In terms of lubrication performance, tapered roller bearings perform better than spherical roller bearings. Mainly in the following two aspects.
a. Tapered roller bearing has self-lubricating pumping effect, that is, when the roller rotates, it can automatically bring lubricating oil from the small end of the roller along the roller body to the large end surface of the roller to achieve lubrication of the roller and the raceway. . Spherical roller bearings do not have this feature. As shown in Figure 2.
Figure 2: Flow direction of lubricating oil in tapered roller bearings under pumping effect
b. From the crystal phase structure of the bearing surface, the surface of the tapered roller bearing subjected to carburization heat treatment contains 25% of retained austenite, and the surface of the hardened spherical roller bearing has 15% retained austenite. Austenite has good toughness relative to martensite. Under the action of lubricating oil pressure, it will produce elastic deformation, which is beneficial to the oil film to separate the contact surface between the roller and the raceway to avoid contact with the rough part. Therefore, under the same surface roughness conditions, the tapered roller bearing can provide better lubrication than the spherical roller bearing. As shown in Figure 3. Since the shearer cutting head bearings operate under high load, high temperature, low speed environment, and the lubrication conditions are poor, the improvement in lubrication can bring about a significant improvement in performance and life.
Figure 3: Surface metallographic structure of fully hardened bearings (left) and surface carburized bearings (right)
It is not difficult to see from the above four aspects that the double row tapered roller is more suitable for the application of the cutting head of the longwall shearer. Although the spherical roller bearing has its inherent self-aligning ability, it can better handle the eccentricity of the shaft when it is under stress. However, the double-row tapered roller bearing is a better solution as a whole, which is more conducive to lifting. Coal machine performance and reliability.
Previous page
The welding neck flange refers to a kind of flange with cone neck and butt welding with cylinder or pipe. It is an integral flange, suitable for high pressure, high temperature or high sealing requirements.
Carbon Steel Welding Neck Flange,Carbon Wn Flange,Raised Face Weld Neck Flange,Long Weld Neck Flange
Jinan Xintai Forging Co., Ltd , https://www.xtdzflange.com