Trapezoid groove mosaic structure for blades and upper canopy of water turbine model runner

Abstract

The invention provides a trapezoid groove mosaic structure for blades and an upper canopy of a water turbine model runner. An original rectangular groove assembling type structure adopted in the upper canopy and the blades of the water turbine model runner is changed into the trapezoid groove mosaic structure, the other structures are not changed, the blades and the upper canopy are tightly held and combined through screws, and therefore trapezoid grooves can make tight contact with side faces of trapezoid protruding blocks. The trapezoid groove mosaic structure is simple, convenient to operate, safe and reliable, machining problems are solved, the assembling difficulty is lowered, the problem that matching gaps exist between rectangular protruding blocks of the blades and rectangular grooves of the upper canopy is thoroughly solved, and the phenomenon that because the gaps exist in the flow passing surface of the upper canopy after assembling, the flow passing surface of the upper canopy is not smooth is eliminated.

Description

Technical field: [0001] The invention relates to a mosaic structure of a water turbine model runner blade and an upper crown trapezoidal groove. Background technique: [0002] In the design of the mixed-flow and reversible turbine model runners, an assembled structure is adopted between the upper crown and the blades: multiple rectangular grooves are processed on the upper crown flow surface according to the number of blades, and the upper crown part of the blade is attached with the upper crown. The rectangular bumps corresponding to the grooves, when assembling, install the blades in the rectangular grooves of the upper crown, and tighten them tightly with bolts, so as to ensure the correctness and accuracy of the relative positional relationship of the blades of the model runner. Therefore, the machining accuracy of the rectangular groove on the crown and the rectangular bump on the blade will determine the manufacturing quality of the entire model runner. Since the recta...

AI Technical Summary

Problems solved by technology

Therefore, the machining accuracy of the rectangular groove on the crown and the rectangular bump on the blade will determine the manufacturing quality of the entire model runner. Since the rectangular groove on the crown and the rectangular bump on the blade are spatial polyhedrons, it is difficult to Measuring and controlling the fit size depends entirely on the accuracy of the CNC equipment itself as a guarantee. Once the processing is completed, it is a fact of inheritance: a small fit gap or interference will increase the difficulty of assembly; a large fit gap will affect the assembly accuracy and cause excessive crowning. There are gaps on the flow surface and it is not smooth, and the manufacturing quality of the model runner is relatively random, which may even have an adverse effect on the model test

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