types of gear box and how to reduce the noises in them

Manufacturing plants and other work environments can be noisy.Multiutde of gears running in unison can cause a lot of noise. The pumps, motors, conveyers, compressors, and fans,
are all potential sources of noise. about 90 decibels of noise is produced when one stands only ten feet from a standard double-reduction speed reducer.
The gearbox noise could be caused by different reasons:
A speed reducer can be taken as an example. The gears, bearings, shafts, cooling devices and lubrication, even its housing starts to vibrate when the reducer operates. pressure pulsations in the surrounding air produced due to this vibration is detected as the noise by human ear. excessively noisy vibrations results when many such devices operates in sync. most noise within a

gearbox emanates from vibration generated by gear mesh action. The level of noise is dependent on :
- Gear tooth geometry.
-Lubrication
-Finished gear tooth surface


transmission load and motor speed are also factors influencing the level of noise. Sometimes switching from spur type gearing to a helical gearing may reduce the noise problem significantly.

For more details, visit :
http://swepcousalubesite/lubepdf/TG_199705.pdf
http://homel.vsb.cz/~tum52/publications/...5_ch47.pdf