#1: How to size a rack and pinion drive
In linear motion applications, ball screws are widely recognized for their ability to provide high thrust forces, while linear motors are gaining market share in high-speed applications, and belt drives continue to maintain their reputation as the best solution for long travel lengths. But rack and pinion drives are the often-overlooked workhorses behind gantry and transport applications that require long travel, high acceleration rates, and high thrust forces at a relatively low cost — a performance-price combination the other drive technologies have difficulty achieving.
Case in point: Unlike ball screw sizing — which must take into account factors such as characteristic and critical speeds, end bearing considerations, and the effects of preload, in addition to basic thrust force and drive torque calculations — rack and pinion drive sizing is primarily based on three factors: the force the rack sees (referred to as the “feed force” or “tangential force”), the torque the pinion sees, and the rotational speed of the pinion.
Filed Under: Linear Motion Tips