Tilt rotor systems and methods for EVTOL aircraft
A system includes a first frame for mounting to the aircraft; a second frame for mounting the proprotor, the second frame being rotatably mounted to the first frame; a first gear located along the rotation axis of the second frame and fixed in position relative to the first frame; a pinion that moves with the second frame and engages the first gear such that the pinion revolves around the first gear, causing the pinion to rotate; a cam that is fixedly connected to the pinion such that the cam rotates with the pinion; and a control rod operatively coupled at a first end with the cam such that rotation of the cam can cause translation of the control rod, wherein the control rod can be coupled at a second end to the blades of the proprotor such that translation of the control rod alters the pitch of the blades.
1 . A proprotor tilting system, comprising:
a first gear fixed in position relative to a first frame;
a pinion that moves with a second frame and is engaged with the first gear such that the pinion revolves around at least a portion of the first gear, wherein revolution of the pinion causes the pinion to rotate;
a cam that is fixedly connected to the pinion such that the cam rotates with the pinion; and
a control rod operatively coupled at a first end with the cam such that rotation of the cam causes translation of the control rod to alter a pitch of blades.
2 . The system of claim 1 , wherein the first gear is attached to the first frame and the first frame is for mounting to the aircraft.
3 . The system of claim 1 , wherein the cam is mounted to a shaft that is fixedly connected to the pinion.
4 . The system of claim 3 , wherein the control rod comprises a clevis with a slot, wherein the shaft is positioned within the slot.
5 . The system of claim 4 , wherein the control rod is prevented from rotating via the engagement between the shaft and the clevis.
6 . The system of claim 1 , comprising a spring engaged with the control rod for biasing the control rod against the cam.
7 . The system of claim 6 , wherein the spring maintains the control rod in compression.
8 . The system of claim 6 , wherein the spring maintains the control rod in tension.
9 . The system of claim 1 , wherein the control rod comprises a follower that engages the cam.
10 . The system of claim 9 , wherein the follower comprises a roller.
11 . The system of claim 10 , wherein the follower engages an outer surface of the cam.
12 . The system of claim 9 , wherein the follower comprises a pin.
13 . The system of claim 12 , wherein the cam comprises a track and the pin engages the track.
14 . The system of claim 9 , wherein the cam comprises a circular portion such that the control rod does not translate when engaged with the circular portion of the cam.
15 . The system of claim 1 , comprising at least one actuator connected to the first frame and the second frame and configured to rotate the second frame relative to the first frame.
16 . The system of claim 15 , wherein the second frame comprises one or more arms connected to the at least one actuator.
17 . The system of claim 15 , wherein the at least one actuator is a linear actuator.
18 . The system of claim 15 , wherein the at least one actuator is a ball screw actuator.
19 . The system of claim 15 , wherein the at least one actuator is a rotary actuator.
20 . The system of claim 1 , wherein the pinion is rotationally coupled to the first frame and the first frame is for mounting to the aircraft.
21 . The system of claim 1 , wherein the first gear is connected to a fixed pin that is mounted to the first frame and the first frame is for mounting to the aircraft.
22 . The system of claim 21 , wherein the fixed pin is surrounded by a rotatable shaft that defines a rotation axis.
23 . The system of claim 22 , wherein a second frame for mounting the proprotor is mounted to the rotatable shaft.
24 . A VTOL (Vertical Takeoff and Landing) aircraft comprising:
a pinion that moves with a proprotor and is engaged with a first gear such that the pinion revolves around at least a portion of the first gear, wherein revolution of the pinion causes the pinion to rotate;
a cam that is fixedly connected to the pinion such that the cam rotates with the pinion; and
a control rod operatively coupled at a first end with the cam such that rotation of the cam causes translation of the control rod to alter a pitch of blades.
25 . A method of operating a VTOL (Vertical Takeoff and Landing) aircraft comprising:
tilting a proprotor of the aircraft, wherein:
a first gear is fixed in position relative to a fixed frame,
a pinion moves with the proprotor and is engaged with the first gear such that the pinion revolves around at least a portion of the first gear, wherein revolution of the pinion causes the pinion to rotate,
a cam is fixedly connected to the pinion such that the cam rotates with the pinion, and
a control rod is operatively coupled at a first end with the cam such that rotation of the cam causes translation of the control rod to alter a pitch of blades of the proprotor.
26 . A proprotor tilting system, comprising:
a first frame for mounting to an aircraft;
a second frame for mounting a proprotor, wherein the second frame is rotatably mounted to the first frame;
a tilt actuator configured to tilt the second frame with respect to the first frame;
a cam configured to rotate when a tilt actuator tilts the second frame; and
a control rod operatively coupled at a first end with the cam such that rotation of the cam causes translation of the control rod to alter a pitch of blades.
27 . The system of claim 26 , wherein a gear is attached to the first frame.
28 . The system of claim 26 , wherein the cam is mounted to a shaft that is fixedly connected to a pinion.
29 . The system of claim 28 , wherein the control rod comprises a clevis with a slot, wherein the shaft is positioned within the slot.
30 . The system of claim 29 , wherein the control rod is prevented from rotating via the engagement between the shaft and the clevis.
31 . The system of claim 26 , comprising a spring engaged with the control rod for biasing the control rod against the cam.
32 . The system of claim 31 , wherein the spring maintains the control rod in compression.
33 . The system of claim 31 , wherein the spring maintains the control rod in tension.
34 . The system of claim 26 , wherein the control rod comprises a follower that engages the cam.
35 . The system of claim 34 , wherein the follower comprises a roller.
36 . The system of claim 35 , wherein the follower engages an outer surface of the cam.
37 . The system of claim 34 , wherein the follower comprises a pin.
38 . The system of claim 37 , wherein the cam comprises a track and the pin engages the track.
39 . The system of claim 34 , wherein the cam comprises a circular portion such that the control rod does not translate when engaged with the circular portion of the cam.
40 . The system of claim 26 , wherein the tilt actuator is connected to the first frame and the second frame and configured to rotate the second frame relative to the first frame.
41 . The system of claim 40 , wherein the second frame comprises one or more arms connected to the tilt actuator.
42 . The system of claim 40 , wherein the tilt actuator is a linear actuator.
43 . The system of claim 40 , wherein the tilt actuator is a ball screw actuator.
44 . The system of claim 40 , wherein the tilt actuator is a rotary actuator.
45 . The system of claim 26 , wherein a pinion is rotationally coupled to the second frame.
46 . The system of claim 26 , wherein a gear is connected to a fixed pin that is mounted to the first frame.
47 . The system of claim 46 , wherein the fixed pin is surrounded by a rotatable shaft that defines a rotation axis.
48 . The system of claim 47 , wherein the second frame is mounted to the rotatable shaft.
49 . A VTOL (Vertical Takeoff and Landing) aircraft comprising:
a frame for mounting a proprotor of the aircraft;
a tilt actuator configured to tilt the frame;
a cam configured to rotate when the tilt actuator tilts the frame; and
a control rod operatively coupled at a first end with the cam such that rotation of the cam causes translation of the control rod to alter a pitch of blades.
50 . A method of operating a VTOL (Vertical Takeoff and Landing) aircraft comprising:
tilting, by a tilt actuator, a frame for mounting a proprotor of the aircraft, wherein:
a cam is configured to rotate when the tilt actuator tilts the frame; and
a control rod operatively coupled at a first end with the cam such that rotation of the cam causes translation of the control rod to alter a pitch of blades.