Redundant aircraft propulsion system using co-rotating propellers joined by tip connectors

Patent metadata

Field	Value
Publication number	US-10232933-B2
Application number	US-201514973610-A
Country	US
Kind code	B2
Filing date	Dec 17, 2015
Priority date	Dec 17, 2015
Publication date	Mar 19, 2019
Grant date	Mar 19, 2019

Abstract

Multiple propeller blades may be joined by tip connectors to form a closed propeller apparatus. The tip connectors may create continuous structure between adjacent tips of a first propeller and a second propeller. Use of the tip connectors may reduce vortices created near the tips of the propeller blades, which cause drag and slow the rotation of the propeller blades. The tip connectors may also reduce noise caused by rotation of propeller blades. Further, the tip connectors reduce or eliminate deflection of the propeller blades by creating a support structure to counteract forces that would otherwise cause deflection of the propeller blades, thereby improving propeller blade loading. In some embodiments, the tip connectors may be formed of a malleable material and/or include one or more joints that enable at least one of the propellers to modify a pitch of blades of the propeller.

First claim

What is claimed is:

1. A propulsion device comprising:
a drive shaft;
a top propeller coupled to the drive shaft, the top propeller including a top longitudinal axis that spans between a top first tip and a top second tip located at opposite ends of the top propeller;
a bottom propeller coupled to the drive shaft, the bottom propeller including a bottom longitudinal axis that spans between a bottom first tip and a bottom second tip located at opposite ends of the bottom propeller, wherein the bottom longitudinal axis is non-parallel to the top longitudinal axis, wherein at least one of the top propeller or the bottom propeller is configured to vary a pitch of blades;
a first tip connector that extends between the top first tip and the bottom first tip;
a second tip connector that extends between the top second tip and the bottom second tip, the first tip connector and the second tip connector creating continuous structure joining the top propeller and the bottom propeller, wherein the first tip connector and the second tip connector comprise a malleable portion of a structure that enables movement of the pitch of the blades while maintaining the continuous structure joining the top propeller and the bottom propeller; and
a motor coupled to the drive shaft to rotate the drive shaft, the top propeller and the bottom propeller.

2. The propulsion device as recited in claim 1 , wherein the top propeller includes a top blade profile that is different than a bottom blade profile of the bottom propeller.

3. The propulsion device as recited in claim 1 , wherein the motor is a first motor, and further comprising second motor coupled to the drive shaft, wherein the first motor is located proximate to the top propeller and the second motor is located proximate to the bottom propeller.

4. The propulsion device as recited in claim 1 , wherein the motor is located between the top propeller and the bottom propeller.

5. The propulsion device as recited in claim 1 , wherein the first tip connector and the second tip connector include one or more joints that enables movement of the pitch of the blades while maintaining the continuous structure joining the top propeller and the bottom propeller.

6. An apparatus comprising:
a first propeller including a first tip and a second tip located at opposite ends of the first propeller, the first propeller associated with a first plane of rotation;
a second propeller including a third tip and a fourth tip located at opposite ends of the second propeller, the second propeller associated with a second plane of rotation that is parallel to the first plane of rotation, wherein the first propeller includes an angle offset from the second propeller in the first plane of rotation of the first propeller, the angle offset causing the first propeller to trail the second propeller during rotation, and wherein at least one of the first propeller or the second propeller is configured to vary a pitch of blades;
a first tip connector that extends between the first tip and the third tip; and
a second tip connector that extends between the second tip and the fourth tip, the first tip connector and the second tip connector creating a continuous structure joining the first propeller and the second propeller, wherein the first tip connector and the second tip connector are formed of a malleable material configured to permit movement of the pitch of the blades while maintaining the continuous structure joining the first propeller and the second propeller.

7. The apparatus as recited in claim 6 , further comprising a drive shaft that couples the first propeller to the second propeller at an axis of rotation of the first and second propeller.

8. The apparatus as recited in claim 7 , wherein the drive shaft includes a first portion that extends outward from a first side of the first propeller and a second portion that extends outward from a second side of the second propeller that is opposite the first side of the first propeller, and further comprising:
a first motor coupled to the first portion of the drive shaft; and
a second motor coupled to the second portion of the drive shaft.

9. The apparatus as recited in claim 8 , further comprising:
a first one-way clutch bearing coupled between the first motor and the drive shaft, wherein the first one-way clutch bearing enables the second motor to rotate the drive shaft when the first motor is inoperable; and
a second one-way clutch bearing coupled between the second motor and the drive shaft, wherein the second one-way clutch bearing enables the first motor to rotate the drive shaft when the second motor is inoperable.

10. The apparatus as recited in claim 6 , further comprising:
a drive shaft that couples the first propeller to the second propeller;
a first frame member;
a first motor coupled to the drive shaft and the first frame member to cause rotation of the drive shaft relative to the first frame member;
a second frame member; and
a second motor is coupled to the drive shaft and the second frame member to cause rotation of the drive shaft relative to the second frame member,
wherein at least one of the first motor and the second motor is located between the first propeller and the second propeller.

11. The apparatus as recited in claim 6 , wherein the first tip connector and the second tip connector include one or more joints that enable movement of the pitch of the blades while maintaining the continuous structure joining the first propeller and the second propeller.

12. The apparatus as recited in claim 6 , wherein the first propeller includes a first blade profile that is different than a second blade profile of the second propeller.

13. The apparatus as recited in claim 6 , further comprising a motor located between the first propeller and the second propeller, the motor to drive rotation of the first propeller and the second propeller.

14. The apparatus as recited in claim 6 , wherein the malleable material is constructed from at least one of rubber or plastic, wherein the first propeller includes first blades having a first pitch of blades and the second propeller includes second blades having a second pitch of blades, and wherein the first pitch of blades is different than the second pitch of blades.

15. An unmanned aerial vehicle (UAV) comprising:
a frame;
a power source coupled to the frame; and
at least one propulsion unit coupled to the frame and connected to the power source, wherein at least one propulsion unit includes:
a first propeller including a first tip and a second tip located at opposite ends of the first propeller, the first propeller associated with a first plane of rotation;
a second propeller including a third tip and a fourth tip located at opposite ends of the second propeller, the second propeller associated with a second plane of rotation;
a first tip connector that extends between the first tip and the third tip;
a second tip connector that extends between the second tip and the fourth tip, the first tip connector and the second tip connector each formed of a malleable material configured to permit relative movement between the first propeller blade and the second propeller blade while creating a continuous structure joining the first propeller and the second propeller;
a drive shaft that couples the first propeller to the second propeller; and
a motor assembly coupled to the frame and the drive shaft, the motor assembly powered by the power source and configured to rotate the drive shaft.

16. The UAV as recited in claim 15 , wherein:
the motor assembly comprises a first motor and a

Assignees

• Amazon Tech Inc

Inventors

• Roberts Nicholas Hampel
• Shiosaki Dominic Timothy
• Welsh Ricky Dean

Classifications

• B64C27/14

  Direct drive between power plant and rotor hub · CPC title

• B64C27/473

  Constructional features · CPC title

• B64C11/48 Primary

  Units of two or more coaxial propellers · CPC title

• B64C27/463

  Blade tips · CPC title

• B64C11/306

  specially adapted for contrarotating propellers · CPC title