Effects of Increasing viscosity of oil
Effects of Increasing viscosity of oil
(OP)
Hello all,
We have only just discovered that our operators are filling a 320 oil into a gear box of planetary type , instead of the 220 oil recommended, what will be the effects of this?, the thought here is that no real damage will occur, in fact it may be better, I have my reservations , please enlighten me on this issue.
Thanks
We have only just discovered that our operators are filling a 320 oil into a gear box of planetary type , instead of the 220 oil recommended, what will be the effects of this?, the thought here is that no real damage will occur, in fact it may be better, I have my reservations , please enlighten me on this issue.
Thanks





RE: Effects of Increasing viscosity of oil
I have increased lubricant viscosity due to higher than original design running speed to provide sufficient film thickness to the gears/bearings.
Ken Culverson
RE: Effects of Increasing viscosity of oil
most gearboxes can run quite well on "one ISO VG grade lower" then recommended, the effect on the lubricating film thickness is related to the square root of the viscosity at operating temperature. in other words: if you want a lubricating film twice as thick, you need four times the original viscosity. be aware also that + or - 10 deg C in operating temperature has a far more profound effect on viscosity then changing from one ISO VG grade to the next higher or lower has.
in your particular application ISO VG220 is already rather viscous, most planetary gears require a lubricant in the order of ISO VG 100 - ISO VG150 since usually planetary gears, due to their design are not that heavy loaded, so ISO VG320 might be overdoing it quite a bit, unless when the gears run very slowly.