Protection Performance of New Polydimethylsiloxane Packaging Method for Aero-Engine Precision Bearings

Packaging that is currently used for aero-engine precision bearings faces several issues, such as insufficient cushioning performance, insufficient sealing performance, and poor visibility. Herein, we propose a new method in which the bearings are fully covered with polydimethylsiloxane (PDMS). Samples were prepared for tensile and moisture-permeability tests according to the optimum ratio 10:1 (PDMS: Curing agent) of PDMS provided in the literature. The stress and strain curves of PDMS were then obtained via the tensile test. Additionally, the permeability of a polyethylene/polyamide composite film (the packaging material currently used) and PDMS were compared via a moisture-permeability test. According to the test results, the cushioning coefficient of silicone was 1.9, and the minimum thickness of the pad was 12 mm. Using a finite-element software, the bearing stress of the buffer pad was compared for thicknesses of 7, 12, 17, and 22 mm. The simulation results indicated that the liner with a pad thickness of 12 mm provided the optimal protection and economy. According to the simulation results, the precision bearing is packed in such a manner that it is fully enclosed, and the suitability of the proposed method wherein the PDMS material is used as a cushion pad was verified by simulating a drop test of the product during transportation. When the thickness of the PDMS cushion was 12 mm, the shock acceleration of the bearing was <1100 m/s². Thus, the proposed method can successfully protect aero-engine precision bearings.