Hydraulic Hybrid VehicleMembers:

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. 2007• Running prototype vehicle by April 2008• Payback period: less than 2 years through fuelsavings and reduced maintenance cost• Major components sourced from commercialmanufacturers

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

D

CAMEK

RPMD

N7425

Where:N-Max safe speedC-.9 for variable speedA-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 diameterD- Outside diameter in feetTaken from Machinery’s Handbook

N=

Flywheel

Max Safe Speed(rpm)

Max Modeling Capability

(mph)

Clark 315 30

UW 3500 20

UW (rings) 3500 37

Trainwheel 2500 39

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

Flywheel Analysis•Flywheel modeled at 1800rpm and 3500rpm

•Centrifugal loading applied to model

1800rpm Centrifugal load3500rpm Centrifugal load

Max Stress: 3.30ksi Max Stress: 13.65ksi

Accumulator Selection

10 Gallon 15 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

M

CV1

Flywheel

PRV1

Control Valve

PRV2

PRV3

Manual Valve

Hydraulically Actuated Valve

Hydraulic Power Source

Control

LP HP

P/M

Brake