Conclusions of Pump-Jack Project

Conclusions

The results from the kinematic analysis indicate that point P1 is moving linearly. The mechanism is intended to translate a rotational input at P02 into motion at the end-point P1. Linear motion at P1 is intended to vertically extract oil out of the ground. My results indicate that this motion was approximately 10 degrees off from vertical, with P1 moving linearly with a velocity direction 100 degrees from horizontal (as opposed to the intended 90 degrees). In order to ensure that P1 is moving vertically in future mechanisms, link lengths would need to be adjusted.

Future Works

Given the circumstances of Covid-19, I was unable to access the ideal materials and tools to assemble this prototype. As a result, the mechanism had quite a bit of friction in each joint. Additionally, it had quite a bit of out-of-plane movement during it's intended in-plane movement. Under more ideal circumstances, I would recommend that the mechanism be built with bearings instead of bolts at each joint. Additionally, the mechanism could be fabricated with aluminum or acrylic links, instead of wood, to minimize friction and improve appearance. By building a CAD model and using precise measurement tools, more exact link lengths and joints widths could be determined, which would reduce out-of-plane "wobble" and the simulated kinematic analysis results would more accurately reflect the performance of the  system.

Code

The MATLAB code in the following  '.mat' file was used to derive the kinematics (velocity and acceleration) for various points and links of the mechanism:

Or the following ZIP folder:

If you have any questions about the code or project, please reach out to Aude Lefranc at Lefranc@utexas.edu

Sources

https://energyeducation.ca/encyclopedia/Pump_jack

https://en.wikipedia.org/wiki/Pumpjack