scope:

This Standard defines the thermal speed rating for rolling bearings and calculation principles. The parameter determined in accordance with this Standard applies to rolling bearings of the given series and sizes of standard design specified in JIS B 1511 or of a design that, from a frictional point of view, can be related to a standard design bearing.

Thrust ball bearings are excluded from this Standard as kinematic effects do not allow the thermal speed rating defined in this Standard to be applied.

NOTE 1 In Annex A mean values for coefficient f_or for calculation of the loadindependent frictional moment and coefficient f_1r for calculation of the load-dependent frictional moment under reference conditions in clause 5 are given.

NOTE 2 In Annex B the reference conditions for grease lubrication are defined. The reference are chosen such that the thermal speed rating for grease lubrication is identical to that for oil bath lubrication.

NOTE 3 The International Standard corresponding to this Standard and the symbol of degree of correspondence are as follows:

ISO 15312: 2003 Rolling bearings-Thermal speed rating-Calculation and coefficients (IDT)

The symbols which denote the degree of correspondence in the contents between the relevant International Standard and JIS are IDT (identical), MOD (modified), and NEQ (not equivalent) according to ISO/ lEC Guide 21-1.