Ultra-precision grinding of asymmetric curved surfaces by line contact with cup wheel

The wheel wear is a crucial factor affecting the shape accuracy while grinding the asymmetric curved surface components. To decrease the effects of the wheel wear and improve the machining accuracy, a novel approach of grinding with large-size and fine-grained cup wheel was suggested. This method has many advantages: a full line contact of the cup wheel against the work-piece can be realized, the wheel shape can be well maintained, and the wheel wear is uniform and can be compensated just by feeding along its axis. Moreover, a mathematical model was developed to analyze the grinding motion and the grinding principle deviation. Two hydrodynamic seal rings with wavy surfaces used in reactor coolant pumps were taken as examples to verify the practicability. It is expected to be an efficient method to manufacture more complex asymmetric curved surfaces with high shape accuracy and high surface quality.