Experimental research on gas bearing of free piston Stirling generator

To study and solve the wear problem caused by piston offset of free piston Stirling generator, the law of the magnetic lateral force change caused by the offset was firstly obtained through the finite element software simulation. It is found that the radial force of the mover is increased linearly with the offset distance and the offset angle, with the slopes of 1 997 N/mm and 1 535 N/(°) respectively, and the direction of force is the same as the direction of offset. Then, the gas bearing structure was designed for the piston, and a bench for testing the performance of the gas bearing based on the static and dynamic friction force theory was built. Research on the influences of different gas bearing diameters, the number of holes, cavity pressure, bearing load on the actual bearing air consumption and bearing capacity were carried out. Results show that the frictional force on the piston increases as the piston offset increases, and the corresponding required floating pressure also increases. Meanwhile, the bearing capacity and air consumption are positively correlated with the gas bearing diameter, the number of holes and cavity pressure. Therefore, it is necessary to comprehensively consider the actual bearing load and efficiency loss to select appropriate value. © 2022, Editorial Board of Journal of Huazhong University of Science and Technology. All right reserved.