A differential is a gear train with three drive shafts that has the property that the rotational speed of one shaft is the average of the speeds of the others. A common use of differentials is in moto
Differential unit for a rear-wheel drive car, built by ZF c. 2004
Differential gears (in yellow) in a punched tape reader, built by Tally c. 1962
Illustration of a ring-and-pinion differential for a rear-wheel drive vehicle
Schematic diagram of a ring-and pinion differential
Rocker-bogie
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The rocker-bogie system is a suspension arrangement invented by NASA engineer Donald B. Bickler in 1988 for use in NASA's Mars rover Sojourner, and which has since become NASA's favored design for rov
A rocker bogie
Rocker bogie on Curiosity
Early wooden model of Bickler's articulated suspension design.
The “Bickler Pantograph”, an early rover prototype, pictured in Bickler's garage.