Michigan State University
Hydraulic Pump Design for Coupe Door System
Modeling of the “Hydraulic Pump Concept”
Assembled Hydraulic Pump design
PISTON
● Piston heads Travels 132.7mm
from fully open to fully closed
● Piston Stem is fixed to vehicle interior
● Provides the Driving Force of the Fluid
Flow due to an Applied Input Force
● Ball bearings permit relatively smooth
travel of the piston within the cylinder
Alternative Hydraulic Pump design
● The relative movement of the piston head resembles the direction of
door motion. Compressive Motion corresponds to a door closing
direction and Tensional Motion corresponds to a door opening direction.
Group Member
Chris Lowe
Jeff Mann
Fai Leung
Doo-hwan Kim
Faculty Advisor
Dr. Farhang Pourboghrat
Sponsor (GM)
James Karlavage
Problem Statement
•To develop a working concept for a side closures system hold open
device, capable of infinite adjustment.
•In essence, the objective is to create a universal door opener that will
allow a car door to stay in whatever position the customer opens it to
and then release when pushed/pulled closed
CYLINDER
● Length is 150mm, Diameter is 40mm
● Grounded to inner portion of the door
● Piston Head is positioned and is
translated axially within cylinder.
● Regulates the distance of Piston travel
HYDRAULIC FLUID
● Dot 3 Breaking Fluid
▪ Relatively high boiling point
▪ Relatively low freezing point
▪ Fluid is very Incompressible
OPENING/CLOSING PASSAGE
● Closing Passage will have twice the cross
•The housing must not exceed 80mm X 40mm
sectional-area of the Opening
•The mechanism should be capable of applying approximately 40Nm
of “hold open” torque to hold the door open
● Radius of closing passage will be 1.414
times (square root of 2) larger than the
Opening
Hydraulic Pump Concept
•Simple Hydraulic Pump System with a stationary piston and moving
cylinder linked to two fluid passage pipes (one for the opening of the
door and the other for closing) and two one-way valves.
•Piston Stem is fixed to vehicle and the cylinder is attached to the inner
door.
•Cylinder and passage pipes are completely filled with hydraulic fluid.
•As door opens, cylinder moves away from the vehicle allowing the
piston head to push fluid backward through the opening passage pipe
and vise-versa for door closing.
•Design is functional and satisfactory based on the constraints and
objective of the project
PRESSURE VALVES
● Each Passage will have 1 one-way
pressure valve attached to entering end
● The closing passage will have a
pressure reducing one-way valve
Schematic of Current Door System (Top
view)
Results
Fluid Leakage Problems are Plausible
Most likely would occur at the mating and bonding sections
Issue: Decreases the efficiency and proficiency
Solution: Add O-ring seals and silicone sealants to affected areas
Infinite Stop Positions Between Fully Open and Fully Close
Equivalent Fluid Pressure on both sides of the Piston Head when
applied force is ceased.
More Force needed to Open than to Close
Using a one-way pressure reducing valve for the closing
compressive direction with a greater diameter than the one-way
valve for the opening tensional direction should resolve this
issue
due to the Theory of Least Resistance.
Conclusion
It would be the best idea to implement the alternative hydraulic
pump design because it is just as efficient as the original pump design
and it better fits within the special constraints of the current GM
vehicle models. Although the price of implementing the alternative
design seems steep (at $10M the first year and $5M for the years
after), these types of prices are minuscule to a prosperous company
like GM. Implementing such a concept that allows infinite door
positions while applying insignificant force increases customer
satisfaction and decreases door opening related accidents. Thus,
overall, this will attract more customers to purchase GM vehicles:
and in the end, we believe that GM will make a huge profit off sales
in comparison to what they would pay to manufacture the pump
units.