The speed increasing gearbox, one of the important components of the wind turbine, operates under high stress and harsh environment. The key components of its bearings and gears must be effectively lubricated and protected. The lubricating oil must be equipped with the best efficient filtration to ensure the normal and effective operation of the gearbox and fan. The speed increasing gearbox, one of the important components of the wind turbine, operates under high stress and harsh environment. The key components of its bearings and gears must be effectively lubricated and protected. The lubricating oil must be equipped with the best efficient filtration to ensure the normal and effective operation of the gearbox and fan.