US3727466A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Gyro noise reduction
Assignee: Honeywell Inc
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Filing: 1970-07-23
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Granted: 1973-04-17
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Expires: 1990-07-23
Abstract
Abstract A method and apparatus for reducing output noise from a gyro having a spinning inertial element surrounded by gas. The mass of gas spinning with the rotor is minimized by shrouding the rotor. Particular shrouding reduces the Reynolds number of the gas proximate the rotor thereby producing a steady laminar gas flow within the gyro gimbal; the elimination of unsteady turbulent flow within the gimbal is accompanied by considerable noise reduction.
Inventors
- 👤 G Kraus
- 👤 J Rupert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 14:01
CPC Classifications
G; G01; G01C; G01C19/00; G01C19/02; G01C19/34; G01C19/38; Y; Y10; Y10T; Y10T74/00; Y10T74/12; Y10T74/1282
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
87 words
Low noise gyroscope apparatus comprising: a. a gyroscope having a spinning rotor inertial element; b. first means for surrounding said spinning rotor inertial element with gas; and c. stationary shroud means spaced a distance h from the inertial element for the purpose of establishing and maintaining the Reynolds number of the flow of the gas proximate said inertial element below the critical Reynolds number during times when the inertial element is at operating speed, whereby steady laminar flow of the gas proximate said inertial element is maintained.
Claim 2
Dependent Claim
87 words
Low noise gyroscope apparatus comprising: a. a gyroscope having a spinning rotor inertial element; b. first means for surrounding said spinning rotor inertial element with gas; and c. stationary shroud means spaced a distance h from the inertial element for the purpose of establishing and maintaining the Reynolds number of the flow of the gas proximate said inertial element below the critical Reynolds number during times when the inertial element is at operating speed, whereby steady laminar flow of the gas proximate said inertial element is maintained.
Claim 3
Dependent Claim
74 words
The apparatus of claim 1 wherein the spinning rotor inertial element has a cylindrical face, and the shroud means is configured so that the distance h between the cylindrical rotor face and the shroud means satisfies the condition Rey < 41, where Rey being the Reynolds number of gas within the shroud, Rho the mass density of the gas, v the gas velocity, Mu the gas viscosity and r the radius of the rotor.
Claim 4
Dependent Claim
60 words
The apparatus of claim 1 wherein the spinning rotor inertial element has a circular face, and the shroud means is configured so that the distance between a circular rotor face and the shroud means is less than twice the boundary layer thickness of the gas proximate the circular rotor face during times when said inertial element is at operating speed.
Claim 5
Dependent Claim
50 words
The apparatus of claim 1 wherein the spinning rotor inertial element has a cylindrical face, and the shroud means is configured so that, for all points on the face which are an equal distance from the rotor spin axis, the distance between those points and the shroud means is equal.
Claim 6
Independent Claim
43 words
A method for minimizing output noise in a gyro having a spinning rotor inertial element surrounded by gas, comprising establishing and maintaining steady laminar gas flow proximate said inertial element, by maintaining the Reynolds number of said flow below the critical Reynolds number.
Claim 7
Independent Claim
43 words
A method for minimizing output noise in a gyro having a spinning rotor inertial element surrounded by gas, comprising establishing and maintaining steady laminar gas flow proximate said inertial element, by maintaining the Reynolds number of said flow below the critical Reynolds number.
Claim 8
Dependent Claim
30 words
The method of claim 5 wherein establishing and maintaining steady laminar gas flow is accomplished by surrounding the rotor with stationary shroud means spaced a predetermined distance from the rotor.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-04-16 | 1976-10-16 | 1977-04-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-16 | 1980-10-16 | 1981-04-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-16 | 1984-10-16 | 1985-04-17 | $7700.00 | Window Closed / Lapsed |