Gearbox Lubrication
Gearbox Lubrication
(OP)
How do I decide how much oil each gear and bearing needs in a gearbox?
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RE: Gearbox Lubrication
RE: Gearbox Lubrication
Many thanks for your response, however the initail contact with the Technical Department of the oil supplier resulted in the following reply :
'Oil specifications and quantities are usually defined by gearbox manufacturers themselves. We then offer our lubricants that meet these specifications and requirements'
I am chasing up via another Oil Supplier (Kluber) who seem a bit more switched on and have asked for details so I will see how that goes. I used to use general rules for quantities (for heat transfer) many years ago but these were based on old fashioned mineral oils whereas modern PAO's have better characterstics. If anyone knows how much oil per kW or HP of transmitted load per gear mesh and for each bearing please let me know.
Many thansk to all.
Ray
RE: Gearbox Lubrication
RE: Gearbox Lubrication
Sorry but we may be at cross purposes, I am aware of the low requirement for the EHD lubrication, however I have to shift a total of nearly 100kW of generated heat from the box, and it is this that concerns me most. I used to use 0.4 litres/minutes per 10kW of transmitted power but these are out of date figures based on mineral oils.
Anyone have any more up to date figures for heat transfer from gears and bearing please, preferably utilising a fully sythetic PAO or similar?
Many thanks
Ray
RE: Gearbox Lubrication
the specific heat of paobased gear oils is not much different from mineral oil based gear oils, so, when operating temperatures and viscosities are the same about the same oil temperature would be the result in a given application. that also means that the original figures you quoted may still be appropriate.
often it is said that gears run cooler when using PAO based lubricants. that usually is the result of the more temperature stable viscosity of pao-based lubricants which means that you might be able to go from an ISO VG220 oil to a ISO VG 100 or 150 - and thus generate less heat due to less churning power needed for the lubricant, not because they have better coolant characteristics.
RE: Gearbox Lubrication