Page 590 - Rollingbearings

7 Needle roller bearings
Alignment needle Combined needle Needle roller / angular
roller bearings roller bearings contact ball bearings

SKF supplies needle roller / angular contact
SKF alignment needle roller bearings have SKF combined needle roller bearings consist ball bearings without seals in two series
an outer ring with a sphered (convex) out- of a radial needle roller bearing combined (ig. 23):
side surface Two polymer seating rings with with a thrust bearing They can accommo-
a sphered (concave) inside surface are date both radial and axial loads They are • NKIA 59 series bearings can accommodate
encased in a drawn sheet steel sleeve and particularly suitable for applications where axial loads in one direction
itted over the outer ring other types of locating bearing arrange- • NKIB 59 series bearings can accommo-
SKF supplies alignment needle roller ments occupy too much space, or where the date axial loads in both directions
bearings with or without an inner ring axial loads are too heavy, the speeds are too
(ig. 22) high, or the lubricant is inadequate for These combined bearings:
arrangements with simple thrust washers
Bearings with an inner ring SKF supplies combined needle roller bear- • consist of a radial needle roller bearing
ings in the following basic designs: and an angular contact ball bearing
• should be used in applications where the • accommodate heavy radial loads, carried
shaft cannot be hardened and ground • needle roller / angular contact ball bearing exclusively by the needle roller bearing
• have limited permissible axial displace- • needle roller / thrust ball bearing • accommodate light axial loads, carried
ment of the shaft relative to the housing • needle roller / cylindrical roller thrust exclusively by the angular contact ball
(product table, page 650), which can be bearing bearing
extended, if needed, by using a wide inner • are low cross section bearings
ring (Needle roller bearing inner rings, Relubrication intervals for the radial and • can operate at high speeds
page 593) thrust part of the bearing must be calculated • are separable, i.e. the inner ring can be
separately The shorter of the two intervals mounted separately from the outer ring
Bearings without an inner ring should be used For additional information and rolling element and cage assemblies
about lubrication, refer to Lubrication, • can be grease or oil lubricated, depending
• are an excellent choice for compact bear- page 110 on the application
7 ing arrangements, if the shaft can be In the case of grease lubrication, both
hardened and ground the needle roller and angular contact ball
bearings should be illed with the same
lubricant prior to mounting

Fig. 22
Alignment needle roller bearing

With an inner Without an inner
ring, PNA ring, RPNA

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