Electric rotor fit onto a turbomachine shaft

An electronically-controlled turbomachine, comprising:

• a rotor;
• and
• a shaft having a wheel coupled to a first end of the shaft, the shaft having an axial portion that mates with the rotor, the axial portion having:
• a first axial section having a first diameter;
• a second axial section having a second diameter;
• and
• a third axial section having a third diameter wherein
• the second axial section is located between the first and third axial sections;
• the second diameter is smaller than the first and third diameters;
• and the wheel is one of a turbine wheel and a compressor wheel,
• and wherein an inside diameter of the rotor is uniform along at least a majority of the length of the rotor, one of a slip fit and an interference fit exists between the rotor and the shaft along the first axial section and one of a slip fit and an interference fit exists between the rotor and the shaft along the third axial section,
• and wherein the shaft has a stop that is located between the third axial section and the wheel;
• the stop has a greater diameter than the third axial section;
• and the stop locates the rotor onto the shaft in an axial direction.

A turbomachine, comprising:

• a shaft of the turbomachine having a turbine wheel coupled to a first end of the shaft;
• a turbine housing section disposed over the turbine wheel;
• a compressor section disposed on a second end of the shaft;
• a compressor wheel disposed within the compressor section, the compressor wheel being secured to the second end of the shaft;
• a rotor fit over a portion of the shaft, the rotor being located between the turbine and compressor wheels wherein:
• the portion of the shaft over which the rotor is fit has first, second, and third axial sections having first, second, and third diameters, respectively;
• an inside diameter of the rotor is greater than the second diameter with a gap defined therebetween;
• and the second axial section is located between the first and third axial sections,
• wherein the shaft is threaded along at least a fraction of the first axial section portion and an inside surface of the rotor is threaded along a portion that engages with the threads on the shaft, and
• wherein the first diameter is equal to the inside diameter of the rotor and the third diameter is greater than the inside diameter of the rotor.

An electronically-controlled turbomachine, comprising:

• a rotor having a bore, the bore having a first axial rotor section, a second axial rotor section and a third axial rotor section;
• and
• a shaft having a wheel coupled to a first end of the shaft, the shaft having an axial portion adapted to engage with the rotor, the axial portion having:
• a first axial shaft section engaged with the first axial rotor section, a second axial shaft section within the second axial rotor section, and a third axial shaft section engaged with the third axial rotor section wherein:
• the second axial shaft section is located between the first and third axial shaft sections;
• and
• a difference between an inner diameter of the second axial rotor section and an outer diameter of the second axial shaft section is greater than a difference between an inner diameter of the third axial rotor section and an outer diameter of the third axial shaft section,
• wherein a part of the first axial shaft section is threaded,
• and wherein a part of the first axial rotor section is threaded and engaged with the threads on the first axial shaft section or the turbomachine further comprises a nut engaged with the threads on the first axial shaft section.