Patent ID: 8365392
Filing Date: 2013-02-05
Classification: H02K,Y10T

Abstract:
1. A method of fabricating a rotor assembly for an electric motor, the method comprising the steps of: inserting a plurality of rotor bars into a corresponding plurality of slots within a stack of laminated discs, wherein a first portion of each of said plurality of rotor bars extends away from a first end surface of said stack of laminated discs, and wherein a second portion of each of said plurality of rotor bars extends away from a second end surface of said stack of laminated discs; inserting a first plurality of slugs between corresponding adjacent rotor bar surfaces of said first portion of said plurality of rotor bars to form a first rotor bar/slug assembly, wherein each slug of said first plurality of slugs is separate and independent from all other slugs of said first plurality of slugs, wherein each of said first plurality of slugs is sized so that a first and a second slug contact surface contacts at least 90% of said corresponding adjacent rotor bar surfaces of said first portion of said plurality of rotor bars, and wherein said first and second slug contact surfaces of said first plurality of slugs are completely coated with a brazing material; inserting a second plurality of slugs between corresponding adjacent rotor bar surfaces of said second portion of said plurality of rotor bars to form a second rotor bar/slug assembly, wherein each slug of said second plurality of slugs is separate and independent from all other slugs of said second plurality of slugs, wherein each of said second plurality of slugs is sized so that a first and a second slug contact surface contacts at least 90% of said corresponding adjacent rotor bar surfaces of said second portion of said plurality of rotor bars, and wherein said first and second slug contact surfaces of said second plurality are completely coated with said brazing material; heating said first rotor bar/slug assembly to form a first plurality of braze joints between said first and second slug contact surfaces of said first plurality of slugs and corresponding adjacent rotor bar surfaces of said first portion of said plurality of rotor bars; heating said second rotor bar/slug assembly to form a second plurality of braze joints between said first and second slug contact surfaces of said second plurality of slugs and corresponding adjacent rotor bar surfaces of said second portion of said plurality of rotor bars; machining said first rotor bar/slug assembly to remove a first circumferential edge portion of said first rotor bar/slug assembly, wherein said first circumferential edge portion is comprised of a region of each of said first plurality of slugs and a region of said first portion of said plurality of rotor bars, wherein said first circumferential edge portion is located at an outermost end region of said first rotor bar/slug assembly; machining said second rotor bar/slug assembly to remove a second circumferential edge portion of said second rotor bar/slug assembly, wherein said second circumferential edge portion is comprised of a region of each of said second plurality of slugs and a region of said second portion of said plurality of rotor bars, wherein said second circumferential edge portion is located at an outermost end region of said second rotor bar/slug assembly; fitting a first containment ring over said first rotor bar/slug assembly, wherein said first containment ring is positioned on said first rotor bar/slug assembly at a location corresponding to said outermost end region of said first rotor bar/slug assembly where said first circumferential edge portion was removed via said step of machining said first rotor/bar slug assembly; and fitting a second containment ring over said second rotor bar/slug assembly, wherein said second containment ring is positioned on said second rotor bar/slug assembly at a location corresponding to said outermost end region of said second rotor bar/slug assembly where said second circumferential edge portion was removed via said step of machining said second rotor/bar slug assembly.