There is a certain gap between the inner ring, the outer ring and the rolling elements of the rolling bearing, so there may be a relative displacement between the inner ring and the outer ring.When there is no load, one ring is fixed, and the other ring moves from one limit part to the other limit part, and the axial and axial directions of the other ring are called radial clearance rate and axial clearance rate, respectively.According to the mode of the bearing, the gap is divided into three types.
(1) Initial clearance.It refers to the clearance in free mode before installing the rolling bearing, which is determined by the manufacturer's handling and assembly.
(2) The installation gap, also known as the fitting period.It refers to the gap between the bearing and the shaft and the housing when it is installed, but not yet running.
Due to interference with the installation, either the inner ring is expanded, or the outer ring is reduced, or both, the installation clearance is smaller than the initial clearance.
(3) Operation license.The clearance of the rolling bearing in the working state, during operation, the temperature of the inner ring rises greatly, and the thermal expansion is greater, thereby reducing the bearing clearance.
Due to the load, elastic deformation occurs at the contact between the rolling elements and the raceway, thereby enlarging the bearing clearance.Whether the running clearance of the bearing is greater than the mounting clearance depends on the combined effect of these two factors.
