Influence Of Gear Form Grinding Process Parameters On Grinding Temperature And Test Study

Gear form grinding is a kind of finishing approach which is widely applied to hard tooth surface. If the grinding process parameters are selected inappropriately in the gear form grinding process, the instantaneous high temperature produced in grinding contact zone would cause tooth surface thermal damage, and even would lead to the breakdown of the gear under serious condition. In order to prevent the tooth surface from grinding burn, it is very necessary to analyze the change of tooth surface temperature and thermal stress with time. Therefore, gear form grinding temperature field and thermal stress field are studied in detail through theoretical calculation, finite element method, computer simulation and grinding burn experiment. What have been mainly finished in this thesis are as follows.1. Based on the single abrasive cutting process, gear form grinding principle and how heat was generated and transferred in grinding zone were analyzed. According to the moving heat source theory, applications of four kinds of heat source models were discussed. Convective heat transfer coefficient of grinding fluid was established in wet grinding. The grinding zone heat distribution was analyzed theoretically, and the calculation formula was deduced between gear form grinding process parameters and grinding zone heat distribution.2. Three kinds of boundary conditions were analyzed about gear form grinding temperature field. Based on the finite element method, finite element mathematical model was deduced to the tooth surface temperature field. Using the thermal analysis module of software ANSYS12.0 and writing the language of APDL, the finite element simulation of 3D transient temperature field has been done to the form grinding tooth surface, and the tooth surface temperature field distribution was obtained under the dry and wet grinding conditions. Besides, the influence of two heat source model on grinding temperature was analyzed. The change law of tooth surface temperature was analyzed by changing the gear grinding process parameters(grinding wheel linear velocity, grinding wheel feed velocity and grinding depth).3. Grinding residual stress was discussed in this paper, and the generating reason and manifestation pattern of gear grinding thermal stress were analyzed. The simulation of 3D thermal-mechanical coupling has been done about the tooth surface thermal stress by the indirect way provided by the software ANSYS, and the thermal stress distribution was obtained as well as its changing characteristics with grinding time.4. Gear grinding burn experiment was been done by using NC gear form grinding machine tool. According to the some different grinding process parameters, the spur gear was grinded. The morphology characteristics of tooth surface grinding burn and the normal tooth surface were observed by using scanning election microscope. The rationality of temperature field simulation was verified indirectly by these results.According to theoretical analysis and calculation of the tooth surface grinding zone heat transfer and distribution, and finite element simulation to the transient temperature field and thermal stress field of tooth surface, and gear form grinding burn experiment. Finally, the fundamental law of gear grinding temperature and thermal stress were acquired. The result has important application value in predicting the tooth surface grinding damage area and how to select gear grinding parameters appropriately.