Solar Electric Boat Drive train System Design Review MEC 440 Group o Kanchan Bhattacharyya Daniel Huang Han John Tse Ting Zhang  Advisor: Dr. Anurag Purwar Stony Brook University Mechanical Engineering

Background This project describes the development of a surface piercing (Arneson) drivetrain system for the annual collegiate Solar Splash Competition. The purpose of the event is to build a single passenger solar electric boat to compete in the sprint, solar endurance, slalom, and qualifying races. Improvements made to the current drivetrain involve changing the propeller type and speed, propeller shaft length and trim angle, motors. The concept is a lighter, more robust surface piercing drivetrain with trim control and two different gear ratios. It takes up half of space of the previous system and is uses less parts while including more features.

Past Drivetrain Design Features Twin Motors on independent mounting plates One shaft with two different gear ratios Disadvantages High center of gravity Difficult to switch chain between gear ratios Difficult access for maintenance and mounting Takes up too much space Sub optimal wiring layout (wires connect to outside of the motors, left motor wires comes from back to the front and gets close to moving chain)

Overview Features Twin Motors on independent mounting plates Two different gears on each motor shaft, allowing for different gear ratios One chain connects the three sprockets (third output sprocket not shown) Advantages over current system Configuration allows for two or one motors Lower center of gravity Ease of switching chain between gear ratios Ease of access for maintenance and mounting

Overview

Internal Drivetrain Spring Loaded Roller Chain Tensioner Interchangeable Gears One or Two Motor Configurations

Chain Tensioner One chain tensioner will be attached on one of the motor plates UHMW polyethylene roller will push against the chain Push down on the tensioner to create slack in the chain for removal

Mounted Bearing Shaft Assembly Two mounted bearings support internal driveshaft Driveshaft connected motors to the propeller shaft

Constant Velocity and Universal Joint

Detail Concept Designs (Housing Tube& Shaft) Housing Tube & Shaft Subassembly is the exterior part of the drivetrain Shaft is mounted through the use of two taper roller bearings at each end of the tube two support angular and axial forces Gimbal attaches to the transom to support the assembly while providing degrees of freedom for steering and trimming

Detail Concept Designs (Piston Mount) Piston mount accommodates both steering and trimming pistons Rod ends and Clevis rod end allows for three degrees of freedom for each piston Steering piston is connected to the steering wheel and driven manually Trimming piston will be controlled electronically to give more precise control (trim angles will range from 0 degrees to 15 degrees) Piston assemblies are both hydraulically driven and commercially purchased

Chain Tensioner

Detail Concept Designs (Housing Tube& Shaft)

Detail Concept Designs (Internal Shaft)

Internal Shaft Stress Analysis

Detail Concept Designs (Housing Tube& Shaft)

Transmission of Power Demonstration https://drive.google.com/file/d/0BxUttcbN-ShDYWc3LUljcFdoZE0/view?usp=sharing

Trimming and Steering Demonstration https://drive.google.com/file/d/0BxUttcbN-ShDaG5OZlYtSUJJMFE/view?usp=sharing https://drive.google.com/file/d/0BxUttcbN-ShDOXhLR2QxYXpqZjQ/view?usp=sharing

Cost Analysis

Cost Analysis (Cont’d)

Cost Analysis (Cont’d) Total $579.52

Acknowledgements Advisors University Dr. Anurag Purwar Dr. Jeff Ge Dr. Thomas Rosati University Henry Honigman Joe Schurz Bob Martin Department of Mechanical Engineering CEAS Solar Racing Team

Thank You