By considering the influence of lubricating oil film on heat transfer, the traditional Blok flash temperature formula is improved, and the calculation formula of spiral bevel gear tooth surface flash temperature under elastohydrodynamic lubrication is obtained. The influence of various thermal properties of lubricating oil on flash temperature is studied, and the calculation results of this formula and Joseito flash temperature method are compared with the results of finite element simulation, and the following conclusions are obtained:
1) Under the working condition of 1000kW input power, the maximum temperature of the tooth surface of the spiral bevel gear used in this paper can reach 90.64 ℃ and 91.56 ℃ respectively under the EHL lubrication, and the flash temperatures are 15.28 ℃ and 19.56 ℃ respectively. And with the increase of input power, the flash temperature will also increase.
2) The calculation results of the improved Blok flash temperature method are stable. Under the working conditions of different input power and different types of lubricating oil, the numerical calculation results are very close to the results of finite element simulation, with a difference of about 4%; The difference between the numerical results of Joseito flash temperature method and the results of finite element simulation is about 12%.
3) The flash temperature of spiral bevel gear tooth surface is directly proportional to the thermal conductivity of lubricating oil, and inversely proportional to the density and specific heat capacity of lubricating oil. The influence of the density and specific heat capacity of lubricating oil on the flash temperature is significantly greater than that of the thermal conductivity.