Why understanding bearing clearance has become so important

Bearing clearance is also known as bearing clearance. When the bearing is not installed in the shaft or bearing box, it will be its inner ring or outer ring of a fixed, and then not be fixed when the side to do radial or axial movement of the amount of movement.

Bearing internal clearance refers to a bearing circle relative to another bearing circle radial movement of the total distance (radial internal clearance) or axial movement (axial internal clearance).

Understanding the importance of bearing clearance
Understanding the Importance of Bearing Clearance

Understanding the importance of bearing clearance

Bearing clearance

1, The so-called bearing clearance, that is, when the bearing is not installed in the shaft or bearing box, the inner ring or outer ring of its side is fixed, and then it is not fixed side to do radial or axial movement when the amount of movement. According to the direction of movement, it can be divided into radial clearance and axial clearance.
  2, Running clearance (called work clearance), the size of the bearing rolling fatigue life, temperature rise, noise, vibration and other performance has an impact.
  3, Measurement of bearing clearance, to get stable measurement value, generally on the bearing to apply the specified measurement load. Therefore, the measurement value obtained from the actual clearance (called theoretical clearance) is significant, increasing the amount of elastic deformation generated by the measurement load. For roller bearings, because the elastic deformation is small, it can be neglected.
  4, The internal clearance of the bearing before the theoretical clearance generally expresses installation.
  5, From the theoretical clearance minus bearing installed in the shaft or shell because of interference with the collar expansion or contraction of the clearance called “installation clearance”. The installation clearance plus or minus the bearing internal temperature difference generated by the amount of dimensional change after the clearance is called “effective clearance”.
  6, Bearing installation has mechanical bearing a specific load placed clearance, that is, adequate clearance plus bearing load generated after the amount of elastic deformation so-called “work clearance”.
  7, When the work clearance for micro-negative value, bearing fatigue life is the longest, but with the increase of negative clearance, fatigue life significantly declines. Therefore, choosing the bearing clearance, generally making the work clearance zero or slightly vivacious, is appropriate. In addition, need to improve the rigidity of the bearing or need to reduce the noise, work clearance to take the negative value further, and in the bearing temperature rise is intense, work clearance is to take the positive value further, etc., also must be used according to the conditions to do specific analysis.

Bearing clearance standard quick reference table

Nterchangeable radial internal clearance for cylindrical roller bearings
Radial Internal Clearance of Deep Groove Ball Bearings (Courtesy of NTN Bearings Corporation)
Nterchangeable radial internal clearance for cylindrical roller bearings
Interchangeable Radial Internal Clearance for Cylindrical Roller Bearings (Courtesy of NTN Bearings Corporation)

Understanding the Importance of Bearing Clearance

Understanding the importance of bearing clearance

Understanding the Importance of Bearing Clearance -TFL