Four-degree-of-freedom rotor model
Aerodynamic thrust and journal bearings

Bearings and thrust bearings, previously described as isolated components, must be integrated into the rotor design of the rotating machine. The rotor can behave either as a rigid solid or as an elastic beam. If the rotor's first natural pulsation is greater than the maximum rotational speed, the rotor can be considered as a rigid beam guided in rotation by two bearings and stopped in translation by a stop (figure 38). The rotor is loaded by its own weight Mg, to which may be added a maneuvering load, and/or by one or more external force torsors { F_extX , F_extY, M_extX , M_extY}. The external torsor can be static (from forces on a propeller, impeller, etc.) or dynamic (unbalance, shock, etc.).

• In stationary operation, the fundamental principle of statics can be...