US3958905A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Centrifugal compressor with indexed inducer section and pads for damping vibrations therein
Assignee: Deere and Co
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Filing: 1975-01-27
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Granted: 1976-05-25
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Expires: 1995-01-27
Abstract
Abstract A centrifugal compressor assembly for a gas turbine engine includes an inducer section and an impeller section mounted for rotation about an axis. Because leading edges of the impeller blades are cambered, damper pads, extending perpendicular to the low pressure sides thereof also extend axially forward. Blades of the inducer section are indexed rotationally rearward of the impeller blades to improve the distribution of compression gases through the impeller section and high pressure surfaces of the inducer blades mate near their leading edges with outward surfaces of the damper pads. Because the pads and inducer blades vibrate at different frequencies, inducer blade vibrations that might otherwise cause fatigue are attenuated by contact with the damper pads. The damper pad arrangement thus permits the damping of vibrations in the inducer blades notwithstanding the indexed relationship between the inducer section and the impeller section.
Inventors
- 👤 Homer J. Wood
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 23:34
CPC Classifications
F; F04; F04D; F04D29/00; F04D29/26; F04D29/28; F04D29/284; F04D29/285; F01; F01D; F01D5/00; F01D5/02; F01D5/04; F01D5/043; F01D5/045; F04D29/66; F04D29/661; F04D29/668; Y; Y10; Y10S; Y10S415/00; Y10S415/914; Y10S416/00; Y10S416/50
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
119 words
A centrifugal compressor for a gas turbine engine comprising: an impeller including a plurality of impeller blades, each of said blades having an inlet edge and a low pressure face; a plurality of damper pads each projecting from the low pressure face of an impeller blade adjacent the inlet edge; and an inducer coupled to the impeller for rotation therewith and including a plurality of inducer blades each being indexed relative to a corresponding impeller blade and each having an outlet edge and a high pressure face, a portion of the high pressure face of each inducer blade adjacent the outlet edge of the inducer blade engaging the damper pad on a corresponding impeller blade without being secured thereto.
Claim 2
Dependent Claim
119 words
A centrifugal compressor for a gas turbine engine comprising: an impeller including a plurality of impeller blades, each of said blades having an inlet edge and a low pressure face; a plurality of damper pads each projecting from the low pressure face of an impeller blade adjacent the inlet edge; and an inducer coupled to the impeller for rotation therewith and including a plurality of inducer blades each being indexed relative to a corresponding impeller blade and each having an outlet edge and a high pressure face, a portion of the high pressure face of each inducer blade adjacent the outlet edge of the inducer blade engaging the damper pad on a corresponding impeller blade without being secured thereto.
Claim 3
Dependent Claim
35 words
A centrifugal compressor, as defined in claim 1, in which each impeller blade has an inlet portion including the inlet edge and in which the inducer blades and the impeller blade inlet portions are cambered.
Claim 4
Dependent Claim
24 words
A centrifugal compressor, as defined in claim 1, in which the damper pads are shaped to minimize disturbance of air flow through the compressor.
Claim 5
Dependent Claim
34 words
A centrifugal compressor as defined in claim 1, in which inducer blades are indexed rotationally rearward relative to corresponding impeller blades, the indexing angle being less than half the angle between adjacent inducer blades.
Claim 6
Dependent Claim
124 words
A centrifugal compressor comprising an inducer section and an impeller section mounted for rotation as a unit about a common central axis, the sections being coaxially disposed in abutting relation, each section including a hub and a plurality of blades extending therefrom, the impeller blades having inlet edges and the inducer blades having outlet edges, the impeller blades being rotationally staggered relative to the inducer blades about the axis forming pairs of adjacent impeller and inducer blades, the outlet edge of each inducer blade defining an opening with the inlet edge of an adjacent impeller blade, and a vibration amplitude limiting means projecting from the impeller blade across the opening and engaging the adjacent inducer blade without being secured thereto to limit vibration therein.
Claim 7
Dependent Claim
124 words
A centrifugal compressor comprising an inducer section and an impeller section mounted for rotation as a unit about a common central axis, the sections being coaxially disposed in abutting relation, each section including a hub and a plurality of blades extending therefrom, the impeller blades having inlet edges and the inducer blades having outlet edges, the impeller blades being rotationally staggered relative to the inducer blades about the axis forming pairs of adjacent impeller and inducer blades, the outlet edge of each inducer blade defining an opening with the inlet edge of an adjacent impeller blade, and a vibration amplitude limiting means projecting from the impeller blade across the opening and engaging the adjacent inducer blade without being secured thereto to limit vibration therein.
Claim 8
Dependent Claim
18 words
A centrifugal compressor, as defined in claim 5, in which the impeller blades and inducer blades are cambered.
Claim 9
Dependent Claim
32 words
A centrifugal compressor, as defined in claim 6, in which the outlet edges of the inducer blades and the inlet edges of the impeller blades lie approximately along a common, radial plane.
Claim 10
Dependent Claim
27 words
A centrifugal compressor, as defined in claim 5, in which the vibration amplitude means is shaped and positioned to minimize disturbance of fluid flow through the compressor.
Claim 11
Dependent Claim
32 words
A centrifugal compressor, as defined in claim 5 above, wherein the inducer and impeller blades are staggered to equalize flow and delay flow separation on low pressure surfaces of the impeller blades.
Claim 12
Dependent Claim
54 words
In a centrifugal compressor having a bladed impeller section and an inducer section with blades indexed relative to corresponding blades of the impeller section, a plurality of pads, each being affixed to an impeller blade near a leading edge thereof and extending into vibration suppressing contact with a corresponding blade of the inducer section.
Claim 13
Dependent Claim
54 words
In a centrifugal compressor having a bladed impeller section and an inducer section with blades indexed relative to corresponding blades of the impeller section, a plurality of pads, each being affixed to an impeller blade near a leading edge thereof and extending into vibration suppressing contact with a corresponding blade of the inducer section.
Claim 14
Dependent Claim
34 words
The pads as set forth in claim 10 above, wherein each pad is approximately shaped as a half cylinder with a semicircular surface disposed adjacent an inducer blade surface which is substantially parallel thereto.
Claim 15
Dependent Claim
29 words
The centrifugal compressor as defined in claim 1, wherein each damper pad is supported solely by an impeller blade at a radially outward extremity of the inlet edge thereof.
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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) | 1979-05-25 | 1979-11-24 | 1980-05-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-05-25 | 1983-11-24 | 1984-05-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-05-25 | 1987-11-24 | 1988-05-25 | $7700.00 | Window Closed / Lapsed |