A Novel Method to Improve Crack Detection Ability in Helical Gear

The helical gear systems have some distinctions such as more precision, long life and more applications in the industry, and less vibration, noise and transmission error compared to spur gear systems. One of the damages that can affect the operation of these systems is the gear tooth root crack. So, the crack detection in its early stages of growth and development is very important. The residual signal method is one of the common methods to extract the effect of crack from the system vibration signal. Since the residual signal calculation requires the information of the vibration response of the healthy state or the system initial parameters, providing a method to extract the effect of crack from the vibrating response without any more information is very helpful. In this research, at first the calculation of the helical gear pair mesh stiffness is explained, and the effect of tooth root crack is also described. Then, a single-stage helical gear system, with the motor and the load, is modeled and solved numerically to achieve the system dynamic response. Then, the effect of present method on the vibration signal obtained from the dynamic simulation of a system with a small crack is Shown and discussed. Finally, the proposed method is applied to the dynamic response signal of a system that presented in one of the previous researches, and its efficiency is illustrated.