Gearbox as a high-speed train to transmit torque, driving the vehicle moving the key components, the safety and stability of the direct impact of EMU vehicle operation reliability. However, due to the complexity of its structure and its operating conditions are relatively poor, gearbox system in recent years, many failures, such as oil leakage (oil), oil temperature is too high, bearing pitting, box cracks and so on. These problems seriously affect the operation of high-speed train safety.

The main function of the gear box box is to support and contain the normal operation of the transmission parts, vibration, noise reduction, as shown in Figure 2-3. High-speed gear box box is characterized by dynamic load, the impact of large, high degree of integration, to withstand the outside world, the structure of complex and compact, light weight, heavy heat, heavy temperature, high temperature, serious impact on gear and bearing life , How to effectively handle the above problems is to improve the performance of gearbox and the life of the key.

In the transmission system, the gearbox is subjected to the motor torque acting under the traction and braking conditions, and at the same time, it is subjected to the line disturbances transmitted by the axle. Therefore, it is necessary to clear and decouple these periodic loads and the source of the random load. And size. A large number of experiments show that the gear box box force analysis, should analyze the two kinds of load, one is the torque load, the other is the vibration load. Torque load from the motor traction and braking, vibration load mainly from the wheel and rail contact with the disturbance.