Vibration analysis of an influence of groove in the bottom land of a spur gear

Abstract

Modern machinery and manufacturing systems are committed to be more accurate and punctual in delivery, which in turn requires a perfect machining and maintenance system. Maintenance has many indispensable tasks, of which vibration control is one of the most challenging for maintenance engineers. Majorly in rotating machinery like gears and turbines, vibration is the predominant factor to be controlled. Hence this paper deals with a novel way of controlling the vibration in spur gears. Generally gear vibrations can be reduced by profile modification or by decreasing the pressure angle or dynamic load and also by means of increasing the contact ratio. In this work, a profile modification is considered. A groove has been generated at the bottom land of the gear in order to increase the thickness and height of the gear tooth at the root. Due to this, the stiffness of the gear tooth at the bottom land of the gear increases which in turn reduces the radial load deflection and the vibration amplitude in the vertical direction (shaft bending direction). Two spur gears (gear A and gear B) having the same gear parameters are selected. In gear B, a groove has been generated at the bottom land. Both the gears are discretized and analyzed by FEA software. The analysis is made under frequency response to identify the amplitude of vibration of the gears due to transmitted (tangential) load and radial load for the existing gear (gear A) and the modified one (gear B). The result shows that the modified gear has a better control in the radial load direction. Hence an increase in the tooth depth within a limit ensures that the control of magnitude of the vibration is effective. Finally, experimental analysis has been done to validate the computational data and the results are in good agreement.