Research On Key Technologies Of In-situ Laser Measurement Of Steam Turbine Blades

As the main component of ocean voyage,steam turbine provides electric energy for thousands of households and they are widely used in the metallurgical industry,ocean exploration and other fields.It’s very important in China.The measurement results of the threedimensional shape of the key parts of the turbine blade determine whether it can work normally.The detection of steam turbine blades has always restricted the development of manufacturing enterprises in China.First,the three coordinate measuring machines currently used for steam turbine blades,especially large steam turbine blades,take up a lot of space,which is not only uneconomical to a certain extent,but also wastes workshop space..The second is the low detection efficiency.Enterprises can only carry out small batch testing,in view of the above problems,this paper for the purpose of using small measuring machine and large batch testing in a short time,this article develops and designs an on-site laser measuring machine for steam turbine blades,which adopts a vertical three-coordinate structure and is equipped with a laser sensor,so that it can perform non-contact measurement of objects.The measuring object range can also be increased,for example,flexible objects and free-form surfaces can be scanned.Not only has a small footprint,good operability,but also high measurement efficiency.With the support of a horizontal project of a blade factory,we independently designed and built an experimental platform for a laser measuring machine for steam turbine blades,and carried out research on key technologies for on-site laser measurement of steam turbine blades.The content of this topic is as follows:(1)Structure design and software development,for the turbine blade,combined with the principle,using the lk-g150 of KEYENCE company as the experimental equipment,and a fixture is designed with Solid Works software to fix the laser displacement sensor.Aiming at the data collection problem of the laser displacement sensor,using the dynamic link library provided by KEYENCE,based on Visual Studio C#,a software that can set parameters and collect data is developed.The laser measurement data acquisition system obtained through programming can quickly and efficiently collect,measure and save measurement data.(2)Build a steam turbine blade measurement system platform and motion test experiment.The hardware composition of the 3D measuring machine system is analyzed and determined.The hardware system includes a precision positioning platform,a laser displacement sensor,a servo driver,a motion control card and a grating displacement sensor.Analyze and design the control software execution process.Based on the Visual C++ environment,a motion control software is designed according to the control execution process.Finally,set up a steam turbine blade measurement system platform,and conduct motion test experiments,and conduct motion accuracy and stability experiments on Y-axis and Z-axis respectively.From the performance of the measuring machine,we can see that the research machine can move well,and has good repeatability.(3)Use finite element software to perform finite element simulation analysis on Y-axis and Z-axis with ANSYS.Firstly,the stress and strain of Y-axis,Z-axis and other parts are analyzed when the measured length of Y-axis reaches the maximum.From the simulation results,the measurement error mainly comes from the deformation of the Y axis.In order to better understand the rigidity of the Y-axis,without considering the effect of gravity,when the Y-axis moves to different positions,different loads are applied to the ends of the Y-axis to analyze the stress and strain conditions.In order to verify the authenticity of the simulation,experimental verification was carried out.The verification result shows that the simulation data and the experimental data basically fit together,and the simulation data is true and reliable.(4)The research object of this subject is corrected and analyzed,and the method of compensation is explored.The analysis shows that the deficiency of the research object comes from the change of the Y axis itself,especially the change of the end.In view of this,the rigidity of y-axis is understood,and the correction method is found.Then,this method is applied in practice,and it is found that it is really good.