1.Hazards to motors caused by running sleeves (1) If the bearing runs jacket phenomenon, it will cause the motor air gap is not uniform, improve the no-load current of the motor, reduce the motor power. In general, small and medium-sized asynchronous motor air gap between 0.2-1.5mm, if the air gap is not uniform, it will cause the motor unilateral magnetic tension increase, motor stator and rotor sweep, produce larger vibration and noise, and damage the rotating shaft, damage the bearings, and seriously affect the use of the motor. (2) If the bearing runs inside the sleeve phenomenon, will cause the journal local heat, bearing lubricating oil will also become liquid out due to temperature rise, which will cause the bearing due to lack of oil and burned, serious will appear sweep phenomenon, accompanied by and with violent vibration and noise, the use of the motor effect and life will cause serious impact. 2.Specific solutions to the problem of running sets (1) after the occurrence of bearing running problem, some places may use the surface sealing glue and in the bearing chamber surface sample punching eyes and other methods to repair, but this will assembly bearing concentricity is not high, and the motor disassembly is more trouble, and still damage the bearing caused by motor damage, can not completely solve the bearing running problem. At present, the more commonly used effective way is to fill the set and welding two ways, when running the outer sleeve using the set, when running the inner sleeve using welding, this method not only can guarantee the repair quality, but also can extend the operating cycle of the motor. (2) Actual operation. When the bearing run outer sleeve occurs, the first thing is to disassemble the motor, clean the end cover of the run outer sleeve, measure the depth of the bearing chamber and record the data, and then draw a processing diagram according to the outer diameter size of the bearing. In order to ensure that the machined hole is round and in accordance with the regulations, the end cap of the motor should be fixed on the chuck of the lathe for alignment, and then the bearing chamber of the original bearing should be enlarged to 6-10mm. thereafter, the set should be machined according to the outer ring of the bearing and the inner ring of the bearing, and after completion, the end cap should be set in the way of cold assembly. In the process of setting into the end cover should be noted, the processed set into the metal container immersed in liquid air to be fully submerged, and to pit but ten minutes after inlay, and after that to be cooled at room temperature and processing to achieve the required size. When the bearing runs inside the sleeve, first of all, we must draw a good processing diagram, and then use the way of repair welding. Before welding, the journal should be cleaned, in order to ensure the quality of welding, generally use the symmetric welding method, welding current control at 100A, after welding is completed, to use insulation cotton for insulation, so that the shaft natural cooling. Finally, the shaft is cut and processed according to the processing drawing drawn in advance.