The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 26, 1996
Filed:
Sep. 29, 1994
Michael K Swann, Gales Ferry, CT (US);
Richard R Shultz, Groton, CT (US);
Glacier RPB Inc., Mystic, CT (US);
Abstract
A damping arrangement (FIG. 1) for axial vibrations in a turbomachine shaft 10 comprises at least one circumferentially extending annular damping chambers 34 and 35 open towards a shaft thrust face 19.sub.A and 19.sub.B of a radially extending collar 20 and to which gas is supplied alternately by gas flow controllers 42.sub.A and 42.sub.B. Each controller contains fluidic devices switched by sensing pressures in radially displaced pressure sensing chambers 51, 53, or even the same chambers, as such pressure are modulated by the variations in shaft and collar position, to divert the gas from source 40. The diversion of gas flow is arranged to cause pressure fluctuations, which exert axial thrust on the thrust faces, advanced in phase to approach of the shaft so as to damp the vibration. The fluidic devices may be implemented by flow amplifiers 47.sub.A, 47.sub.B or fluid logic flip flop 61 (FIG. 2) and may be multistage devices to increase gain, all of which may be formed without moving parts and embedded in the housing. Flow diversion may be effected by other forms of sensing, such as leakage from a nozzle facing the shaft. The arrangement may be combined with, or serve as, a gas seal or be part of a bearing arrangement.