Design and development of a test rig for performance evaluation of ball bearings

Most of the bearings used in industrial machines and domestic equipment to support the rotating shafts are rolling bearings. Low friction at the contacts between the balls and the races has positive effects such as reduced temperature rises, lower vibration amplitudes, higher fatigue life and reduced premature bearing failures. This can be achieved by enhancing the availability of lubricant/grease at the contacts. Among the various available methods surface texturing of the bearing components by employing micro-tracks and micro-dimples/grooves has been extensively used. In this connection, to explore the performance behaviour of a modified/newly developed bearings a test rig has been indigenously designed and fabricated to measure tribodynamic parameters such as frictional torque, film thickness formation, temperature rise, and vibrations by implementing load cell, capacitance-based approach, thermocouple, and miniature type accelerometer respectively. The development of test rig includes selection of commercially available components (support bearings along with suitable pedestal, variable speed motor, timing belt and pulleys for power transmission), design and manufacturing of components (shaft, test bearing housing and base frame) and adopting suitable techniques for the parameters to be measured. Also, modal analysis of the test rig and bearing components have been carried out by employing FEA software to find out the natural frequencies and their corresponding modes. The developed test rig has the capability to operate up to 3,000 rpm and measure/estimate capacitance, frictional torque and temperature rise in the range of 10-1500 pF, 0-900 N.mm and 0-200 °C respectively. In addition, the vibration rms velocity of the test bearings can be measured and analysed in both time and frequency domain.