The gear box is an important part of the wide application in mechanical transmission. When a pair of gears mesh, there is inevitably a tooth pitch, tooth shape and other errors. During the operation, an meshing impact will occur and a noise corresponding to the gear mesh frequency will occur. Frictional noise occurs between the tooth faces due to relative sliding. Since gears are the basic part of the gearbox drive, reducing gear noise is necessary to control gearbox noise. In general, the causes of gear system noise mainly have the following aspects:
1. Gear design. Improper parameter selection, too small coincidence, improper or no shape modification, and unreasonable gearbox structure. In the gear processing, the base section error and the tooth profile error are too large, the flank clearance is too large, and the surface roughness is too large.
2. Gear train and gearbox. The assembly is eccentric, the contact precision is low, the parallelism of the shaft is poor, the rigidity of the shaft, the bearing and the support is insufficient, the rotation precision of the bearing is not high, and the gap is not good.
3. Input torque in other aspects. Fluctuation of load torque, torsional vibration of the shafting, balance of the motor and other transmission pairs, etc.