Patent ID: 8035273
Filing Date: 2011-10-11
Classification: H02K

Abstract:
1. A rotor for an electric machine having a number of poles, the rotor comprising: a shaft extending along a portion of an axis and defining an outer surface; a first core portion formed as a single inseparable component and including a first portion that extends from the outer surface at a first axial position to a first outside diameter to define a first thickness, and a second portion extending axially from the first portion toward a second axial position and including a reduced back portion extending from an inside diameter to the first outside diameter to define a second thickness that is less than the first thickness, the first core portion defining a first space between the outer surface and a surface of the first core portion that defines the inside diameter, the first core portion including a plurality of fingers that extend radially to directly contact the outer surface and define finger spaces between adjacent fingers where the first core portion does not directly contact the outer surface; and second core portion that extends from the outer surface at the second axial position and including a second outside diameter that is substantially the same as the first outside diameter, wherein the first core portion and the second core portion interconnect to define a rotor core having a first end adjacent the first axial position, a second end opposite the first end adjacent the second axial position, and a hollow space including the first space between the first core portion and the second core portion, wherein the interconnection between the first core portion and the second core portion is substantially air-tight without any sealant therebetween.