Multi-speed gear box for a rotary wing aircraft

Patent metadata

Field	Value
Publication number	US-11655880-B2
Application number	US-202016923445-A
Country	US
Kind code	B2
Filing date	Jul 8, 2020
Priority date	Jul 8, 2020
Publication date	May 23, 2023
Grant date	May 23, 2023

Abstract

A gear system for a rotary wing aircraft includes a first gear including an inner gear portion having a first pitch and an outer gear portion having a second pitch that is distinct from the first pitch. A second gear includes a third pitch driven at a driving rotational speed. An actuator member is coupled to the second gear while driven at the driving rotational speed. The actuator member shifts the second gear along the first gear to engage with one of the inner gear portion and the outer gear portion to drive the first gear at a first rotational speed and engage with other one of the inner gear portion and the outer gear portion to drive the first gear at a second rotational speed. A controller is operable to control the actuator member to shift the second gear between the inner gear portion and the outer gear portion.

First claim

What is claimed is:

1. A gear system for a rotary wing aircraft comprising:
a first gear including an inner gear portion having a first pitch and an outer gear portion having a second pitch that is distinct from the first pitch;
a second gear including a third pitch which is driven at a driving rotational speed;
an actuator coupled to the second gear while the second gear is driven at the driving rotational speed, the actuator configured to shift the second gear along a radius of the first gear to selectively engage with one of the inner gear portion and the outer gear portion to drive the first gear at a first rotational speed, and to selectively engage with the other of the inner gear portion and the outer gear portion to drive the first gear at a second rotational speed other than the first rotational speed;
a controller operable to selectively control the actuator to shift the second gear between the inner gear portion and the outer gear portion
a first sensor mounted to the first gear and operably connected to the controller; and
a second sensor mounted to the second gear and operably connected to the controller, the controller being operable to determine a rotational position of the second gear relative to the first gear.

2. The gear system according to claim 1 , wherein the outer gear portion includes a first plurality of gear teeth, the inner gear portion includes a second plurality of gear teeth, and the second gear includes a third plurality of gear teeth, wherein the first sensor is arranged in one of the first and second pluralities of gear teeth and the second sensor is arranged in one of the third plurality of gear teeth.

3. The gear system according to claim 2 , wherein the first sensor includes a first sensor element arranged in one of the first and second pluralities of gear teeth and a second sensor element arranged in another one of the first and second pluralities of gear teeth.

4. The gear system according to claim 2 , wherein the first sensor includes a first sensor element arranged in one of the first plurality of gear teeth and a second sensor element arranged in an adjacent one of the first plurality of gear teeth.

5. The gear system according to claim 1 , wherein the first gear includes a first surface supporting the inner gear portion and the outer gear portion and a second, opposing surface supporting another inner gear portion and another outer gear portion.

6. The gear system according to claim 5 , wherein the second gear includes a first pinion gear selectively engaged with the inner gear portion and the outer gear portion and a second pinion gear selectively engaged with the another inner gear portion and the another outer gear portion.

7. A rotary wing aircraft comprising:
a main rotor assembly including a main rotor shaft, a rotor hub connected to the main rotor shaft, and a plurality of rotor blades connected to the rotor hub;
at least one prime mover connected to the main rotor assembly; and
a gear system mechanically connecting the at least one prime mover and the main rotor assembly, the gear system comprising:
a first gear including an inner gear portion having a first pitch and an outer gear portion having a second pitch that is distinct from the first pitch;
a second gear including a third pitch which is driven at a driving rotational speed;
an actuator coupled to the second gear while driven at the driving rotational speed, the actuator configured to shift the second gear along a radius of the first gear to selectively engage with one of the inner gear portion and the outer gear portion to drive the first gear at a first rotational speed, and to selectively engage with the other of the inner gear portion and the outer gear portion to drive the first gear at a second rotational speed other than the first rotational speed; and
a controller operable to selectively control the actuator to shift the second gear between the inner gear portion and the outer gear portion.

8. The rotary wing aircraft of claim 7 , wherein the gear system further comprises:
a first sensor mounted to the first gear and operably connected to the controller; and
a second sensor mounted to the second gear and operably connected to the controller, the controller being operable to determine a rotational position of the second gear relative to the first gear.

9. The rotary wing aircraft of claim 8 , wherein the outer gear portion includes a first plurality of gear teeth, the inner gear portion includes a second plurality of gear teeth, and the second gear includes a third plurality of gear teeth, wherein the first sensor is arranged in one of the first and second pluralities of gear teeth and the second sensor is arranged in one of the third plurality of gear teeth.

10. The rotary wing aircraft of claim 9 , wherein the first sensor includes a first sensor element arranged in one of the first and second pluralities of gear teeth and a second sensor element arranged in another one of the first and second pluralities of gear teeth.

11. The rotary wing aircraft of claim 9 , wherein the first sensor includes a first sensor element arranged in one of the first plurality of gear teeth and a second sensor element is arranged in an adjacent one of the first plurality of gear teeth.

12. The rotary wing aircraft of claim 7 , wherein the first gear includes a first surface supporting the inner gear portion and the outer gear portion and a second, opposing surface supporting another inner gear portion and another outer gear portion.

13. The rotary wing aircraft of claim 12 , wherein the second gear includes a first pinion gear selectively engaged with the inner gear portion and the outer gear portion and the gear system further comprising a second pinion gear selectively engaged with the another inner gear portion and the another outer gear portion.

14. The rotary wing aircraft of claim 13 , wherein the prime mover includes a first engine operatively connected to the first pinion gear and operatively connected to the second pinion gear.

Assignees

• Lockheed Corp

Inventors

• Hansen Bruce D

Classifications

• F16H3/34 Primary

  with gears shiftable otherwise than only axially · CPC title

• F16H3/366

  the teeth of the set of coaxial gears being arranged on a generally flat, e.g. disc-type, surface · CPC title

• F16H2200/0034

  the gear ratios comprising two forward speeds · CPC title

• B64C27/06

  with single rotor · CPC title

• B64C27/12 Primary

  Rotor drives · CPC title