Document
United States Patent 1193 [ill Patent Number: 4,583,704
Krauss et al.
1451 Date of Patent: Apr. 22, 1986
PNEUMATIC SYSTEM STRUCTURE FOR FOREIGN PATENT DOCUMENTS CIRCULATION CONTROL AIRCRAm
205240 12/1908 Fed. Rep. of Germany ... 416/90 A
304250 8/1920 Fed. Rep. of Germany ... 416/90 A
Krauss, Harwinton; Inventors: Timothy A.
Stephan Roman, Shelton; Robert J.
OTHER PUBLICATIONS Beurer, West Haven, all of Conn.
Reader et al., “Status Report on Advanced Devel.
Prog. Utilizing CCR Technology”, Sep. 1978, Ass.
Assignee: United Technologies Corporation, Italy of Astronautics and Aeronautics.
Hartford. Conn.
Barnes et al., “CCR Flight Demonstration”, Aug. 1976, American Helicopter Society Symposium.
Appl. No.: 565,433 L. Barefoot Primary Examiner-Galen Filed: Dec. 27, 1983 Attorney, Agent, or Firm-Russell M. Lipes, Jr.
ABSTRACT
Int. (3.4 .............................................. B64C 27/12
A plenum for a circulation control rotor aircraft which U.S. C1. .............................. 2 4 4 / 1 7 . 1 1 ; 416/20 A; surrounds the rotor drive shaft (18) and is so con- 416/90 A; 244/207 structed that the top ( 3 2 ) , outer (38) and bottom (36) Field of Search .................... 244/207, 17.11, 7 R, walls through compressed air is admitted are fixed to 244/7 A; 416/90 R, 90 A, 20 aircraft structure and the inner wall (34) through which air passes to rotor blades (14) rotates with the drive References Cited shaft and rotor blades.
U.S. PATENT DOCUMENTS ..............................
3,464,650 9/1969 Girard 416/90 A 1 Claim, 2 Drawing Figures
U.S. Patent Apr. 22,1986 Sheet 1 of2 4,583,704
U S Patent Apr. 22,1986 Sheet 2 of 2 4,583,704
4,583,704
aircraft which is relatively safer and more compact PNEUMATIC SYSTEM STRUCTURE FOR because of its construction.
CIRCULATION CONTROL AIRCRAFT Still another object of the invention is the provision of a plenum chamber in the pneumatic system of a circu- The Government has rights in this invention pursuant 5 lation control aircraft in which the rotating members to NASA Contract No. NAS2-11058. are inside the chamber away from the helicopter air- frame.
TECHNICAL FIELD The foregoing and other objects and advantages of This invention relates to the rotor and pneumatic the present invention may be seen by referring to the system structure for an aircraft utilizing a circulation 10 following description and claims, read in conjunction control rotor system and more particularly to the ple- with the accompanying drawings.
num chamber construction.
BRIEF DESCRIPTION O F THE DRAWINGS BACKGROUND ART FIG. 1 is a top view of a circulation control aircraft An X-wing aircraft is a rotary wing aircraft that uses 15 of the X-wing type.
a rigid rotor/wing utilizing circulation control airfoils. FIG. 2 is a schematic section through the rotor sys- The rotor is driven mechanically and the rotor blades tem hub area of the aircraft of FIG. 1 showing the operate essentially in fBed pitch. The rotor may rotate, pneumatic system plenum chamber and associated as in a helicopter, or it may be stopped and positioned so structure.
as to act like a fixed wing. Collective and cyclic control 2o BEST MODE FOR CARRYING OUT THE is achieved by control of air circulation about the blade INVENTION airfoils. This is done by blowing compressed air through leading edge and trailing edge ducts in the The aircraft of FIG. 1 includes fuselage 10 on top of rotor blades and modulating the amount of air being which is mounted rotor system 12 including four blades ejected through spanwise slots on the leading and trail- 25 14 and hub portion 1 6 . Blades 14 are circulation control ing edges of the rotor blades. airfoils, each blade having leading edge and trailing The rotor system for an X-wing aircraft includes a edge slots through which compressed air from a pneu- hub and attached rotor blades and a pneumatic system matic system is ejected. Control is obtained by cycli- for delivering compressed air separately to the leading cally and collectively modulating the amount of ejected edge and the trailing edge of the individual rotor blades 30 airflow. In certain flight regimes such as landing and at a desired pressure and mass flow. The pneumatic taking off, the rotor system rotates, and in other flight system includes a compressor, a stationary air supply to regimes such as forward flight the rotor system is sta- the rotor, valving for controlling the flow of air to the tionary and is stored in the position shown.
leading edge and the trailing edge of the blades, and a In FIG. 2 the hub portion of the rotor system and the rotating air distribution arrangement. The system also 35 area below it is shown schematically in some detail.
includes a compressed, air storage chamber, or plenum, Rotor drive shaft 18 which is connected to and drives and it is the plenum which is the subject of this inven- the rotor blades is supported by standpipe 20 which tion. A plenum chamber construction is described in surrounds the drive shaft and is fixedly connected to copending application Ser. No. 431,475 filed Sept. 20, transmission housing 22. The upper end of the drive 1982. 40 shaft is connected to and guided by sleeve 24 which A circulation control rotor system is described in the surrounds the upper end of the standpipe. Bearings 26 and 28 provide for relative rotational movement be- report titled “Circulation Control Rotor Flight Demon- strator” by David R. Barnes, Douglas G. Kirkpatrick tween the standpipe and sleeve and carry the load.
and George A. McCoubrey presented at an American Plenum 30, the compressed air storage chamber, sur- Helicopter Society Mideast Region Symposium in Au- 45 rounds the rotor shaft and is located under and as near gust, 1976. The report titled “Status Report on Ad- as possible to the plane of rotation of the rotor blades.
vanced Development Program Utilizing Circulation The plenum includes top annular wall 32, inner circum- Control Rotor Technology” by Kenneth R. Reader, ferential wall 34, bottom annular wall 36, and outer Douglas G. Kirkpatrick and Robert M. Williams, Paper circumferential wall 38 as the principal elements defin- No. 44 presented at the Fourth European Rotorcraft 50 ing the air storage chamber. Compressed air is delivered and Powered Lift Aircraft Forum, Stresa, Italy, Sep- to the plenum through one or more pipes 40 connected tember 13-15, 1978 describes an X-wing development to the outer wall although the air could be delivered program. through the bottom wall. Top wall 32, outer wall 38 and Davidson et al U.S. Pat. No. 3,139,936 and Flint et al bottom wall 36 are joined together as a unit and this unit U.S. Pat. Nos. 3,348,618 and 3,349,853 describe a con- 55 is fixed to and supported by annular flange 42 which is trol mechanism for a helicopter having circulation con- fixed to transmission housing 22.
trol with compressed air being supplied through the Inner circumferential wall 34 is a rotating wall, being connected to and rotating with the rotor system. Bear- rotor pillar. Cheeseman et a1 U.S. Pat. No. 3,524,711 and Seed U.S. Pat. No. 3,567,332 describe helicopter ings 44 and 46 between inner wall 34 and top wall 32 rotors employing circulation control. 60 and bearing 48 between the inner wall and bottom wall 36 are provided for and permit rotation of the inner wall DISCLOSURE OF INVENTION which is connected to sleeve 24 by a number of brackets 50. The inner wall has a plurality of ports at two cir- An object of the present invention is to provide an cumferential levels for the delivery of air to each rotor improved plenum chamber construction for the pneu- matic system of an aircraft having a circulation control 65 blade 14. One or more upper ports 52 is connected by rotor system. duct 54 to a rotor blade to provide air to the leading Another object of the invention is to provide a pneu- edge slot in the blade, and one or more ports 56 is con- nected by duct 58 to the same rotor blade to provide air matic system plenum chamber for a circulation control
4, 5 83,704
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be made without departing from the spirit or scope of to the trailing edge slot in the blade. The inner wall, air this as defined by the claims.
ducts and rotor blades thus rotate as a unit, and bv their position the inner wall and ducts are at an interio; loca- We 1. In a pneumatic system for an aircraft using a circu- away from the airframe and generally in 5 lation control rotor, said aircraft having a helicopter a safer and more compact location than if they rotated rotor assembly including drive connected to about the outer circumference of the plenum. rotor blades, said pneumatic system including a com- Within plenum 30 are two circumferential levels of pressed air storage chamber surrounding said drive bell-mouth passageways having valves therein to con- means and having a top wall, a bottom wall, an inner trol the flow of air from the plenum to the rotor blades, 10 Circumferential Wall and an Outer CirCUmfereRtial Wall, and ducting for conducting air from said storage cham- the passageways being evenly spaced circumferentially around the plenum. Upper passageways 6o are aligned ber to said rotor blades, characterized in that said top wall, bottom wall and outer circumferential wall are with inner upper ports 52 to air to mounted in a stationary manner relative to said helicop- the leading edge Of the rotor and lower passage- 15 ter airframe, said inner circumferential wall being freely ways 62 are aligned axially with inner wall lower Ports rotatable with respect to said top, bottom and outer 56 to control air to the trailing edge of the rotor blades. circumferential walls, said ducting being connected to Adjustable butterfly valves 64 in each passageway con- said inner circumferential wall radially inward from trol the flow of air through the passageways. The pas- said wall and between said wall and said drive means sageways are mounted On an annular member 66 and 20 and also being connected to said blades, said inner cir- cumferential wall including a first level of passageways together they constitute a fixed inner surface of the which air is admitted to said ducting and the plenum.
leading edge of said rotor blades and a second level of It should be understood that the invention is not lim- passageways through air is admitted to said duct- ited to the particular embodiment shown and described 25 ing and the trailing edge of said rotor blades.
e * * * * herein, but that various changes and modifications may