Foil bearing structure with damping

A bearing and damping structure of a foil bearing, the bearing and damping structure comprising:

• interleaved spring plates and damper plates,
• each spring plate comprising an annular array of fingers to support a foil body of the foil bearing against radially-directed compressive forces,
• one or more of the spring plates having a unique characteristic stiffness, and
• friction induced between each damper plate and neighboring spring plates causing one or more of the fingers to resist deformation due to the radially-directed compressive forces for damping associated with spring plate characteristic stiffnesses,
• wherein the one or more of the spring plates having the unique characteristic stiffness have unique material properties as compared to other ones of the spring plates.

A foil bearing, comprising:

• a bearing sleeve;
• a foil body;
• a shaft disposed in the foil body;
• a clamp;
• and
• a bearing and damping structure radially interposed between the bearing sleeve and the foil body and comprising interleaved spring plates and damper plates,
• each spring plate comprising an annular array of fingers to support the foil body against radially-directed compressive forces and that each comprise outboard-preload and inboard-operating sections,
• the shaft preloading the bearing and damping structure for alignment by deforming the outboard-preload section of one or more of the fingers, and
• the clamp exerting, on the bearing and damping structure with the preload applied thereto, an axially-directed clamping force that induces damper-spring plate friction causing the inboard-operating section of one or more of the fingers to resist deformation due to the radially-directed compressive forces for damping.

A method of assembling a foil bearing capable of damping, the method comprising:

• forming spring plates to each comprise an annular array of fingers to support a foil body against radially-directed compressive forces and that each comprise outboard-preload and inboard-operating sections;
• forming damper plates;
• interleaving the damper plates with the spring plates to assemble a bearing and damping structure;
• radially interposing the bearing and damping structure between a bearing sleeve and the foil body;
• disposing a shaft in the foil body to preload the bearing and damping structure for alignment by deforming the outboard-preload section of one or more of the fingers;
• and
• exerting, on the bearing and damping structure having been preloaded, an axially-directed clamping force that induces damper-spring plate friction causing one or more of the fingers to resist deformation due to the radially-directed compressive forces for damping.