The meshing impact of the gear teeth in the double arc gear transmission. The impact force is considered in consideration of the change in the stiffness of the teeth of the teeth. In the above analysis, only the impact caused by the decrease in the number of meshing points is considered, and it is assumed that the meshing point is out of the meshing line before the coefficient is in equilibrium. In fact, even without considering the effects of system torsional vibration, the system is not in equilibrium until a meshing point is disengaged, in terms of the change in gear stiffness. That is, changes in the stiffness of the teeth near the piercing end will have an effect on the impact of the biting process. Experimental studies have shown that the deflection of the circular gear teeth under the concentrated load is very different in the direction of the tooth length. The tooth end deflection is more than twice the middle deflection value, so the gear tooth stiffness curve is in the shape of a bathtub. Because the influence factors of stiffness are complex, and the existing theory can not provide the calculation method of arc gear stiffness, this paper will analyze the impact problem by the variation of gear tooth stiffness given by the test results.
The gear tooth stiffness is almost the same in the middle of the tooth width; there is a significant rise and fall change near the two ends; the curve is symmetrical to the midpoint of the tooth width. The curve is simply expressed on the premise of maintaining the characteristics of the original curve. The average stiffness and the tooth end stiffness of the middle of the tooth width are respectively caused by the double circular arc gear. The distribution of the meshing point on the meshing line varies with the gear parameters. A more unfavorable situation is discussed. At the meshing point, before the engagement is withdrawn, there is an impact between the teeth due to the change of the tooth stiffness near the engaging end, and thus the impact of the two impacts of the additional impact load acting on the teeth during the engagement is continuously effected. The impact dynamic load of the impact shock tends to a limit value when the gear speed is extremely high, acting on the average load of each meshing point. There is an impact during the process of biting and engaging the double-arc gear teeth. As an important part of the additional dynamic load of the gear, the impact load will have an adverse effect on the bending strength of the gear teeth. The cause of the impact is the presence of an effective weekly difference. It depends not only on the precision of gear manufacturing, but also on the deformation of the gear teeth. Increasing manufacturing precision and proper shaping of the teeth at the end will help reduce the impact of the impact. The essence of the impact is the physical factor - the excitation caused by the change in the meshing stiffness. Even in the ideal gear without any error, the impact is inevitable.