Hydraulic Hybrid Vehicle

2. Members: Kevin Alexander Phillip Bacon Tyler Degen Brandon Diegel Nick Hemenway Luke Jackson Christian L’Orange Grant Mattive Dean Simpson Advisors: Dr. Kirkpatrick, CSU Dr. Guy Babbitt, Czero Inc. Mr. Chris Turner, Czero Inc. Hydraulic Hybrid Vehicle

3. Outline • Objectives and Constraints • Scope Changes • Test Skid Progress • Component Selection • Accumulator • Pump/Motor • Modeling Progress • Current Schedule • Budget • Conclusions

4. Background/Review

5. Objectives and Constraints • Design components to retrofit existing vehicles • Operational Test Skid by Dec. 2007 • Running prototype vehicle by April 2008 • Payback period: less than 2 years through fuel savings and reduced maintenance cost • Major components sourced from commercial manufacturers

6. Scope Changes • Test Skid • Test skid from University of Wisconsin, Madison • Initial set-up: Stock configuration at 2000psi • Final set-up: Sized components at 5000psi • Marketing • Partnered with CSU College of Business GSSE • Controls • Partnered with CSU team of electrical engineers

7. Test Skid Progress • Acquired test skid from University of Wisconsin • Installed at the EECL • Flywheel-to-pump coupler ordered • Flywheel FEA conducted • EECL donated hydraulic power supply • Installed HPS near test skid • Evaluated condition of components • HPS is currently operational

8. Flywheel Selection • Sizing flywheel to simulate reflected inertia of bus • Options considered: Clark flywheel at EECL (5 ft diameter) Trainwheel (3 ft diameter) University of Wisconsin Flywheel (2 ft diameter) In house fabricated flywheel • Main concern is safety

9. Flywheel Selection N= Where: N-Max safe speed C-.9 for variable speed A-1.5 for disk type (no spokes) M-2.75 for plate/forged steel (60ksi) E-1.0 for solid rim (no bolted joints) K- ~2000 for thickness of 5% outside diameter D- Outside diameter in feet Taken from Machinery’s Handbook

10. Flywheel Selection • New Constraint: If building own test stand, moment of inertia must be under 4 kg-m2 for safety purposes • Decided to use UW test stand since it was professionally designed and best utilization of tight time frame • Will still allow for sufficient modeling capabilities when inertia rings are designed and added

11. Flywheel Analysis • Flywheel modeled at 1800rpm and 3500rpm • Centrifugal loading applied to model Max Stress: 3.30ksi Max Stress: 13.65ksi 3500rpm Centrifugal load 1800rpm Centrifugal load

12. Accumulator Selection 10 Gallon 15 Gallon

13. Accumulator Selection • 15 gallon capacity • Suitable for testing equipment • Bladder type accumulator • Bladder material Hydrin (desirable temperature and cost properties) • Steel construction • Best performance to cost ratio • Top repairable • Desirable for ease of maintenance Accumulator considerations

14. Pump/Motor Selection Size of P/M dependant on acceleration path

15. Pump/Motor Selection • Variable Displacement Axial Piston Pump/Motor • Through Shaft Swash Plate type • No extra coupling gearbox to mount to vehicle • Bosch Rexroth A11VL0 • Displacement- 145 cm^3/rev • Maximum Pressure of 400 Bar • Max Speed of 2500 rpm • 73 kg

16. Modeling Progress • Simulink models • Drive cycle: fuel economy, accelerating and braking capabilities • Hydraulic model: component sizing, pressure considerations • Hysan models • Hydraulic schematic: pressure considerations, line losses, and modes of failure

19. Current Schedule

20. Issues List

21. Budget • Components needed for test skid • Low and High Pressure Accumulator ~$6000 • Final set-up pump/motor ~$7000 • Donations • Talked to City of Fort Collins for a donated vehicle • In talks with hydraulic suppliers for possible donations

22. Questions Special Thanks To: Dr. Kirkpatrick (Advisor-Colorado State University) Dr Guy Babbitt (Advisor-Czero Inc.) Chris Turner (Advisor-Czero Inc.) Staff and Employees of The Engines and Energy Conversion Laboratory Hysan Modeling

23. Test Skid Schematic