Viscosity Question
Viscosity Question
(OP)
I have a gearbox at my plant which is running hot.
I cleaned the heat exchanger on the oil cooler and have good flow on the water and on the oil sides.
I noticed the oil in the box is viscosity grade 220 and then consulted the OEM literature which recommends VG 320.
My questions is: Would using a lower viscosity oil than recommended cause the box to run hotter?
Thanks for your help.
I cleaned the heat exchanger on the oil cooler and have good flow on the water and on the oil sides.
I noticed the oil in the box is viscosity grade 220 and then consulted the OEM literature which recommends VG 320.
My questions is: Would using a lower viscosity oil than recommended cause the box to run hotter?
Thanks for your help.





RE: Viscosity Question
RE: Viscosity Question
Is that wrong?
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RE: Viscosity Question
electricpete,
Your statement is essentially correct when using a higher speed gear box. The reason for my statement is for that type call out I assumed a large slow speed box that depends on the tackiness of the oil to track the gears, no auxiliary pumping.
RE: Viscosity Question
You might check some other factors which can cause overheating.
A high oil level can cause overheating.
Overloading can cause overheating.
Misalignment or gear problems might cause overheating?
You might look at vibration data and lube oil samples to help diagnose the gearbox as well as comparing the operating conditions to the design conditions.
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RE: Viscosity Question
Although the main functions of a gear lubricant are wear prevention and friction reduction by providing a film between mating surfaces, in the case of enclosed gears the lube also has the function of carrying away the heat developed by friction.
This function requires greater thermal conductivities than supplied by conventional oils.
I was told the AGMA 250.2 standards describe the correct selection and provides a classification of gear lubricants.
RE: Viscosity Question
RE: Viscosity Question
Beside all what has been said consider also the practicality of an external oil cooler, the oil circulated with a small gear pump.
RE: Viscosity Question
"What You Need to Know When Selecting Gear Oils"
http:
"Lubrication Selection for Enclosed Gear Drives"
http://ww
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RE: Viscosity Question