1. Remove the drive pulley (coupling). Loosen the set screw on the drive pulley (coupling), and pull out the drive pulley (coupling) with a puller. If there is no looseness when pulling, you need to add lubricating oil into the set screw hole; if it still cannot be pulled out, you can use a kerosene lamp or alcohol lamp to heat around the outer circle of the drive pulley (coupling) shaft sleeve before pulling it. Pay attention to temperature control during heating to prevent deformation of the shaft sleeve and motor shaft extension. 2. Remove the bearing cover and rotor. Remove the front bearing cover, windshield and rear end cover bolts and screws, and then use a mallet to tap the shaft extension end toward the rear end cover to separate the rear end cover from the base, and then use your hand or The balance crane pulls out the rotor with the back end cover. 3. Remove the front end cover Before disassembling the winding rotor, first lift or remove the brushes, brush holders and lead wires, and then remove the front end cover. 4. Disassembling, cleaning and inspecting the bearing: (1) Disassemble, fasten the inner ring of the bearing with a suitable tension tool and pull out the bearing. (2) Cleaning (except for fully enclosed bearings). Rotate the outer ring of the bearing by hand to make the bearing rotate in gasoline to clean the remaining oil stains, and then use a dry cloth to wipe off the oil and water. (3) Check to see if there are rust and stains between the bearing raceways and the surface of the balls or rollers, and then rotate the outer ring of the bearing by hand to observe whether the rotation is flexible, and finally determine whether the bearing can continue to be used and cannot be replaced by the user .