FINITE ELEMENT ANALYSIS OF LOCALISED FAULT IN DEEP GROOVE BALL BEARING

Abstract

Rolling element bearings as an important component in almost all types of rotating machines have been wide spreadly used and its failure is one of the foremost causes of failure and breakdowns in rotating machinery, resulting in significant economic loss. It is highly imperative to investigate the failure causes in order to improve the design and operating conditions to bear with the decreasing overall efficiency and economics involved. In present age many industries benefit from the use of deep groove ball bearings like, Agricultural, food processing, machine tool, material handling, medical / pharmaceutical and wind energy etc. Deep groove ball bearings are versatile as they can carry radial and axial loads, they have a wider range of applications for many industries and they lead to cost savings because they create less friction torque, this lowers operating temperature (which extends the life of the bearing) and reduces energy cost of running equipment (such as conveyor belts). Require less upkeep because of their simple design, low operating temperature, and low friction, deep groove ball bearings have a longer expected shelf life than other bearings. They do not require additional lubrication after installation, which also means less maintenance downtime. But due to mishandling, environmental effects and failure in operational conditions there is development of localized and distributed defects over the time, which lead to lead to seizing of machinery gradually that leads to down time. From practical conditional monitoring to FEA and dynamic models have been developed for these defects in ball bearing and thus to minimize the detrimental effects associated. Finite element analysis is used to model the localised faults in inner race of deep groove ball bearing. Ansys workbench’s transient module is used to simulate the impact over the defect and nodal parameters are captured to understand the severity of vibrations generated by the defects upon interaction with the balls in one contact simulation. The feasibility of FEA is also established for the modelling of faults in ball bearing and simplistic approach for most convenient way of simulating such defects have been developed for further studies in this field. The project focuses on procedural detailing and using apt solvers to arrive to most time efficient simulation technique. Dynamics of the system is very well projected by the transient model of faulted ball bearing. Emphasis is laid on analysing the impact of varying sizes of the faults on the severity of vibrations created upon interaction of ball over the defect on the inner race for single pass. Comparative study between cylindrical and square faults of same longitudinal and lateral sizes have been done to implicate their detrimental effects on the operation of the faulted deep grove ball bearing. Simulation results show that as defect size increases the severity of vibration increase drastically and rectangular defects prove to produce much adverse effects as compared to cylindrical defects. Further research avenues for modelling and simulation of faults in bearing have been suggested.