What is backlash on a gear?

Backlash on a gear refers to the play or clearance between the mating teeth of two gears when they are not in contact. This clearance is essential because it allows for smooth operation and prevents binding, particularly under load. Without sufficient backlash, gears could jam due to thermal expansion or misalignment during operation, potentially causing damage to both the gears and the associated machinery.

This play also compensates for any inaccuracies in manufacturing and provides a margin for any lubrication between the gear teeth, which is crucial for reducing wear. Having a controlled amount of backlash is necessary in mechanical systems to ensure efficient and reliable functioning. In contrast, too much backlash can lead to reduced precision in applications requiring high-quality motion transfer, such as in robotics or precision machinery.