US4108571A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Bladed rotor assembly for a gas turbine engine
Assignee: Rolls Royce PLC
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Filing: 1977-02-01
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Granted: 1978-08-22
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Expires: 1997-02-01
Abstract
Abstract A bladed rotor assembly for a gas turbine comprises blades whose roots are held in slots in a blade carrying member. In order to retain the blades against movement in the slots locking members engage with the blades and the member. At least one of the engagements comprises a projection defining an undercut into which an edge of the locking member engages. In order to reduce frettage, the edge and the undercut are shaped to form a groove which tapers so that its section reduces in the radially outward direction, and a wedging member is mounted in the groove so that it tends to centrifuge outward in the groove and wedge the edge in the undercut against a wall of the undercut.
Inventors
- 👤 Robert James Mawson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 02:52
CPC Classifications
F; F01; F01D; F01D5/00; F01D5/30; F01D5/3007; F01D5/3015
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
242 words
A bladed rotor assembly for a gas turbine engine comprising: a plurality of blades each having a root portion, a blade carrying member having a plurality of slots in its periphery, each slot being arranged to receive and engage the root portion of one of said blades to radially retain the same to said blade carrying member, and lock members in engagement with said blades and said blade carrying member for preventing longitudinal movement of the root portion of each of the blades in the slots in at least one direction, at least one of the engagements comprising a projection defining an undercut and an edge of each of the lock members engaging in said undercut, said edge of each of said lock members having a chamfered edge which cooperates with a surface of said undercut to form a tapered groove therebetween having a section which reduces in a radially outward direction, and a wedging member separate from said lock members and from said undercut, said wedging member being mounted in said tapered groove and cooperating with both said chamfered edge of each of said lock members and said surface of said undercut so that in operation of the bladed rotor assembly centrifugal effects on said wedging member cause the wedging member to tend to move radially outward in the tapered groove to longitudinally wedge said edge of each of said lock members in said undercut against a wall of the same.
Claim 2
Dependent Claim
242 words
A bladed rotor assembly for a gas turbine engine comprising: a plurality of blades each having a root portion, a blade carrying member having a plurality of slots in its periphery, each slot being arranged to receive and engage the root portion of one of said blades to radially retain the same to said blade carrying member, and lock members in engagement with said blades and said blade carrying member for preventing longitudinal movement of the root portion of each of the blades in the slots in at least one direction, at least one of the engagements comprising a projection defining an undercut and an edge of each of the lock members engaging in said undercut, said edge of each of said lock members having a chamfered edge which cooperates with a surface of said undercut to form a tapered groove therebetween having a section which reduces in a radially outward direction, and a wedging member separate from said lock members and from said undercut, said wedging member being mounted in said tapered groove and cooperating with both said chamfered edge of each of said lock members and said surface of said undercut so that in operation of the bladed rotor assembly centrifugal effects on said wedging member cause the wedging member to tend to move radially outward in the tapered groove to longitudinally wedge said edge of each of said lock members in said undercut against a wall of the same.
Claim 3
Dependent Claim
47 words
A bladed rotor assembly as claimed in claim 1 in which said chamfered edge on said edge of each of said lock members is an inner edge and in which said wedging member wedges said lock members longitudinally outwardly against an inwardly facing surface of said undercut.
Claim 4
Dependent Claim
19 words
A bladed rotor assembly as claimed in claim 1 and in which said wedging member comprises a malleable wire.
Claim 5
Dependent Claim
58 words
A bladed rotor assembly as claimed in claim 1 in which there are projections from each of said blades defining undercuts and from said blade carrying member defining an undercut, the undercuts on the projections from said blades facing the undercut on the projection from the blade carrying member, and said lock members engaging between said facing undercuts.
Claim 6
Dependent Claim
32 words
A bladed rotor assembly as claimed in claim 4 and in which said projections from said blades abut to form an annular projection, the undercuts also abutting to form an annular undercut.
Claim 7
Dependent Claim
29 words
A bladed rotor assembly as claimed in claim 5 and in which the projection from the blade carrying member comprises an annular projection having an annular undercut formed therein.
Claim 8
Dependent Claim
32 words
A bladed rotor assembly as claimed in claim 6 and in which said lock members comprise part-annular members which abut together to form a complete annulus which extends between said annular undercuts.
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) | 1981-08-21 | 1982-02-20 | 1982-08-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-08-21 | 1986-02-20 | 1986-08-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-08-21 | 1990-02-20 | 1990-08-22 | $7700.00 | Window Closed / Lapsed |