Estimating the Lifetime of the Pneumatic Cylinder in Machine Tool Subjected to Repetitive Pressure Loading

• 作者: Seong-woo Woo
• 来源期刊: 美中公共管理:英文版
• 学科: 政治法律
• 关键词: reliability design LIFETIME PARAMETRIC ACCELERATED life testing PNEUMATIC CYLINDER system
• 年，卷（期）: 2018,（5）
• 页码范围: 221-238
• 页数: 18页
• 分类号: D

摘要

To estimate the lifetime of pneumatic cylinder in machine tool (or automatic assembly line), new reliability methodology for parametric accelerated life testing (ALT) is suggested. It consists of parametric ALT plan, generalized life-stress failure model with a new effort concept, acceleration factor, and sample size equation. This new parametric ALT enables an engineer to estimate the lifetime of a commercially parts by uncovering the failure through accelerated testing under severe conditions. As a case study, two commercial products of the pneumatic cylinder in machine tool were tested. For company A, we found the hardening and wear of piston seal like that of field at normal conditions. As increasing the pressure, the pneumatic cylinders were tested. Based on the accelerated conditions—0.8 MPa and 1.2 MPa at 23℃, B1 life at 0.63 MPa and 23℃ was extrapolated as 2.39 × 10^6. On the other hand, for company B, we found the rod cap blocked by slurry like those of field samples. Based on the accelerated conditions—0.8 MPa and 1.4 MPa at 23℃, B1 life at 0.63 MPa and 23℃ was extrapolated as 2.51 × 10^6. Comparing them with testing data at normal use conditions, we knew that the estimation error for both companies was less than 10%.