The sand washing machine often affects production due to motor failure during use. The main failure phenomena are:
1. Overhaul of stator and rotor core failures
Both the stator and the rotor are laminated with mutually insulated silicon steel sheets, which are the magnetic circuit parts of the motor. The damage and deformation of the stator and rotor cores are mainly caused by the following reasons.
①Excessive wear of the bearing or poor assembly will cause the stator and rotor to rub together, damage the surface of the iron core, and then cause a short circuit between the silicon steel sheets, increase the iron loss of the motor, and cause the temperature of the motor to rise too high. At this time, use fine files and other tools to remove the burrs, eliminate the short circuit of the silicon steel sheet, clean it up, apply insulating paint, and heat and dry it.
② Excessive force is used when removing the old windings, which will skew and open the stolen slot. At this time, use needle-nose pliers, wooden coconut and other tools to trim, to reset the teeth, and add hard insulating materials such as green shell paper and bakelite between the silicon steel sheets with gaps that are not easy to reset.
③ The surface of the iron core is corroded due to moisture and other reasons. At this time, it needs to be polished with sandpaper, and then coated with insulating varnish after cleaning.
④ High heat generated around the group grounding burns the core slot or tooth part. Use tools such as chisel or scraper to remove the fused deposits and apply insulating paint to dry.
⑤The combination between the iron core and the base is loose, and the original positioning screws can be tightened. If the positioning screw fails, re-drill the positioning hole on the machine base and tap it, and tighten the positioning screw.
2. Overhaul of bearing failure
The rotating shaft is supported by the bearing to rotate. It is the heaviest part and the part that is easy to wear.
①Fault check
Check during operation; when the rolling bearing is short of oil, you will hear the sound of "gulugulu"; if you hear the sound of discontinuous "stalking", it may be that the bearing steel ring is broken. When the bearing is mixed with sand and other debris or the bearing parts are slightly worn, a slight noise will be generated. Check after disassembly; first check the bearing rolling elements, inner and outer steel rings for damage, corrosion, scars, etc., then pinch the inner ring of the bearing with your hand, and make the bearing level, and push the outer rigid ring with the other hand, if the bearing is in good condition, The outer steel ring should rotate smoothly, without vibration and obvious blocking phenomenon during rotation, and the outer steel ring should not retreat after stopping. Otherwise, the bearing can no longer be used. Hold the outer ring with your left hand, pinch the inner steel ring with your right hand, and push hard in all directions. If you feel loose when pushing, it means serious wear.
②Trouble repair
The rust spots on the outer surface of the bearing can be wiped off with No. 00 sandpaper, and then cleaned in gasoline; or when the bearing is cracked, the inner and outer rings are broken, or the bearing is excessively worn, replace the bearing with a new one. When replacing a new bearing, use the same bearing as the original model.
3. Rotating shaft troubleshooting
①The shaft is bent; If the bending is not large, it can be repaired by polishing the journal and slip ring; if the bending is more than 0.2mm, the shaft can be placed under the press, and the bend can be corrected under pressure. The corrected shaft the surface is cut and polished with a lathe; if the bend is too large, a new shaft needs to be replaced.
②Axle journal wear; when the journal wear is not large, a layer of chromium can be plated on the journal and then ground to the required size; when there is more wear, the journal can be surfacing and then cut and polished on the lathe; If the journal is worn too much, turn 2-3mm on the journal, then turn a sleeve, put it on the journal while it is hot, and then turn to the required size.