Rotor brake effect by using electric distributed anti-torque generators and opposing electric motor thrust to slow a main rotor

Patent metadata

Field	Value
Publication number	US-11186185-B2
Application number	US-201715609779-A
Country	US
Kind code	B2
Filing date	May 31, 2017
Priority date	May 31, 2017
Publication date	Nov 30, 2021
Grant date	Nov 30, 2021

Abstract

The present invention includes a system and method for slowing the rotation of a rotor using, for example, rotor brake system for a rotorcraft comprising: one or more generators connected to a main rotor gearbox; an electric distributed anti-torque system mounted on a tail boom of the rotorcraft comprising two or more electric motors connected to the one or more generators, wherein the two or more electric motors are connected to one or more blades; and wherein a rotation of the rotor is slowed by placing a drive load on the main rotor gearbox with the one or more generators to bleed the mechanical power from rotor into electrical power via the two or more electric motors, wherein the electric distributed anti-torque system generates thrust in opposing directions.

First claim

What is claimed is:

1. A rotor brake system for a main rotor of a rotorcraft comprising:
one or more generators connected to a main rotor gearbox, wherein the main rotor gearbox is connected to the main rotor;
an electric distributed anti-torque system mounted on a tail boom of the rotorcraft and electrically connected to the one or more generators, wherein the electric distributed anti-torque system comprises two or more electric motors and each of the two or more electric motors is directly connected to one or more blades such that each of the one or more blades can operate independently; and
wherein a rotation of the main rotor is slowed by placing a drive load on the main rotor gearbox with the one or more generators to convert mechanical power from the main rotor into electrical power, and wherein the electrical power is dispersed by using at least one of the two or more electric motors to generate thrust in one direction and at least another of the two or more electric motors to generates thrust in an opposing direction.

2. The system of claim 1 , further comprising a flight control computer that controls an amount of electrical power generated from the one or more generators and directed to each of the two or more electric motors that minimizes or eliminates a side load on the tail boom.

3. The system of claim 1 , wherein the two or more electric motors are least one of: a self-commutated motor, an externally commutated motor, a brushed motor, a brushless motor, a linear motor, an AC/DC synchronized motor, an electronic commutated motor, a mechanical commutator motor (AC or DC), an asynchronous motor (AC or DC), a pancake motor, a three-phase motor, an induction motor, an electrically excited DC motor, a permanent magnet DC motor, a switched reluctance motor, an interior permanent magnet synchronous motor, a permanent magnet synchronous motor, a surface permanent magnet synchronous motor, a squirrel-cage induction motor, a switched reluctance motor, a synchronous reluctance motor, a variable-frequency drive motor, a wound-rotor induction motor, an ironless or coreless rotor motor, or a wound-rotor synchronous motor.

4. The system of claim 1 , wherein the electric distributed anti-torque system is defined further as comprising 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, or more electric motors.

5. The system of claim 1 , wherein the two or more electric motors are at least one of: turned on or off independently, turned on or off as a group, turned on or off in pairs, turned on and off in pulses, or each motor can operate independently to direct thrust in a same or a different direction, wherein an overall thrust generated by the two or more electric motors fails to provide a significant side load on the tail boom.

6. The system of claim 1 , wherein additional electrical power is bled from the one or more generators by at least one of: operating an air-conditioning and a heater simultaneously, charging a battery on the rotorcraft or on the ground, or an inductive transfer of electrical power.

7. The system of claim 1 , wherein additional electrical power is bled from the one or more generators by converting electrical power into heat via a heat sink, deicing blankets, compressing a gas or liquid in a reservoir.

8. The system of claim 1 , wherein the two or more electric motors are a different size, the plurality of blades are a different size, the two or more electric motors are individually ducted, or the blades and the two or more electric motors are on a pivot that allows for rotation of the two or more electric motors to minimize loads in any direction and to minimize or eliminate a side load on the tail boom.

9. The system of claim 1 , further comprising a control logic in a flight control computer that calculates the overall torque generated by the electric distributed anti-torque system to reduce or eliminate torque and reduce the speed of the main rotor prior to applying a mechanical rotor brake.

10. The system of claim 1 , wherein the one or more blades are fixed-pitch blades, variable-pitch blades, or a combination thereof.

11. A rotor brake system for a rotor of a rotorcraft comprising:
one or more generators connected to a main rotor gearbox;
an electric distributed anti-torque system mounted on a tail boom of the rotorcraft that comprises two or more variable speed electric motors connected to the one or more generators, wherein each of the two or more variable speed electric motors are directly connected to one or more blades such that each of the one or more blades can operate independently and provide anti-torque thrust;
wherein a rotation of the rotor is slowed by placing a drive load on the main rotor gearbox with the one or more generators to bleed the mechanical power from the rotor into electrical power via the two or more variable speed electric motors, wherein at least one of the two or more variable speed electric motors generate thrust in one direction and at least another of the two or more variable speed electric motors to generates thrust in an opposing direction; and
a mechanical rotor brake.

12. The system of claim 11 , further comprising a flight control computer that controls the electrical power generated by the one or more generators and directed to the two or more variable speed electric motors to minimize, reduce, or eliminate a side load on the tail boom.

13. The system of claim 11 , further comprising a logic in a flight control computer that controls at least one of: the speed, the direction, or both the speed and direction, of each of the two or more electric motors to minimize, reduce, or eliminate a side load on the tail boom.

14. The system of claim 11 , wherein the two or more variable speed electric motors is at least one of: a self-commutated motor, an externally commutated motor, a brushed motor, a brushless motor, a linear motor, an AC/DC synchronized motor, an electronic commutated motor, a mechanical commutator motor (AC or DC), an asynchronous motor (AC or DC), a pancake motor, a three-phase motor, an induction motor, an electrically excited DC motor, a permanent magnet DC motor, a switched reluctance motor, an interior permanent magnet synchronous motor, a permanent magnet synchronous motor, a surface permanent magnet synchronous motor, a squirrel-cage induction motor, a switched reluctance motor, a synchronous reluctance motor, a variable-frequency drive motor, a wound-rotor induction motor, an ironless or coreless rotor motor, or a wound-rotor synchronous motor.

15. The system of claim 11 , wherein additional electrical power is bled from the one or more generators by at least one of: operating both an air-conditioning and a heater simultaneously, charging a battery on the rotorcraft or on the ground, or inductive transfer.

16. The system of claim 11 , wherein additional electrical power is bled from the one or more generators by converting electrical power into heat via a heat sink, deicing blankets, compressing a gas or liquid in a reservoir.

17. The system of claim 11 , wherein the two or more variable speed electric motors are a different size, the plurality of blades are a different size, the two or more variable speed electric motors are individually ducted, or each of the blades and the two or more variable speed electric motors are on a pivot that allows for rotation of each of the two or more variable speed electric motors to minimize loads in any direction.

18. The system of claim 11 , further comprising a control logic in a flight control computer that calculates the overall torque generated by th

Assignees

• Bell Helicopter Textron Inc
• Textron Innovations Inc

Inventors

• Haldeman Andrew
• Sinusas Eric
• Stamps Frank Bradley

Classifications

• B64C2027/8227

  comprising more than one rotor · CPC title

• Y02T10/64

  Electric machine technologies in electromobility · CPC title

• B64C27/12 Primary

  Rotor drives · CPC title

• B64C2027/8236

  including pusher propellers · CPC title

• Y02T10/7072

  Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors · CPC title