Support the rotating shaft and parts on the shaft, and maintain the normal working position and rotation accuracy of the shaft. The rolling bearing is easy to use and maintain, reliable in work, good starting performance, and high load capacity at medium speed. Compared with sliding bearings, rolling bearings have larger radial dimensions, poorer damping ability, low life at high speeds, and greater noise.
1. Outer ring-installed in the bearing seat hole, generally does not rotate
2. Inner ring-installed on the journal, rotating with the shaft
3. Rolling element-the core element of rolling bearing
4. Cage-evenly separate the rolling elements to avoid friction
Lubricant is also considered as the fifth largest part of rolling bearing, it mainly plays the role of lubrication, cooling, cleaning, etc.
1. Low friction resistance, low power consumption, high mechanical efficiency and easy start;
2. The size is standardized, interchangeable, easy to install and disassemble, and easy to maintain;
3. Compact structure, light weight, and reduced axial size;
4. High precision, large load, small wear and long service life;
5. Some bearings have self-aligning performance;
6. Suitable for mass production, with stable and reliable quality and high production efficiency;
7. The transmission friction torque is much lower than that of hydrodynamic bearings, so the friction temperature rise and power consumption are lower;
8. Starting friction torque is only slightly higher than rotating friction torque;
9. The sensitivity of bearing deformation to load changes is less than that of hydrodynamic bearings;
10. Only a small amount of lubricant is needed for normal operation, and lubricant can be provided for a long time during operation;
11. The axial size is smaller than the traditional hydrodynamic bearing;
12. It can bear combined radial and thrust loads at the same time;
13. In a large load-speed range, the unique design can obtain excellent performance;
14. Bearing performance is relatively insensitive to fluctuations in load, speed and operating speed.
1. Loud noise.
2. The structure of the bearing seat is more complicated.
3. Higher cost.
4. Even if the bearings are well lubricated, installed correctly, dust-proof and moisture-proof, and running normally, they will eventually fail due to the fatigue of the rolling contact surface.
Rolling bearing code is a product symbol that uses letters and numbers to indicate the bearing structure, size, tolerance level, technical performance and other features. The national standard GB/T272-93 stipulates that the code of the bearing is composed of three parts: the front code, the basic code, and the rear code. The basic code is the basis of the bearing code. The pre-code and post-code are supplementary to the bearing code. They are only used when there are special requirements for bearing structure, shape, material, tolerance level, technical requirements, etc., and can be partially or completely omitted in general.
a. Basic code
The basic code indicates the basic type, structure and size of the bearing. It consists of bearing type code, size series code, and inner diameter code.
a1: Bearing type code Use numbers or letters to indicate different types of bearings.
a2: The size series code consists of two digits. The first number represents the width series (radial bearings) or the height series (thrust bearings), the latter number represents the diameter series. The size series means that the bearings with the same inner diameter can have different outer diameters, and the same outer diameter has different widths (or heights), so as to meet various requirements of load capacity.
a3: Inner diameter code indicates the size of the nominal inner diameter of the bearing, expressed in numbers.
Example: bearing 2 32 24
2-type code, spherical roller bearing; 32-size series code; 24-inner diameter code, d=120mm;
Example: bearing 6208-2Z/P6
6-type code, deep groove ball bearing; 2-size series code; 08-inner diameter code, d=40mm;
2Z-Bearing with dust cover on both ends; P6-tolerance class meets standard 6
L separable inner ring or outer ring of separable bearing
R Bearings without separable inner ring or outer ring (needle roller bearings are only applicable to NA type)
K roller and cage assembly
WS Thrust Cylindrical Roller Bearing Ring
GS Thrust Cylindrical Roller Bearing Race