high noise level in a parallel shaft speed multiplier 1

[lombardo]

How can i reduce the noise level in a parallel shaft speed multiplier acoppled between a 700 hp electric motor and a srew ammonia refrigeration compressor, im using the best high film synthetic lubricant, the temperature is ok, but the noise level is 102 dB, what can i do?

 

[shopguy]

O.K.
I suspect that the reason that you are not getting a lot of responses to this is because gear noises are caused by just about any part of the entire drive assembly. A lot of times, the gears aren't the cause of the problem. Resonance can be a major factor. Sometimes the box itself is resonating.
If the gears are out of balance, or if the ratio happens to be a harmonic of any of the other turning / vibrating / pulsing parts. . ., all of these can be causing problems. The American Gear Manufacturers Association (AGMA) has a specification on gear noise. If you contact them, you can probably purchase a copy from them. It may provide you with some insight.

 

If the noise is definately coming from the gearbox then there is not much you can do without checking the gears. Noise originates from transmission errors so these must be minimised. Take the inspection cover off and check for wear or damage, especially in the roots and on the tips, if none you, may try soundproofing with a cover.
Also check everything is in line.

 

[ajaymule]

Yes u can do the inspection of gear wear by opening the cover.In additon to that u can try out molybldenum di sulfide additive in the syn. oil with manufacturers recommendation.Feel free to contact at ajaymule@hotmail.com

 

[GregPerry]

Check with the gearbox manufacturer what noise level is normal. If yours is abnormal why not do some vibration analysis and phase analyis to pinpoint any possible problems.

 

[beloka]

Before you start spending money I suggest you make sure you have the detail history on the complete installation: Has the noise been there since the original installation??; If not what has changed ??; Is the present installation still installed/adjusted correctly??. Has the drive been setup/aligned for running at normal operating temperatures??. Was a complete drive train torsional analysis part of the original design??. If it is a new installation the equipment may be under warranty. Check any auxilliary equipment that can generate noise such as oil pumps, relief valves.
Detail vibration analysis may be needed.