Abstract: A rotor assembly in which the front and back ends of the rotor are coupled by a shaft assembly extending therethrough. Preferably, the shaft assembly includes a slip joint, such that the shaft is able to accommodate for thermal expansion of the assembly, while maintaining a torsional and bending moment coupling between the front and back ends of the rotor. The rotor assembly is particularly advantageous for use in superchargers having large acceleration and pressure increase requirements, such as superchargers utilized in drag racing. However, the rotor assembly may also be utilized in other devices such as blowers, compressors, or vacuum pumps which may have large acceleration requirements.