RU2310965C2 - Winding of electric machine with short overhang of frontal parts - Google Patents

Abstract

FIELD: electric engineering and electro-mechanical industry, namely, windings of electric machines.

SUBSTANCE: winding of electric machine, consisting of rigid coils, is made of rectangular cross-section wire and has groove and frontal parts. In accordance to the invention, each rod of winding during transition from groove part to frontal part and backwards is twice bent along the line passing at an angle of 45 degrees to longitudinal axis of wide side of rod, and frontal parts of coils of different phases of winding are positioned one after the other along the rotation axis of machine and bent along a circle.

EFFECT: ensured minimal possible overhang of frontal parts of winding coils due to their radial positioning, and also due to simplified manufacturing technology of coil and reduced fault probability of winding isolation due to the fact that rods are bent along their wide side.

5 dwg

Description

The invention relates to electrical engineering, in particular to the windings of electrical machines, and can be applied in the design and construction of electrical machines having rod windings.

At the moment, there are a number of designs of two-layer rod windings of electrical machines. Known two-layer winding made of conductors of rectangular cross section, consisting of active rectilinear groove parts and conjugate with them curved with the presence of a transitional loop of the frontal parts [1].

The disadvantage of such a winding is the large overhang of the frontal parts, the high complexity of its manufacture and the insufficient reliability of the coils due to the possibility of damage to the coil insulation when stretching the billet of the coil (boat) on a stretching machine.

Also known is a coil of a rigid two-layer winding made of conductors of rectangular cross section, consisting of active rectilinear groove parts and associated frontal parts curved along the involute [2]. The winding, consisting of such coils, also has a large overhang of the frontal parts, and their bending along the involute presents significant technological difficulties.

Another coil of a two-layer winding is known, made of a wire of rectangular cross section, having a frontal part curved in an oval helix with a middle line arranged in a spiral on a surface formed by rotation around the longitudinal axis of the oval machine, the major axis of which is an acute angle with the longitudinal axis of the machine, and the cross section of the coil is smoothly rotated in the frontal part around the midline by an angle equal to the sum of 180 and the central angle between the grooves occupied by the coil [3].

The manufacture of such a coil is a time-consuming process due to the need to rotate the cross section of the billet (boat) in the frontal part around the midline by an angle equal to the sum of 180 and the central angle between the grooves occupied by the coil. This requires a special device, and turning the coil cross-section through such a large angle leads to deformation and damage to the coil insulation in the frontal part, stratification of the coils due to changes in the radii of bends and mates, which reduces the reliability of the winding.

Closest to the invention in technical essence is a winding according to the copyright certificate [4]. In this winding, the coil of a rigid two-layer winding of an electric machine is a collection of n-turns of rectangular wire and has straight groove parts and frontal parts curved along an oval-helical line. The latter, in turn, have upper and lower branches, conjugated with the groove parts and between themselves by arcs of circles. Moreover, in the frontal part there is a rotation of each coil around the midline of the coil, external in the cross section of the coil. The set of all the other turns rotated around the midline of the outer turn forms a cross section of the coil, smoothly rotated 180 degrees in the frontal part.

In a coil of this design for the formation of the frontal parts, a template of a special shape is needed, and in addition, the departure of the frontal parts is not reduced.

The purpose of the invention is to reduce the departure of the ice part of the winding, simplifying the technology of molding the frontal parts, reducing damage to the insulation and increasing the reliability of the winding.

This goal is achieved as a result of the fact that the rods, when passing from the active part 1 to the frontal 2, when leaving the grooves 3, bend 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 windings of a phase rotor).

Figure 1 shows the transition of the rod from vertically arranged conductors to the frontal part under the rod located in an adjacent groove; figure 2 - transition to the frontal part of the coil of the rod with horizontally located conductors; figure 3 shows the frontal part of one coil group; figure 4 - the relative position of the frontal parts of the phases; figure 5 shows the relative position of the rods of the winding in the area of the frontal parts.

Each rod of the winding 1, leaving the groove 3 at some distance from the end face of the stator core (rotor) 4, determined by the voltage class, double bends 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 this, the rod is bent flat either along an arc of a circle or in a straight line and forms the frontal part of the winding 2. 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 frontal parts of the rods lying in adjacent grooves and forming one coil group are located under each other.

The frontal parts of the coils of different phases are displaced relative to each other along the axis of rotation by the amount required by the conditions of electric strength. The rods of coils lying in one groove and belonging to the same phase are bent in opposite directions in the following sequence: first lower, then upper.

Thus, in comparison with the known designs of the core windings, the proposed design of the winding gives a minimum overhang of the frontal parts of the winding, significantly simplifies the technology of their molding and improves the reliability of the winding by reducing the damage to its insulation.

Information sources

1. Kaganov L.M. Rigid stator winding technology. M. - L .: Energy, 1965, p. 12-16.

2. Wiedemann G., Kellenberger V. Designs of electrical machines. L., Energy, 1972, p. 189, Fig. 7-20.

3. Copyright certificate of the USSR No. 521633, cl. H02K 3/04, 1976.

4. Copyright certificate of the USSR No. 1725319, cl. Н02K 3/04, 1987. - prototype.

Claims (1)

The winding of an electric machine, consisting of rigid coils, made of rectangular wire and having groove and frontal parts, characterized in that each winding rod, when moving from the groove to the frontal and back, is twice bent along a line passing at an angle of 45 ° to the longitudinal the axis of the wide side of the rod, and the frontal parts of the coils of different phases of the winding are placed one after another along the axis of rotation of the machine and bend around the circumference.

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