Hydraulic Hybrid Vehicle 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.

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

Background/Review

Objectives and Constraints Design components to retrofit existing vehicles Operational Test Skid by Dec 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

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

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

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

Flywheel Selection 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 N= Flywheel Max Safe Speed (rpm) Max Modeling Capability (mph) Clark31530 UW UW (rings) Trainwheel250039

Flywheel Selection New Constraint: If building own test stand, moment of inertia must be under 4 kg-m 2 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

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

Accumulator Selection 10 Gallon15 Gallon

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 Selection Accumulator considerations

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

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

Current Schedule

Issues List

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

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

Test Skid Schematic