Abstract: A rotor assembly for a multi-stage pump is provided. The assembly includes a drive shaft, a rotor component and a drive component. The rotor component is located on the drive shaft and includes a rotor element for displacing fluid through the pump when the drive shaft is rotated. The drive component is anchored to the drive shaft and transmits torque from the drive shaft to the rotor component to effect rotation of the rotor component. A sleeve element is integrated with either the drive component or the rotor component and is used to space the rotor element from the drive component. An interface surface is located on the sleeve element for interacting with the other one of the drive component and the rotor component in order to maintain orthogonal alignment between the rotor element and the drive shaft. A driver is provided for transmitting torque between the drive component and the rotor component.