Abstract: A supercharger comprises a housing, a gear box, and a shaft. The shaft comprises a first end and a second end, wherein the first end is located closer to the gear box than the second end. The supercharger comprises a shaft bore comprising a base wall, wherein the second end of the shaft is located in the shaft bore. The supercharger comprises a rotor bore in the housing and a rotor located on the shaft in the rotor bore. The rotor comprises an axis. The supercharger comprises a bearing surrounding the shaft and located closer to the second end of the shaft than the first end of the shaft, wherein the bearing comprises an outer ring abutting the shaft bore and an inner ring abutting the shaft. The supercharger comprises a biasing device abutting the bearing, wherein the biasing device moves the rotor along the axis.