Load Application Analysis: Hydraulic Cylinders October 5, 2013Rochester Institute of Technology1  Benefits:  Load Accuracy  Required Analysis (Incompressible Fluid)  Drawbacks:  Safety  Maintenance  From PRP and Markus’s Thesis:  Up to 900lbs (4000N) applied force  Up to 2000 rom shaft speed (33Hz)  Journal to sleeve clearance: 35 to 95 microns  Compressor Operating Rpm: 360rpm (Dr. Kolodziej)

Load Application Analysis: Hydraulic Cylinders October 5, 2013Rochester Institute of Technology2  Parker Electro-Hydraulic Actuator (EHA)  Hybrid combining benefits of hydraulic cylinder and electric servo  Self-contained unit  Speed and Load Range  Size

Load Application Analysis: Hydraulic Cylinders October 5, 2013Rochester Institute of Technology3  Calculations for Parker EHA (w/ Motor B and gear):  Distance for Piston to move (conservative): 95µm= "; "*2= “ ≈ 0.01" (cushion)  Piston Speed from Graph ≈ 1.8in/s  Cycle time: (0.01in)/(1.8 in/s)*2(extend & retract)= 0.011secs/cycle  Actuator Frequency: 1/(0.011 secs/cycle)= 90 cycles/second = 90Hz

Load Application Analysis: Hydraulic Cylinders October 5, 2013Rochester Institute of Technology4

Load Application Analysis: Hydraulic Cylinders October 5, 2013Rochester Institute of Technology5 Shaft Operating RPM360RPM Shaft Cycle Time0.1667s Shaft Frequency6Hz EHA Piston Velocity1.8in/s EHA Piston Displacement0.01in EHA Displacement Time0.0056s EHA Cycle Time0.0111s EHA Frequency90Hz EHA X-Direction Force Cycles2cycles/rotation EHA X-Direction Force Frequency12Hz EHA Y-Direction Force Cycles4cycles/rotation EHA Y-Direction Force Frequency24Hz Challenges: Are EHA’s load input based or displacement input based? Response time to inputs Piston Velocity varies with load Extension load, as opposed to retract (Additional actuator(s)?){$$$}