Gearbox Oil Varnish and Oil Selection

[matt.oakley]

Has anyone experienced oil varnish issues in their ACC fan drive gearboxes? A few of our plants with wet cooling towers have OE with premature gearbox failures due to overheating and varnish. Damage observed included bearing failures and excessive gear wear/spalling. Also would like to know what type of oil is specified in ACC gearboxes, and if anyone has switched their oil type to address any problems. The fix applied to our cooling tower gearbox failures involved replacement with larger gearboxes, switched oil type from polyalphaolefin (PAO) to polyalkylene glycol (PAG), and installed filtration units.

[bdelcorio]

Yes have experienced gearbox failures on ACC due to lubrication failure. Only get about 3000 hrs between that and get a lot of varnish. OEM says 4000 hours but cannot make that. Our gearboxes run high oil temps since oil coolers are under sized. Do get not expected oil life, so for now have shortened oil change out interval. Looking to install some type of filtration.

[bdelcorio]

Yes have experienced gearbox failures on ACC due to lubrication failure. Only get about 3000 hrs between that and get a lot of varnish. OEM says 4000 hours but cannot make that. Our gearboxes run high oil temps since oil coolers are under sized. Do get not expected oil life, so for now have shortened oil change out interval. Looking to install some type of filtration.

[matt.oakley]

Thanks for the feedback. I have a few follow up questions so I can better understand your situation. What type of gearboxes do you have and what is the design of the oil coolers? Do you know what type of oil you are using? Are you looking at a permanent filtration system or using a mobile filtration cart? If you’d rather respond directly, I can provide my contact information as well.

[Author]

Posts