Fluid reaction surfaces (i.e. – impellers) – With fluid passage in working member communicating with... – Both inlet and outlet to working fluid
Patent
1992-12-11
1994-05-24
Look, Edward K.
Fluid reaction surfaces (i.e., impellers)
With fluid passage in working member communicating with...
Both inlet and outlet to working fluid
416231B, 416500, 416 23, B64C 2746
Patent
active
053143086
ABSTRACT:
Higher harmonic control (hereinafter HHC) of helicopter rotor blade vibrations is provided by an actively controlled, rotatable, slotted cylinder which is mounted at an outboard section of each blade. Continuous rotation of each cylinder about its longitudinal axis produces a periodic aerodynamic force on the blade at a frequency of twice the rotational frequency of the cylinder. The amplitude of force is controlled by the size of a slot opening in the cylinder while the rotational speed of the cylinder is synchronized to run at a multiple of the speed of a rotor blade drive shaft. The amplitude and phase of the HHC force is regulated, either manually or by active feedback control, to minimize any vibratory load transmitted to the airframe through the rotor blade drive shaft. A significant advantage offered by this concept relative to other HHC methods, such as high-frequency blade pitch motions actuated either by the swash plate or by moveable tabs at the blade trailing edge, is its low power requirement.
REFERENCES:
patent: 1785333 (1930-12-01), Trey
patent: 2344515 (1944-03-01), Massey
patent: 2569983 (1951-10-01), Favre
patent: 3326296 (1967-06-01), Hill et al.
patent: 3649132 (1972-03-01), Arcidiacono
patent: 3692259 (1972-09-01), Yuan
patent: 4040578 (1977-08-01), Yuan
patent: 4236607 (1980-12-01), Halwes et al.
patent: 4514143 (1985-04-01), Campbell
patent: 4655685 (1987-04-01), Fradenburgh
patent: 4809553 (1989-03-01), Reed, III
patent: 4953098 (1990-08-01), Fischer, Jr. et al.
patent: 4965879 (1990-10-01), Fischer, Jr.
patent: 5099430 (1992-03-01), Hirsch
Dynamic Engineering Inc.
Larson James A.
Look Edward K.
Scafetta, Jr. Joseph
LandOfFree
System for controlling higher harmonic vibrations in helicopter does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with System for controlling higher harmonic vibrations in helicopter , we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and System for controlling higher harmonic vibrations in helicopter will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1968973