Auxiliary bearing system for magnetically supported rotor system

A method of supporting a shaft, the method comprising:

• coupling an inertia ring to the shaft, wherein the shaft is at least partially disposed in a casing;
• compliantly mounting at least two body members to the casing so that each of the body members is permitted to move relative to the casing and the other body members;
• supporting the shaft with a primary bearing system;
• and
• engaging the inertia ring with one or more of the compliantly-mounted body members when the primary bearing system fails.

A rotor system, comprising:

• a shaft;
• a primary bearing system that supports the shaft during normal operating conditions;
• and
• an auxiliary bearing system that supports the shaft when the primary bearing system fails, the auxiliary bearing system comprising:
• an inner ring of a roller element bearing coupled to the shaft;
• an outer ring of the roller element bearing disposed radially outward from the inner ring;
• an inertia ring coupled to the outer ring;
• at least two mounting pad assemblies disposed radially outward from the inertia ring, wherein a radial gap is defined between the inertia ring and an inner surface of each of the mounting pad assemblies when the primary bearing system is supporting the shaft;
• and
• a casing to which each of the mounting pad assemblies is compliantly mounted.