Patent ID: 7565731

Claim:
A method for making a rotor assembly, comprising: providing a left part and a right part of a stub shaft, each of the left part and the right part of the stub shaft having a stub shaft diameter; providing a magnet between the left part and the right part of the stub shaft, the magnet having a magnet diameter smaller than the stub shaft diameter; inserting a plurality of screws into the left part and the right part of the stub shaft to hold the magnet in place; drilling a hole through the magnet, the left part and the right part of the stub shaft; cooling an inner shaft; inserting the inner shaft into the hole, the inner shaft extending through the magnet and further extending into the left part and the right part of the stub shaft; warming the inner shaft to provide an interference fit of the inner shaft in the hole; and removing the plurality of screws from the left part and the right part of the stub shaft.