Description
I love to design functioning models of everyday mechanisms. There is something special about taking a mechanism that you have seen or used throughout your entire life and figuring out exactly how it functions. When I designed a combination lock, I was amazing by have clever the mechanism is. The design of the differential feels the exact same way.
You may not know what a differential is or what is does, but you have undoubtably felt its impact. When a car goes around a turn, the inside wheels turns slower than the outer wheels. This is because the inner wheel travels a shorter distance than the outer wheel in the same amount of time. How does the car make this possible? The adjacent wheels clearly can’t be attached to the same axle and still go at different speeds, but both adjacent wheels still need to be powered from the drive shaft in the car. The differential takes in the power from the drive shaft and delivers it to the two wheels such that the average speed of the two wheels is proportional to the speed of the drive shaft, but the two wheels can travel at different speeds to make corners possible.
In my Engineering class we were tasked with designing lego pieces in CAD. Most of my class was learning CAD for the first time, but I have years of experience. Therefore, I needed to make something cool. This differential snaps onto a lego plate at the bottom, and all the gears connect with lego axles. My dad put together a lego 6 speed transmission designed by David Gustafsson. The yellow battery powers the motor above it, the power is controlled by the transmission in the middle, and the red differential transfers the power to the wheels.
Sean Cavalieri 