High-speed wire rod mill bearing and its application

my country's metallurgy (content: extraction of metals or metal compounds from ores) industry has introduced dozens of high-speed wire rod production lines from abroad in recent years in order to meet the increasing demand for steel used in architecture. /s varies, and the annual output is mostly between 60 × 104 ~ 100 × 104t. Due to the particularity of the work of the high-speed wire mill, stricter requirements are put forward for the matched bearings. This paper briefly introduces the working characteristics, structural forms, design points and manufacturing keys of high-speed wire rod rolling mill bearings (hereinafter referred to as high-speed wire rolling mill bearings).
1 Performance (xìng néng) requirements
1.1 High reliability
The most notable feature of the high-speed wire rod production line is the high reliability of the continuous operation of the rolling mill. Due to the high unit output of the high-speed wire rod production line, it is required that the bearing, which is a key component of the rolling mill, has higher reliability than the general rolling mill bearing within the specified inspection period. If the failure of the bearing will lead to the shutdown of the entire production line, this is not tolerated by the manufacturer. Therefore, when designing and manufacturing high-speed wire rolling mill bearings, the reliability of continuous operation under high-speed operation conditions should be guaranteed.
1.2 Wear resistance (a basic type of component failure)
The bearing of the high-speed wire rolling mill has strong wear resistance and can be adapted to high-speed rotating work occasions. When the center line of the spherical roller bearing does not coincide with the center line of the bearing seat and there is an angular error, or when the shaft is bent or inclined due to the force of the shaft, the axis of the inner and outer rings of the bearing will be skewed. At this time, a self-aligning bearing with a certain self-aligning performance or a spherical ball bearing with a seat should be used. Example: For a high-speed wire rod production line, the outlet line speed is 63m/s, and the working diameter of the outlet rolling mill roll is 330mm, then the working speed of the bearing is 3650r/min. Long-term operation under high speed and heavy load will not affect the bearing resistance. Wear (a fundamental type of component failure) will be a tough test. This requires that the supplied bearings must have wear resistance requirements.
1.3 Long fatigue life (lifetime)
The fatigue life of high-speed wire rolling mill bearings is longer. Under normal circumstances, the high-speed wire mill bearings provided abroad are used for three years (because half of the time the roller (gǔn) components need to be unloaded for maintenance and refurbishment, the actual working time is one and a half years), so the user requires domestic bearings at least Can be used for two years.
1.4 Better impact toughness
The impact toughness of the bearing of the high-speed wire rolling mill is better, especially the bearing used in the rough rolling mill. In the process of rolling the continuous casting billet into a bar, the impact load is very large. When the center line of the spherical roller bearing does not coincide with the center line of the bearing seat and there is an angular error, or when the shaft is bent or inclined due to the force of the shaft, the axis of the inner and outer rings of the bearing will be skewed. At this time, a self-aligning bearing with a certain self-aligning performance or a spherical ball bearing with a seat should be used. Therefore, the high-speed rolling mill bearing should not be broken when working at high speed and high impact.
To sum up, the job characteristic of the bearing of the high-speed wire rolling mill is that it can work continuously, stably and reliably under the condition of high speed and high impact, and has a long fatigue life.
2 Bearing structure
There are two types of high-speed wire rolling mill bearings: four-row tapered roller bearings and double-row cylindrical roller bearings. Tapered roller bearings are a type of rolling bearing and are widely used in modern machinery. It relies on rolling contact between the main elements to support the rotating parts. Roller bearings are now mostly standardized. Roller bearings have the advantages of small torque required for starting, high rotation accuracy, and convenient selection. In general, four-row tapered roller bearings are used in rough and medium rolling mills, double-row cylindrical roller bearings are used in finishing mills, and the same type of bearings are used in horizontal rolling mills and plumb rolling mills.
Whether it is a four-row tapered roller bearing or a double-row cylindrical roller bearing, its basic structure is similar to that of a traditional rolling mill bearing, but the design of each part fully considers lubrication. Lubrication) and heat dissipation (radiating) problems, that is, the inner ring, outer ring, spacer (for four-row tapered roller bearings), cage, roller (for double-row cylindrical roller bearings) are separated Many slots, holes, etc. In this way, the lubrication and heat dissipation channels formed by the grooves and holes form a reliable lubrication and heat dissipation system, and the channels on the bearing seat and the roll form a reliable lubrication and heat dissipation system. Coupled with a good sealing device, the bearing can be stable at high speed and high pressure. (Explanation: stable and stable; no change) operation.