US4593566A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Vibration monitoring in rotary machines
Assignee: Rolls Royce PLC
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Filing: 1984-07-06
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Granted: 1986-06-10
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Expires: 2004-07-06
Abstract
Abstract A rotary bladed machine (10) is provided with two probes (16,17) which provide output signals upon the passage past them of the tips (15) of an annular array of rotor blades (14) mounted within the machine (10). Electrical circuitry associated with the probes (16,17) incorporates a ramp generator (29) which provides steadily increasing and decreasing voltages as the blade tips (15) successively pass the probes (16,17). The ramp generator (29) voltage is sampled at regular intervals, the circumferential spacing of the probes (16,17) and the rates of the ramp generator (29) voltage change being chosen such that the sample voltage is zero in the event of the spacings between the blade tips (15) having a predetermined value but is not zero in the event that those spacings depart from the predetermined value. The sampled voltage is a function of the amplitude and frequency of vibration of the disc (13) carrying the blades (14).
Inventors
- 👤 Victor E. H. Ellis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 09:00
CPC Classifications
G; G01; G01H; G01H1/00; G01H1/003; G01H1/006
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
181 words
A rotary machine comprising: a rotor; a plurality of rotor elements circumferentially spaced around the rotor at generally equal spacings; at least two probes mounted close to the path of portions of said elements which are subject to vibrational motion, the probes being circumferentially spaced from each other by a spacing which is non-integral with the spacing of the elements; an electrical circuit connected to receive the outputs of the probes, and comprising: first means providing an output which can change progressively in either of two opposite senses at predetermined rates; triggering means for causing the output of said first means to commence changing in a first said sense on passage of a said element portion past a first said probe, and subsequently to commence changing in the second said sense on passage of a said element portion past a second said probe; and output means, which registers the output of the first means on passage of a said element portion past one of the probes, whereby the output from the output means is indicative of vibration of said element portions.
Claim 2
Dependent Claim
181 words
A rotary machine comprising: a rotor; a plurality of rotor elements circumferentially spaced around the rotor at generally equal spacings; at least two probes mounted close to the path of portions of said elements which are subject to vibrational motion, the probes being circumferentially spaced from each other by a spacing which is non-integral with the spacing of the elements; an electrical circuit connected to receive the outputs of the probes, and comprising: first means providing an output which can change progressively in either of two opposite senses at predetermined rates; triggering means for causing the output of said first means to commence changing in a first said sense on passage of a said element portion past a first said probe, and subsequently to commence changing in the second said sense on passage of a said element portion past a second said probe; and output means, which registers the output of the first means on passage of a said element portion past one of the probes, whereby the output from the output means is indicative of vibration of said element portions.
Claim 3
Dependent Claim
44 words
A rotary machine as claimed in claim 1 wherein said electrical circuit incorporates divider means so arranged that said progressively changing output means is triggered only by signals emanating from a group of three of said rotor elements for each revolution of said rotor.
Claim 4
Dependent Claim
29 words
A rotary machine as claimed in claim 1 wherein said electrical circuit incorporates means to provide an electrical output which is proportional to the rotary speed of said rotor.
Claim 5
Dependent Claim
42 words
A rotary machine as claimed in claim 1 wherein said machine includes a third said probe, and said triggering means causes the output means to register the output of the first means on passage of said element portion past the third probe.
Claim 6
Dependent Claim
18 words
A rotary machine as claimed in claim 1 wherein each of said probes is of the capacitive type.
Claim 7
Dependent Claim
31 words
A rotary machine as claimed in claim 1 wherein said rotary machine is the compressor or turbine of a gas turbine engine and said rotor elements are radially extending aerofoil blades.
Claim 8
Dependent Claim
17 words
A rotary machine as claimed in claim 1 wherein said first means comprises an up-down ramp generator.
Claim 9
Dependent Claim
17 words
A rotary machine as claimed in claim 1 wherein said first means comprises an up-down frequency counter.
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) | 1989-06-09 | 1989-12-09 | 1990-06-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-06-09 | 1993-12-09 | 1994-06-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-06-09 | 1997-12-09 | 1998-06-10 | $7700.00 | Window Closed / Lapsed |