and back into the hole, the bunches are fan-shaped.  2. The transformer according to claim 1, characterized in that the thickness of each beam on the outer side of the toroidal core is equal to h, where h is equal to the thickness of the flexible conductor.  5. The transformer according to claim 1, characterized in that the fill factor of the hole of the toroidal core exceeds 0.8.