The difference between plain bearings and rolling bearings

The difference between plain bearings and rolling bearings

Rolling

In the work of rolling friction bearings. Rolling easy maintenance, reliable, good starting performance, at moderate speed higher carrying capacity. Comparison with the sliding bearing, the radial rolling bearing large size, poor damping capacity, high speed, low life, sound larger. Rolling bearings in the heart (mainly radial force) is usually held by the inner, outer, rolling and rolling rack 4 parts. Inner sleeve and rotates together with the shaft in the journal, the outer ring mounted in the housing bore. In the inner circumference of the outer periphery of the inner and outer rings are formed with the raceway. When the relative rotation of the inner and outer ring, rolling body that is including the raceway of the outer ring, which are separated by a cage, to avoid friction. Thrust bearing tight circle and living circle divided into two parts. Tight circle with the sleeve tight, live ring bearing in the bearing housing. Rings and rolling elements are usually made of high strength, good wear resistance rolling bearing steel, surface hardness after quenching should reach HRC60 ~ 65. Cage mostly mild steel stamping made of copper alloys can also be used cloth bakelite or plastic manufacturing.

Bearing

In the sliding friction bearings work. Bearing smooth, reliable, no noise. In the liquid lubrication conditions, the sliding surfaces are separated and not in direct contact with the lubricating oil, but also can greatly reduce the friction loss and surface wear, the film also has a certain vibration absorption capacity. But the starting frictional resistance is large. Bearing portion of the shaft is called the journal, and the journal bearing mating parts called. In order to improve the friction properties of the surface of the pad on its inner surface layer of the cast friction material called bushing. Bearings and bearing liner materials collectively known as the bearing material. Bearing applications generally carried out at low speed heavy working conditions.

Advantages compared with sliding bearings, rolling bearings

1, under normal conditions, efficiency and hydrodynamic lubrication of bearings Rolling quite, but more mixed-lubricating bearings to be higher;

2, relatively small radial clearance, radial angular contact bearings available Available preload preload to eliminate backlash, high precision operation;

3, for the same size of the shaft, the ratio of the width of the rolling bearing sliding bearing small, can compact the axial structure of the machine;

4, most of the rolling bearing can simultaneously by radial and axial load bearing composite structure so simple;

5, consume less lubricant, easy to seal, easy to maintain;

6, no useful for non-ferrous metals;

7, high degree of standardization, mass production, low cost.

Compared with sliding bearings, roller bearings disadvantages:

1, less able to withstand impact loads;

2, high-speed heavy load under low bearing life;

3, vibration and noisy;

4, the radial dimension than the sliding bearings.