Metal Gap Sealing Cylinder Life Test

The metal sealing type cylinder is a new type pneumatic cylinder of low friction, low working pressure and high speed merits. Therefore it is wildly used in transferring precision components, cutting glass and lenses and in which the sensitive tension control or the high speed is required.However the metal sealing cylinder is a new type cylinder, there is still no necessary life test and the study for the failure modes. The lake of these data would directly affect the cylinder's application in important industrial field. Therefore study of the new cylinder's life test and failure modes is necessary and urgent. Due to unique features of metal sealing cylinders, the critical failure values in the current ISO testing standard for rubber sealing cylinders may not be suitable for the new ones. It is necessary to research for the critical failure values in the ISO standard combined with the life testing.In this paper, experimental studies are conducted focusing on the working life and failure modes of the metal sealing cylinder. Some results are obtained as follows.(1) Considering the metal sealing type cylinder's character and refereeing to the ISO standard for the rubber sealing cylinders, the basic test condition of life test are proposed and the life test system for the metal sealing type cylinders is designed and constructed.(2) After six months continuous life testing and data collection, a large number of experimental data is obtained. Through deep data analysis and considering the structure and character of the metal sealing cylinders, the conclusion is obtained that the critical failure values-for the metal sealing pneumatic cylinders are not suitable for adopting the current values in ISO standard for the rubber sealing pneumatic cylinders. On this basis, the new critical failure values for the life test of metal sealing pneumatic cylinders, such as leakage, minimum working pressure and stroke time are proposed.(3) The failure analysis and life analysis are carried out based on the proposed critical failure values. The computation indicates that the character life of the test pneumatic cylinders is 1.6192×10' cycles. Then the cylinders are disassembled and the abrasion components are checked. The main factors which affect the cylinder's life are discovered. The metal sealing cylinders'main failure factors are the abrasion of the cylinder's ball bushing and the cylinder's lubrication condition deterioration.