Resources Contact Us Home
Dual piston drag damper for rotary-wing aircraft rotor

Image Number 5 for United States Patent #6676074.

A drag damper for use on a rotary wing aircraft rotor comprises a body defining two variable volume chambers linked by a piston. The chambers are filled with fluid and are connected by a restriction port (35) and by a channel (32) of larger cross-section than the restriction port. A secondary piston slidable and pressure-tight piston is fitted in the channel and loaded by an elastic bias (34). The equivalent mass of this secondary piston (33) and of the fluid which it displaces, and the stiffness of the elastic bias (34) are such that the secondary piston is resonant in the channel (32) at the rotation frequency of the rotor, to filter the dynamic component at this frequency of stresses applied to the damper (20). Furthermore at the natural drag frequency of the corresponding blade, the elastic bias substantially blocks the secondary piston (33) in its channel (32), and the flow of fluid between the chambers (29, 30) of the damper (20) takes place mainly via the restriction port (35) calibrated to provide substantial damping at this frequency.

  Recently Added Patents
Case for camera
Insulin derivative
Live-attenuated compositions for bacterial infections
Image stabilization
Enhanced claims damage estimation using aggregate display
Monitoring activity of a user in locomotion on foot
Headset, terminal, and method capable of switching headset mode
  Randomly Featured Patents
Positive-type photosensitive electrodeposition coating composition and process for producing circuit plate
Pyrolytic reducer and condenser apparatus
Impact initiated venting system and method of using same
Metal terminal locking method and device
Dispenser for at least one liquid or pasty product comprising a closure system that allows no ingress of air, and preservation process using the said dispenser
Coin display methods and apparatus
Serial host interface generates index word that indicates whether operation is read or write operation
Method for constructing fault classification tables of analog circuits
Weight loss device and method
Practice drumhead assembly