Propeller blade indentations for improved aerodynamic performance and sound control

Patent metadata

Field	Value
Publication number	US-10399665-B2
Application number	US-201815968137-A
Country	US
Kind code	B2
Filing date	May 1, 2018
Priority date	Dec 18, 2015
Publication date	Sep 3, 2019
Grant date	Sep 3, 2019

Abstract

Sounds are generated by an aerial vehicle during operation. For example, the motors and propellers of an aerial vehicle generate sounds during operation. Disclosed are systems, methods, and apparatus for actively adjusting the position of one or more propeller blade treatments of a propeller blade of an aerial vehicle during operation of the aerial vehicle. For example, the propeller blade may have one or more propeller blade treatments that may be adjusted between two or more positions. Based on the position of the propeller blade treatments, the airflow over the propeller is altered, thereby altering the sound generated by the propeller when rotating. By altering the propeller blade treatments on multiple propeller blades of the aerial vehicle, the different sounds generated by the different propeller blades may effectively cancel, reduce, and/or otherwise alter the total sound generated by the aerial vehicle.

First claim

What is claimed is:

1. An aerial vehicle comprising:
a first motor configured to rotate a propeller such that the propeller generates a lifting force;
the propeller including:
a hub that is coupled to the first motor so that the first motor can rotate the propeller;
a first propeller blade extending from the hub, the first propeller blade including:
a first leading edge;
a first tip;
a first trailing edge;
a first surface area that extends from the hub and the first tip and between the first leading edge and the first trailing edge, the first surface area having an upper side, and a lower side; and
a first plurality of indentations formed in at least a portion of the first surface area, the first plurality of indentations having a first depth and a first shape, wherein the first plurality of indentations increases a duration in which air passing over the first propeller blade remains attached to the first propeller blade; and

a second propeller blade extending from the hub, the second propeller blade including:
a second leading edge;
a second tip;
a second trailing edge;
a second surface area that extends from the hub and the second tip and between the second leading edge and the second trailing edge, the second surface area having an upper side, and a lower side; and
a second plurality of indentations formed in at least a portion of the second surface area, the second plurality of indentations having a second depth and a second shape, wherein the second plurality of indentations increases a duration in which air passing over the second propeller blade remains attached to the second propeller blade;

where at least one of the first depth of the first plurality of indentations is different from the second depth of the second plurality of indentations, or the first shape of the first plurality of indentations is different from the second shape of the second plurality of indentations.

2. The aerial vehicle of claim 1 , wherein the first plurality of indentations are positioned toward the first tip of the first propeller blade and alter a tip vortex caused by rotation of the first propeller blade.

3. The aerial vehicle of claim 1 , further comprising:
a third plurality of indentations formed in at least a portion of the first surface area, the third plurality of indentations having a third depth that is different than the first depth and a third shape that is different than the first shape.

4. The aerial vehicle of claim 1 , wherein a density of the first plurality of indentations is higher toward the first tip of the first propeller blade than toward the hub of the first propeller blade.

5. The aerial vehicle of claim 1 , further comprising:
a third plurality of indentations formed along the first leading edge of the first propeller blade.

6. A propeller, comprising:
a hub;
a first propeller blade, comprising:
a first tip;
a first surface area that extends between the hub and the first tip, the first surface area having an upper side, a lower side, a leading edge, and a trailing edge; and
a first plurality of indentations formed in the first surface area; and

a second propeller blade, comprising:
a second tip;
a second surface area that extends between the hub and the second tip, the second surface area having an upper side, a lower side, a leading edge, and a trailing edge; and
a second plurality of indentations formed in the second surface area;

wherein at least one of a first size, a first shape, a first depth, or a first position of the first plurality of indentations is different from a second size, a second shape, a second depth, or a second position of the second plurality of indentations.

7. The propeller of claim 6 , wherein each of the first plurality of indentations have a first shape selected from a group of shapes consisting of: a circle, a square, a rectangle, an oval, a triangle, a semi-circle, a trapezoid, a parallelogram, a hexagon, a rhomboid, a quadrilateral, an irregular shape, a polygon, or an octagon.

8. The propeller of claim 6 , wherein:
the first plurality of indentations have a first depth and a first shape; and
the second plurality of indentations have a second depth and a second shape.

9. The propeller of claim 8 , wherein:
the first plurality of indentations are formed into the upper side of the first surface area; and
the second plurality of indentations are formed into the lower side of the second surface area.

10. The propeller of claim 8 , wherein the first plurality of indentations are interspersed along at least a portion of the first surface area of the first propeller blade, and the second plurality of indentations are interspersed along at least a portion of the second surface area of the second propeller blade.

11. The propeller of claim 6 , wherein the first plurality of indentations are arranged in a first pattern, and the second plurality of indentations are arranged in a second pattern.

12. The propeller of claim 11 , wherein the first plurality of indentations are configured to create a first sound, and wherein the second plurality of indentations are configured to create a second sound.

13. The propeller of claim 12 , wherein the second sound comprises an anti-sound that at least partially cancels out the first sound.

14. The propeller of claim 12 , wherein at least one of the first sound or the second sound comprises an anti-sound that at least partially cancels out a third sound generated by a motor that rotates the propeller.

15. The propeller of claim 6 , wherein the at least one of a size, a shape, a depth, or a position of the first plurality of indentations varies over at least a portion of the first surface area of the first propeller blade.

16. An aerial vehicle, comprising:
a frame;
a motor coupled to the frame;
a first propeller blade coupled to and rotatable by the motor, the first propeller blade including a first plurality of indentations having a first depth into a first surface area of the first propeller blade; and
a second propeller blade coupled to and rotatable by the motor, the second propeller blade including a second plurality of indentations having a second depth into a second surface area of the second propeller blade, wherein the first depth is different than the second depth.

17. The aerial vehicle of claim 16 , wherein:
the first plurality of indentations are positioned in a first arrangement on the first surface area of the first propeller blade such that the first propeller blade, when rotating, generates a first sound; and
the second plurality of indentations are positioned in a second arrangement on the second surface area of the second propeller blade such that the second propeller blade, when rotating, generates a second sound.

18. The aerial vehicle of claim 17 , wherein the second sound comprises an anti-sound that at least partially cancels out the first sound.

19. The aerial vehicle of claim 17 , wherein at least one of the first sound or the second sound comprises an anti-sound that at least partially cancels out a third sound generated by the motor.

20. The aerial vehicle of claim 16 , wherein the first plurality of indentations are positioned on the first surface area of the first propeller blade to alter a vortex generated by rotation of the first propeller blade.

Assignees

• Amazon Tech Inc

Inventors

• Beckman Brian C
• Kimchi Gur
• Ko Allan

Classifications

• B64U2101/60

  for transporting passengers; for transporting goods other than weapons · CPC title

• B64C2230/28

  at propeller or rotor blades · CPC title

• B64C11/00

  Propellers, e.g. of ducted type; Features common to propellers and rotors for rotorcraft · CPC title

• B64C23/06

  by generating vortices · CPC title

• B64C27/463

  Blade tips · CPC title