MULTI-RATIO ROTORCRAFT DRIVE SYSTEM AND A METHOD OF CHANGING GEAR RATIOS THEREOF

• US 20120208673A1
• Filed: 03/12/2012
• Published: 08/16/2012
• Est. Priority Date: 07/14/2009
• Status: Active Grant

• Current Assignee: Bell Helicopter Textron Incorporated (Textron Inc)
• Original Assignee: Bell Helicopter Textron Incorporated (Textron Inc)
• Inventors: Ehinger, Ryan T., Fenny, Carlos A., Kilmain, Charles J., Sinusas, Eric A., Worrell, Kevin
• Granted Patent: US 8,449,432 B2
• Time in Patent Office: Days
• US Class Current: 477/84
• CPC Class Codes: B64C 27/08 with two or more rotors
• CPC Class Codes: B64C 27/12 Rotor drives
• CPC Class Codes: B64U 10/10 Rotorcrafts

Abstract

A multi-ratio rotorcraft drive system and a method of changing gear ratios thereof are disclosed. According to one embodiment, the multi-ratio rotorcraft drive system comprises a rotor system comprising one or more rotors and one or more engines. Each engine of the one or more engines is coupled to the rotor system through a multi-ratio transmission. The multi-ratio transmission comprises an output shaft coupled to the rotor system, an input shaft coupled to a respective engine of the one or more engines, a high speed clutch integrated into a high speed gear train, and a low speed clutch integrated into a low speed gear train. The high speed clutch and the low speed clutch are freewheeling clutches without a friction plate and are capable of disconnecting the output shaft and the input shaft in an overrunning condition when the output shaft spins faster than the input shaft.

Claims

1. A drive system comprising:

a driven system comprising one or more output drives;

one or more power units, each power unit of the one or more power units being coupled to the driven system through a multi-ratio transmission, the multi-ratio transmission comprising;

a rotating output coupled to the driven system;

a rotating input coupled to a respective power unit of the one or more power units;

one or more high speed clutches integrated into one or more high speed gear trains; and

one or more low speed clutches integrated into one or more low speed gear trains,

wherein the one or more high speed clutches and the one or more low speed clutches are capable of disconnecting the rotating output and input in an overrunning condition when the output rotates faster than the input; and

wherein the multi-ratio transmission shifts between a high speed gear train of the one or more high speed gear trains and a low speed gear train of the one or more low speed gear trains by engaging or disengaging the high speed clutch of the respective high speed gear train and modulating the speed of the coupled power unit.

2. The drive system of claim 1, wherein the one or more high speed clutches and the one or more low speed clutches are freewheeling clutches.

3. The drive system of claim 1, wherein the one or more low speed clutches are permanently engaged.

4. The drive system of claim 1, wherein the output of the multi-ratio transmission is coupled to the driven system either through gears or an interconnect driveshaft system.

5. The drive system of claim 1, wherein the one or more high speed clutches are selectively disengaged and engaged for respective reducing and increasing the speed of the driven system.

6. The drive system of claim 1, wherein the one or more high speed clutches and the one or more low speed clutches are self-energizing freewheeling clutches with an overrunning capability.

7. The drive system of claim 1, wherein the driven system does not transmit torque to the one or more power units via the one or more high speed clutches or the one or more low speed clutches in an overrunning condition.

8. The drive system of claim 1, wherein the driven system is a rotor system.

9. The drive system of claim 1, wherein one or more of the one or more output drives are rotors.

10. The drive system of claim 1, wherein the one or more power units are engines.

11. The drive system of claim 1, wherein the rotating output and the rotating input of the multi-ratio transmission are output and input shafts.

12. A drive system comprising:

a driven system comprising one or more output drives;

one or more power units, and

one or more multi-ratio transmissions, separate ones of the one or more multi-ratio transmissions being coupled at a transmission output to the output drive system and at a transmission input to separate ones of the one or more power units, wherein separate ones of the one or more multi-ratio transmissions comprising;

a plurality of gear trains, each of the plurality of gear trains having a gear train input, a gear train output and an integrated clutch capable of disconnecting the gear train output and gear train input in an overrunning condition when the gear train output rotates faster than the gear train input, wherein separate ones of the plurality of gear trains having different gear ratios; and

wherein the multi-ratio transmission shifts between separate ones of the plurality of gear trains engaging or disengaging the clutch of the separate ones of plurality of gear trains and modulating the speed of the coupled power unit.

13. The drive system of claim 12, wherein the plurality of gear trains includes one or more high speed gear trains and one or more low speed gear trains.

14. The drive system of claim 12, wherein one or more clutches of the plurality of gear trains are freewheeling clutches.

15. The drive system of claim 13, wherein the clutches of one or more low speed gear trains are permanently engaged.

16. The drive system of claim 12, wherein the output of the multi-ratio transmission is coupled to the driven system either through gears or an interconnect driveshaft system.

17. The drive system of claim 12, wherein one or more of the clutches are selectively disengaged and engaged for respective reducing and increasing the speed of the driven system.

18. The drive system of claim 12, wherein one or more of the clutches are self-energizing freewheeling clutches with an overrunning capability.

19. The drive system of claim 12, wherein the driven system is a rotor system.

20. The drive system of claim 12, wherein one or more of the one or more output drives are rotors.

21. The drive system of claim 12, wherein the one or more power units are engines.