| Improving energy utilization is becoming increasingly important given the impact that energy resource management can have on the environmental, economic, and security. Reducing friction losses in mechanical systems is an effective approach to improve energy efficiency. Engineering the surface of bearing components with designed micro-sized texture is a potential method of improving the tribological performance, specifically friction reduction. The present research aims to advance surface texturing technology by developing cost effective, investigating its friction reduction potential in journal bearing applications and by developing an effective micro-texture machining method that is easily adaptable to an industrial manufacturing environment.First, the vibro-mechanical texturing (VMT) method is developed, which is based on the original work of C. Wang and K. Ehmann this technique is conveniently based on a standard machining method so that it is easily retrofitted on a common lathe setup. The method is tested for its versatility and accuracy in treating a variety of bearing types and materials. An improved closed-loop control system is implement that reduces micro-feature dimension error to less than 11%. Second, tribological performance of textured surfaces are investigated for the mechanism of lubrication enhancement in journal bearing applications. A local optimal micro-dimple design is determined at 215 mum diameter, 5 mum depth and 5% coverage density, which is shown experimentally to reduce the friction transition speed by 76% compared to the non-textured baseline. Third, the fatigue of textured surface is studied under an extreme condition of concentrated rolling contact to reveal the limit of application of VMT surfaces. Experimental evaluation shows that the durability of textured components is compromised in these applications, and the dimple design significantly influences the amount of fatigue life reduction.This research advances the understanding and potential application of surface texture technology to enhance tribological performance while introducing a micro-texturing technique that is effective and easily adaptable to an industrial manufacturing setting. |
