Main bearing of tube mill utilizing rolling bearing
According to long-term research, testing and long-term utilization, main bearing of ball mill utilizes rolling bearing to replace slide bearing which is a perfect new technology, main bearing of tube mill utilizes rolling bearing which began to be utilized in the early of 19s centries, while the applicable space was small and the development was slow and the main reason is that the structure and shape of bearing is not suitable for construction price. For example rolling bearing utilized at first status at primary is short & cylindrical bearing, while utilizing this kind of bearing need to take use of lower spherical base to solve the aligning problem, thus this kind of manufacturing & processing is trouble.
On the second status of design utilizes the circle jacket of short & cyliderical bearing as spherical body shape, though leaved the lower spherical seating out, but it was still aligning of sliding situation, resistance of aligning was large which was not perfect. Entering into 3rd status utilized dual line aligning rolling bearing, the specification of bearing is large, the spoke is wide, lubrication is hard, periodic repair & clean for bearing is not convenient, and bearing assembly has a group of damaged bearing which need to be changed. In order to solve the above disadvantages of three kind of bearing to gain lower construction price and practical, thus LMGU lower half ring spoke dual aligning rolling bearing is born. Main characters are as follows:
1）When ball mill is operating, the bear force of main bearing is downward with small axial force and lateral force and without upward force. Standard aligning rolling bearing, short cylindrical bearing, etc. could bear the axial force on all locations in circumference. But when they are used as main bearing of mill, only lower halves of the circle is bearing force, the other half is left unused. After a period of time on operation, the entire spoke will turn up the camber wear. Though Though the location of spoke could be exchanged in the circle direction normally, but this action should be implemented when stopping production meanwhile the disassembly of the larger bearing base is different. Mentioned U type bearing body could solve the above exiting problem, it optimizes designing & manufacturing, make the spoke of bearing into lower halves of ring into structure shape which is put into bearing box and its structure has enough live load capacity, according to the complement of structure between bearing and bearing base, it could reach smaller material consumption o rolling bearing and it also simplifies processing process and shortens the production circle which reduces the construction cost of the entire bearing body.
2）The outline dimension of rolling bearing of ball mill is decided according to the specification of mill and value of live load, it could be more suitable for the utilization of ball mill, meanwhile the manufacturing cost decreases largely and the economic suitability is stronger.
3）Implment good lubrication and extend the useful life of bearing. When utilizes international dual aligning rolling bearing, diameter and amplitude will be large, the distance of lubricating oil entering into the center of movement body is long, time is slow, if the oil quantity inside of bearing box could not reach over two-thirds which couldn´t form oil pressure and it could turn up insufficient lubrication due to lack of oil. In order for this utilizes rolling bearing, but due to insufficient lubrication, the friction factory of bearing is still large, thus it couldn´t reduce the friction drag torque of bearing and it couldn´t save the power. After Utilizing new developed LMGU rolling bearing, the upper havels of the spoke will be exposed in the outside, lubrication oil in bearing box couldn´t exceed 50% of oil level which could form good lubrication, and it could reach the good effect on energy saving and useful life of bearing.
4）It is very covenient for bearing inspection & cleaning at the end of year. As the rolling body of bearing and upper half of the holder are exposed in the outside, waste oil and impurity will be cleaned. While the movement of the spoke of international bearing is small, rolling body and the holder couldn’t be entirely exposed, thus the waste oil and impurity couldn’t be entirely cleaned which will affect future utilization.
5）LMGU rolling bearing is composed of inner ring, outer ring, holder and rolling body. It could change every parts at any time and eliminate the disadvantages that if one part of old bearing is broken, the entire bearing should be changed. In order to make the bearing develop into the trendency of seriation, standardization, this company undertakes the drafting work of 《Bush (bearing) of cement industry》- Chinese building material industry standard which passed the deliberation of specialists in the industry and it has been approved on Dec. 1st of 2006 to be implemented by Chinese State Development and Reform Commssion.
6）Reduce working current: choose to utilizes reasonable rolling bearing to the mill, produced frication factory will be just 0.0025 during roation which is 16 times lower than slide bearing, according to calculation and utilization example, comsumped motor power of rolling bearing of mill will be 0.5-1% of configured motor power, this will reduce normal working power consumption which implement the electrical cost saving, production coast decreasing, improve the good effect on economical benefical of enterprise.
7）Reduce starting current: due to large friction resistance force of slide bearing, when starting, the friction between shaft and bearing to accelerate until reaching the fixed revolution, motor need to overcome the large friction drag torque, normally starting current is 5-6times of working current. After utilizing rolling bearing, start current is just 2 times of working current, the reason for that residue power of motor under normal working is due to slide bearing. After changing the main bearing into rolling bearing, it could reduce the configured motor power or improve feeding quantity of mill grinder, improve motor efficiency, reduce idle work and improve the production.
8）Reduce lubrication oil comsumption: slide bearing utilizing thin oil lubrication could work normally, due to the ungood sealing of thin oil lubrication bearing box, thin oil is easy to sneak into powder or impurity meanwhile the pressure produced between shaft and bearing make deterioration of thin oil more serious, thus the consumption and waste on thin oil is serious. After changing to utilize rolling bearing, thus the revolution is low, load capacity is large which couldn’t produce friction heat source, thus utilizing lubrication grease could meet the requirements which could leave the thin oil lubrication station out, save 90% oil consumption.
9）Reduce maintenance, improve operation rate: the useful life of slide bearing is 1-3 years. Mill main shaft will be wear, if the maintentance is not good, some factories will change one pair bearing for several months. During normal working of slide bearing, it is not allowed to lack of lubrication oil, cooling water or too high temperature of bearing. Once it happened to stop for inspection, thus low operation is exiting normally.
10）Save cooling water, improve environmental health: after utilizing rolling bearing, wet process mill and cement raw mill could leave the bearing circular cooling water device which will not affect the useful life of bearing,after rolling bearing base utilizes dry oil lubrication, there is no oil stains which has improved environmental health.
Jiangsu Pengfei Group Co., Ltd
www.pengfei.com.cn
