Hinged rotor blade to provide passive variable pitch

Patent metadata

Field	Value
Publication number	US-11827335-B2
Application number	US-202217956573-A
Country	US
Kind code	B2
Filing date	Sep 29, 2022
Priority date	May 8, 2017
Publication date	Nov 28, 2023
Grant date	Nov 28, 2023

Abstract

A hinged propeller comprising a hub and one or more blades is disclosed. In various embodiments, a blade is connected to the hub via a hinge, wherein at least a substantial part of the blade has a longitudinal axis that is substantially parallel to a line extending radially from a center of the hub, and wherein the hinge has an axis of hinge rotation that is oriented at a non-zero acute angle to a line that is perpendicular, in a plane of rotation of the hub, to said longitudinal axis.

First claim

What is claimed is:

1. A propeller for an aircraft, comprising:
a hub;
a blade including a neck portion angled away from a plane of rotation of the hub, wherein the blade has a longitudinal axis extending through a center of the blade and running from a tip of the blade to an end of the neck portion; and
a hinge including a pivotal link, the hinge connecting the blade to the hub, wherein:
the hinge has an axis of hinge rotation that is offset from a line perpendicular to the longitudinal axis of the blade; and
the hinge responds to forces acting on the blade to vary a pitch of the blade including causing the blade to be at a lower pitch and higher dihedral angle in a vertical flight mode relative to a forward flight mode, the dihedral angle being an angle of the blade relative to the plane of rotation of the hub.

2. The propeller of claim 1 , wherein said hinge comprises a single pivotal link.

3. The propeller of claim 1 , wherein said hinge comprises a pin positioned on said axis of hinge rotation.

4. The propeller of claim 1 , wherein said hinge permits the blade to fold back towards a central axis of the hub if no force is being applied to rotate the propeller.

5. The propeller of claim 1 , wherein said hinge is integrated with a structure mounted fixedly to said hub.

6. The propeller of claim 5 , wherein said structure mounted fixedly to said hub includes at least one tab portion.

7. The propeller of claim 6 , wherein said hinge comprises a pin positioned on said axis of hinge rotation and said pin runs through a transverse hole in an end of the blade nearest to the hub and at least one hole on said at least one tab portion.

8. The propeller of claim 1 , wherein said hub comprises a nose cone.

9. The propeller of claim 1 , wherein said hub comprises a nose structure.

10. The propeller of claim 1 , wherein the hinge is oriented in a plane that is in the plane of rotation of the hub.

11. The propeller of claim 1 , wherein the hinge comprises a forward end associated with a leading edge of the blade and a rearward end associated with a trailing edge of the blade, and wherein the forward end lies further from a geometric center of the hub than the rearward end.

12. The propeller of claim 1 , wherein the neck portion has a neck portion longitudinal axis that is substantially orthogonal to the axis of hinge rotation and wherein a substantial part of the blade is coupled to the hub by the neck portion.

13. The propeller of claim 1 , wherein a substantial part of the blade comprises a primary airfoil portion of the blade.

14. The propeller of claim 13 , wherein the neck portion is positioned between the primary airfoil portion and the hinge.

15. The propeller of claim 1 , wherein in a first propeller orientation associated with a first mode of flight, the blade deploys to a first stable position associated with a first pitch, and in a second propeller orientation associated with a second mode of flight the blade rotates about the axis of hinge rotation to a second stable position associated with a second pitch.

16. The propeller of claim 15 , wherein the first propeller orientation comprises a substantially horizontal plane of rotation.

17. The propeller of claim 15 , wherein the second propeller orientation comprises a substantially vertical plane of rotation.

18. The propeller of claim 15 , wherein the first mode of flight corresponds to the vertical flight mode.

19. The propeller of claim 15 , wherein the second mode of flight corresponds to the forward flight mode.

20. The propeller of claim 1 , further comprising a stop that prevents the blade from moving beyond a point associated with the stop.

Assignees

• Kitty Hawk Corp

Inventors

• Reichert Todd

Classifications

• B64C11/06 Primary

  for variable-pitch blades · CPC title

• B64C11/14

  Spinners · CPC title

• B64C11/343

  actuated by the centrifugal force or the aerodynamic drag acting on the blades · CPC title

• B64C29/0033

  the propellers being tiltable relative to the fuselage · CPC title

• B64C11/28

  Collapsible or foldable blades · CPC title