Rotation of disengaged rotor

Patent metadata

Field	Value
Publication number	US-2017190417-A1
Application number	US-201515324524-A
Country	US
Kind code	A1
Filing date	Jul 6, 2015
Priority date	Jul 8, 2014
Publication date	Jul 6, 2017
Grant date	—

Abstract

Embodiments of the invention include a vehicle including an engine and a rotor including a plurality of rotor blades in a path of exhaust from the engine. The vehicle includes a rotor control assembly configured to connect the rotor to a rotation force source to rotate the rotor and configured to rotate the rotor at a prescribed minimum rotation rate greater than zero based on at least one of disengaging the rotor from the rotation force source and receiving a control signal to disengage the rotor from the rotation force source. The rotor control assembly is designed to rotate the rotor at the prescribed minimum rotation rate based on at least one system attribute of the vehicle that is affected by a rotation rate of the rotor.

First claim

1 . A vehicle, comprising:
an engine; a rotor, comprising a plurality of rotor blades, in a path of exhaust from the engine; and a rotor control assembly configured to connect the rotor to a rotation force source to rotate the rotor, and configured to rotate the rotor at a prescribed minimum rotation rate greater than zero based on at least one of disengaging the rotor from the rotation force source and receiving a control signal to disengage the rotor from the rotation force source, the rotor control assembly designed to rotate the rotor at the prescribed minimum rotation rate based on at least one system attribute of the vehicle that is affected by a rotation rate of the rotor.

2 . The vehicle of claim 1 , wherein the rotor control assembly includes a clutch to selectively connect the rotor to the rotation force source to drive the rotor, and
the rotor control assembly is configured to generate the prescribed minimum rotation rate by applying a predetermined level of rotational force to the rotor based on the rotor being disengaged by the clutch from the rotation force source.

3 . The vehicle of claim 2 , wherein the clutch is designed to have an internal resistance sufficient to provide the predetermined level of rotational force to the rotor based on the clutch disengaging the rotor from the rotation force source.

4 . The vehicle of claim 1 , wherein the prescribed minimum rotation rate is based on a heat tolerance of the rotor.

5 . The vehicle of claim 4 , wherein the prescribed minimum rotation rate is such that each blade of the rotor is subjected to a level of heat less than a heat tolerance of each blade.

6 . The vehicle of claim 5 , wherein the prescribed minimum rotation rate is based on a material of the rotor, a size of the rotor, and a portion of the rotor exposed to the exhaust from the engine.

7 . The vehicle of claim 1 , wherein the rotation force source includes a drive shaft,
the rotor control assembly includes a gearbox to convert a first rotation rate of the drive shaft to a second rotation rate of the rotor, and the gearbox includes a first gear to drive the rotor based on a command being received from a vehicle controller to engage the clutch, and the gearbox includes a second gear configured to cause the rotor to rotate at the prescribed minimum rotation rate, the rotor being engaged with the second gear based on a command being received from the vehicle controller to disconnect the rotor from the rotation force source.

8 . The vehicle of claim 1 , wherein the vehicle is a helicopter.

9 . The vehicle of claim 8 , wherein a rotation path of the rotor defines a circular planar shape having a flat circular surface, and
the rotor is configured relative to the engine such that the path of exhaust from the engine intersects the flat circular surface of the circular planar shape.

10 . The vehicle of claim 8 , wherein the rotor is a tail rotor arranged substantially perpendicular to a nose-to-tail axis of the helicopter.

11 . A method of fabricating a rotor control assembly, comprising:
identifying at least one predetermined system attribute of a rotor system in which a rotor control assembly is to be implemented; identifying a prescribed minimum rotation rate of a rotor controlled by the rotor control assembly necessary to satisfy the at least one predetermined system attribute; providing at least one rotation-inducing element to the rotor control assembly to cause the rotor control assembly to rotate the rotor at the prescribed minimum rotation rate based on receiving, by the rotor control assembly, a control command to disengage the rotor from a rotation force source.

12 . The method of claim 11 , wherein the at least one predetermined system attribute includes a level of heat directed onto a rotor by engine exhaust.

13 . The method of claim 12 , wherein the prescribed minimum rotation rate is based on a material of the rotor, a size of the rotor, and a portion of the rotor exposed to the engine exhaust.

14 . The method of claim 12 , wherein a rotation path of the rotor defines a circular planar shape having a flat circular surface, and
the rotor is configured relative to an engine such that a path of exhaust from the engine intersects the flat circular surface of the circular planar shape.

15 . The method of claim 11 , wherein the at least one rotation-inducing element is a component in a clutch of the rotor control assembly to cause the clutch to control the rotor to rotate at the prescribed minimum rotation rate when the clutch is in a disengaged state.

16 . The method of claim 15 , wherein the at least one rotation-inducing element includes a lubricating fluid having a prescribed viscosity sufficient to cause the rotor to rotate at the prescribed minimum rotation rate.

17 . The method of claim 15 , wherein the at least one rotation-inducing element is one or more of a friction pad and a pressure plate configured to maintain contact between a force-supplying and force-receiving side of the clutch to cause the rotor to rotate at the prescribed minimum rotation rate.

18 . The method of claim 11 , wherein the predetermined system attribute includes one or more of an acoustic output level of a system including the rotor control assembly, an electromagnetic signature of the system, a prescribed safety requirement of the system, a level of drag of the system, and an operability of sensors in the system.

19 . The method of claim 11 , wherein the at least one rotation-inducing element is a component in a gearbox between a rotation force source and the rotor.

20 . The method of claim 19 , wherein the component in the gearbox is a gear configured to rotate the rotor at the prescribed minimum rotation rate.

Assignees

• Sikorsky Aircraft Corp

Inventors

• Devito Ashley
• Voegeli Henry E
• Pantalone Iii Joseph

Classifications

• B64C2027/8236

  including pusher propellers · CPC title

• B64C2027/8272

  comprising fins, or movable rudders · CPC title

• B64C27/12

  Rotor drives · CPC title

• B64C27/82 Primary

  characterised by the provision of an auxiliary rotor or fluid-jet device for counter-balancing lifting rotor torque or changing direction of rotorcraft · CPC title