Exciter having thermally isolated diode wheel and method of removing diode wheel for same

An exciter for starting a power generator, the exciting comprising:

• an exciter rotor shaft having a positive stop member;
• a thermal insulation layer mounted to the exciter shaft;
• and
• a diode wheel having a wheel hub, the wheel hub of the diode wheel being mounted by an interference fit to overlie and abuttingly contact at least a portion of the thermal insulation layer positioned on the exciter rotor shaft, wherein the thermal insulation layer is positioned on the exciter rotor shaft and between the shaft and the diode wheel in a location where electrical insulation is not necessary, and wherein the diode wheel is positioned to abuttingly contact the positive stop member on the rotor shaft,
• wherein the thermal insulation layer has a minimum compressive yield strength, and wherein pressure from the diode wheel on the thermal insulation layer is below the minimum compressive yield strength of the thermal insulation layer and the interference fit is at least at a minimum interference to maintain the diode wheel in contact with the exciter rotor shaft during operation of the exciter in predetermined maximum overspeed conditions.

An exciter for starting a power generator, the exciter comprising:

• an exciter rotor shaft having a positive stop member;
• a diode wheel having a wheel hub and being mounted to the exciter rotor shaft by an interference fit;
• and
• a thermal insulation layer bonded to the exciter shaft and positioned between the shaft and the diode wheel in a location where electrical insulation is not necessary, wherein the thermal insulation layer has a minimum compressive yield strength, and wherein pressure from the diode wheel on the thermal insulation layer is below the minimum compressive yield strength of the thermal insulation layer and the interference fit is at least at a minimum interference to maintain the diode wheel in contact with the exciter rotor shaft during operation of the exciter in predetermined maximum overspeed conditions.