PITCH CONTROL SYSTEM

• US 20170225776A1
• Filed: 08/27/2015
• Published: 08/10/2017
• Est. Priority Date: 08/28/2014
• Status: Active Grant

• Current Assignee: Sikorsky Aircraft Corporation (Martin Marietta Corporation)
• Original Assignee: Sikorsky Aircraft Corporation (Martin Marietta Corporation)
• Inventors: Cyr, Mark M., Gradzki, Karl
• Granted Patent: US 10,676,184 B2
• Time in Patent Office: Days
• CPC Class Codes: B64C 11/30 Blade pitch-changing mechanisms
• CPC Class Codes: B64C 11/301 characterised by blade position indicating means
• CPC Class Codes: B64C 13/12 Dual control apparatus
• CPC Class Codes: B64C 2027/8236 including pusher propellers
• CPC Class Codes: B64C 27/56 characterised by the control initiating means, e.g. manually actuated
• CPC Class Codes: B64C 27/57 automatic or condition responsive, e.g. responsive to rotor speed, torque or thrust
• CPC Class Codes: B64C 27/82 characterised by the provision of an auxiliary rotor or fluid-jet device for counter-balancing lifting rotor torque or changing direction of rotorcraft

Abstract

A pitch control system configured to vary a pitch angle of a plurality of propeller blades of a propeller system is provided including a motor having a motor shaft configured to rotate about an axis. A rotary switch having a tab protruding generally outwardly is coupled to the motor shaft and is configured to move between a first position and a second position. The pitch control system also includes a position sensor configured to monitor the position of the rotary switch. The position of the rotary switch is proportional to the pitch angle of the plurality of propeller blades.

Claims

1. A pitch control system configured to vary a pitch angle of a plurality of propeller blades of a propeller system, comprising:

a motor having a motor shaft configured to rotate about an axis;

a rotary switch including a tab protruding generally outwardly, the rotary switch being coupled to the motor shaft and configured to move between a first position and a second position; and

a position sensor configured to monitor a position of the rotary switch, wherein the position of the rotary switch is proportional to the pitch angle of the plurality of propeller blades.

2. The pitch control system according to claim 1, wherein the first position of the rotary switch corresponds to a maximum pitch angle of the propeller blades in a first direction of rotation.

3. The pitch control system according to claim 2, wherein the second position of the rotary switch corresponds to a maximum pitch angle of the propeller blades in a second direction of rotation, the second direction of rotation being opposite the first direction of rotation.

4. The pitch control system according to claim 3, wherein a third, generally central position of the rotary switch corresponds to a zero pitch angle of the propeller blades.

5. The pitch control system according to claim 4, wherein at least a portion of the pitch control system is arranged within a pilot interface.

6. The pitch control system according to claim 5, wherein the pilot interface is one of a collective control and a cyclic control.

7. The pitch control system according to claim 5, wherein the pilot interface further comprises a raised marker configured to align with the tab of the rotary switch when the rotary switch is in a third position.

8. The pitch control system according to claim 1, wherein the position sensor is operably coupled to a flight control computer of a flight control system, the position sensor being configured to provide the position of the rotary switch as an input to the flight control computer.

9. The pitch control system according to claim 8, wherein the flight control computer is configured to activate one or more actuators coupled to the plurality of propeller blades in response to input from the position sensor.

10. The pitch control system according to claim 1, wherein a roughened material is positioned about at least a portion of the tab.

11. A rotary wing aircraft includes a propeller system having a plurality of propeller blades, comprising:

a first pilot interface having a first pitch control system configured to adjust a pitch angle of the propeller blades of the propeller system, the first pitch control system including;

a first motor having a first motor shaft configured to rotate about a first axis;

a first rotary switch including a first tab protruding generally outwardly, the first rotary switch being coupled to the first motor shaft and configured to move between a first position and a second position; and

a first position sensor configured to monitor a position of the first rotary switch, wherein the position of the first rotary switch is proportional to the pitch angle of the plurality of propeller blades;

a second pilot interface having a second pitch control system configured to adjust a pitch angle of the propeller blades of the propeller system;

a second motor having a second motor shaft configured to rotate about a first axis;

a second rotary switch including a second tab protruding generally outwardly, the second rotary switch being coupled to the second motor shaft and configured to move between a first position and a second position; and

a second position sensor configured to monitor a position of the second rotary switch, wherein the position of the second rotary switch is proportional to the pitch angle of the plurality of propeller blades; and

a flight control system including a flight control computer operably coupled to the first pitch control system and the second pitch control system such that the second rotary switch is configured to rotate in response to rotation of the first rotary switch such that the first rotary switch and the second rotary switch are in generally identical positions.

12. The rotary wing aircraft according to claim 11, wherein the first rotary switch is configured to rotate in response to rotation of the second rotary switch such that the first rotary switch and the second rotary switch are in generally identical positions.

13. The rotary wing aircraft according to claim 11, wherein the first position of both the first rotary switch and the second rotary switch corresponds to a maximum pitch angle of the propeller blades in a first direction of rotation.

14. The rotary wing aircraft according to claim 13, wherein the second position of both the first rotary switch and the second rotary switch corresponds to a maximum pitch angle of the propeller blades in a second direction of rotation, the second direction of rotation being opposite the first direction of rotation.

15. The rotary wing aircraft according to claim 14, wherein a third, generally central position of both the first rotary switch and the second rotary switch corresponds to a zero pitch angle of the propeller blades.

16. The rotary wing aircraft according to claim 11, wherein the first pilot interface and the second pilot interface are one of a collective control and a cyclic control.

17. The rotary wing aircraft according to claim 11 wherein at least one of the first pilot interface and the second pilot interface further comprises a raised marker configured to align with the first tab or the second tab when the first rotary switch or the second rotary switch is in a third position.

18. A method of adjusting a pitch angle of a plurality of propeller blades of a propeller system comprising:

rotating a rotary switch of a pitch control system to a first position;

transmitting the first position of the rotary switch to a flight control computer;

generating a signal indicative of an amount and direction of rotation for at least one of the plurality of propeller blades to achieve a pitch angle corresponding to the first position of the rotary switch; and

rotating at least one of the plurality of propeller blades to the pitch angle.