Fatigue design optimization of valve actuator welded scotch-yoke for high-cycle applications

摘要

High-cycle applications are sometimes requested by end-users. This application is surely mostly burdensome for heavy-duty actuators due to the high number of cycles required [1]. In order to obtain the best performances in relation to fatigue resistance a design optimization process is implemented. The present paper illustrates the fatigue analysis for the design of a scotch-yoke. The scotch-yoke for the heavy-duty application currently assembled on the LPS/LHS actuator series of FLOWSERVE - Limitorque is manufactured in a common structural steel. The component in object is essentially composed by three parts: one tube and two plates welded to the tube with a MIG/MAG fillet welds. The welded assembly is then machined in order to create slots in the two plates for the slider blocks movement and two or four key seats in the tube. Three different designs of the component are analyzed. Technical drawings of each design version are reported in 1(a) to 1(c).