System for aligning a propeller

Patent metadata

Field	Value
Publication number	US-9586673-B2
Application number	US-201414184560-A
Country	US
Kind code	B2
Filing date	Feb 19, 2014
Priority date	Aug 19, 2011
Publication date	Mar 7, 2017
Grant date	Mar 7, 2017

Abstract

A motor assembly that includes a motor ( 102 ) having a rotatable shaft, a hub coupled to the rotatable shaft, the hub having a propeller indexer to receive a propeller ( 104 ), when the propeller is present, a sensor trigger rotatable with the shaft ( 100 ) and positioned at a propeller offset angle θ PROP from the propeller indexer, and a sensor coupled to the motor and positioned to detect the sensor trigger so that the propeller indexer may be positioned at the propeller offset angle θ PROP from the sensor through rotation of the shaft so that said sensor is proximate to the sensor trigger.

First claim

What is claimed is:

1. A method of securing a propeller, comprising:
commutating a sensor trigger by commutating a shaft of a motor, said motor having stators and rotors;
commutating a propeller indexer by commutating said shaft, said propeller indexer configured to align a propeller, when a propeller is present, at an angular position that is a propeller offset angle θ PROP from said sensor trigger as referenced by a center of rotation of said shaft;
sensing said sensor trigger as said sensor trigger rotates to a point adjacent a sensor fixedly coupled to said motor; and
switching a control signal to rotatably hold said rotors driving said rotatable shaft in response to said sensor sensing said sensor trigger;
wherein said propeller indexer may be held in position at the propeller offset angle θ PROP from the sensor by commutating said shaft and holding the rotors so that the sensor is proximate to the sensor trigger; and
wherein said propeller propels an aircraft having an aircraft wing, and wherein said sensing said sensor trigger step further comprises sensing said sensor trigger as said propeller aligns with the aircraft wing.

2. The method of claim 1 , wherein said switching a control signal comprises turning off two of three phase circuits driving said rotors so that a third phase current remains to provide a holding force to said rotors so that said sensor trigger is proximate to said sensor.

3. The method of claim 2 , further comprising:
increasing current to said third phase circuit in response to said sensor sensing said sensor trigger is drifting away from said sensor.

4. The method of claim 3 , further comprising:
commutating said shaft in response to said sensor trigger drifting away from said sensor.

5. The method of claim 3 , further comprising:
holding said increasing current at a maximum holding current to recapture said sensor trigger; and
reducing said maximum holding current to a nominal holding current in response to said sensor sensing said sensor trigger.

6. The method of claim 1 , wherein said sensing said sensor trigger comprises sensing a magnet using a Hall Effect sensor.

7. The method of claim 1 , wherein said sensor trigger is a mirror and said sensing said sensor trigger comprises sensing electromagnetic radiation reflected by said mirror.

8. A method of securing a propeller, comprising:
commutating a sensor trigger by commutating a shaft of a motor, said motor having stators and rotors;
commutating a propeller indexer by commutating said shaft, said propeller indexer configured to align a propeller, when a propeller is present, at an angular position that is a propeller offset angle θ PROP from said sensor trigger as referenced by a center of rotation of said shaft;
sensing said sensor trigger as said sensor trigger rotates to a point adjacent a sensor fixedly coupled to said motor;
switching a control signal to rotatably hold said rotors driving said rotatable shaft in response to said sensor sensing said sensor trigger;
calculating a sensor trigger angular location verses time
determining said sensor trigger will not pass said sensor in a next rotation of the sensor trigger; and
initiating said switching said motor to electrically couple phase circuits in response to said determining said sensor will not pass said sensor in a next rotation of the sensor trigger step;
wherein said propeller indexer may be held in position at the propeller offset angle θ PROP from the sensor by commutating said shaft and holding the rotors so that the sensor is proximate to the sensor trigger; and
wherein said switching a control signal to rotatably hold said rotors comprises switching the motor to electrically couple phase circuits to magnetically hold said rotors.

9. The method of claim 8 , wherein said initiating said switching motor to electrically couple phase circuits further comprises calculating a nearest position of said sensor trigger to said sensor for a next rotation of said sensor trigger and initiating said switching motor to electrically couple said phase circuits at said nearest position.

10. A method of securing a propeller, comprising:
commutating a sensor trigger by commutating a shaft of a motor, said motor having stators and rotors;
commutating a propeller indexer by commutating said shaft, said propeller indexer configured to align a propeller, when a propeller is present, at an angular position that is a propeller offset angle θ PROP from said sensor trigger as referenced by a center of rotation of said shaft;
sensing said sensor trigger as said sensor trigger rotates to a point adjacent a sensor fixedly coupled to said motor; and
switching a control signal to rotatably hold said rotors driving said rotatable shaft in response to said sensor sensing said sensor trigger;
wherein said propeller indexer may be held in position at the propeller offset angle θ PROP from the sensor by commutating said shaft and holding the rotors so that the sensor is proximate to the sensor trigger; and
wherein said propeller propels an aircraft having an aircraft wing and wherein said sensing said sensor trigger step further comprises sensing said sensor trigger as said propeller is not aligned with the aircraft wing.

11. A motor assembly, comprising:
a motor having a rotatable shaft;
a hub coupled to said rotatable shaft, said hub having a propeller indexer to receive a propeller, when the propeller is present;
a sensor trigger rotatable with said shaft and positioned at a propeller offset angle θ PROP from said propeller indexer; and
a sensor coupled to said motor and positioned to detect said sensor trigger;
wherein said propeller indexer is positioned at the propeller offset angle θ PROP from the sensor through rotation of said shaft so that said sensor is proximate to the sensor trigger, and wherein said sensor trigger is coupled to said propeller.

12. The assembly of claim 11 , wherein said sensor trigger is a magnet.

13. The assembly of claim 12 , wherein said sensor is a Hall Effect sensor.

14. The assembly of claim 11 , wherein said sensor trigger is coupled to said hub.

15. The assembly of claim 14 , further comprising:
a second sensor trigger coupled to said hub on a side of said hub opposite from said sensor trigger to weightably balance said hub.

16. The assembly of claim 11 , wherein said sensor trigger is a mirror.

17. The assembly of claim 16 , wherein said sensor is an infrared detector.

18. The assembly of claim 16 , wherein said sensor is a light detector.

19. The assembly of claim 11 , wherein said propeller indexer is a channel to receive said propeller.

20. The assembly of claim 11 , wherein said propeller indexer is a tab to seat said propeller.

21. A motor assembly, comprising:
an aircraft having a wing;
a motor coupled to said aircraft to provide propulsion, said motor having a rotatable shaft;
a hub coupled to said rotatable shaft, said hub having a propeller indexer to receive a propeller, when a propeller is present;
a magnet coupled to said hub;
a Hall Effect sensor coupled to an interior casing for said motor; and
a motor controller electrically coupled to said motor, said motor controller configured to commutate said propeller to a horizontal position indicated by the proximity of said Hall Effect sensor to said magnet
wherein the propeller, if present, is aligned with said wing, the alignment based on the proximity of said Hall Effect sensor to said magnet.

22. The as

Assignees

• Aerovironment Inc

Inventors

• Firanski Jason Allen
• Mcallister Justin Bates
• Olch Ronald Howard
• Dalan Lane Dennis
• Ghapgharan Emil

Classifications

• B64C11/002 Primary

  Braking propellers, e.g. for measuring the power output of an engine · CPC title

• H02K29/10

  using light effect devices · CPC title

• H02P6/14

  Electronic commutators · CPC title

• H02K29/12

  using detecting coils {using the machine windings as detecting coil} · CPC title

• H02K29/08

  using magnetic effect devices, e.g. Hall-plates, magneto-resistors (H02K29/12 takes precedence) · CPC title