US 9,809,318 B1
Tiltrotor aircraft having spherical bearing mounted pylon assemblies
Jeffrey Matthew Williams, Fort Worth, TX (US); George Ryan Decker, Fort Worth, TX (US); James Everett Kooiman, Fort Worth, TX (US); Andrew G. Baines, Fort Worth, TX (US); and Daniel J. Sweigard, Fort Worth, TX (US)
Assigned to Bell Helicopter Textron Inc., Fort Worth, TX (US)
Filed by Bell Helicopter Textron Inc., Fort Worth, TX (US)
Filed on Jan. 17, 2017, as Appl. No. 15/407,481.
Application 15/407,481 is a continuation in part of application No. 13/966,726, filed on Aug. 14, 2013.
Int. Cl. B64D 27/26 (2006.01); F16C 17/02 (2006.01); F16C 17/26 (2006.01); B64C 29/00 (2006.01); B64C 27/26 (2006.01); B64C 3/32 (2006.01); B64D 35/00 (2006.01); F16H 57/02 (2012.01)
CPC B64D 27/26 (2013.01) [B64C 3/32 (2013.01); B64C 27/26 (2013.01); B64C 29/0033 (2013.01); B64D 35/00 (2013.01); F16C 17/022 (2013.01); F16C 17/26 (2013.01); B64D 2027/266 (2013.01); F16H 2057/02043 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A propulsion system for a tiltrotor aircraft having a helicopter mode and an airplane mode, the tiltrotor aircraft having an airframe including a fuselage and a wing, the propulsion system comprising:
an engine supported by the airframe proximate an outboard end of the wing;
a fixed gearbox operably coupled to the engine and having an output gear;
inboard and outboard pedestals supported by the airframe and positioned above the wing;
a pylon assembly rotatably coupled between the inboard and outboard pedestals, the pylon assembly including a spindle gearbox having an input gear, a mast operably coupled to the input gear and a proprotor assembly operable to rotate with the mast, the spindle gearbox rotatable about a conversion axis to selectively operate the tiltrotor aircraft between the helicopter mode and the airplane mode; and
a common shaft configured to transfer torque from the output gear of the fixed gearbox to the input gear of the spindle gearbox, the common shaft rotatable about the conversion axis;
wherein, each of the inboard and outboard pedestals further comprises a spherical bearing providing a self-aligning coupling between the pylon assembly and the inboard and outboard pedestals, thereby reducing alignment sensitivity between the inboard and outboard pedestals.