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US 6,641,365 B2Granted
Optimum speed tilt rotor
OwnerAbraham E. Kareminventor
Life of this patent
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OwnerAbraham E. Kareminventor
Estimating the term…
A variable speed helicopter tilt rotor system and method for operating such a system are provided which allow the helicopter rotor to be operated at an optimal angular velocity in revolutions per minute (RPM) minimizing the power required to turn the rotor thereby resulting in helicopter performance efficiency improvements, reduction in noise, and improvements in rotor, helicopter transmission and engine life. The system and method provide for an increase in helicopter endurance and range. The system and method also provide a substantial improvement in helicopter performance during take-off, hover and maneuver. All such improvements are valid in helicopter mode when the helicopter is supported by rotor vertical lift, in airplane mode when the helicopter is supported by wing lift and the rotor is tilted forward to provide propulsive thrust and in conversion from helicopter mode to airplane mode.
A method for improving the efficiency of a rotorcraft for a specific flight condition, the rotorcraft comprising a rotor having radially extending blades and an engine for providing power to rotate the rotor, wherein the rotor operates at an RPM level between and including a maximum rotor RPM level and a minimum rotor RPM level, the method comprising:
A method for improving the efficiency of a tilt rotor rotorcraft comprising a tilt rotor, the tilt rotor being capable of tilting to and operating in a helicopter mode, a conversion mode, and an airplane mode, and having radially extending blades and an engine for providing power to rotate the rotor at various RPM levels, the tilt rotor being capable of operation at a maximum RPM level in helicopter mode, the method comprising the steps of:
A variable speed tilt rotor, wherein the tilt rotor tilts from a helicopter mode position to an airplane mode position, wherein when in helicopter mode the tilt rotor provides lift to a rotorcraft and when in airplane mode the tilt rotor provides thrust to the rotorcraft, the rotor having a radius measured from a center of rotor rotation and a diameter and comprising:
A variable speed tilt rotor, wherein the tilt rotor tilts from a helicopter mode position to an airplane mode position, wherein when in helicopter mode the tilt rotor provides lift to a rotorcraft and when in airplane mode the tilt rotor provides thrust to the rotorcraft, the rotor having a radius measured from a center of rotor rotation and a diameter and comprising:
A rotor for a rotorcraft comprising:
Dependencies are inferred from the claim text.