What factors will cause noise during gear transmission

Gears are easy to wear parts in various machines. In the process of use, you can often hear the rattling noise. This is due to the continuous impact and vibration on the gear teeth when the gear is engaged with Guo Chenzhong.

The theory of involute gear transmission shows that after the base circle of the equivalent gear is determined, its transmission ratio is constant, and the transmission remains connected and stable. However, in fact, there must be errors in the processing and installation of the gear, and the tooth profile surface cannot be an accurate involute surface, and deformation will be caused due to the force in the meshing process. These are the reasons for the noise. Without any machining and installation errors, the change of the relative speed of the two gear teeth will cause the change of the friction between the tooth surfaces, resulting in pulsating impact force and pitch line impact force. For ideal gear transmission, the pitch line impulse is the main reason for generating gear contrast.

Secondly, the gear must transmit force and torque in the transmission process. The right contact stress on the tooth surface and the bending stress on the gear teeth will cause elastic and plastic deformation after being stressed. The amount of deformation will change with the size of the stress. When the stress and deformation on the tooth surface change alternately, it will also cause vibration and noise.

In addition, because the machined tooth profile cannot be a theoretical involute, there must be errors, and the tooth pitch cannot be equal, it is impossible to keep constant rotation during transmission. Whether the driving gear or driven gear is rotating, it accelerates and decelerates from time to time, and the tooth surface is subject to pulse type additional dynamic load. The additional dynamic load caused by force deformation and machining error is collectively referred to as meshing impulse. The vibration and noise generated during gear transmission are caused by the meshing impulse, among which the noise produced by tooth profile and pitch error is more prominent.

In fact, the gear noise in the gear transmission mechanism can also be caused by some other reasons, such as the change of the load of the transmission link, the runout of the drive shaft, the unstable rotation of the motor, etc., which will cause the impact between teeth and also cause noise. Therefore, the gear noise in the gear transmission mechanism is a kind of noise with complex factors.