Design and research of a heavy load fatigue test system based on hydraulic control for full-size marine low-speed diesel engine bearings

As the power density design indicators of marine low-speed diesel engines gradually increased, resulting the loads of marine low-speed diesel engine bearings become increasingly complex. It's easy to cause crankshaft fatigue damage, leading to a very significant economic loss. Due to the maximum thrust loads of full-size-bearing is larger than 2000kN, the bearings performance tests are very expensive on a complete diesel engine. So, newly developed bearings must be verified on a specialized test rig. The research goal is to design a novel fatigue life test system (Bearing diameter: 300mm–520mm, Speed: 5r/min-200r/min, Thrust: 0kN–2800kN) that can simulate the working conditions of full-size low-speed marine diesel engine bearings. Adopting the advanced hydraulic-based control passive pressurization technology. Multi-platform joint simulation technology is used to make sure that the maximum thrust of the test rig is proportional to the eccentricity of the eccentric shaft. The final eccentricity of the shaft is determined by 3mm for test rig. The results based on 475mm×150mm bearing is published for the first time. The test load can be well enveloped in the load of the target diesel engine, with maximum load fluctuation less than 0.2%. The test rig can meet the performance testing requirements of full-size bearings.