Abstract: A homopolar generator (HPG) having the stator and an inner brush mechanism housed within the machine support structure utilizes a rotor separated into halves electrically insulated from each other, so as to fit around the stator and brush mechanism. A shaft is mounted in the support structure to carry the rotor. A first rotor half is thermally shrunk-fit onto the shaft, and the second rotor half is hydraulically expansion fit thereon. To hydraulically fit the second rotor on the shaft, a shaft is provided having a downward taper from its midpoint toward one end. The shaft also has a circumferential groove and a port therethrough from the end of the taper for communicating high pressure oil from an external pump to the shaft-rotor interface. High-pressure seals on each side of the groove prevent leakage. The application of high-pressure oil expands the bore in the rotor half and shrinks the shaft diameter.

Abstract: A homoplanar generator (HPG) having the stator and an inner brush mechanism housed within the machine support structure utilizes a rotor separated into halves electrically insulated from each other, so as to fit around the stator and brush mechanism. A shaft is mounted in the support structure to carry the rotor. A first rotor half is thermally shrunk-fit onto the shaft, and the second rotor half is hydraulically expansion fit thereon. To hydraulically fit the second rotor on the shaft, a shaft is provided having a downward taper from its midpoint toward one end. The shaft also has a circumferential groove and a port therethrough from the end of the taper, for communicating high pressure oil from an external pump to the shaft-rotor interface. High-pressure seals on each side of the groove prevent leakage. The application of high-pressure oil expands the bore in the rotor half and shrinks the shaft diameter.