Design Of One Spherical Plain Bearing Test Machine And Structure Optimization Of Important Parts

The spherical plain bearing is widely used in the aerospace sector because of itscompact structure, strong carrying capacity and long service life. In order to offer anaccurate assessment of its accuracy, life and reliability, it’s necessary to conduct work testsonce the design is finished. The movement state of the spherical plain bearing is socomplicated that it’s difficult to be simulated. It costs such a long time to finish theoperating condition test because the spherical plain bearing is always so strong.Sometimes, accelerated test is necessary to get results as soon as possible.In order to guarantee the smooth going of the test process and the reliability of results,not only the test machine shall have comprehensive function, but also important parts shallhave enough structural stability and long life. Therefore, the function requirement needsbe satisfied, and the structure of important parts needs be optimized.In this thesis, one new model of test machine is designed aiming at the spherical plainbearing used in the helicopter rotor system. According to the working condition of thespherical plain bearing, the concrete function and the technical parameters are determined,the comprehensive simulation of the movement and load condition and work atmosphereare realized, and the oscillating frequency requirements of both of operating condition andaccelerated test are satisfied.For the purpose of decreasing the stress level of important parts, the structure of theloader and fixture is optimized. The effect of structure parameters upon the performancesof these parts is analyzed, the optimum parameters are decided, the structural stabilityand life are both improved, and the accuracy and reliability of test results are guaranteed.To decrease the incline of the baseboard in the environmental cabinet and the stresslevel of the foundation, the structure of the foundation is optimized. The concentricity ofbearings that support the transmission shaft is improved. The influence of temperature onthe stress of the foundation is reduced.