Lightweight Gearbox for Air Cushion Vehicles
Navy SBIR 2018.1 - Topic N181-072
NAVSEA - Mr. Dean Putnam - firstname.lastname@example.org
Opens: January 8, 2018 - Closes: February 7, 2018 (8:00 PM ET)
ACQUISITION PROGRAM: PMS
377-6 Division, Landing Craft Technical
OBJECTIVE: Develop a
lightweight gearbox for Air Cushion Vehicles (ACV) that reduces fuel
consumption and improves maintainability.
Ship-to-Shore Connector (SSC) is an Air Cushion Vehicle (ACV), or “hovercraft”,
providing amphibious transportation of equipment and personnel from
ship-to-shore and shore-to-shore. Development of a performance-improving,
robust, maintainable, lightweight (max. 4,730 lbs), and variable-speed gearbox
is paramount to SSC operation. The craft contains two gearboxes (port and
starboard), each combining high-speed inputs from two longitudinally mounted
engines to power a single lift fan forward and a single propeller aft. The
gearbox transfers approximately 12,000 Shaft Horse Power (SHP) with speed
reduction ratios approximately 12:1 for the prop and 8:1 for the lift fan.
Each gearbox interfaces with Engineering Control System (ECS) and craft
lubrication oil system. Any changes to the gearbox design interfaces need to
take into account the current craft configuration and asses the overall impact.
PHASE I: Define and develop a
concept for a new gearbox for SSC that meets the requirements as described
above. Demonstrate the feasibility of the concept in meeting Navy needs and
also demonstrate that the lightweight gearbox concept can be readily and
cost-effectively manufactured through standard industry practices by material
testing and analytical modeling. The Phase I Option, if awarded, should
include the initial layout and capabilities to build the prototype in Phase II.
Develop a Phase II plan.
PHASE II: Based on the
results of the Phase I effort and the Phase II Statement of Work (SOW), develop
and deliver a prototype lightweight gearbox for evaluation by performing a 100
hr loaded cyclic test in accordance with MIL-G-17859. Evaluate the prototype
to determine its compatibility with current craft layout and ability to perform
to requirements. Demonstrate system performance at the power train test site
before installation on a SSC Test Craft. Use evaluation results to refine the
prototype into a design that will meet the SSC Craft Specifications. Prepare a
Phase III development plan and cost analysis to transition the technology to
PHASE III DUAL USE
APPLICATIONS: If Phase II is successful, support the Navy in transitioning the
lightweight gearbox for Navy use on the ACV program. Refine the design of the
gearbox, according to the Phase III SOW for evaluation to determine its
effectiveness in an operationally relevant environment. Support the Navy for
test and validation in accordance with Craft Specifications to certify and
qualify the system for Navy use and for transition into operational SSCs.
Following testing and validation, ensure that the end design will provide an
overall lower-weight, variable-speed lift fan with increased maintainability,
reduced fuel consumption, increased efficiency, and compatibility with existing
systems aboard the craft.
1. Mancini, Joseph H. “An
Overview of Advancement in Helicopter Transmission Design.” https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19830011853.pdf
2. Segade-Robleda, Abraham,
Vilán-Vilán, José-Antonio, López-Lago, Marcos and Casarejos-Ruiz, Enrique.
“Split Torque Gearboxes: Requirements, Performance and Applications.”
University of Vigo, Spain. http://cdn.intechopen.com/pdfs/35257.pdf
3. White, G. “Design study
of a split-torque helicopter transmission.” Cleveland, OH: Transmission
Research Inc. http://journals.sagepub.com/doi/abs/10.1243/0954410981532180?journalCode=piga
4. Rashidi, Majid, and
Krantz, Timothy. “Dynamics of a Split Torque Helicopter Transmission.”
Cleveland State University, Lewis Research Center. http://engagedscholarship.csuohio.edu/cgi/viewcontent.cgi?article=1127&context=scholbks
KEYWORDS: Compact Gearbox;
Ship-to-Shore Connector; Landing Craft Air Cushion 100; Fuel Efficiency;
Hovercraft; Variable Speed Gearbox Lift Fan