Measurement and control system design for the assembly of stator can

Stator can assembly is one of difficult issues in the manufacturing of AP1000 nuclear reactor coolant pumps. A new measurement and control system is developed to ensure precise assembly of the ultrathin stator can with large length to thickness ratio on the stator core. The system includes three parts: hydraulic pressure measurement and control, deformation measurement of the can and displacement measurement of valve core. Since deformation of the can is hard to measure, a new method by measuring the bulge displacement of the can is proposed. With the help of the system, the loading path can be accurately controlled and the deformation can be precisely measured. The system provides possibility for the detailed study of assembly process. Finally, the feasibility of the system in the experiment rig of a reduced scale is verified. (paper)