NTN Tapered Roller Bearings

                          ● Tapered Roller Bearings




                            Single row tapered              Double row tapered
                               roller bearing                 roller bearing


Tapered Roller Bearings   1. T
                              ypes, design features, and characteristics

                          Tapered roller bearings are designed so the                          available in both metric and inch series. Each
                          tapered vertex of the raceway surfaces of the                        type and associated characteristics are shown
                          inner and outer rings and rollers converge at                        in Table 1. For four-row tapered roller bearings,
                          one point on the centerline of the bearing (see                      see section “C. Special Application Bearings”.
                          Fig. 1).
                            The tapered rollers are guided by the
                          combined force of the inner and outer raceway
                          surfaces which keep the rollers pressed up
                          against the large rib on the inner ring.
                            A large variety of these bearings, including
                          single, double, and four row arrangements, are
                                                                                                                           Fig. 1
                          Table 1 Tapered roller bearing types and characteristics
                             Type                                                        Characteristics

                                       (1) There are both metric and inch series adhering to the standards shown in the following table.
                                           Dimension series
                                                           Metric series                            Inch series
                                                            JIS B 1534
                                                                                   ABMA
                                            Standard        JIS B 1512-3
                                                                                   (includes metric J-series)
                                                            ISO 355
                                                                                Inner ring no. / outer ring no.
                                              Basic    Example, 30210
                                                                                (“J” appears at the beginning of the basic number
                                            number              ＊T2EE040
                                                                                in the case of J-series.)
                                          ＊Dimension series previously not covered by 3XX are regulated under JIS B 1512-3;
                                           dimensions previously missing from 3XX will henceforth use the bearing number.
                                       (2) In addition to the standard design, there are also medium contact angle and large contact angle types,
                          Single row        denoted by the contact angle codes at the end of the part numbers (C and D, respectively).
                           tapered     (3) Subunits
                                           Tapered roller bearings can be disassembled into parts: the inner ring, rollers, and cage (collectively known
                             roller
                                           as the “CONE”) and the outer ring (known as the “CUP”). These are the bearing’s “subunits”. Subunit
                           bearings        dimensions are standardized under ISO or ABMA standards, and unified subunits are interchangeable within
                                           each dimensional standard. However, high precision grade bearings are generally not interchangeable,
                                           and these subunits must be used by assembling only subunits with identical manufacturing numbers.
                                               Aside from any cautionary notes that may appear, the single row tapered roller bearings listed in the dimension
                                           tables have subunits standardized for both metric and inch systems (including J series) (see Fig. 2).

                                             Subunit dimensions


                                                                                                2α      E

                                             E : Outer ring (cup) nominal small-end diameter
                                             α : Nominal contact angle
                                                                                Fig. 2                                   Continued to the next page

                                                                                       B-127