Air foil bearing installation structure
The present invention relates to an airfoil bearing installation structure in which a spacer is provided on a bent portion of a foil assembly, the spacer has catching pieces having elasticity, and catching projections are formed on an inner wall surface of a slot formed in a housing so that the catching pieces are caught by the catching projections. Therefore, it is possible to prevent an axial movement and separation of the foil assembly without additionally installing a separate component for blocking an inlet of the slot.
1 . An airfoil bearing installation structure configured to be installed in a housing of an air compressor, the airfoil bearing installation structure comprising:
a foil assembly including a bump foil and a top foil that overlap each other in a cylindrical shape; and
a spacer mounted on a bent portion protruding from the foil assembly in a radial direction, the spacer comprising two opposite side plate portions extending in an axial direction and a connection portion connecting axially rear ends of the two opposite side plate portions,
wherein the foil assembly and the bent portion are inserted into a bearing installation hole and a slot formed in the housing
wherein the spacer is configured to eliminate a circumferential gap in the slot by fitting between the foil assembly and an inner surface of the slot, and
wherein catching pieces are formed by cutting axially front end portions of the side plate portions and bending upper portions of the cut areas outward in radial directions.
2 . The airfoil bearing installation structure of claim 1 , wherein the catching pieces are elastically deformable and restorable in radial inward and outward directions relative to the spacer.
3 . The airfoil bearing installation structure of claim 1 , wherein accommodation portions are formed in two opposite wall bodies located closer to an inlet side of the slot than an opposing end of the slot so that the catching pieces of the spacer are inserted into the accommodation portions, and catching projections are formed at end portions of the accommodation portions to engage ends of the catching pieces.
4 . The airfoil bearing installation structure of claim 1 ,
wherein a plurality of rectilinear fastening holes is formed in the bent portion of the foil assembly,
wherein a plurality of fastening holes, equal in number to the plurality of rectilinear fastening holes formed in the bent portion of the foil assembly, is formed in two opposite side plate portions of the spacer, and
wherein fastening members are installed through the plurality of rectilinear fastening holes in the bent portion and through corresponding fastening holes of the plurality of fastening holes in the plate portions so that the spacer is fixed to the bent portion.
5 . The airfoil bearing installation structure of claim 4 , wherein each fastening member comprises:
a base configured to be in surface contact with one radial side surface of the spacer;
extension portions horizontally extending from respective upper side edges of the base and configured to penetrate the fastening holes of the spacer and the bent portion; and
catching portions bent in a radial inward direction from ends of the extension portions and configured to be in surface contact with the other radial side surface of the spacer.
6 . The airfoil bearing installation structure of claim 1 , wherein one end of the spacer is open so that the spacer is axially insertable over an outer circumferential surface of the bent portion of the foil assembly.