Main failure symptoms and solutions for crushers

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1. Repair of stator and rotor core faults The stator and rotor are both composed of laminations of silicon steel sheets that are insulated from one another; they constitute the magnetic circuit of the motor. Damage and deformation of the stator and rotor cores are mainly caused by the following factors: 1. Excessive wear of the bearings or improper assembly, which leads to friction between the stator and rotor, resulting in damage to the surface of the cores. This in turn causes short circuits between the silicon steel sheets, increases the magnetic losses of the motor, and leads to excessive temperature rise. In such cases, tools such as fine files should be used to remove burrs and eliminate short circuits between the silicon steel sheets. After cleaning, insulating paint should be applied, followed by heating and drying. 　　2. Excessive force was used when removing the old windings, causing the tooth grooves to become skewed and flare outward; in such cases, tools such as needle-nosed pliers or wooden hammers should be used to adjust them so that the grooves return to their proper position. Hard insulating materials such as green paper or bakelite should be inserted between the silicon steel sheets that are difficult to align and have gaps. 　　3. If rust forms on the surface of the core due to moisture or other reasons, it must be polished clean with sandpaper, and after cleaning, insulated paint should be applied. 　4. High heat generated during assembly can cause the core bars or teeth to burn; use tools such as chisels or scrapers to remove the melted material completely, then apply insulating paint and let it dry. 　　5. If the connection between the core and the frame is loose, the existing set screws can be tightened. If these set screws are no longer effective, new set holes can be drilled in the frame and threaded, after which the set screws can be tightened again. 2. Bearing failure repair 　　2. The rotating shaft rotates with the support of bearings; it is the part that bears the greatest load and is also prone to wear. 　　1. Fault inspection 　　Inspection during operation: When a rolling bearing is lacking in oil, a \"grinding\" sound can be heard ； If a discontinuous \"clinking\" sound is heard, it may be that the bearing ring has cracked. A slight noise is generated when the bearing contains debris such as sand, or when the bearing components are slightly worn. 　　Inspection after disassembly: First, check the bearing rollers as well as the inner and outer rings for any damage, rust, scars, etc. Then, hold the inner ring of the bearing with one hand and level it out, while using the other hand to push on the outer ring firmly. If the bearing is in good condition, the outer ring should rotate smoothly, without any vibration or noticeable sticking, and it should not move backward once it stops rotating. Otherwise, the bearing can no longer be used. Hold the outer ring with the left hand and the inner ring with the right hand, then push them firmly in various directions; if they feel very loose when pushed, it indicates severe wear. 　　2. Fault repair The rust spots on the outer surface of the bearing can be removed using 00-grit sandpaper, after which it should be cleaned in gasoline ； If the bearing has cracks, the inner and outer rings are broken, or the bearing is excessively worn, it should be replaced with a new one. When replacing a bearing, choose one of the same model as the original. 　　3. Repair of rotating shaft faults 　　1. Bent shaft ； 　　If the bending is not severe, it can be repaired by polishing the journal and slip rings ； If the bending exceeds 0.2 mm, the shaft can be placed under a press to apply pressure and correct the bending; after correction, the surface of the shaft is machined and polished using a lathe ； If the bending is too severe, a new shaft must be replaced. 　　2. Journal wear ； 　　When the wear on the journal is not severe, a layer of chromium can be plated on it and then ground to the desired size ； When there is significant wear, surfacing can be performed on the journal, followed by machining and polishing on a lathe ； If the journal wear is excessive, machine 2-3 mm off the journal, then machine a sleeve which is fitted onto the journal while it is still hot, and finally machine it to the desired size.