| Wind power generation is a kind of renewable energy production technology,which does not produce greenhouse gases and wastes,it is the most effective use of wind resources,became an important part of global renewable energy.At present,the most widely used wind turbines are all single wind turbine structure.The double wind turbine is a new structure,which has higher wind energy capture rate and higher utilization rate of wind resources.Two pairs of spiral bevel gears are used in the third gear increasing mechanism of double wind turbine,spiral bevel gears meet the design requirements of the gearbox of wind turbine because of its advantages such as large overlap coefficient,strong bearing capacity,high transmission ratio and compact structure.In recent decades,the research on spiral bevel gears in China has achieved fruitful results,the precision machining of spiral bevel gear generally adopt the technology of "milling teeth-heat treatment-grinding teeth",grinding teeth as the last process,the impact on the surface quality of the workpiece is very important.The main research contents of this paper include:(1)Considering the complexity of spiral bevel gear space helical tooth surface,in this paper,firstly study the structure and grinding principle of CNC grinding machine of seven axis and five linkage special for spiral bevel gears,then analyze the influence factors on the grinding surface performance of spiral bevel gears,and establish the mathematical models of grinding force and grinding heat.Aiming at the complex grinding process of spiral bevel gears,compare the advantages and disadvantages of moving heat source loading simulation and single abrasive grinding simulation,consider the impact of grinding consumption on grinding processing,this paper adopt the single abrasive surface grinding for simulation analysis.(2)The ABAQUS finite element software is used to establish the single abrasive grinding model,simulate single abrasive plastic grinding,the stress-strain field and temperature field of grinding process are obtained,analyze the formation process of abrasive dust.(3)Use the single variable method,finite element simulation analysis is carried out by changing grinding speed and grinding depth parameters,investigate the influence of the two factors on grinding equivalent stress and grinding temperature.The influence of grinding wheel speed,workpiece speed,grinding depth and grindingtimes on grinding is analyzed qualitatively by theory,and quantitatively analyze the influence of grinding amount on grinding process by experiment,the experiment and theory verify the reliability of simulation results.(4)Considering the interference between grinding particles during grinding,a three-dimensional simulation model for double-abrasive grinding was established,the grinding process of double abrasive was simulated and analyzed,the surface stress,strain and temperature of the workpiece after grinding are compared between single and double grinding particles,analyze the reasons for the differences,the phenomenon of temperature field interference on materials between abrasive particles is also investigated.(5)Study the causes and influencing factors of grinding residual stress,analyze theoretically the distribution of surface residual stress after grinding.Introduce the measuring method and principle of residual stress in plane grinding of single abrasive,reference experimental data of residual stress measured by X-ray diffraction,verify the correctness of theoretical analysis and finite element simulation results.Considering the influence of cooling condition on residual stress after grinding,the experimental results show that the residual stress of the surface of the workpiece after dry grinding is tensile stress,and the residual stress of the secondary surface is compressive stress;oil-based grinding fluids can alleviate the residual tensile stress generated by the surface of the workpiece after grinding.The above analysis verify the single abrasive grinding simulation has certain reliability. |
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