A rotor securing arrangement for directly or indirectly securing a rotor to a shaft. The rotor has at least one through hole along a axial direction of the rotor. A second hole diameter of the at least one through hole at either or both of axial ends of the rotor is greater than a first hole diameter of the at least one through hole at a portion other than the axial ends of the rotor. The rotor securing arrangement includes a first securing member corresponding to the first hole diameter of the at least one through hole, and a second securing member corresponding to the second hole diameter of the at least one through hole. The first securing member is configured to directly or indirectly secure the rotor to the shaft with at least a portion of the second securing member between the first securing member and the rotor.