The quality of finished bearings is related to the stability of bearing use and the length of life. Jinrui Bearing pays attention to the quality of bearings, takes the mission of providing customers with better bearings, and strictly implements national standards in the manufacturing process.

The basic requirements for the quality of finished bearings are as follows:

1. Measurement temperature: The standard temperature for measurement is 20°C. If the measurement temperature is not equal to 20°C, the standard part or gauge block of the bearing is to be tested and the measuring instrument should be at the same temperature. The working temperature of rolling bearings is determined according to material selection, heat treatment process, lubrication conditions during work, product design, and production process.

(1) Material selection

• General bearings can choose high carbon chromium bearing steel under normal working temperature; such as deep groove ball bearings, self-aligning ball bearings, cylindrical roller bearings, tapered roller bearings, angular contact ball bearings, self-aligning roller bearings, thrust ball bearings, Thrust roller bearings.

• High-temperature bearings can choose high-temperature bearing steel when the working temperature exceeds 300°C.

• The working temperature of low-temperature bearings is lower than -60°C. Stainless steel bearing steel 9Cr18 and 9Cr18Mo are commonly used, and materials such as beryllium bronze and ceramics can also be used.

(2) The heat treatment process is to use different standard heat treatment processes according to different temperature types of bearings.

(3) Rolling bearing operating temperature

A. General-purpose bearings 

General-purpose bearings are made of high-carbon chromium-bearing steel and processed according to the specified heat treatment process. After the rolling bearing is in normal working condition (room temperature), different lubrication conditions have different temperatures. The temperature of the outer ring of the bearing is not allowed to exceed 80°C when it is lubricated with grease, such as deep groove ball bearings; when it is lubricated with oil, it is not allowed to exceed 95°C, such as self-aligning ball bearings.

B. Bearing working temperature under high-temperature conditions:

Rolling bearings are made of high-carbon chromium bearing steel, and the working temperature is between 150°C and 350°C. The suffixes of the bearing models can be marked with S0-S4 respectively, such as spherical roller bearings and thrust roller bearings.

High-temperature bearing steel is used for rolling bearings, and its working temperature can reach above 300°C. The specific working temperature is given separately according to the working conditions.

C. Working temperature of low-temperature bearings: 

high-carbon chromium stainless bearing steel is used for rolling bearings, and its working temperature is lower than minus 60°C, such as single-row deep groove ball bearings and cylindrical roller bearings.

2. Measurement area: the measurement of the inner diameter and outer diameter should be carried out in the area away from the largest chamfer of the end face of the ferrule

3. Dimensional basis for measurement: measure according to the dimensional tolerance specified in the national standard GB/T307.1-1994 "Measurement Method of Rolling Bearing Tolerance" and the standard parts or gauge blocks specified by the competent department of the industry or bearing manufacturer.

4. Measuring instruments: When measuring, the instruments used must be calibrated, and have the accuracy and magnification ratio suitable for the bearing to be measured.

5. Measurement error: The total measurement error generated during the measurement process is in principle less than 10% of the tolerance value. The finished bearings that leave the factory should not exceed the tolerance limits specified in the standard on the grounds of measurement errors. During the measurement, it is necessary to select the appropriate precision instrument and environmental conditions according to the tolerance range of the measured part, so that the measurement error is controlled within a certain range.

6. Measuring radius and measuring force: To reduce the measuring error, it is necessary to reduce the measuring force as much as possible and increase the radius of curvature of the probe.

Choosing the right bearing manufacturer can reduce the defective rate of bearings, and the cooperation will be smoother. If you want to have long-term cooperation, you cannot do without the bearing manufacturer's guarantee of bearing quality. Jinrui Bearing can provide you with bearings of better quality and better prices.