Tolerance for Tapered Bore:
Tolerance for tapered bore refers to the deviation of the diameter of the bore from a theoretical ideal diameter. This deviation is used to ensure that the bearings fit securely on the shaft and function properly. In most cases, a tolerance of H7 or H8 is used for tapered bore bearings. This means that the deviation from the theoretical ideal diameter is within 7 or 8 hundredths of a millimeter. The actual tolerance used for a specific application will depend on the requirements for the application and the design of the bearing.
Tapered bore tolerance:
Tapered bore tolerance is the permissible deviation from the specified size of a tapered bore in a spherical roller bearing. Tapered bores are used to fit the bearings onto the shaft with an interference fit. The tolerance is given as the difference between the maximum and minimum diameters of the bore. The tolerance class for a tapered bore is specified in international standards, such as ISO 15, ISO 286-2 and ABMA (American Bearing Manufacturers Association) standard 19.2. Tolerance classes range from IT01 to IT5, with higher tolerance classes having tighter tolerances and more precise dimensions. The tolerance class used will depend on the specific application requirements, such as load and speed conditions, and the manufacturer's recommendations.
d = Nominal Bearing bore diameter
d1 = Basic diameter at the theoretical Large and of a tapered bore
In case of 1/12 taper
In case of 1/30 taper
⊿ d mp = Mean Bore diameter deviation at theoretical small end of a tapered bore
⊿ d1 mp = Mean Bore diameter deviation at theoretical large end of a tapered bore
B = Nominal bearings inner ring width
∝ = Nominal taper angle (half of cone angle)
In case of 1/12 taper
∝ = 2" 23' 9.4"
= 2.38594 º
= 0.041643 rad
In case of 1/30 taper
∝ = 0" 57' 17.4"
= 0.95484 º
= 0.016665 rad
