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Hammer crusher is a kind of equipment for crushing materials in the form of impact, which is divided into single rotor and double rotor. It is a crusher used to directly crush materials with larger particle size of 600-1800 mm to 25 mm or less. Hammer crusher is suitable for crushing medium hardness materials in cement, chemical, electric power, metallurgy and other industrial sectors. The crushed materials are coal, salt, chalk, gypsum, brick, limestone, etc. It can also be used to crush paper, asbestos and other fibers. Hammer crusher can not only be used in crushing production line, sand production line, but also can replace cone crusher in mineral processing production line.
The crusher used in the mine production often has a hammer broken bearing lock. What is the hammer broken bearing lock?
The so-called bearing locking is that a large amount of heat is generated during the operation of the bearing, which can not be dissipated in a short time, resulting in a sharp rise in the temperature of the bearing and eventually locking the bearing. This phenomenon is very common in equipment overhaul and production service site. The specific causes of bearing heating are as follows:
1、 Improper assembly
1. Improper fit of bearing outer ring with bearing seat hole or bearing inner ring with shaft during assembly.
During the assembly process, the inner hole was not polished and its size was measured, and the new bearing was replaced for assembly. After the test run, the temperature rise was found to be too high. During the disassembly and measurement, it is found that the bearing pedestal hole has been deformed and the outer ring of the bearing is squeezed, which leads to the decrease of the radial clearance of the bearing, the uneven rotation of the rolling element and the aggravation of the wear. The clearance between the bearing inner ring and the shaft is too large, and the bearing inner ring rotates with the rolling element and the shaft, resulting in friction, heating and vibration of the bearing.
2. Improper control of bearing heating temperature during assembly.
If the temperature of the commissioning bearing heater is too high during the heating operation, it will produce tempering and reduce the hardness and accuracy, so that the bearing temperature will rise and the bearing wear will be aggravated.
3. Improper adjustment of bearing clearance during assembly.
In the actual work, many installation sometimes only by hand debugging, gap is too large or too small, can not meet the production needs. If the axial clearance is too small, it is easy to cause bearing heating, accelerate pitting, and even make the rolling element stuck or glued damage; if the axial clearance is too large, the impact force of the moving pair increases, and the stiffness decreases, it will cause abnormal sound in operation, and even cause serious vibration or damage to the cage.
2、 Oil seal problem
Oil seal is used to seal the rotating shaft of mechanical equipment, and the cavity is basically static, so oil seal is also called rotating shaft lip seal ring. For the oil seal with auxiliary lip, the auxiliary lip plays a role of dust prevention, preventing impurities from invading, so as to extend the service life of the oil seal. However, the auxiliary lip is often poorly lubricated, with high friction, resulting in damage due to dry friction of the oil seal. Therefore, when installing the double lip oil seal, it is necessary to fill grease between the two lips.
3、 Gap problem
In the assembly process, if the spacer size is not checked carefully and the assembly test run is carried out, the temperature will rise rapidly after a certain period of time. The outer ring size of the bearing has been determined by the end cover and the end stop of the bearing seat, the spacer size is reduced, the inner ring size will be adjusted by the round nut, and finally compressed, so that the axial clearance of the bearing becomes smaller, which makes it hot during operation.
4、 Lubrication problems
Too much grease should not be used in the bearing. Too much grease will increase the friction torque and temperature of the bearing. Too little grease will not obtain reliable lubrication and cause dry friction. Generally speaking, the appropriate amount of grease is 1 / 3 ~ 1 / 2 of the total volume of the gap in the bearing. Therefore, it is necessary to inject proper amount of grease regularly according to the use requirements.