Development Of A Small-sized And High-speed Bearing Test Rig

Rolling bearings are employed in the rotor system of aerocraft engines. Theysupport the spindle, which has a surprisingly influence on the reliability andperformance of aerocraft engines. As performance requirements increase in hightemperature and high load condition, specialized bearing test rig should be developedto improve and perfect bearing design. The development of bearing test rig, which cansupply reliable performance data on evaluating the property of bearings, has beenstudied over the past several decades.This paper reports on the modeling of a small-sized and high-speed bearing testrig to test high-speed rolling bearings such as the main-shaft bearings of aerocraftengines. The rig design was focused on the assessment of the lubricationcharacteristics of bearings in an environment similar to that of aerocraft engines, suchas the same bearing support structure and the operating conditions. With the moduledesign of the system, the bearings can be tested up to42000r/min and4000N axialand radial load, including ball bearings and rolling bearings.Throughout the paper, we will present the composition of the testing system,including mechanical structure design. Pro/Engineer is made use of on the modeling ofthe test rig. Static mechanical and modal analysis of the test rig will be achieved usingFEM. The main-shaft FEM model can be formed by simplifying bearing to springelement. Static characteristics demonstrate the calculation method of the rigidity forthe spindle system. The resonance frequency is directly identified from finite elementmode analysis, providing assurance for automatic controlling rotation spectrum.Harmonic response analysis addresses the influence on dynamic response by frequencyof excitation force, meanwhile equivalent stress and amplitude are calculated. Stressdistribution can be obtained by simplifying the load on bearing housing. Results ofmodal analysis, the natural frequency and vibration mode, can be reference to optimizemechanical structure. Successful design and performance assessment are validated bythe static and dynamic analysis.The assembly and adjustment of mechanical structure are accomplished.Throughout the effort to coordinate other modules, including motorized-spindle,lubrication system, servo loading system and data acquisition system, demonstratingthe possibility of performing bearing tests.