Double-row radial spherical ball bearings and double-row radial spherical roller bearings have good self-aligning performance. Improve manufacturing accuracy and reduce costs. The viscosity of the oil is generally 0. The bearing working speed should be lower than the limit speed. It is difficult for general-purpose rolling bearings to meet various requirements.

The amount of grease in the bearing should not exceed 1/2 to 1/3 of the bearing space, otherwise the bearing will overheat due to excessive Mechanical ball bearing stirring of lubricant. Selecting high-precision bearings, improving cage structure and material, using oil mist lubrication, and improving cooling conditions can all increase the limit speed. Grease lubrication is not easy to leak, easy to seal, long use time, easy maintenance and high oil film strength, but the friction torque is larger than oil lubrication, and it is not suitable for high speed.12 to 0.

The allowable inclination angles of various rolling bearings are different, such as 8'-16' for single-row radial ball bearings, 2°～3° for double-row radial spherical ball bearings, and tapered roller bearings ≤2'. This puts many new requirements on rolling bearings, such as reducing the size while requiring the bearing to maintain or even increase the rated load, and adopt new technologies to improve the process.

If the bearing is designed according to the theory of elastohydrodynamic pressure lubrication and the viscosity of the lubricant is selected, the contact surface will be separated by an oil film.2 cm/sec. Lubrication methods include oil bath lubrication, drip lubrication, oil mist lubrication, oil spray lubrication and pressure oil lubrication. Modern machines, instruments and other equipment are developing in terms of high speed, heavy load, precision, lightness, etc. Limit speed The maximum speed allowed by the bearing under certain load and lubrication conditions.

While strengthening standardization, increase varieties and expand the proportion of special bearings.Self-aligning performance The ability of the bearing to still work normally when the centerline of the shaft is inclined relative to the centerline of the bearing housing hole. The oil lubrication and cooling effect is good, but the sealing and oil supply device are more complicated. The development of modern industry also requires special bearings that work under special working conditions, such as bearings that work in high speed, high temperature, low temperature, strong magnetic fields, or in acid, alkali and other media.

When the load is large, the oil with high viscosity should be used when the working temperature is high, and the oil with low viscosity should be used when the speed is high. The limit speed is related to bearing type, size, accuracy, clearance, cage, load and cooling conditions. At this time, under stable load, the bearing life can be increased many times.

Roller bearings and needle roller bearings are not allowed to have relative inclination of the axis of the inner and outer rings.. During oil bath lubrication, the oil level should not be higher than the center of the lowest rolling element. Bearing lubrication mainly includes grease lubrication and oil lubrication. For machinery and equipment with a large production volume, special bearings should be designed and manufactured