Patent US3754433A successfully refreshed from Google Patents.
US3754433A
Expired / Lapsed
US
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Fluidic proximity sensor
Assignee: Bendix Corp
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Filing: 1971-09-17
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Granted: 1973-08-28
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Expires: 1991-09-17
Abstract
Abstract A fluidic proximity sensor particularly adapted to sense clearance between gas turbine engine compressor blade tips and adjacent wall of a compressor housing. In one embodiment, there is provided an air flow passage having a chamber with an inlet and a restricted outlet in series flow relationshp. The inlet receives compressor pressurized air and is arranged in a predetermined relatively close spaced-apart relationship with a compressor blade tip which sweeps the inlet to vary the effective flow area thereof. The resulting pressure pulses are integrated in the chamber and the resulting pressure compared to a regulated reference fluid pressure by means of a pressure differential responsive device, the output of which represents the radial clearance between the compressor blade tips and adjacent housing wall. In another embodiment, a second air flow passage connected in parallel flow with the above-mentioned air flow passage is provided with a pair of series flow restrictions between which a reference pressure is generated. The inlet to the second passage is not affected by the compressor blade tips. The reference pressure is compared to the chamber pressure representing the radial clearance between the compressor blade tips and adjacent wall.
Inventors
- 👤 J Hyer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 16:14
CPC Classifications
G; G01; G01B; G01B13/00; G01B13/12
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
166 words
A fluidic proximity sensor in a housing for determining the clearance between a first surface member and a spaced-apart movable second surface member having spaced-apart projections, said sensor comprising: means defining a gas chamber having a gas inlet operatively connected flush with an inner wall of said first surface member and a gas outlet in series flow relationship therewith; a source of pressurized gas to which said inlet is exposed; a source of relatively lower pressure gas to which said outlet is exposed thereby establishing gas flow through said fluid chamber; said spaced-apart projections movably arranged to sweep adjacent said inlet in succession to vary the effective flow area thereof depending upon the clearance between said projections and said inlet and generate a corresponding series of gas pressure pulsations which are integrated in said chamber; and gas pressure responsive means connected to said chamber and responsive to said integrated gas pressure therein for providing an output signal representing the clearance between said projections and said inlet.
Claim 2
Dependent Claim
166 words
A fluidic proximity sensor in a housing for determining the clearance between a first surface member and a spaced-apart movable second surface member having spaced-apart projections, said sensor comprising: means defining a gas chamber having a gas inlet operatively connected flush with an inner wall of said first surface member and a gas outlet in series flow relationship therewith; a source of pressurized gas to which said inlet is exposed; a source of relatively lower pressure gas to which said outlet is exposed thereby establishing gas flow through said fluid chamber; said spaced-apart projections movably arranged to sweep adjacent said inlet in succession to vary the effective flow area thereof depending upon the clearance between said projections and said inlet and generate a corresponding series of gas pressure pulsations which are integrated in said chamber; and gas pressure responsive means connected to said chamber and responsive to said integrated gas pressure therein for providing an output signal representing the clearance between said projections and said inlet.
Claim 3
Dependent Claim
42 words
A fluidic proximity sensor as claimed in claim 1 wherein: said gas outlet provides a predetermined fixed flow area; said gas pressure in said chamber varies as a predetermined function of the effective flow area ratio of said gas inlet and outlet.
Claim 4
Dependent Claim
50 words
A fluidic proximity sensor as claimed in claim 2 wherein: said gas outlet provides a predetermined fixed flow area and said source of relatively lower pressure gas does not exceed a pressure approximately one half of the gas pressure in said chamber to thereby maintain sonic flow through said outlet.
Claim 5
Dependent Claim
61 words
A fluidic proximity sensor as claimed in claim 1 wherein said first and second members, respectively, correspond to an air compressor housing and a compressor rotor mounted therein and provided with radially outwardly extending circumferentially spaced-apart blades having a predetermined radial spaced-apart relationship with said housing, and wherein: said inlet includes an opening in said housing communicating with compressor pressurized air.
Claim 6
Dependent Claim
56 words
A fluidic proximity sensor as claimed in claim 1 wherein: said inlet is circular and has an effective flow area which varies in accordance with the relationship h2 pi d2 wherein h2 < or = d2/4 and designates the clearance between one of said projections and said inlet and d2 designates the diameter of said inlet.
Claim 7
Dependent Claim
19 words
A fluidic proximity sensor as claimed in claim 1 wherein: said source of relatively lower gas pressure is sub-atmospheric.
Claim 8
Dependent Claim
53 words
A fluidic proximity sensor as claimed in claim 4 wherein: said housing is adjustable toward and away from said compressor rotor; and said gas pressure responsive means is operatively connected to said housing for adjusting the same to vary the clearance between the same and said blades in response to said output signal.
Claim 9
Dependent Claim
36 words
A fluidic proximity sensor as claimed in claim 7 wherein: said operative connection between said gas pressure responsive means and said housing includes servo means operatively connected to said housing and responsive to said output signal.
Claim 10
Dependent Claim
108 words
A fluidic proximity sensor as claimed in claim 1 and further including: a gas conduit including a restricted inlet exposed to said first named source of pressurized gas and a restricted outlet exposed to said source of relatively lower pressure gas; said restricted inlet and outlet being in series flow relationship and having a predetermined constant flow area ratio whereby the gas pressure intermediate the same varies as a predetermined function of the pressure of the gas at said first named source to provide a reference gas pressure; said gas pressure responsive means including pressure differential responsive means responsive to said reference pressure and said chamber gas pressure.
Claim 11
Dependent Claim
47 words
A fluidic proximity sensor as claimed in claim 1 and further including: means for generating a reference gas pressure; said gas pressure responsive means communicating with said reference gas pressure and being responsive to the pressure differential between said reference gas pressure and said chamber gas pressure.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-08-27 | 1977-02-26 | 1977-08-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-27 | 1981-02-26 | 1981-08-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-27 | 1985-02-26 | 1985-08-28 | $7700.00 | Window Closed / Lapsed |