Joint Bearing Basic Knowledge

Joint bearing is a kind of spherical sliding bearing, its sliding contact surface is an inner spherical surface and an outer spherical surface, the movement can be rotated in any angle swing, it adopts surface phosphating, blowing mouth, gasketing, spraying and other special technology processing methods to make. The joint bearing has the characteristics of large load capacity, impact resistance, corrosion resistance, wear resistance, self-aligning, good lubrication, etc.

Structure of joint bearing

The structure of joint bearings is simpler than rolling bearings, which mainly consists of an inner ring with an outer spherical surface and an outer ring with an inner spherical surface. The joint bearing is generally used for low speed oscillating motion (i.e. angular motion), because the sliding surface is spherical, it can also be tilted in a certain angle range (i.e. spherical motion), and can still work normally when the support shaft and shaft housing hole is not concentric.

Joint bearing characteristics

Joint bearings can withstand large loads. According to its different types and structure, it can bear radial load, axial load or radial, axial at the same time the combined load. As the outer spherical surface of the inner ring is inlaid with composite material, so the bearing can produce self-lubrication in operation. Generally used for low speed swing movement, and low speed rotation, but also in a certain angle range for tilting movement, when the support shaft and shaft shell hole is not the center degree is large, but still can work normally.

Joint bearing application

Joint bearings are widely used in engineering hydraulic cylinders, forging machine tools, engineering machinery, automation equipment, automotive shock absorbers, water conservancy machinery and other industries. Joint bearings are spherical plain bearings, the basic type is composed of inner and outer rings with spherical sliding spherical contact surface. According to its structure and type, it can bear radial load, axial load, or radial, axial simultaneous action of the combined load.

Joint bearing composition

A spherical plain bearing consists mainly of an outer ring and an inner ring. The inner spherical surface of the outer ring and the outer spherical surface of the inner ring form a rolling friction pair.

Joint bearing performance

Since the structural form and working mechanism of spherical bearings are completely different from those of rolling bearings, spherical bearings have their own technical characteristics and maintenance requirements.

1.Operating temperature

The allowable operating temperature of the spherical plain bearing is mainly determined by the material paired between the sliding surfaces of the bearing, especially the plastic material sliding surface of the self-lubricating spherical plain bearing, the bearing capacity will have a decreasing trend at high temperature. If the sliding surface of lubricated spherical plain bearings is paired with steel/steel, the allowable working temperature depends on the allowable working temperature of the lubricant. However, for all lubricated and self-lubricating spherical plain bearings, they can be used in the temperature range of -30℃ to +80℃ and maintain the correct bearing capacity.

2.Tilting angle

The tilting angle of spherical plain bearings is much larger than that of general adjustable rolling bearings, which is suitable for use in the supporting parts with low concentricity requirement. 


In any case, spherical joint bearings selected to fit shall not make the collar uneven deformation, the nature of its fit and grade selection must be based on bearing type, support form and load size and other working conditions to decide.

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