| The Three Gorges hydraulic turbine runner is the greatest size interflow type runner now, in the world, the weight is nearly 500 tons, the maximum outer diameter is about 10 meters, its leaf blade thickness amounts to 300 millimeters, occupies the world first place. The hydraulic turbine runner consists of the top crown and the lower ring through the leaf blade which are welded together and generates power. It is the heart of the hydraulic turbine. therefore its quality is very important. The top crown weights 115 tons/The gross weight 180 tons, the external dimensions Φ8.4×Φ1.6×3M,formed like a thin-wall horn, the lower ring amounts to 81 tons, the external dimensions Φ10×Φ9.4×2.3M formed like a thin-wall tube. The material quality is ASTM A743M (ZG00Cr13Ni4Mo) the austenite stainless steel. First, because of the shape, it is difficult to clamp and turn over the piece. Second, because of the good toughness of the piece, it is easy to have the collection filings lump in the process to produce. The cutting tool selection is very important. Third, their spool thread section outline is composed of the basic straight line, the circular arc and some coordinates, which brings difficulties to machining and measuring, Fourth, their walls are thin, the diameter is about 67 thicker than the wall thickness, and is easy to distort. This brings the difficulty for the transportation and the processing. The article is intended to elaborate the solution theoretically and pragmatically. The main achievements and characteristics of this research are as follows:(1) In view of the enterprise machine-finishing craft condition and the processing ability, had determined ponder principle for the heavy casting and the... |
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