Propeller blade indentations for improved aerodynamic performance and sound control

• US 10,011,346 B2
• Filed: 12/18/2015
• Issued: 07/03/2018
• Est. Priority Date: 12/18/2015
• Status: Active Grant

• Current Assignee: Amazon Technologies, Inc. (Amazon.com, Inc.)
• Original Assignee: Amazon Technologies, Inc. (Amazon.com, Inc.)
• Inventors: Beckman, Brian C., Kimchi, Gur, Ko, Allan
• Primary Examiner(s): Benedik, Justin M
• Application Number:
  US14/975,249
• Publication Number:
  US 20170174318A1
• Time in Patent Office: 928 Days
• CPC Class Codes: B64C 11/00 Propellers, e.g. of ducted type; Features common to propellers and rotors for rotorcraft
• CPC Class Codes: B64C 11/18 Aerodynamic features
• CPC Class Codes: B64C 2230/14 achieving noise reductions
• CPC Class Codes: B64C 2230/28 at propeller or rotor blades
• CPC Class Codes: B64C 23/06 by generating vortices
• CPC Class Codes: B64C 27/463 Blade tips
• CPC Class Codes: B64C 39/024 of the remote controlled vehicle type, i.e. RPV
• CPC Class Codes: B64U 10/10 Rotorcrafts
• CPC Class Codes: B64U 10/13 Flying platforms
• CPC Class Codes: B64U 10/14 with four distinct rotor axes, e.g. quadcopters
• CPC Class Codes: B64U 20/20 for noise reduction
• CPC Class Codes: B64U 2101/60 for transporting passengers; for transporting goods other than weapons
• CPC Class Codes: B64U 30/20 Rotors; Rotor supports
• CPC Class Codes: B64U 30/29 Constructional aspects of rotors or rotor supports; Arrangements thereof
• CPC Class Codes: B64U 50/31 generated by photovoltaics
• CPC Class Codes: Y02T 50/10 Drag reduction
• CPC Class Codes: Y02T 50/60 Efficient propulsion technologies, e.g. for aircraft

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.

Claims

1. An aerial vehicle comprising:

a first motor configured to rotate a first propeller such that the first propeller generates a first lifting force;

the first propeller including;

a first hub that is coupled to the first motor so that the first motor can rotate the first propeller;

a first propeller blade extending from the first hub, the first propeller blade including;

a leading edge;

a tip;

a trailing edge;

a surface area of the first propeller blade that extends from the first hub to the tip and between the leading edge and the trailing edge, the surface area of the first propeller blade having an upper side, and a lower side; and

a first plurality of indentations formed in at least a portion of the surface area of the first propeller blade, 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 motor configured to rotate a second propeller such that the second propeller generates a second lifting force;

the second propeller including;

a second hub that is coupled to the second motor so that the second motor can rotate the second propeller;

a second propeller blade extending from the second hub, the second propeller blade including;

a leading edge;

a tip;

a trailing edge;

a surface area of the second propeller blade that extends from the second hub to the tip and between the leading edge and the trailing edge, the surface area of the second propeller blade having an upper side, and a lower side; and

a second plurality of indentations formed in at least a portion of the surface area of the second propeller blade, 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; and

wherein the first depth of the first plurality of indentations of the first propeller blade is different than the second depth of the second plurality of indentations of the second propeller blade.

2. The aerial vehicle of claim 1, wherein the first plurality of indentations are positioned toward the 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,

wherein the second depth of the second plurality of indentations of the second propeller blade is greater than the first depth of the first plurality of indentations of the first propeller blade, and the second shape of the second plurality of indentations of the second propeller blade is different than the first shape of the first plurality of indentations of the first propeller blade.

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

5. The aerial vehicle of claim 1, further comprising:

a third plurality of indentations formed along the leading edge of the first propeller blade.

6. An aerial vehicle, comprising:

a frame;

a first motor coupled to the frame;

a first propeller coupled to and rotatable by the first motor, the first propeller including a first plurality of indentations having a first depth into a surface area of the first propeller;

a second motor coupled to the frame; and

a second propeller coupled to and rotatable by the second motor, the second propeller including a second plurality of indentations having a second depth into a surface area of the second propeller, wherein the first depth is different than the second depth.

7. The aerial vehicle of claim 6, wherein:

the first plurality of indentations are positioned in a first arrangement on the surface area of the first propeller such that the first propeller, when rotating, generates a first sound; and

the second plurality of indentations are positioned in a second arrangement on the surface area of the second propeller such that the second propeller, when rotating, generates a second sound.

8. The aerial vehicle of claim 6, wherein the first plurality of indentations are positioned on the surface area of the first propeller to alter a vortex generated by rotation of the first propeller.

9. The aerial vehicle of claim 6, wherein the first propeller includes a third plurality of indentations formed in the surface area of the first propeller, the third plurality of indentations having at least one of a size, a shape, or a depth that is different than a size, a shape, or the first depth of the first plurality of indentations.

10. The aerial vehicle of claim 9, wherein the first plurality of indentations and the third plurality of indentations are interspersed along at least a portion of the surface area of the first propeller.

11. The aerial vehicle of claim 6, wherein the first propeller comprises:

a hub;

a tip;

the surface area of the first propeller that extends between the hub and the tip, the surface area of the first propeller having an upper side, a lower side, a leading edge, and a trailing edge; and

the first plurality of indentations formed into the surface area of the first propeller.

12. The aerial vehicle of claim 6, wherein each of the first plurality of indentations have a 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, and an octagon.

13. The aerial vehicle of claim 6,

wherein:

the first plurality of indentations have a first shape; and

the second plurality of indentations have a second shape.

14. The aerial vehicle of claim 6, wherein:

the first plurality of indentations are formed into at least one of the upper side or the lower side of the first propeller; and

the second plurality of indentations are formed into at least one of an upper side or a lower side of the second propeller.

15. The aerial vehicle of claim 6, wherein the first plurality of indentations are arranged in a pattern.

16. The aerial vehicle of claim 6, wherein a density of the first plurality of indentations varies over at least a portion of the surface area of the first propeller.

17. The aerial vehicle of claim 6, further comprising:

a first plurality of protrusions extending from the surface area of the first propeller blade.

18. The aerial vehicle of claim 17, wherein the first plurality of indentations and the first plurality of protrusions are interspersed along at least a portion of the surface area of the first propeller.

19. The aerial vehicle of claim 6, wherein 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 surface area of the first propeller.

20. The aerial vehicle of claim 6, wherein at least some of the first plurality of indentations are formed along a leading edge of the surface area of the first propeller.