IL42948A - Helicopter rotor - Google Patents
Helicopter rotorInfo
- Publication number
- IL42948A IL42948A IL42948A IL4294873A IL42948A IL 42948 A IL42948 A IL 42948A IL 42948 A IL42948 A IL 42948A IL 4294873 A IL4294873 A IL 4294873A IL 42948 A IL42948 A IL 42948A
- Authority
- IL
- Israel
- Prior art keywords
- selectively shaped
- rotor according
- selectively
- droop stop
- stop member
- Prior art date
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64C—AEROPLANES; HELICOPTERS
- B64C27/00—Rotorcraft; Rotors peculiar thereto
- B64C27/32—Rotors
- B64C27/322—Blade travel limiting devices, e.g. droop stops
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64C—AEROPLANES; HELICOPTERS
- B64C27/00—Rotorcraft; Rotors peculiar thereto
- B64C27/32—Rotors
- B64C27/35—Rotors having elastomeric joints
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Aviation & Aerospace Engineering (AREA)
- Support Of The Bearing (AREA)
- Toys (AREA)
- Centrifugal Separators (AREA)
- One-Way And Automatic Clutches, And Combinations Of Different Clutches (AREA)
Claims (25)
1. An articulated helicopter rotor including a rotor hub adapted to be mounted for rotation, at least one helicopter blade projecting substantially radially from said hub and having a pitch change axis, a lead-lag axis, and a flapping axis intersecting at a common point, means supporting said blade from said hub for universal motion about the intersection of said axes, characterized in that a ring member is mounted on said blade for rotation relative thereto about said pitch change axis and at a station radially outward of said point of intersection, said ring member having a selectively shaped surface positioned to move toward said hub as said blade droops downwardly, and that a droop stop member is connected to said hub and has a selectively shaped surface positioned to intercept said ring member when said blade droops downwardly to a first selected angle and which surface is shaped to present a corresponding mating surface with said ring member surface to effect relative rotation therebetween as said blade moves in lead-lag motion when said surfaces are in contact,
2. A rotor according to claim 1, characterized in that said droop stop member surface is conical with the apex thereof located at said point intersection of said axes,
3. A rotor according to claim 1, characterized in that the mating surfaces of said droop stop member and said ring member are concave-convex for mating engagement,
4. A rotor according to claim 1, characterized in that selectively shaped surfaces of said ring member and droop stop member are frustoconical with the apexes thereof positioned at said point of intersection.
5. A rotor according to claim 1, characterized in that a centrifugally responsive member having a first selectively shaped surface corresponding to said selectively shaped sur~ face of said ring member and a second selectively shaped surface corresponding to said selectively shaped surface of said droop stop member is pivotally mounted with respect to said blade and hub for motion between a first position wherein said pivotally mounted member is positioned between the selectively shaped surfaces of said ring member and said droop stop member at low rotor speeds or when the rotor is stopped and oriented so as to present its first selectively shaped surface to said selectively shaped surface of said ring member for mating engagement therewith and to present its second selectively shaped surface to said selectively shaped surface of said droop stop member for mating engagement therewith when said blade droops downwardly beyond a second selected angle, and a second position remote from said ring member and said droop stop 'member.
6. A rotor according to claim 5, characterized in that said droop stop member is wedge shaped between said first and second selectively shaped surfaces so that said droop stop member is locked in position between said ring member and said droop stop member when in said first position.
7. A rotor according to claim 5, characterized in that said selectively shaped surfaces of said droop stop member, said ring member and said centrifugally responsive member are arcuate with said first selectively shaped su face of said centrifugally responsive member shaped to be in mating engagement with and corresponding to said selectively shaped surface of said ring member and with said second selectively shaped surface of said centrifugally responsive member shaped to be in mating engagement with and corresponding to said selectively surface of said droop stop member when said centrifugal responsive member is in said first position.
8. A rotor according to claim 5, characte ized in that said selectively shaped surfaces of said ring member and said droop stop member and said selectively shaped surfaces of said centrifugally responsive member are shaped so that concave-convex mating occurs between said first selectively shaped surface of said centrifugally responsive member and said ring member and between said second selectively shaped surface of said centr fugally responsive member and said droop stop member when said centrifugally responsive member is in said first position.
9. A rotor according to claim 8, characterized in that sa centrifugally responsive member is of wedge-shaped cross section between said first and second selectively shaped surfaces thereof so that said centrifugally actuated member is locked in said first position when its first and second selectively shaped surfaces, respectively, matingly engage the selectively shaped surfaces of said ring member and said droop stop member.
10. A rotor according to claim 5, characterized in that said second selected angle is less than said first selected angle.
11. A rotor according to claim 1, characte ized in that said droop stop member is a circular segment which lies in a substantially horizontal plane and the center of which lies on the lead-lag axis.
12. A rotor according to claim 1, characterized in that a coning limit stop member is connected to said hub and having a selectively shaped surface positioned to intercept said ring member when said blade flaps or cones upwardly to a selected angle and which surface is shaped to present a corresponding mating surface with said ring member surface to effect relative rotation therebetween as said blade moves in lead-lag motion when said surfaces are in contact.
13. A rotor according to claim 12, characterized in that said coning limit member is a circular segment which lies in a substantially horizontal plane, the center of which lies on said lead-lag axis.
14. A rotor according to claim 1, characterized in that said selectively shaped surface of said ring member and said selectively shaped sEface of said droop stop member are shaped to be spherical about either a point on the pitch change axis or a point on the lead-lag axis so as to be in line contact when said surfaces engage and rotate relative to one another.
15. A rotor according to claim 15, characterized in that the selectively shaped surface of the coning limit stop is frustoconical with its apex positioned at said point of intersection and concentric about said lead-lag axis, and which is shaped to form line contact when said selectively shaped surfaces of said ring member and said coning angle limit member rotate relative to one another while in continuous contact and with said blade at constant flapping angle.
16. A rotor according to claim 15, characterized in that the selectively shaped surface of the coning limit stop is spherical about a point on the lead-lag axis or the pitch change axis and which corresponds in curvature with said selectively shaped surface of said ring member and is positioned to contact said selectively shaped surface of said ring member when said blade coning angle reaches a selected maximum so as to be in line contact when said selectively shaped surface of said ring member and said coning angle limit stop member engage and rotate relative to one another,
17. A rotor according to claim 5, characterized in that the said selectively shaped surfaces of said ring member, said droop stop member, and said centrifugally responsive member are spherical about points located on said pitch change axis or said lead-lag axis and of common radius and wherein said selectively shaped surfaces of said droop stop member and said centrifugally responsive member are concentric about said lead-lag axis, and said selectively shaped surface of said ring member is concentric about said pitch change axis.
18. A rotor according to claim 1, characte ized in that said selectively shaped surfaces of said ring member and said droop stop member are segmented spheres concentric about said pitch change axis or said l¾ad-.lag axis.
19. A rotor according to claim 5, characte ized in that said selectively shaped surface of said droop stop member is barrel shaped and concentric with respect to the lead-lag axis and positioned and shaped to matingly engage said selectively shaped surface of said ring member when said blade droops downwardly to said first selected angle and that said second selectively shaped surface of said centri-^ fugally responsive member is barrel shaped and corresponds in shape to said barrel shaped surface of said droop stop member.
20. A rotor according to claim 19, characte ized in that said centrifuga lly responsive member is a cam member and that a counterweight is connected to said cam member.
21. A rotor according to claim 19, characterized in that means are provided to bias said centrifugally responsive member to position said cam member between said ring member and said droop stop member.
22. A rotor according to any one of claims 19 to 21, characterized in that said centrifugally responsive member is loosely pivotally connected to said droop stop member and that said loose pivotal connection between said centri-fugally responsive member and said droop stop member is oriented so that when misalignment occurs in said blade-from-hub supporting means, said centr ifugally responsive member will pivot with respect to said droop stop member to bring said barrel shape surfaces of said droop stop member and said centr ifugally responsive member into mating engagement and to retain said selectively shaped surface of said ring member and said first selectively shaped surface of said centrifugally responsive member in line engagement.
23. A rotor according to any one of claims 19 to 23, chara terized in that said droop stop member barrel shaped surface is shaped in cross section as segments of circles which lie in substantially horizontal planes concentric about and perpendicular to the lead-lag axis.
24. A rotor according to claim 22, characte ised in that said loose pivotal connection between said centrif gally responsive member and said droop stop member includes a pin member supported from said droop stop member, and a support member connected to said centr ifugally responsive member and having ertures therein which are substantially oversized with respect to and through which said pin passes.
25. A rotor substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings,,
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US28650972A | 1972-09-05 | 1972-09-05 | |
| US28650872A | 1972-09-05 | 1972-09-05 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| IL42948A0 IL42948A0 (en) | 1973-11-28 |
| IL42948A true IL42948A (en) | 1976-05-31 |
Family
ID=26963874
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| IL42948A IL42948A (en) | 1972-09-05 | 1973-08-10 | Helicopter rotor |
Country Status (6)
| Country | Link |
|---|---|
| AU (1) | AU466704B2 (en) |
| DE (1) | DE2344395C2 (en) |
| FR (1) | FR2197764B1 (en) |
| GB (1) | GB1439237A (en) |
| IL (1) | IL42948A (en) |
| IT (1) | IT993875B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3932059A (en) * | 1975-01-10 | 1976-01-13 | United Technologies Corporation | Droop stops for helicopter rotor having elastomeric bearings |
| US4297078A (en) * | 1978-05-17 | 1981-10-27 | Westland Aircraft Limited | Helicopter rotors |
| GB2025338B (en) * | 1978-06-02 | 1982-08-04 | Aerospatiale | Helicopterrotor |
| FR2764577B1 (en) * | 1997-06-13 | 1999-08-20 | Eurocopter France | ROTOR OF A GIRAVION WITH BEAT STOPS FIXED ON BLADES AND HUB, AND WITH LAW NOT DETERMINED |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR948570A (en) * | 1946-05-30 | 1949-08-04 | Bristol Aeroplane Co Ltd | Improvements to rotary wing aircraft |
| US2614640A (en) * | 1951-02-01 | 1952-10-21 | United Aircraft Corp | Rotor blade support |
| US3501250A (en) * | 1968-03-22 | 1970-03-17 | Boeing Co | Rotor hub |
-
1973
- 1973-08-10 IL IL42948A patent/IL42948A/en unknown
- 1973-08-22 AU AU59524/73A patent/AU466704B2/en not_active Expired
- 1973-09-03 DE DE2344395A patent/DE2344395C2/en not_active Expired
- 1973-09-05 FR FR7332694A patent/FR2197764B1/fr not_active Expired
- 1973-09-05 IT IT28591/73A patent/IT993875B/en active
- 1973-09-05 GB GB4172773A patent/GB1439237A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| IT993875B (en) | 1975-09-30 |
| FR2197764A1 (en) | 1974-03-29 |
| FR2197764B1 (en) | 1976-11-19 |
| AU5952473A (en) | 1975-02-27 |
| AU466704B2 (en) | 1975-11-06 |
| DE2344395C2 (en) | 1985-03-07 |
| GB1439237A (en) | 1976-06-16 |
| DE2344395A1 (en) | 1974-03-14 |
| IL42948A0 (en) | 1973-11-28 |
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