Gear An Effective Way To Reduce Noise

Influencing Factors of Gear Transmission Noise

Gear noise is more accurately referred to as gear drive noise, the sound source for the gear meshing drive in the collision. The impact in gear transmission is mainly caused by the periodic change of gear meshing rigidity and the error of gear transmission and installation error.

The Influence of Periodic Change of Gear 's Meshing Rigidity on Transmission Noise

The change of the meshing rigidity refers to the change of the load of the meshing gear due to the difference of the number of simultaneous meshing gears in the gear transmission, and thus the change of the tooth tooth deformation amount. In the spur gear, the number of simultaneous teeth on the meshing line varies between 1 and 2, and the torque of the drive is approximately constant. Therefore, when a pair of teeth are engaged, all the loads are applied to the pair of teeth, the deformation of the larger; when the two pairs of teeth when the load, the load by the two pairs of teeth together, the load on each pair of teeth minus Half, this time the amount of tooth deformation is small. This results in the fact that the actual meshing point of the gear is not always at the theoretical engagement of the meshing line, and the resulting transmission error causes the movement of the output shaft to lag behind the movement of the input shaft. When the main and passive gears enter the meshing outside the meshing line, the instantaneous difference in speed causes a collision at the crest of the driven gear. The degree of noise produced by the gears under different loads is different because the amount of deformation produced by the gears under different loads is different and the impact degree is different.

2 gear transmission error and installation error on the transmission noise

When the gear drive is running without load, the influence factors of transmission noise are gear machining error and installation error, including tooth error, pitch error, ring gear beating, shaft stiffness of installation gear, parallelism and center distance error The Of course, these errors also affect the transmission noise of the drive under load. ① The tooth error will cause the same transmission error and noise as the meshing frequency, which is the main cause of the noise component at the meshing frequency. Concave tooth profile is unacceptable, the processing should be avoided. ② The pitch error is a random error, the noise frequency is different from the meshing frequency, and the noise amplitude at the meshing frequency is not increased, but the bandwidth of the gear noise is widened.

③ The unevenness of the projection of the axis on the plane of the plane, the error of the tooth and the deformation of the shaft under the transmission load will shorten the contact length of the teeth in the tooth width direction, resulting in the decrease of the engaging rigidity, the resulting transmission error and gear transmission The periodic variation of the meshing rigidity is another reason for the generation of noise, which has a greater effect on the helical gear transmission.

An Effective Way to Control Gear Noise - Gear

Experiments show that when the teeth into the meshing and out of the meshing area, due to the tooth error and load deformation caused by angular velocity pulsation changes in the impact and noise, this phenomenon, even the high precision gears are also very high Difficult to avoid. In the past, people always strive to make the accuracy of the teeth as close as possible to the theoretical tooth profile, practice has proved that in the high-speed high-power transmission, in line with the theoretical tooth-shaped teeth but can not meet the requirements. The use of tooth top and tooth root repair edge, tooth to repair, effectively improve the gear teeth meshing performance, reduce gear noise. The impact of gear transmission is the main cause of noise, so to eliminate or reduce the impact of gear transmission is an effective way to reduce noise. The use of gear repair can effectively reduce the impact in the gear transmission, thus controlling the gear transmission noise, so the method in the gear drive design has been widely used. Gear profile is more effective in some situations than to improve gear accuracy.