Studies On Mechanisms Of High-efficiency Grinding For Gear Materials

To meet the demands of high-speed, heavy-load, low-noise and long-life geardrive, the gear tooth surface need to be developed into higher precision and higherhardness. To fit in with the needs, almost all these high-speed gear adopt the newprocess of high precision, hard tooth surface, tooth profile and longitudinal correctionmodification. Gear grinding machine is the main means and tool to of making highspeed and high performance gear. According to the form principle of involute toothsurface, gear grinding machine can be divided into two categories, form grinding andgenerating grinding. Traditionally generating grinding method which is low-efficientbut requires very highly precise transmission chain is adopted. Compared with it,form grinding which has the advantages of simple structure, high grinding precision,and high work efficiency, is up to the requirement of modern gear manufacturing.With the common materials of gears20CrMnTi, high-efficiency form grindingprocess experiments are carried out. Effects of grinding wheels, grinding fluids andprocess parameters on wheel redress life, grinding force, grinding temperature,surface quality and specific grinding energy are investigated via orthogonalexperiments. Based on these work, a three-dimensional numerical simulation on theheat transfer of gear form grinding is also conducted. In this paper, the main workspecifically includes:（1） The method of gear form grinding, the development status of gear grindingequipments and the research status of grinding heat transfer analysis aresystematically introduced on the basis of literatures.（2）By comparing and analyzing involute gear form grinding and V-groove formgrinding on the grinding principles, the normal grinding depth and grinding length atevery point of involutes are demonstrated. In addition, the similarities and differencesbetween involute gear form grinding, V-groove form grinding and surface grinding areanalyzed as well. Combined the objectives of this research task with the existinggrinding process technology, an experimental program of this topic is proposed.（3） The influence of grinding wheel, grinding fluid on grinding process areinvestigated. And the effects of grinding parameters on grinding force, grindingtemperature, surface morphology of the specimen and surface roughness of thespecimen are also comprehensively investigated. In addition, related auxiliary methods are used to explain these issues.（4） On the heat transfer of gear form grinding, a three-dimensional numericalsimulation is conducted. This approach takes into account the non-linear relationshipbetween physical property parameter of the specimen material and temperature. Andtriangle thermal source model is used to conduct the instance simulation. The resultshows the temperature field of the specimen and the changing course of thetemperature. In addition, the influence of different grinding modulus involute gear onthe temperature field are discussed and analyzed. The contour map of the temperaturedelivered from the simulation, have a certain significance on analyzing the thermalaffected layer depth of the specimen.