Analysis of the cause of wear of the bearing bit of the roller press and the exchange of on-line repair technologyDate: 2019-06-21 Views:
The roller press is one of the important equipment in the process of cement production. It is mainly used for roller pressure of cement clinker. Some cement enterprises are also used to replace the cement vertical mill with a roller press to roll the limestone. Once the roller press has failed, the effect on the whole cement production line is very large, which will cause great economic loss to the enterprise.
In the fault of roller press, the bearing wear of roller press is one of the most common problems, and it is also the most difficult problem to be solved in enterprises. Because the weight of a single roller of roller press is often between 30 and 50T, it is difficult to disassemble, assemble and transport, which is very time-consuming, and the comprehensive cost of offline repair is generally not less than 200000 yuan. Its repair cycle is also relatively long, generally no less than 15 days of repair cycle. If the repair work is carried out during the inspection period, the impact on the enterprise will be relatively small, but if it occurs in the normal production stage, the impact will be very large. So how to solve the problem of bearing position wear with high efficiency and high quality on the spot is very important. important。
After the appearance of Sorey carbon nano-polymer material repair technology, the problem of wear and tear of roller bearing position is solved very well. It does not need a lot of disassembly, only needs to remove bearing seat and bearing, and the whole repair cycle will be completed within 24 hours.
1. So why does the bearing position of the roller press wear? What is the root cause?
Before repairing, we should carefully analyze the main causes of bearing wear of roller compressor, and then fundamentally eliminate the problem of bearing wear of roller compressor, so as to really prolong the service life of the equipment.
In view of the causes of bearing wear and tear of roller presses, I would like to introduce you to a case in which you may be able to see some fundamental problems:
The main parameters of this equipment are 1:12 taper shaft, bearing position small neck size 900 mm, wear width 500 mm, bearing position wear depth 4 ≤ 5 mm.
At the scene, we found that two employees used tools to clean up the mud in the bearing seat (a mixture of grease and clinker powder). Next to the bearing seat was a trolley parked next to the bearing seat. After about an hour, the mud from the bearing seat was cleaned up, and the amount of mud cleared was very surprising, a whole cart. How did this mud come into being? After careful inspection, it is found that the seal of the bearing seat is completely damaged, and the sealing groove has been seriously worn out, so a large amount of clinker dust enters the bearing seat and is mixed with lubricating oil to form a large amount of silt. During the on-the-spot communication, our engineers learned that the enterprise The new bearing needs to be replaced, but the stop plate and seal have never been replaced. The failure of the striker plate and the failure of the seal are the root cause of the bearing damage.
The bearing position of the roller press is generally 1:12 cone or 1:30 taper shaft, and the bearing position of a small part of the roller press is a straight shaft. The majority of the bearings used are two-row, double-row, self-aligning bearings, with fewer N-series cylindrical roller bearings. the friction coefficient of the bearing itself is very small, and in the normal state of the bearing operation, the shearing force of the bearing inner ring and the bearing position in the circumferential direction is relatively small, Then the shear force in the circumferential direction of the bearing inner ring and the bearing bit matching surface can be increased instantaneously. When the shear force is greater than the pre-tightening force between the bearing cone and the bearing bit, that A relative movement between the bearing cone and the bearing position will occur, resulting in wear of the roller press bearing position.
2. So how to carry out on-line repair operation after the bearing position of roller compressor is worn out?
We think that the following data should be guaranteed in order to repair the bearing position of roller compressor online:
The main results are as follows: (1) concentric degree: the repair of any shaft is very important to ensure that the concentric degree deviation is too large, which will cause vibration of the equipment, thus reducing the service life of the repaired part and seriously affecting the bearings and other parts of the equipment.
The method of ensuring concentric degree is to use the front and rear shoulders of roller press as the repair benchmark and to process the template ruler according to the original drawings of the equipment. The template ruler is machined by wire cutting technology, so the overall error is small. Using the template ruler as the standard measuring tool to measure the specific wear size of the bearing position, and then spot welding the positioning point on the shaft surface, the height of the positioning point is found out through the template ruler, and all the positioning points are evenly distributed in the circumferential direction, so as to ensure that the positioning point plays the role of positioning concentric degree after the bearing is installed. Because it is a field repair, there will always be a certain error in accuracy, and the overall deviation of concentric degree will not exceed 0.2 mm. The rotating speed of roller press is one The deviation within 0.2mm will not affect the normal operation of the roller press;
(2) complete taper surface: before we used sample size and positioning point to locate concentric degree, then we used bearing inner ring as repair tool to complete the repair of bearing taper surface. Solay carbon nano-polymer material SD7101H is paste, thixotropic performance is good, easy to form. The fitting surface repaired in this way can reach 100% of the matching surface of the bearing inner ring. The larger the matching area is, the more uniform the force is, and the better the effect is.