According to the qualitative analysis of the reliability of the front transmission assembly system of an equipment, the failure of the bevel gear has a great impact and is prone to structural damage caused by contact fatigue. Therefore, the reliability analysis of the spiral bevel gear in the front transmission assembly system is carried out. In the front drive assembly system, the material of spiral bevel gear is 20Cr2Ni4A, the basic parameters of spiral bevel gear are shown in Table 1, and the material parameters of spiral bevel gear are shown in Table 2.
Parameter name
Parameter value
Density / 10 (4 kg · M-3)
7.83
Young’s modulus / 10(11)pa
2.07
Poisson’s ratio
0.29
Tensile strength / MPa
1175
Yield strength / MPa
1080
Material parameters of spiral bevel gears
In mass processing, because various factors such as environment and operation are independent of each other and have no dominant tendency, it is considered that its distribution obeys the normal distribution. In the reliability model of spiral bevel gear contact fatigue, there are many factors affecting the reliability. In order to more intuitively verify the correctness and effectiveness of the proposed second-order reliability analysis method based on random interval mixed uncertainty, in this case, only tooth width B is taken as the random variable, speed n and torque T are taken as the interval variables. In the process of gear design, because the tooth width coefficient is 1 0/3. 5~1. 0/3. A value within the range of 0. For the tooth width of spiral bevel gear, there is a tolerance range. It is assumed that the tolerance of tooth width is ± Δ B (generally B follows normal distribution), and its statistical parameters are: μ b =b ˉ，σ b = Δ b 3； The selection of simulation working condition affects many aspects of the design performance of spiral bevel gear. Due to the instability of torque and speed in the simulation working condition, the design simulation working condition here is n ± Δ n、T ± Δ T. Then its numerical distribution is shown in Table 3.
