I have had problems in the use of bearing type Deep Groove Ball Bearings with serial number 61 940 M brand ZWZ used for spindle lubrication system coupling with air mixed with oil.The problem that occurs is when rotated with a speed of 1000 rpm on the bearing temperature can reach 90 degrees. I want to ask what the maximum temperature while working and whether lubrication with wind and oil mixing system effectively.thanks for the advice to be given to me.