Research On Tapping Technology Straddling Between Rotors And Blades Of Turbine

In the steam turbine, in order to make the heat energy and kinetic energy of steam can be efficiently transformed into mechanical rotation of the rotor. The rotor and blades must be firmly connected into a whole. The connection of the blades and rotor of turbine is usually through fixed thread hole between the rotor and blades. The technology need drilling and tapping hole straddling between rotors and blades. The screw hole is a blind hole. According to the optimization of process requirements, the technology need to use single handle tap and complete the straddle tapping in the depth of 65 mm. Firstly, standard straddle tapping experiment was finished. The taps’ materials and models were decided according to the analyzing tap wear status. Then the torque model was established based on a theoretical analysis of straddle tapping process characteristics. Based on ABAQUS finite element software, a simplified model of straddle tapping was built and it greatly reduces the computational finite element analysis. A new method to improve the reliability and stability of the saddle tapping process systems was proposed. It’s an optimization of joint torsional force and eccentric force by changing geometric parameters and processing parameters of saddle taps. After the above work, taps static stress analysis and dynamic analysis with the optimal parameters combination to verify the reliability of the tap. Eventually the parameters of rake angle 6 °, helix angle 35 °, speed 25 r / min was selected. Finally tapping experiment was finished with the optimal straddle tap and it obtained better results. The research provides a valuable theoretical and experimental basis for the actual tapping.