Detailed analysis of internal bearing clearance

Clearance is the clearance of the bearing inner ring, outer ring, rolling body between; is an important national technical standards for quality projects, or one bearing applications important technical indicators are also important to check the project. Internal clearance of the bearing comprises a radial clearance of two oil clearance and axial oil. Radial oil gap into five groups 2,0,3,4,5, 0 Group as the basic clearance, which in turn increases the value of universal code (C) shows. Internal clearance and bearing life bearing temperature prosperity, vibration and noise are closely related.

Radial clearance defined in different angular directions, do not accept any external load, a ring relative to the other rings from one extreme position to the radial eccentric arithmetic mean of the radial distance of the opposite limit position. In theory, radial clearance (radial bearing) is the outer ring raceway contact diameter minus the inner ring raceway contact diameter minus twice the diameter of the rolling element.

Axial clearance definition does not accept any external load, an arithmetic mean of the ring relative to the other rings from one extreme position to the opposite axial limit position of axial distance.

In the design and practical work, often again clearance into the design clearance, the original clearance, clearance and installation work oil clearance.

Design clearance conditions according to the theory of theoretical calculations obtained clearance value set with values. The original clearance bearing clearance is installed before the original clearance values ??are generally given in the various standards. Installation clearance is bearing clearance after installation due to the interference fit relationship, the installation clearance is less than the original clearance. Clearance work is under actual operating conditions clearance. Bearing at work, since the inner and outer temperature difference of the reasons the mounting clearance is reduced, while the role of the work load of the rolling bodies and rings elastic deformation causes the original clearance increases, under normal circumstances, total operating clearance It is greater than the installation clearance, and must be less than the original clearance.

Internal clearance selection and application

Bearing in operation, the temperature rise so that the outer ring temperature changes, will install clearance reduction, while the load is applied to the rolling bodies and rings elastically deformed, will increase the clearance. Operating clearance is slightly larger than usual installation clearance, in order to get the most satisfactory work performance, you should select the appropriate clearance work.

Bearing through a certain amount of negative clearance requirement may have some bearing preload, aims to improve the rigidity of the bearing, the bearing life can be improved; when the preload exceeds the upper limit of the optimum range, bearing rigidity increment little friction and heat has increased dramatically, but also a sharp decline in bearing life. When clearance is too large, the load-bearing rolling elements fewer, larger body to withstand the maximum load of the rolling bearing life will be reduced.