Patent ID: 6688926
Filing Date: 2004-02-10
Classification: B63H

Abstract:
A motor for driving a propeller having a plurality of propeller blades, including:a first output shaft having a drive axis for driving the propeller around the drive axis; a second output shaft having a drive axis common with the drive axis of the first output shaft; coupling means for coupling the second output shaft to each propeller blade of the propeller for rotating the propeller blades about respective radial axes transverse to the drive axes of the first and second output shafts to change the pitch of the propeller blades relative to the radial axes; an input for supplying input rotary power to the first and second output shafts for driving the first and second output shafts about the drive axes to transmit rotary power to the propeller; phase adjusting means for adjusting the phase relationship between the first and second output shafts so that one of the output shafts rotates relative to the other of the output shafts with the relative rotation causing the coupling means to rotate the propeller blades about the respective radial axes to change the pitch of the blades relative to the radial axes; backlash preventing means for preventing oscillation of the propeller blade about the radial axes due to any backlash in the phase adjusting means so any backlash is not transmitted to the propeller blades which may otherwise cause the propeller blades to oscillate; and wherein the phase adjusting means comprises: a cage coupled to the input via the first and second output shafts and the input for input of rotary power; a first gear on the first output shaft; a second gear on the second output shaft; a first planet gear in meshing engagement with the first gear on the first output shaft; a second planet gear in meshing engagement with the second gear on the second output shaft; a first orbit gear arranged for rotation relative to the first and second output shafts and meshing with the first planet gear and a second orbit gear arranged for rotation relative to the output shafts and engaging the second planet gear, one of the first or second orbit gears being fixed and the other of the first and second orbit gears being movable relative to the said one of the orbit gears; and adjusting means for moving the movable orbit gear to cause the planet gear associated with that orbit gear to advance or regress relative to the other planet gear to thereby change the phase relationship between the first and second output shafts and to alter the pitch of the propeller blades via the coupling means which couples the second output shaft to each propeller blade.