No abstract

Cage is the core component of a rolling element bearing, and its dynamic characteristics directly determine the performance and service life of a bearing. Metamaterial is a new structural material with topology optimization design, which has many special physical properties that traditional materials do not possess. Utilizing 3D printing technology to prepare metamaterials can increase manufacturing flexibility, give full play to its advantages in complex structure manufacturing, and realize the integrated manufacturing of structure and function. In this paper, a bearing cage with pentamode metamaterial structure was designed and fabricated by using selective laser sintering (SLS), and its deformation simulation and experimental tests were carried out. The results show that the 3D printed metamaterial structure cage has desired mechanical properties, and is workable in preliminary tests. Compared with the original commercial cage, the quality factor increased by one order of magnitude, which means it is easier to deform under shear force than pressure. This characteristic is beneficial to the high speed operation of rolling element bearings. In addition, due to its unique holes structure, its weight was reduced by 50% and more grease could be stored, resulting in a lower friction coefficient. When running steadily under the same condition, the power consumption of the bearing assembled with the 3D printed cage is 25% lower than that of the bearing assembled with the original cage. The study has demonstrated that 3D printed cages are of great research significance and broad application prospects.

This study proposes an adaptive CNC machining process based on on-machine measurement to control the machining error of near-net-shaped blades. The multi-source and multi-process machining error transmission model of a near-net-shaped blade is established, and the reduction effect of the machining error transmission chain by the adaptive CNC machining process is qualitatively analyzed based on the machining error transmission flow model. The effects of the adaptive CNC machining process on the positioning benchmark error, machining position error, and machining contouring error are explored based on an experiment for the adaptive CNC machining process. In particular, the ability of the adaptive CNC machining process to cooperatively control the blade position error and the contouring error is discussed in relation to the stiffness of the blade-fixture system. The results show that the adaptive CNC machining process can reasonably reduce the machining errors caused by the positioning benchmark. The final deviation band of the blade body is reduced by 60% based on this adaptive CNC machining process. The adaptive CNC machining process can optimize the contouring error and the position error of the blade tenon root with only the stiffness of the blade-fixture system prerequisite being ensured. The adaptive CNC machining process has the excellent ability to control machining errors to improve the machining quality of the blade.