I need to make thermal analysis for new gear box design to get the answer: do I need additional heat exchanger for that gearbox? I would like to get a help as a source for engineering calculations. Of course, I have already calculated power losses in bearings with TIMKEN software. I don’t have enough information how to estimate oil churning losses and other power losses in gearbox. And finally, what the best modern calculations methodology you can suggest me for temperature balance? Thanks.