A spur gear drive consists of a small pinion gear driving a larger
gear. Typical gear ratios are in the range from 6:1 to 10:1. As the gear
ratio increases, there is less gear error averaging because there are
fewer teeth in mesh. The stiffness is also lowered. Lubrication is also
required reducing the stiffness. The efficiency is high and allows back driving. They have higher contact ratio that makes them smooth and quiet in operation. They are available for corrosion resistant operation. They are among the most cost-effective type of gearing.
They are used in construction equipment, machine tools, indexing equipment, multi spindle drives, roller feeds, and conveyors.
Applications
The smoothness is a function of accuracy of the machining of the gear teeth. It is possible to use spur gear drives on astronomical telescopes with higher resolution position feedback derived from the telescope axis rotation. The servo system uses the spur gear drive system and drives the servo motor to correct the gear errors based upon the actual rotation of the telescope axis.