How can we learn to appreciate design choices from the manufacturing perspective?
By manufacturing something!
A multitude of manufacturing techniques were utilized including machining, casting, water jetting, and laser cutting.
Part 2: Fuel Injection Rotary Vane Pump Design
This heavy-duty pump is built for harsh conditions including a wide operation temperature range, high outlet pressure, and long life between service intervals.
Design Criteria
Temperature: -40F to 140F
Inlet Pressure: 4bar
Outlet Pressure: 300bar
Speed: 1000RPM
MTBF: 200,000 miles of vehicle travel
Yearly Production: 2,000,000 units
Design criteria provided a foundation for in-depth research and investigation into the target application.
Research
Initial Inquiry
How does a rotary vane pump (RVP) really work?
In what applications are RVPs typically used?
What principles guide the design of a RVP?
What calculations are needed to move forward?
Are there areas of concern for this specific application?
What are the properties of gasoline?
*Gif courtesy of Thomas Pumps
Calculations
Hoop Stress
Bolt Torque
Vane Deflection
Vane Wear Rate
Bearing Loads
Iterative Design
Identify Areas of Improvement
Unoptimized inlet and outlet locations
Bolts should not be used for locating
Gasket failures
Low quality mounting system
Fastener features are a pain point
Material Research
Production volume per year
Stresses from pressure
Material wear over cycles
Gasoline properties
ANSYS Granta Edupack
Materials Considered
Cast Iron
Aluminum
Hardened Bronze
Carbon Fiber Graphite
CF Reinforced PEEK
Vane Design and Analysis
CAD Iteration
V1
Initial concept
Wall thicknesses increased due to hoop stress
Mount created to bolt pump to frame rail
V2
Bolts correctly sized
O-ring face seals
High pressure shaft seals
V3
Check diameters added to all mating parts
Bearings sized based on semi truck engine pulley loads
Low pressure shaft seals for open bearings
Retaining rings added to shaft ends to limit axial movement
Final (V4)
Completed rear bearing housing with low pressure shaft seal
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