Abstract: An anti-rotation device for preventing rotation of a wheel with respect to a shaft, wherein the wheel is primarily secured to the shaft by an interference shrink fit, should the interference shrink fit loosen, comprises an annular member separate from yet irrotatably secured to the periphery of the shaft, such as by an interference shrink fit, and a pair of spaced apart restraining tabs coupled to the annular member for receiving a portion of the wheel therebetween. A portion of the radial inner surface of the member may be outwardly tapered toward an axial end to assist dispersion of fluid which may accumulate in the region of the anti-rotation device. The device may include spacing protrusions for axially spacing the device from the wheel and may be disposed between a pair of wheels for preventing undesirable rotation of one or both wheels.

Abstract: A method and apparatus is disclosed for determining whether certain rotor stress values are exceeded during the thermal cycle of a turbomachine. The invention takes into account the rotor material and the behavioral characteristics of the rotor material above and below the Fracture Appearance Transition Temperature (FATT). The acquired data is stored to develop a rotor history useful in determining a rotor condition for maintenance and longevity purposes and further useful in determining the operating pattern of the turbomachine.