How Are You Dealing with the Bias Error in Your Helical Gears?

摘要

This paper initially defines bias error-the "twisted tooth phenomenon." Using illustrations, we explain that bias error is a by-product of applying conventional, radial crowning methods to produced crowned leads on helical gears. The methods considered are gears that are finished, shaped, shaved, form and generated ground. The paper explains why bias error occurs in these methods and offers techniques used to limit/eliminate bias error. Sometimes, there may be a possibility to apply two methods to eliminate bias error. In those cases, the pros/cons of these methods will be reviewed. Profile and lead inspection charts will be used to detail bias error and the ability to eliminate it. The paper details the simultaneous interpolation of multiple axes in the gear manufacturing machine to achieve the elimination of bias error. It also explains that the CNC machine software can be used to predict bias error. Equally important, the software can be used to create an "engineered bias correction" to increase the load-carrying capacity of an existing gear set.