Thrust bearing system with inverted non-contacting dynamic seals for gas turbine engine

A method of controlling a net thrust load on a thrust bearing of a gas turbine engine spool comprising:

• providing a spool defining a longitudinal axis and including a thrust bearing supporting a hub and a compressor mechanically coupled to a turbine by said hub;
• establishing a first sealing relationship along the spool, including positioning a first non-contacting dynamic seal relative to the spool, the first non-contacting dynamic seal including a first body attached to a first floating shoe that seals with first rotatable inner surfaces of the spool to define a first flow cavity, and the first floating shoe radially inward of the first rotatable inner surfaces with respect to the longitudinal axis;
• establishing a second sealing relationship along the spool, including positioning a second non-contacting dynamic seal relative to the spool, the second non-contacting dynamic seal including a second body attached to a second floating shoe that seals with second rotatable inner surfaces of the spool to define a second flow cavity, and the second floating shoe radially inward of the second rotatable inner surfaces with respect to the longitudinal axis;
• and
• establishing a third sealing relationship along the spool, including positioning a third non-contacting dynamic seal relative to the spool, the third non-contacting dynamic seal including a third body attached to a third floating shoe that seals with rotatable outer surfaces of the hub, the third non-contacting dynamic seal positioned axially between the first and second floating shoes relative to the longitudinal axis to define the first flow cavity and the second flow cavity, and the third floating shoe radially outward of the rotatable outer surfaces with respect to the longitudinal axis.