End winding restraint in an electrical machine

Abstract

The rotor body of an electrical machine has end windings supported by a plurality of circumferentially spaced rakes having tines between which the end windings pass in an arcuate pattern from and for return to an axial orientation within the rotor body. The rakes are supported on axial beams secured to the rotor body. An end disk is secured at the opposite ends of the beams and to a shield overlying the end windings. The rakes, beams and end disks provide axial end winding restraint. The end disk is weighted at selected circumferential locations to resist tendencies of the end windings to distort, e.g., toward an elliptical or non-concentric configuration about the rotor axis.

Description

BACKGROUND OF THE INVENTION [0001] The present invention relates generally to electrical machines of the type having a rotor and field windings, including end windings about the rotor body and particularly relates to restraints for restraining axial movement of the end windings and minimizing distortion of the rotor end windings in circumferential and axial directions. [0002] In electrical machines, for example, generators, there is provided a rotor body having field windings which in part extend from the rotor body to form arcs at the opposite ends of the rotor body called end windings. The end windings extend generally axially from the rotor body and cross over supports or spindles in a circumferential direction adjacent opposite ends of the body for return in an axial direction into and along the rotor body. In a typical generator construction, the windings are located in slots in the rotor body and wedges secure the windings in the slots. The end windings are typically separated...

AI Technical Summary

Benefits of technology

[0005] In a further preferred embodiment according to the present invention, there is provided an arrangement for restraining deformation of end windings of a rotor about a rotor axis in an electrical machine comprising a rotor body, field windings extending along the rotor body including the end windings and a support assembly for the end windings including a disk extending generally normal to the axis of rotation of the rotor body, the rotor body having a quadrature axis and the disk having a weight distribution thereabout such that the disk has a greater diametrically symmetrical weight along the quadrature axis than the diametrically symmetrical weight along a direct axis perpendicular to the quadrature axis and the axis of rotation.

Problems solved by technology

In both types of generator constructions, the end windings can become distorted, i.e., elliptically deformed and lose concentricity if not supported.

Also, the end windings have a tendency to displace axially when the generator is operated at speed.

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