In the Xinjiang region, there is an extremely harsh environment, with extreme heat and cold conditions. The location of the wind turbine often experiences extreme weather such as wind and sand, coupled with the uncertainty and non-uniformity of the wind flow size, resulting in the randomness of the input load of the speed increasing gearbox and the extreme changes in temperature difference, which cause changes in the meshing stress of the planetary gears. Therefore, the operation of wind power growth gearbox and ordinary gearbox has the following significant characteristics:
(1) The wind flow is strong and unpredictable, with significant changes in input load, and the stress situation of planetary gears is complex.
(2) The temperature of the environment varies greatly. At low temperatures, the lubricating oil becomes viscous, which significantly increases the friction force during planetary gear meshing. At high temperatures, the oil film thins and the friction force also increases.
(3) In windy and sandy environments all year round, it is easy to cause sediment of sand particles and other debris in the box, which is more likely to cause wear, cracks, and tooth breakage of planetary gears.
| Parameters | Planetary gear | Solar wheel |
| Number of teeth z | 32 | 25 |
| Normal modulus m/mm | 20 | 20 |
| Pressure angle α/ (°) | 20 | 20 |
| Helix angle β/ (°) | 7.5 | 7.5 |
| Tooth width b/mm | 120 | 120 |
In the wind power growth planetary gear system, the size of the sun gear is the smallest, the speed is the fastest, and the number of teeth meshing is also the highest within the same time. Therefore, the tooth root of the sun gear is more prone to forming cracks. This article will study the time-varying meshing stiffness of solar and planetary gears during operation based on the generation of cracks with different shapes and sizes on the solar wheel. The basic parameters are shown in the table.