Fluid bearing

• US 4,808,070 A
• Filed: 08/17/1987
• Issued: 02/28/1989
• Est. Priority Date: 08/17/1987
• Status: Expired due to Term

• Current Assignee: G Fonda-Bonardi
• Original Assignee: G Fonda-Bonardi
• Inventors: Fonda-Bonardi, G.
• Primary Examiner(s): Garrett, Robert E.
• Assistant Examiner(s): Kwon, John T.
• Application Number:
  US07/085,704
• Time in Patent Office: 561 Days
• Field of Search: 415/104, 415/106, 415/110, 415/170 R, 415/111, 384/115, 384/113, 384/273, 384/272, 384/397
• US Class Current: 415/110
• CPC Class Codes: F01D 25/22 using working-fluid or other gaseous fluid as lubricant
• CPC Class Codes: F04D 29/057 hydrostatic; hydrodynamic
• CPC Class Codes: F16C 17/22 with arrangements compensating for thermal expansion
• CPC Class Codes: F16C 33/107 Grooves for generating pressure

Abstract

A gas bearing including a support having a longitudinally extending cylindrical bore, of a predetermined diameter and an elongated generally cylindrical shaft rotatable within the bore of the shaft being of a predetermined diameter less than the diameter of the bore in the support. The outer surface of the shaft is uniquely provided with a plurality of circumferentially spaced, longitudinally extending recesses of a predetermined depth, each of which defines an elongated, generally radially outwardly extending step of a predetermined height. The outer surface of the shaft is also provided with a plurality of circumferentially spaced, longitudinally extending grooves of a predetermined depth disposed proximate the steps. At least one end of each of the grooves is in communication with a source of gas at a predetermined pressure so that as the shaft rotates the gas will be drawn into the space between the inner walls of the cylindrical bore and the outer surfaces of the shaft and will function to maintain concentricity of the shaft.

Claims

1. A bearing comprising:

(a) a support having a longitudinally extending bore, generally circular in cross-section at any point, said bore being of a predetermined diameter and defining an inner surface, said support being disposed within a gaseous atmosphere and including longitudinally spaced faces;

(b) an elongated generally cylindrical shaft rotatable within said bore of the support, said shaft being of a predetermined diameter less than the diameter of said bore in said support and defining an outer surface, said outer surface of said shaft having;

(i) a plurality of circumferentially spaced, longitudinally extending recesses of a predetermined depth, each said recess defining an elongated, generally radially outwardly extending step of a predetermined height; and

(ii) a plurality of circumferentially spaced, longitudinally extending grooves of a predetermined depth disposed proximate said steps, said grooves including an end portion extending beyond one of said longitudinally spaced faces of said support into said gaseous atmosphere whereby gas will be drawn into said recesses upon rotation of said shaft relative to said support, at least one end of each of said grooves being in communication with a source of fluid at a predetermined pressure.

2. A bearing as defined in claim 1 in which said support is compliant whereby said bore is expandable outwardly in response to fluid under pressure disposed between said shaft and inner surface of said support.

3. A gas bearing as defined in claim 2 including means for controlling the pressure of gases within said recesses.

4. A gas bearing as defined in claim 2 further including means for yielding resisting diametrical expansion of said support and for maintaining substantial concentricity thereof.

5. A gas bearing as defined in claim 2 in which said support comprises a metal strip rolled into a generally cylindrical configuration.

6. A gas bearing as defined in claim 2 in which said support comprises a thin walled tubular member having a longitudinally extending cut through the wall thereof.

7. A gas bearing as defined in claim 6 in which said longitudinally extending cut extends radially outwardly through said wall.

8. A gas bearing as defined in claim 6 in which said longitudinally extending cut extends diagonally outwardly through said wall, causing the edges to overlap by a predetermined angular extent.

9. A bearing comprising:

(a) a support having a longitudinally extending bore, generally circular in cross-section at any point, said bore being of a predetermined diameter and defining an inner surface, said support being disposed within a gaseous atmosphere and including longitudinally spaced faces;

(b) an elongated generally cylindrical shaft rotatable within said bore of said support, said shaft being of a predetermined diameter less than the diameter of said bore in said support defining an outer surface, said outer surface of said shaft having;

(i) a plurality of circumferentially spaced, longitudinally extending recesses of a predetermined depth, each said recess defining an elongated, generally radially outwardly extending step of a predetermined height; and

(ii) a plurality of circumferentially spaced, longitudinally extending grooves of a predetermined depth disposed proximate said recesses, said grooves including an end portion extending beyond one of said longitudinally spaced faces of said support into said gaseous atmosphere whereby gas will be drawn into said recesses upon rotation of said shaft relative to said support.