As one of the main equipment of the coal mining face, the shearer is required to have high reliability in order to ensure the smooth mining of coal. The function of the rocker gear box is to transfer the power to the cutting coal wall of the shearer in the fully mechanized coal face, and the components that often break down have become the weakest link of the reliability of the mechanical part of the shearer, which seriously restricts the output of the fully mechanized coal face.

The rocker gear box is one of the important parts of the cutting part of the shearer. Through the rocker gear box, the power of the cutting motor is transmitted to the drum, so as to realize the coal falling and loading. The rocker gear box of Shearer has the following characteristics:

1) One end of the motor gear shaft is connected with the motor output shaft to transfer the motor power to the second shaft, and the other end is connected with the hydraulic brake.

2) The function of the idler gear group is to transfer the power without adjusting the speed.

3) The traction shaft is connected with the central gear set, which is the second reduction part of the device and bears a large load.

4) The central gear set includes the big gear and the sun wheel, which are respectively connected with the planet wheel of the upper traction shaft and the lower planetary reducer, and the power is finally transmitted to the planet wheel.

5) The traction planetary reducer is a two-stage planetary reducer. The number of two-stage planetary wheels is three and four respectively. The planet carrier and sun wheel are floating structures, which can make the internal planetary wheel bear even force.

Among them, the gear and bearing on the second shaft assembly often fail, the tooth surface pitting and peeling off, tooth breakage and so on lead to shutdown maintenance, which brings serious economic losses to the production. Therefore, this paper mainly focuses on the research of the second shaft gear shaft assembly.