"24V DC Cooling Fan" timed lubricating. Because ceiling fan bearings, adding a year or two. First remove the fan out of the rotor refueling, then wash with gasoline grease on the bearings, the grease selection of quality, "butter", and table fans, floor fans, box fans, etc., because there is no bearing on the shaft, so regular fuel, the specific time is when the "24V DC Cooling Fan" running off the power to see the rotation of the blades, as that is a little turn a few laps to stop, you need to refuel, grind to a halt if they can rotate more than a dozen laps, then without refueling. Selection of oil and sewing machine oil mixed oil when refueling. Unscrew the motor housing, find two filling holes before adding an appropriate amount of mixed oil. For box fans and no refueling hole "24V DC Cooling Fan", to remove the rotor wash with gasoline after the rotor and stator lubricating grease is added, and finally installed motors.