US4053227A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for automatic and contactless measurement of the height of moving blades of a turbine
Assignee: Siemens AG
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Filing: 1975-10-03
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Granted: 1977-10-11
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Expires: 1995-10-03
Abstract
Abstract A method and apparatus for measuring the height of a blade of a turbine rotor as the rotor is being rotated characterized by deflecting a laser beam at a given deflection frequency across the path of the moving blade so that a portion of the deflected beam will be reflected by the end of the blade, sensing the reflected portion to produce a reflected signal, synchronizing the speed of rotation of the rotor with the frequency of deflection so that the end of the blade and the deflected beam reach the same point simultaneously and applying the reflected laser signal and a reference signal from the laser beam to an electronic analysis system to determine the height of the individual blade. Preferably, the synchronizing is accomplished by sensing the blade frequency, converting it to a converted blade frequency, comparing the converted blade frequency with the frequency of deflection to obtain an error signal and using the error signal to control the speed of rotation of the rotor. By including a counter circuit in the electronic analysis circuit and by sensing a mark on the rotor during each rotation of the rotor, adjustments can be made to either determine the height of each blade in a stage of blades during one revolution or to determine the height of a single individual blade of the stage.
Inventors
- 👤 Viktor Bodlaj
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:03
CPC Classifications
G; G01; G01B; G01B11/00; G01B11/02; G01B11/06; G01B11/0608; G01B11/14; G01B11/24
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
138 words
A method for automatic, contactless measurement of the height of individual blades on a rotating turbine rotor comprising rotating the turbine rotor having the blades arranged thereon, deflecting a laser beam from a given path at a known frequency of deflection to move the deflected beam across the path of the moving blade to have a portion of the beam reflected from an end of the blade, sensing the portion of the beam reflected from the end of the blade to create a reflected signal, sychronizing the speed of rotation of the rotor with the frequency of deflection so that the end of the blade and deflected beam reach the same point simultaneously, and applying the reflected signal and a reference signal from the beam to an electronic analysis system to determine the height of the individual blade.
Claim 2
Independent Claim
138 words
A method for automatic, contactless measurement of the height of individual blades on a rotating turbine rotor comprising rotating the turbine rotor having the blades arranged thereon, deflecting a laser beam from a given path at a known frequency of deflection to move the deflected beam across the path of the moving blade to have a portion of the beam reflected from an end of the blade, sensing the portion of the beam reflected from the end of the blade to create a reflected signal, sychronizing the speed of rotation of the rotor with the frequency of deflection so that the end of the blade and deflected beam reach the same point simultaneously, and applying the reflected signal and a reference signal from the beam to an electronic analysis system to determine the height of the individual blade.
Claim 3
Dependent Claim
83 words
A method according to claim 1, wherein the analyzing system includes a counter circuit and means for converting a measured pulse into a measurement and wherein the method includes sensing the passing of a mark on the rotor during each revolution thereof to obtain a starting signal, and applying the starting signal to start the counting circuit so that the height of each blade in a stage of blades passing beneath the deflected laser beam during one revolution of the rotor is measured.
Claim 4
Dependent Claim
95 words
A method according to claim 1, wherein the electronic analyzing system includes a counter circuit and means for converting a measured value pulse into a measurement and wherein the method includes adjusting the counting circuit to enable display of the measurement of a particular blade in a stage of blades of the turbine rotor during each revolution, sensing the beginning of a revolution to obtain a starting signal and applying the starting signal to the counting circuit, so that only the height of a single individual blade is measured during each revolution of the rotor
Claim 5
Dependent Claim
68 words
A method according to claim 1, wherein the step of synchronizing includes sensing the blades passing a given point during rotation of the turbine rotor to obtain a blade frequency, converting the blade frequency to a converted blade frequency, comparing the converted blade frequency with the deflection frequency to obtain an error signal and adjusting the speed of rotation of the rotor in response to the error signal.
Claim 6
Dependent Claim
84 words
A method according to claim 4, wherein the analyzing system includes a counter circuit and means for converting a measured value pulse into a measurement, and wherein the method includes sensing the passing of a mark on the rotor during each revolution thereof to obtain a starting signal, and applying the starting signal to start the counting circuit so that the height of each blade in a stage of blades passing beneath the deflected laser beam during one revolution of the rotor is measured.
Claim 7
Dependent Claim
94 words
A method according to claim 4, wherein the electronic analyzing system includes a counter circuit and means for converting a measured value pulse into a measurement, and wherein the method includes adjusting the counter circuit to enable display of the measurement of a particlar blade in a stage of blades of the rotor during each revolution, sensing the beginning of a revolution to obtain a starting signal, and applying the starting signal to the counting circuit so that only the height of a single individual blade is measured during each revolution of the rotor.
Claim 8
Independent Claim
126 words
An apparatus for measuring the height of individual blades of a stage of blades of a rotating turbine rotor, comprising means for rotating the rotor, a laser projecting a laser beam, means for obtaining a reference signal from the laser beam, means for deflecting the laser beam across the path of moving blades at a given frequency of deflection, means sensing a portion of the deflected laser beam reflected by an end of the blade to obtain a reflected signal, means synchronizing the speed of rotation of the rotor and a deflecting frequency so that the deflected beam and end of the blade reach the same point simultaneously, and means analyzing the reflected signal and the reference signal to determine the height of the individual blade.
Claim 9
Independent Claim
126 words
An apparatus for measuring the height of individual blades of a stage of blades of a rotating turbine rotor, comprising means for rotating the rotor, a laser projecting a laser beam, means for obtaining a reference signal from the laser beam, means for deflecting the laser beam across the path of moving blades at a given frequency of deflection, means sensing a portion of the deflected laser beam reflected by an end of the blade to obtain a reflected signal, means synchronizing the speed of rotation of the rotor and a deflecting frequency so that the deflected beam and end of the blade reach the same point simultaneously, and means analyzing the reflected signal and the reference signal to determine the height of the individual blade.
Claim 10
Dependent Claim
69 words
An apparatus according to claim 7, wherein the means for synchronizing includes means sensing the blade frequency, means converting the sensed blade frequency to a converted blade frequency, means comparing the converted blade frequency with the frequency of deflection to produce an error signal, and means applying the error signal to the means for rotating the rotor to change the speed of rotation in response to the error signal.
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) | 1980-10-10 | 1981-04-11 | 1981-10-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-10-10 | 1985-04-11 | 1985-10-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-10-10 | 1989-04-11 | 1989-10-11 | $7700.00 | Window Closed / Lapsed |