ISO/TR 1281-1-2021 pdf download

ISO TR 1281-1-2021 pdf download.Rolling bearings一Explanatory notes on ISO 281一 Part 1: Basic dynamic load rating and basic rating life. 7.2 FactorsX, Yande 7.2.1 Radial ball bearings 7.2.1.1 Values of . For single row radial contact groove ball bearings, Reference [5] gives a value of = 1,2 based on the results of tests, and for other bearings = 1,5 which are close to the theoretical curves. However, based on later tests, ISO/R281 took values of = 1,05 for radial contact groove ball bearings and single row angular contact groove types with a = 5; . = 1,25 for other angular contact groove types; and = 1,5 for self-aligning types (Reference [4]). 7.2.1.2 Values of , The reduction factor, ij, depends on the contact angle, a, and is given by =1—ksina (76) Based on experience and preliminary tests, Reference [5] gives k = 0,4 and Reference [ft] k = 015 to 0,33. In ISO/R281, k = 0,4 (= 1/2,5) was used for radial contact groove bearings (a = 5°) and angular contact groove bearings with a = 5°, 10° and 15° and k = (1/2,75) is used for angular contact groove bearings with a = 20° to 45° (see Reference [4]). NOTE ISO/R281 did not include factors for bearings with a = 45°. Factors for this angle are specified in ISO 28 1:2007. 7.2.1.3 Values of contact angle a’ For radial contact groove ball bearings as well as angular contact groove bearings with nominal contact angle a < 15°, the real contact angle varies considerably with the load. Consequently, ISO 281:2007, Table 3, gives all factors as functions of the relative axial load.ISO TR 1281-1 pdf download.