Fault Diagnosis of Gear by Vibration Analysis Aditendra Jaiswal M Tech Final year Mechanical Department Priyadarshini College of Engineering Nagpur, India Dr. K.S. Zakiuddin HOD and Professor Mechanical Department Priyadarshini College of Engineering Nagpur, India V.V. Shukla Assistant Professor Mechanical Department Priyadarshini College of Engineering Nagpur, India Abstract - Unexpected production delays cause substantial costs in many branches of industry. A machine consists of many potentially defective elements, such as gears, bearings, shafts etc. During operation, each element contributes to the overall vibration of the machine. Each specific machine element has its own vibration signature. The purpose of machine vibration monitoring is to use the modified vibration signature to detect, localize, diagnose and prognosticate the defective gear so that relevant maintenance can be planned. When a defect e.g., a fatigue crack, appears in an element, e.g., a gear, its signature is modified. The dynamic response of gears is a matter of concern because of noise generation and dynamic loads. The present study is focused on the different modes failures observed in gears which are detected by using vibration based monitoring technique Fast Fourier Transform. A test rig is prepared to carry out the analysis by simulating faults in the gear and generating spectrums of specific faults which are compared with the spectrum of a new gear indicating severity and specificity of fault. The experimental setup has been designed to facilitate generation of spectrum for different pairs of new and defective gears. The modified spectrum from combination of new and defective gears can be attributed to variation from the defective gear, thus identifying the defective gear in the pair. In this paper the empirical data generated by the experimental setup for both new and defective gear for a gear pair used in an automotive transmission is analysed and discussed. Keywords - Vibration based condition monitoring, Fast Fourier Transform, Modes of Gear failure. I. INTRODUCTION Transmission is an important subsystem of engineering systems such as power, automotive gear trains, manufacturing machinery etc. Effectiveness of such systems is dependent on their continued availability through reliability of subsystems. Maintenance of equipment and machines has graduated from breakdown to condition based predictive maintenance. Right information at the right time is crucial aspect of condition-based maintenance strategy in industries. Condition-based maintenance (CBM) consists of real time monitoring of condition of machine systems, identifying faults before catastrophic breakdown occurs. Condition monitoring based maintenance improves the availability by predicting faults facilitating scheduling and planning of maintenance activities, defective components like gears can be withdrawn from service before their condition impairs performance. Gears are critical part of power transmission system. Numerous condition monitoring (CM) and diagnostics methodologies are utilized to identify the machine faults to take corrective action. A number of condition monitoring techniques have emerged such as wear debris analysis, visual inspection through strobe lights, vibration signature analysis, lubricant signature analysis, noise signature analysis, and temperature monitoring, with the use of appropriate sensors /transducers, different signal conditioning, and analyzing hardware /software. The use of vibration analysis as one of the fundamental tools for condition monitoring has been developed extensively over last six decades. Failure mode analysis of gears obtained from published industry data shows the following failures Crack, wear, pitting, corrosion, scoring, plastic flow, tooth breakage. Failure mode analysis of gears obtained from published industry data shows the following failures Crack , wear, pitting, corrosion, scoring, plastic flow, tooth breakage . The paper attempts to collect vibration spectrum of five different simulated gear defects through design of an experimental setup for comparison with the reference signals. A reusable set up was therefore conceptualized and designed for multiple gear fault International Journal of Latest Trends in Engineering and Technology (IJLTET) Vol. 3 Issue 1 September 2013 26 ISSN: 2278-621X