1 Overview

Gear noise should be accurately called gear transmission noise, which refers to the noise radiated by the gear body vibration caused by mutual collision or friction when the meshing gear pair or gear set is in transmission.

2. Gear noise analysis and causes

Gear noise analysis

In order to reduce the noise of the gear transmission system from a design point of view, we should first analyze the types and mechanism of gear system noise.

In the gear system, according to different mechanisms, noise can be divided into acceleration noise and self-sounding noise. On the one hand, when the gear teeth mesh, the gear generates a great acceleration due to the impact and will cause disturbances in the surrounding medium. The sound radiation generated by this disturbance is called the acceleration noise of the gear. On the other hand, under the action of the dynamic meshing force of the gears, the parts of the system will vibrate, and the sound radiation generated by these vibrations is called self-sounding noise.

For open gear transmission, acceleration noise is directly radiated from the impact of gear teeth, and self-sounding noise is radiated from the wheel body, transmission shaft, etc. For closed gear transmission, acceleration noise is first radiated into the air and lubricating oil in the gear box, and then radiated through the gear box. The self-humming noise is caused by the vibration of the gear body through the transmission shaft to cause the support to vibrate, and then is radiated by the vibration of the gear box wall. Generally speaking, self-sounding noise is the main sound source of closed gear transmission. Therefore, the noise intensity of the gear system is not only related to the dynamic excitation force of the gear tooth meshing, but also related to the structure, dynamic characteristics and the transmission characteristics of the dynamic meshing force between the wheel body, the transmission shaft, the bearing and the box body. .