Most of us are familiar with the egg beater. As technology advanced we went from a hand powered device to an electric powered device. A gear reduction was a part of the hand egg beater because it was difficult to hand beat eggs fast enough. The reverse occurred when electricity was employed. The motor spun too fast but did not have enough torque to beat the eggs. In both cases a gear reduction was the answer.

Many electric mixers use a worm gear reduction. It is not very efficient but achieves a high ratio reduction in two gears saving cost. Correct choice for a mixer where efficiency does not factor into the purchasing decision.

planetary gears are high efficiency

Henry Ford recognized the advantage of a planetary gear set early in the evolution of motorized vehicles. His transmission utilized two sets of planetary gears. Using both sets in series produced the amount of torque needed for low gear. This gearing approach has been fanned out into most of our vehicles including high output torque vehicles like bulldozers.

Servo motor used for steering an autonomous vehicle

Planetary gearing is also ideal for coupling low torque high speed servo motors to autonomous vehicle steering systems. The low friction within the planetary gear set makes it possible to manually operate the vehicle simply by turning off the power to the servo motor. Even though a worm gear set has the same reduction the internal friction makes it impossible to rotate the gear set from the output end. This is actually what is happening within the planetary set when the servo motor power is off. In summary, many of the improvements that we desire are obtained by choosing better working guts.