US4080823A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Vibration measurement
Assignee: RTX Corp
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Filing: 1976-11-05
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Granted: 1978-03-28
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Expires: 1996-11-05
Abstract
Abstract Apparatus and methods for measuring deflection of rotating fan blades of a gas turbine engine is disclosed. The measurement of bending and torsional deformation in response to integral and to nonintegral vibration as well as to structural loading is developed. Optical measuring techniques including the projection of collimated light beams into the fan section of the engine are employed. A linear readout of angular deflection is displayed on a distant screen for amplification of the actual deflection. The plurality of beams provide a deflection profile covering the full surface of the blade.
Inventors
- 👤 Hans Stargardter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 15:39
CPC Classifications
G; G01; G01H; G01H9/00; G01H1/00; G01H1/003; G01H1/006
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
101 words
Apparatus for measuring torsional and bending deflection in a rotating blade of an operating rotary machine, comprising: a plurality of reflecting surfaces spaced along the surface of the blade to be measured; means for directing a collimated beam of light energy into the path of each reflecting surface so as to be reflected by each of said surfaces at each machine revolution; and a display screen spaced from the blade for intercepting the beams reflected from the surfaces to display a composite pattern of the multiple reflections which is representative of torsional and bending deflection along the surface of the blade.
Claim 2
Dependent Claim
101 words
Apparatus for measuring torsional and bending deflection in a rotating blade of an operating rotary machine, comprising: a plurality of reflecting surfaces spaced along the surface of the blade to be measured; means for directing a collimated beam of light energy into the path of each reflecting surface so as to be reflected by each of said surfaces at each machine revolution; and a display screen spaced from the blade for intercepting the beams reflected from the surfaces to display a composite pattern of the multiple reflections which is representative of torsional and bending deflection along the surface of the blade.
Claim 3
Dependent Claim
32 words
The invention according to claim 1 wherein said means for directing a beam of light energy comprises an array of individual light sources, each source being directed at an individual reflecting surface.
Claim 4
Dependent Claim
53 words
The invention according to claim 1 wherein said means for directing a beam of light energy comprises a single source of collimated light energy and an array of beam splitters which are adapted to direct a portion of the light energy emanated from said collimated beam to each of the individual reflecting surfaces.
Claim 5
Dependent Claim
40 words
The invention according to claim 1 wherein each of said reflecting surfaces is a diffraction grating and said means for directing a beam of collimated light energy comprises a single source of energy which is projected upon the diffraction gratings.
Claim 6
Dependent Claim
40 words
The invention according to claim 1 wherein said means for directing a beam of light energy is optically positioned behind said screen and wherein said screen is formed to allow the passage of said beam of collimated light energy therethrough.
Claim 7
Dependent Claim
16 words
The invention according to claim 5 wherein said screen has at least one aperture disposed therein.
Claim 8
Dependent Claim
26 words
The invention according to claim 1 which further comprises recording means disposed in operative relationship to said screen for recording the composite pattern produced during operation.
Claim 9
Dependent Claim
26 words
The invention according to claim 2 which further comprises recording means disposed in operative relationship to said screen for recording the composite pattern produced during operation.
Claim 10
Dependent Claim
26 words
The invention according to claim 3 which further comprises recording means disposed in operative relationship to said screen for recording the composite pattern produced during operation.
Claim 11
Dependent Claim
19 words
The invention according to claim 1 wherein said screen is positioned at approximately 20 feet from said reflecting surfaces.
Claim 12
Dependent Claim
19 words
The invention according to claim 2 wherein said screen is positioned at approximately 20 feet from said reflecting surfaces.
Claim 13
Dependent Claim
19 words
The invention according to claim 3 wherein said screen is positioned at approximately 20 feet from said reflecting surfaces.
Claim 14
Independent Claim
117 words
A method for measuring the angular deflection of a rotor blade in a blade system subjected to nonintegral vibration, which comprises the steps of: disposing a plurality of reflecting surfaces along the span of the blade on which deflection is to be measured; rotating the blade system at an operational speed at which nonintegral vibration is produced; directing a beam of collimated light energy against each of said reflecting surfaces; reflecting said beam to a display screen to visually display the pattern of reflected light energy produced in response to torsional and bending deflection of the blade; measuring the linear dimensions of the displayed pattern; and relating the measured linear dimensions to angular deflection of the blade.
Claim 15
Independent Claim
117 words
A method for measuring the angular deflection of a rotor blade in a blade system subjected to nonintegral vibration, which comprises the steps of: disposing a plurality of reflecting surfaces along the span of the blade on which deflection is to be measured; rotating the blade system at an operational speed at which nonintegral vibration is produced; directing a beam of collimated light energy against each of said reflecting surfaces; reflecting said beam to a display screen to visually display the pattern of reflected light energy produced in response to torsional and bending deflection of the blade; measuring the linear dimensions of the displayed pattern; and relating the measured linear dimensions to angular deflection of the blade.
Claim 16
Independent Claim
171 words
A method for measuring the angular deflection of a rotor blade in a blade system subjected to resonant vibration, which comprises the steps of: disposing a plurality of reflecting surfaces along the span of the blade on which deflection is to be measured; rotating the blade system at an operational speed just below the speed at which peak resonant vibration is produced; directing a beam of collimated light energy against each of said reflecting surfaces; reflecting said beam to a display screen to visually display a first position of the reflected beam on the screen; recording said first position of the reflected beam; rotating the blade system at an operational speed just above the speed at which peak resonant vibration is produced; reflecting said beam to a display screen to visually display a second position of the reflected beam on the screen; recording said second position of the reflected beam; determining the linear distance between said first and second portions; and relating said linear distance to angular deflection of the blade.
Claim 17
Independent Claim
171 words
A method for measuring the angular deflection of a rotor blade in a blade system subjected to resonant vibration, which comprises the steps of: disposing a plurality of reflecting surfaces along the span of the blade on which deflection is to be measured; rotating the blade system at an operational speed just below the speed at which peak resonant vibration is produced; directing a beam of collimated light energy against each of said reflecting surfaces; reflecting said beam to a display screen to visually display a first position of the reflected beam on the screen; recording said first position of the reflected beam; rotating the blade system at an operational speed just above the speed at which peak resonant vibration is produced; reflecting said beam to a display screen to visually display a second position of the reflected beam on the screen; recording said second position of the reflected beam; determining the linear distance between said first and second portions; and relating said linear distance to angular deflection of the blade.
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) | 1981-03-27 | 1981-09-26 | 1982-03-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-03-27 | 1985-09-26 | 1986-03-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-03-27 | 1989-09-26 | 1990-03-28 | $7700.00 | Window Closed / Lapsed |