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US4732531A Expired / Lapsed US ⏱️ 0.0 years remaining

Air sealed turbine blades

Assignee: NATIONAL AEROSPACE LABORATORY OF SCIENCE & TECHNOLOGY AGENCY A CORP OF JAPAN
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Filing: 1986-12-12
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Granted: 1988-03-22
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Expires: 2006-12-12
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Abstract

Abstract A gas turbine has a casing forming a fluid passage through which a primaryluid flows, and a rotor blade disposed in the fluid passage with a clearance between distal ends of the rotor blades and the casing. The casing has a plurality of spaced blow holes extending circumferentially thereof for communicating an external secondary fluid chamber with the clearance, the blow holes being formed at an incline with respect to the wall of the casing in such a manner that a secondary fluid discharged from the blow holes is imparted with a flow component that opposes a flow of the primary fluid leaking from the clearance. The amount of the secondary fluid discharged from the blow holes and the discharge pressure are controlled to hydromechanically vary the resistance which the secondary fluid offers to the primary fluid leakage flow, thereby making it possible to mimimize the leakage flow.

Inventors

  • 👤 Mitsuhiro Minoda
  • 👤 Shigeo Inoue
  • 👤 Hiroshi Usui
  • 👤 Hiroyuki Nouse

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 09:09
CPC Classifications
F; F01; F01D; F01D11/00; F01D11/08; F01D11/10; Y; Y10; Y10S; Y10S415/00; Y10S415/914

Claims Analysis

Total Claims: 4
Claim 1
Independent Claim 125 words
A turbomachine comprising: a casing forming a fluid passage through which a primary fluid flows; rotor blades disposed for rotation in the fluid passage with a clearance between distal ends of said rotor blades and said casing; a secondary fluid chamber being provided radially outwardly of said casing; and said casing having a plurality of spaced blow holes extending circumferentially thereof for communicating the secondary fluid chamber with the clearance, said blow holes being formed at an incline with respect to the wall of said casing in such a manner that a secondary fluid discharged from said blow holes is imparted with a flow component that opposes a direction of rotation of the blades and a flow of the primary fluid leaking from the clearance.
Claim 2
Dependent Claim 125 words
A turbomachine comprising: a casing forming a fluid passage through which a primary fluid flows; rotor blades disposed for rotation in the fluid passage with a clearance between distal ends of said rotor blades and said casing; a secondary fluid chamber being provided radially outwardly of said casing; and said casing having a plurality of spaced blow holes extending circumferentially thereof for communicating the secondary fluid chamber with the clearance, said blow holes being formed at an incline with respect to the wall of said casing in such a manner that a secondary fluid discharged from said blow holes is imparted with a flow component that opposes a direction of rotation of the blades and a flow of the primary fluid leaking from the clearance.
Claim 3
Dependent Claim 40 words
The turbomachine according to claim 1, wherein said blow holes are inclined at an angle of 30° with respect to the wall of said casing, said blow holes being arranged in a plurality of rows spaced axially of the machine.
Claim 4
Dependent Claim 28 words
The turbomachine according to claim 2, wherein the blow holes in each of said rows have diameters different from the blow holes in the other of said rows.

References Cited (Backward Citations)

US2685429A Cited
US3029011A Cited
FR1163559A Cited
US3365172A Cited
US3883263A Cited
US4161318A Cited
US4303371A Cited
US4311431A Cited
JPS5741407A Cited
US4419044A Cited
JPS57157002A Cited
US4526226A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1991-03-22 1991-09-21 1992-03-22 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1995-03-22 1995-09-21 1996-03-22 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1999-03-22 1999-09-21 2000-03-22 $7700.00 Window Closed / Lapsed

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