The main bearing is an important part of the ball mill. It should have large load, high linear speed, and can withstand certain impact and vibration. These distinctive characteristics require ball mill manufacturers to control their shape, size and surface finish.
The main bearing of the ball mill machine is basically composed of three parts: main bearing bush, bearing seat and lubrication system. The main bearing bush is the top priority of the main bearing.
The ball mill main bearing bush is spherical and installed at the concave spherical surface at the bottom of the bearing. It is generally made of lead base bearing alloy.
CICMech has three types of ball mill machine, they are overflow ball mill, wet grid ball mill and dry ball mill. Ball mill main bearing has good strength, plasticity, polymerization, antifriction, wear resistance, lubricity, heat transfer and simple replacement. Only with these characteristics can overflow ball mill, wet grid ball mill and dry ball mill meet the requirements of good lubrication of the main bearing and well adapt to the low-speed and heavy-duty working environment of the ball mill.
The main bearing oil ring runs with the hollow shaft of the ball mill and carries oil. The oil brought by the oil ring is scraped onto the oil distributor by the oil scraper, and then the oil is evenly scattered onto the hollow shaft by the oil distributor. An oil film is formed between the contact surface of the hollow shaft and the main bearing to separate the friction surface and obtain liquid dynamic pressure lubrication, so as to reduce the wear between the hollow shaft and the main bearing, ensure the normal operation of the ball mill.
If the temperature is too high, the Babbitt alloy on the surface of the main bearing bush melts, resulting in bush burning, and the ball mill cannot work.
Cause: there is a lot of heat in the main bearing, which can not dissipate in time and accumulated continuously, and the temperature rise is too high. It can also be analyzed from two aspects:
1) Various faults of ball mill
Poor scraping and grinding of main bearing bush, improper selection of lubrication type, poor lubrication system, inadequate operation, poor thermal insulation between hollow shaft and spiral drum, feeding overheated materials for a long time, poor ventilation, insufficient external cooling, cracks in main bearing, etc.
2) Quality problems of main bearing bush
Pay attention to two aspects, the material quality of ball mill and the manufacturing quality of firing casting.
Properly shorten the length of drenching oil pipe of main bearing of ball mill to make more lubricating oil enter between main shaft and bearing bush. The convex spherical surface of the main bearing and the concave spherical surface of the bearing seat are transformed. The spherical surface is contacted and positioned at 45 degrees in the circumferential direction. After scraping and grinding, the contact surface is coated with molybdenum disulfide grease to ensure the flexible rotation of the ball pad. Reduce the contact angle between the bearing bush and the hollow shaft and enlarge the wedge gap between them.