RU2275729C1 - Electrical machine winding - Google Patents

Abstract

FIELD: electrical engineering; multipole ac electrical machines and their stator and rotor windings.

SUBSTANCE: proposed electrical machine winding has at least most of end-portion conductors made in the form of jumpers whose sectional area at points of connection to bars averaged lengthwise of slot; is smaller than that of winding bars being connected; junctions between mentioned jumpers and bars of winding upper layer are disposed on toothed surface end of core; junctions between these jumpers and bars of winding lower layer are disposed on core yoke end; cross-sectional areas of winding phase lead conductors at junctions between them and bars averaged lengthwise of slot are smaller than those of bars they are connected to.

EFFECT: reduced overhang of end windings, facilitated manufacture, reduced material input.

4 cl, 5 dwg

Description

The invention relates to electric machines, structures of stators and rotors of AC machines. It can be used in the design and manufacture of AC electric machines with a significant number of poles.

Known wave rod windings of electrical machines (Voldek A.I. Electrical machines. L., 1978, S. 497-409). It includes rods located in the upper part of the grooves of the core, forming the upper layer of the winding, and rods located in the lower parts of the grooves of the core, forming the lower layer of the winding, conductors of the frontal parts located at the ends of the core, including conductors between the rods of each coil and conductors for connection coil groups, as well as conductors of the terminals of the winding phases. The frontal parts of the winding are rigid and do not have inter-turn isolation. However, the overhang of the frontal parts of the winding is very large.

Known winding of an electric machine (rotor) (RF patent No. 2152117, RU BIPM No. 18, 06/27/2000), containing in the grooves of the core electrically insulated conductors-rods connected by short-circuit rings - frontal parts of the winding made of elementary short-circuit rings. The invention allows to reduce electrical losses in the short-circuited rotor winding from higher time voltage harmonics when the machine is powered from a non-sinusoidal voltage source.

The disadvantage of this winding is the possibility of its use only in machines with a squirrel-cage rotor.

Also known is the winding of an electric machine (Lytkin V.V. A method for organizing the frontal parts of electric machines with a minimum axial reach. Vestnik UGTU No. 5 (25), Yekaterinburg, 2003. p.190-193), which is closest to the proposed one. It also includes rods located in the upper part of the grooves of the core, forming the upper layer of the winding, and rods located in the lower parts of the grooves of the core, forming the lower layer of the winding, conductors of the frontal parts located at the ends of the core, including conductors between the rods of each coil and conductors for connections of coil groups, as well as conductors of the terminals of the winding phases.

To reduce the departure of the frontal parts of the winding, the rods are bent when they exit the grooves in a plane perpendicular to the axis of rotation along radii towards the outer diameter of the stator core (stator winding) or to the axis of rotation (for winding the phase rotor). Each winding rod, coming out of the groove at some distance from the end face of the stator core (rotor), determined by the voltage class, bends twice along a line passing at an angle of 45 degrees to the axis of the rod along its wide side. Due to the fact that the rod bends along its wide side, the probability of damage to the insulation of the winding rods is significantly lower than when the rods bend to the rib, as happens in coils of a conventional design when moving from the upper rod to the lower one. After the second bend, the rod is in a plane perpendicular to the axis of rotation, and is located along the radial line. In this case, the distance between the fold lines is selected so that after two bends the rod passes under the rod located in the adjacent groove. After that, the rod bends flat, either along an arc of a circle, or in a straight line and forms the frontal part of the winding. Then, after two of the same bends, going in the opposite order, the rod goes into the groove corresponding to the step of the winding. For rods in which the conductors are in a horizontal position, the frontal part is formed after two bends.

The disadvantage of this winding is a significant overhang of the frontal parts, the complex technology of its manufacture, the possibility of manufacturing only concentric windings.

The purpose of the invention is to reduce the departure of the frontal parts of the winding, simplifying the technology of its manufacture, saving material (for example, copper).

This goal is achieved by the fact that in the winding of an electric machine, including rods located in the upper part of the grooves of the core closer to the tooth surface of the core, forming the upper layer of the winding, and rods located in the lower parts of the grooves of the core closer to the yoke of the core, forming the lower layer of the winding, conductors of the frontal parts located at the ends of the core, including electrically insulated conductors between the terminals of the winding coils and electrically insulated conductors for connecting the coil groups, as well as electrically insulated conductors of the outputs of the winding phases, at least most of the conductors of the frontal parts are made in the form of jumpers, the cross-sectional areas of which at the points of their connection with the rods are less than the cross-sectional area of the connected winding rods averaged over the length of the groove, and the joints of the said jumpers the rods of the upper layer of the winding are located on the side of the tooth surface of the core, and the joints of these jumpers with the rods of the lower layer of the winding are located on the side of the core, while the conductors of the terminals of the winding phases also have cross-sectional areas at their junctions with the rods less than the cross-sectional area averaged over the length of the groove of the rods with which they are connected.

In addition, the said jumpers between the coil rods are made in the form of two rings of coil jumpers, including alternating electrical conductive layers and insulation layers alternating in the cross section of these rings, mechanically firmly interconnected. In this case, the conductors of the conclusions of the phases of the winding are made as a single unit with the rods with which they are connected.

In addition, for the purpose of better cooling, an air gap is made between the surfaces of the rings of the coil bridges not connected to the rods and the end surfaces of the core and the rods not connected to the coil bridges.

An example of a specific implementation of the invention is illustrated in figures 1, 2, 3, 4, 5.

Figure 1 shows the sector of the active part of the stator of an alternating current machine with the proposed winding. It includes grooves 1, 2, 3, 4, 5 of the core 6, in which the upper layer of the winding with the rods 7, 8, 9, 10, 11 and the lower layer of the winding with the rods 12, 13, 14, 15, 16. These rods separates the interlayer insulation 17, shown in the grooves with a thickened dashed line. Shown are coil bridges 18, 19, a layer of insulating material 20 and a coil bridle 21. The rods 10 and 12 are connected by a jumper 19, the cross-sectional areas of which are shaded at the junctions with the rods and are approximately two smaller than the cross-sectional areas of the rods 10 and 12. Similarly, the bridges 18 , 21, etc., connecting the rods of the coils.

As can be seen from figure 1, the junction of the jumpers with stubs of the upper layer of the winding are located on the side of the surface 22 of the tooth layer of the core 6, and the junction of the jumpers with the rods of the lower layer of the winding are located on the yoke side 23 of this core. This achieves the formation of a place above the rods at the ends of the core, in which the coil bridges of the frontal parts of the winding are located.

Figure 1 also shows a jumper 24 for connecting coil groups. As can be seen, the hatched cross-sectional area at the points of its connection with the rods 13, 16 is almost 2 times less than the cross-sectional areas of the rods.

The conclusions of the phases of the winding at the junction with the rods have a cross-sectional area of almost 2 times less than the cross-sectional area of the rods, for example, the output of phase B (Fig. 1) connected to the rod 11.

Between the coil jumpers there are layers of insulation, for example (Fig. 1) layer 25 - between the jumpers 18 and 19, indicated by thickened lines. There are insulation layers between the coil jumpers and jumpers for connecting the coil groups, for example layer 26. There are also insulation layers between the coil jumpers and the conductors of the terminals of the winding phases, for example layer 27. The rods are isolated from the core.

Figure 2 shows a diagram of the winding corresponding to the proposed design of the winding. The numbering of the grooves corresponds to figure 1. Here n is the number of grooves in the core. Designations correspond to the technical literature, for example, A. Voldek. Electric cars. L., 1978, p. 497-499.

Figure 3 presents a view of the stator with the rings of the coil jumpers 28, 29 and the leads of the stator windings A, B, C. The air gap between the surfaces of the rings 28, 29 of the coil jumpers not connected to the rods and the end surfaces of the core 6 not connected to the coil jumpers rods marked δl. The design of the ring 28 is similar to the design of the ring 29 shown in figure 1.

Figure 4 presents a view of section aa, corresponding to figure 1. Shown are alternating conductive layers 18, 19, 21 and insulation layers 20, 25. The lower end surfaces of the bridges 18, 21 are connected (for example, by soldering) to the end surfaces of the rods 9, 14. Similarly, the remaining rods are connected to the coil bridges of the rings 28, 29 windings.

Figure 5 shows the implementation of the findings of the proposed winding. For mechanical strength, the findings are made as a unit with the rods. For example, terminal B is made as a unit with the rod 11 located in the groove of the core 6.

Thus, the proposed winding of an electric machine allows you to make connections between the rods at the shortest distance between them, which allows to minimize the outflow of the frontal parts of electric machines with such windings.

Claims (4)

1. The winding of an electric machine, including rods located in the upper part of the grooves of the core closer to the tooth surface of the core, forming the upper layer of the winding, and rods located in the lower parts of the grooves of the core closer to the yoke of the core, forming the lower layer of the winding, conductors of the frontal parts located along the ends of the core, including electrically insulated conductors between the terminals of the winding coils and electrically insulated conductors for connecting the coil groups, as well as electrically insulated wired conductors of the outputs of the winding phases, characterized in that at least most of the conductors of the frontal parts are made in the form of jumpers, the cross-sectional areas of which at the points of their connection with the rods are less than the cross-sectional area of the connected winding rods averaged over the length of the groove, and the joints of the coil jumpers with the rods the upper layer of the winding is located on the side of the serrated surface of the core, and the joints of these jumpers with the rods of the lower layer of the winding are located on the side of the yoke of the core, This phase coil conductors findings are also cross-sectional area at the connection with the rods is less than the average length of the cross-sectional area of the slot bars to which they are connected. 2. The winding of an electric machine according to claim 1, characterized in that the said jumpers between the coil rods are made in the form of two rings of coil jumpers, including alternating electrical conductive layers and insulation layers alternating in the cross section of these rings, mechanically firmly interconnected. 3. The winding of an electric machine according to claim 1, characterized in that the conductors of the terminals of the phases of the winding are made as a unit with the rods with which they are connected. 4. The winding of an electric machine according to claim 2, characterized in that, for the purpose of better cooling, an air gap is made between the surfaces of the rings of the coil bridges that are not connected to the rods and the end surfaces of the core with the rods that are not connected to the coil jumpers.

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