SU381132A1 - ELECTRIC MACHINE STATOR - Google Patents

Description

In the known stators of electric machines containing a core winding with direct gas cooling, a core in which the cooling gas circulates from its back to the bore, pressure plates holding active steel packages with accelerating wedges with studs and an insulating partition located between the end shields and by the heads of the winding rods, there is a greater non-uniformity of cooling of the winding and active steel packages. The most heated are the frontal parts and end packs. The gas circulating from the back of the stator to the bore does not provide cooling of the intensely heated parts due to the large local losses due to the fact that the aerodynamic resistance of the channels between the arc sections of the rods is much greater than the resistance of the windows between the rods at the point of their exit from the stator slots . In this case, the cooling gas passes predominantly through the windows and cools off only a small part of the winding. At the same time, pelvic flows, cooling steel end packs are also shunted.

In the proposed stator in order to intensify the cooling of the frontal parts of the winding and end packages of the stator on the surfaces of the pressure plates facing the housing

an insulating casing with calibrated holes, some of which are aligned with the corresponding holes made in the pressure plates, and

The coaxial holes communicate with an annular gap formed by the outer surface of the stud and the channel of the pressure plate in which it is located, and on the end surface of the extreme pressure plate there is an annular insulation wall adjacent to the winding frontal part.

FIG. 1 shows a longitudinal section of a stator of a turbogenerator with a cross section of pressure plates outside the channel for a pin; in fig. 2 -

longitudinal section of the pressure plates along the channel with a pin.

An insulating partition / of a cylindrical or conical shape is made between the heads of the stator rods and shields. On the surfaces of the pressure plates 2 facing the housing of the mask 5 there is a casing 4 of insulating material with calibrated holes 5, some of which are coaxial with the corresponding holes 6 made in

pressure llith. The holes 6 communicate with the vent 7 between the pressure plate 2 and the steel end stack 8 by means of annular gaps (slots) 9 formed by the outer surface of the iO pinch

accelerating wedges and push channels

plates in which they are placed. An annular insulating partition 12 is installed on the end surface of the extreme pressure plate // tightly attached to the retaining rings 13. Between the housing 3, the annular partition, the insulating partition- and the surface of the frontal parts 14 a chamber 15 is formed, parallel to it along the gas flow the second chamber 16, limited by the plates 17, 18 of the pressure plate, the casing 4, the annular partition 12 and the surface of the frontal portions 14. Both chambers communicate with the cold gas zone. Chamber 15 is in direct communication, and chamber 16 is through openings in the casing 4. The cross section of these openings is chosen so as to limit the flow of gas passing through the pressure plates and the windows between the rods at the exit from the slots to the required value. This leads to a decrease in the total flow rate through the nascina due to the elimination of the unproductively used part of it and, consequently, to a decrease in power losses per ventilation and an increase in the pressure developed by the fan. At the same time, the gas flow through the frontal parts of the winding (through chamber 15) increases and the gas flows almost throughout their length. Gas consumption through the stator active steel packs also increases to a certain extent. In order to intensify the cooling of the end packs, an additional supply of cold gas to the ventilation duct 7 is provided through annular gaps (slots) 9 and openings made in the casing 4 - the corresponding openings 6 of the pressure plate in the - area of the studs.

Subject invention

The stator of an electric machine, such as a turbogenerator, containing a rod winding with direct gas cooling, a core in which the protective gas circulates, from its back to the bore, clamp plates holding active steel packages with spreader wedges with studs and an insulating partition located between end shields and winding rod heads, characterized in that, in order to intensify the cooling of the winding frontal parts and extreme stator packages, on the surface of the pressure plates facing to The machine has an insulating casing with calibrated holes, some of which are coaxial with the corresponding holes in the pressure plates, and the coaxial holes communicate with the annular gap formed by the outer surface of the pin and the channel of the pressure plate in which it is placed , and on the end surface of the extreme pressure plate, an annular insulating partition is installed adjacent to the winding frontal part.