ROTOR AND BEARING SYSTEM FOR ELECTRICALLY ASSISTED TURBOCHARGER.

摘要

A turbocharger having an electric motor for assisting spin up of the rotor employs a shaft carrying the turbine and compressor impeller with a unitary pinned semi-floating bearing supporting the shaft and a spacer collar carrying the electric motor magnet. The unitary bearing has integral thrust faces engaging a hub of the turbine wheel and the spacer collar. A reduced diameter of the shaft received in the spacer collar allows the collar to engage a greater diameter bearing land allowing the attachment of the compressor impeller with a nut on the shaft extending through a bore in the impeller to firmly engage the impeller, spacer collar and bearing land of the shaft to fix the rotor length. The pinned semi-floating bearing with integral thrust faces provides enhanced reaction moments for negative spring forces created by the electric motor in operation and the additional length of the rotor created by the motor.