Is the gear noisy?

Are the gears noisy?In fact, under normal circumstances, gear noise is not big, low noise, and if your product is noisy, these factors may be affected, you have to find a corresponding solution to deal with it!

Gear noise:

Gear noise should be more accurately calledgearTransmission noise, its sound source is the mutual impact in the product meshing transmission.

The impact in gear transmission is mainly caused by periodic changes in gear meshing rigidity, transmission error and installation error.

The degree of noise generated by the gear transmission under different loads is different. The reason is that the amount of deformation of the gear teeth under different loads is different, and the degree of impact is different.

helical gearThe meshing rigidity depends on the total length of the contact line of the meshing gear teeth, so the change of the number of meshing teeth at the same time has little effect on the meshing rigidity.

When the gear transmission is running under no load, the main influencing factors of transmission noise are gear machining error and installation error, including tooth profile error, tooth pitch error, ring gear runout, gear axis degree, parallelism and center distance error after installation, etc. .

Of course, these errors also have an impact on the transmission noise of the transmission device running under load.

1. The tooth profile 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.The concave tooth profile is unacceptable and should be avoided as much as possible during processing.

2. The pitch error is a random error, and the noise frequency generated is different from the meshing frequency, which will not increase the noise amplitude at the meshing frequency, but will broaden the bandwidth of the gear noise audio frequency.

3. The non-parallel projection of the axis on the pitch plane, the tooth direction error and the deformation of the shaft under the transmission load will shorten the contact length of the gear teeth in the tooth width direction, resulting in a decrease in the meshing rigidity, resulting in transmission errors and products The periodic change of transmission meshing rigidity is another cause of noise, which has a greater impact on helical gear transmission.

Effective ways to control gear noise:

1. Gear trimming

The impact in gear transmission is the main cause of noise. Therefore, eliminating or reducing the impact in transmission is an effective way to reduce noise.The use of gear trimming can effectively reduce the impact in the transmission, thereby controlling the transmission noise.

2. Control the quality of raw materials

High-quality raw materials are a prerequisite for the production of high-quality products. The most used materials are 40Cr and 45 gears.

Regardless of the way, the raw materials must undergo strict chemical composition inspection, grain size determination, and purity evaluation after they arrive at the factory.The purpose is to adjust the heat treatment deformation in time to improve the quality of the tooth profile processing.

3. Control the accuracy of gears

The basic requirements of gear accuracy: after verification, the product accuracy must be controlled at GB10995-887~8, the line speed is higher than 20m/s gear, the pitch limit deviation, the radial runout tolerance of the gear ring, and the tooth direction tolerance must be stable Achieve level 7 accuracy.In the condition of reaching the 7-level precision tooth, the tooth part must be reversed and the tooth root boss must be strictly prevented.

4. Prevent heat treatment deformation

After rough machining, the tooth blank becomes a fine forging, which is normalized or quenched and tempered.

5. Adopt other materials and heat treatment and surface treatment methods

6. Civilized production

More than 30% of gear transmission noise is caused by burrs and bumps.

High-quality gears have the characteristics of precise and stable transmission, high speed, long life and low noise. Regarding their noise problems, if you have any unclear points or related processing requirements, you can consult EP for free.