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Bottom roller bearings for textile machinery
                                                                                                              NTN



           Bottom Roller Bearings for Textile Machinery


             These bottom roller bearings for textile machinery are  W) (latter two types---classified by the fixing method
           grease-prefilled needle roller bearings intended to support  applied).
           the bottom rollers (fluted rollers) of a fine spinning   These bearings can be supplied with saddle thereon on
           machine, a roving frame or a drawing frame. Type FRIS  request, similarly to A-series.
           is applied to a fine spinning machine and a roving frame,  Type FR is used to support the rollers of a drawing
           and Type FR applied to a drawing frame.                frame. This bearing type is composed of two drawn cup
                                                                  type needle roller bearings which are configured in a
                                                                  housing. These have no inner ring and use a shaft as the
           Types and construction                                 direct raceway surface. Synthetic rubber seal is fitted in
             Bottom roller bearing FRIS is used to support the    the both ends of the housing. This bearing type is fixed to
           bottom rollers of a fine spinning machine and a roving  a support stand with knock pins press-fitted in the
           frame. The outer ring outer profile of this bearing type is  housing.  The knock pin is provided with an grease hole
           spherical, which can allow, to some extent, mounting   to enable grease replenishing.
           error in the bottom rollers. On the other hand, the inner
           ring is provided with a rib at its both ends and a clearance
           between the outer ring and each inner ring rib is
           minimized.  Furthermore, the rib outer surface is knurled
           to prevent invasion of cotton pieces into the bearing.
             These bottom roller bearings are classified into
           internationally interchangeable A-series bearings with
           bearing fixing saddle (to fix a bearing to a support stand)
           and B-series bearings adaptable to the dimensions of JIS
           Fluted Rollers.
             A-series bearings are further classified into one
           bearing type (bearing number + tail code SA) wherein
           inner ring and outer ring are separable from one another
           according to saddle type and another bearing type                        Fig. 4  Type FR
           (bearing number + tail code SB) wherein inner ring and
           outer ring are non-separable. Of course, these bearings
           can also be supplied without saddle.
                                                                  Nominal bearing number
                                                                    Nominal bearing number comprises type code,
                                                                  dimension code [shaft dia. (d or Fw)] and tail code.


                                                                       FRIS   19   SB

                                                                                                 Tail code
                                                                                                 Dimension code
                                                                                                 Type code
                Fig. 1  Type FRISʝSA    Fig. 2  Type FRISʝSB
                                                                                        Fig.5
             On the other hand, B-series bearings are further
           classified into bearing type with grease nipple (bearing
                                                                  Bearing fits
           number + tail code N) , bearing type with knock pin on its
           outer ring (bearing number + tail code P) and bearing    Table 1 shows bearing fits on/in shaft and housing.
           type with knock hole on its outer ring (bearing number +
                                                                  Table 1  Bearing fits
                                                                                       Shaft
                                                                   Bearing type                      Housing (stand)
                                                                              Screwed joint  Spline joint
                                                                      FRIS      g5 (g6)     j5 (j6)       H10
                                                                      FR              h5 (h6)             H10





                             Fig.3  Type FRIS


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