Epicyclic geartrains are known to provide high power density and have become the geartrain of choice for the main power flow in virtually all rotorcraft designs. This paper presents a unique compound planetary design targeting a helicopter main gearbox transmission application. The design significantly improves power density over conventional geartrains through its innovative planet gear load-sharing configuration along with the utilization of high-performance materials for gears and bearings. Design studies were conducted comparing the power density of this new design to a baseline gearbox design. The results of these studies demonstrate an estimated 38% power density improvement over the baseline configuration. Of the total improvement, 86% is attributed to the novel load-sharing configuration while 14% is attributed to utilization of advanced materials and processes.

References

References
1.
Lestine
,
J.
, and
White
,
G.
, 1970, “
Advanced Technology VTOL Drive Train Configuration Study
,” Sikorsky Aircraft, USAAVLABS Technical Report No. 69-69, U.S. Army Aviation Material Laboratories, Fort Eustis, VA.
2.
Bruyne
,
N. D.
,
1974
, “
Design and Development Testing of Free Planet Transmission Concept
,” Curtiss Wright Corporation, NJ, Report No. USAAMRDL TR-74-27, Eustis Directorate, Fort Eistis VA.
3.
Drago
,
R. J.
,
Lenski
,
J. W.
, Jr.
, and
Robuck
,
M. J.
,
2005
, “
High Ratio, Reduced Size Epicyclic Gear Transmission for Planetary Wing Aircraft With Improved Safety and Noise Reduction
,” U.S. Patent No. 6,966,865 B2.
4.
Brown
,
F. W.
,
Robuck
,
M. J.
,
Roddis
,
G. K.
, and
Beck
,
T. E.
,
2004
, “
Design of a High Ratio, Ultra-Safe, High Contact Ratio, Double Helical Compound Planetary Transmission for Helicopter Applications
,”
American Gear Manufacturers' Association 2004 Fall Technical Meeting
, Milwaukee, Wisconsin.
5.
Brown
,
F.
,
Robuck
,
M.
, and
Kozachyn
,
M.
,
2009
, “
Design, Fabrication, Assembly and Test of a Double Helical Planetary Gear System for Helicopter Applications
,” The Boeing Company, American Helicopter Society 65th Annual Forum, Grapevine, TX.
6.
Robuck
,
M.
,
2009
, “
Epicyclic Gear Transmission for Rotary Aircraft
” U.S. Patent No. 7,507,180 B2.
7.
Ai
,
X.
,
Orkin
,
C.
,
Kruse
,
R.
,
Forbes
,
R.
, and
Wilmer
,
M.
, 2011, “
High Ratio Epicyclical Gear Transmission With Improved Load Carrying Capacity
,” PCT patent application WO/2011/100499 A1.
8.
Ai
,
X.
,
Orkin
,
C.
,
Kruse
,
R.
,
Forbes
,
R.
,
Wilmer
,
M.
, and
Chiavaroli
,
N.
, 2011, “
Gear Transmission Load Sharing Mechanism
,” PCT patent application WO/2011/112930 A1.
9.
Ai
,
X.
,
Orkin
,
C.
,
Kruse
,
R.
,
Forbes
,
R.
,
Wilmer
,
M.
,
Smith
,
B.
, and
Chiavaroli
,
N.
, 2011, “
Load Split Mechanism for Gear Transmission
,” PCT patent application WO/US2011/130352 A1.
10.
Gilbert
,
R.
,
Craig
,
G.
,
Filler
,
R.
,
Hamilton
,
W.
,
Hawkins
,
J.
,
Higman
,
J.
, and
Green
,
W.
,
2008
, “
3400 HP Apache Block III Improved Drive System
,” The Boeing Company, Redstonr Arsenal, American Helicopter Society 64th Annual Forum, Montreal, Quebec, Canada.
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