Have you ever heard of gear backlash? It doesn’t refer to a gear-based revolt against manufacturers. Instead, backlash is an error in motion that happens naturally in systems where gears change direction. If unaccounted for, backlash can cause major problems in gear degradation and can even compromise the entire system.
So how do we prepare for it?
What Is Backlash?
Backlash is a term that can refer to either the error in motion that occurs, or the gap between two gears that is responsible for that error. Backlash only occurs in gear systems that change direction. Why?
No matter what, there’s always a tiny gap that forms between the trailing face of a forward-pushing gear tooth and the leading face of the tooth behind it. This alone isn’t a problem, but when gears try to reverse momentum, this gap (the backlash) has to be closed.
In a perfect world, where gears are flawlessly designed and produced, with absolutely no lubrication, no expansion, and no contraction interfering with the system, you could have a set of gears with “zero” backlash. Unfortunately, reality is much more complicated, and much more prone to variables. Therefore, all gear systems need to be designed to account for backlash, especially if precise controls are vital for the system to operate effectively.
Strategies to Reduce Backlash
So what do we do to minimize backlash in a gear system? Generally, we rely on two main strategies (and a host of other techniques).
Sometimes, we split teh gear on a plane perpendicular to its axis, and add torque to the system by using the two halves together with springs. Essentially, this system functions like a single gear with expanding teeth.
We also taper teeth (in the axial direction), and allow the gear to slide in that same direction to fill the gap more easily.
As long as you’re prepared for backlash, it won’t be a problem in your gear system. If you need help designing and manufacturing gears that account for backlash, contact Federal Gear today!