Two-bearing housings PD series Housings in the PDR series
The bearing arrangement for housings in the PDR series comprises († fig. 7): • a single row cylindrical roller bearing in the NU 3 ECP series, in the non-locating bearing position • a cylindrical roller bearing in the NU 3 ECP series in combination with a single row deep groove ball bearing in the 63 series (with C3 clearance), in the locating bearing position The deep groove ball bearing acts as a pure thrust bearing, accommodating the axial loads in both directions, and is mounted with radial clearance in the housing. To prevent the outer ring from turning, an O-ring is inserted in a groove in the cover that abuts the outer ring. The bearings support heavier radial loads than bearings in both PDN and PDP series housings. Non-standard bearing arrangements Housings in the PDN series are designed to accommodate two deep groove ball bearings. For special applications, the housings can be fitted with various combinations of deep groove ball bearings, angular contact ball bearings, cylindrical roller bearings and spherical roller bearings.
SKF can supply the following combinations, available as assembled units († fig. 8): • PDNA .. DD units, incorporating a deep groove ball bearing in the non-locating bearing position and a pair of universally matchable angular contact ball bearings, mounted back-to-back, in the locating bearing position. Smaller housings accommodate axial loads in only one direction, while larger housings can withstand axial loads in both directions (a) • PDND units, incorporating an NJ design cylindrical roller bearing on each end to form a cross-located (“floating”) bearing system (b) • PDNE units, an NJ design cylindrical roller bearing and a deep groove ball bearing to form a cross-located (“floating”) bearing system (c) • PDNF .. DD units, incorporating an NJ design cylindrical roller bearing and a pair of universally matchable angular contact ball bearings, mounted back-to-back, to form a cross-located (“floating”) bearing system (d) • PDNL units, incorporating a spherical roller bearing on each end to form a cross-located (“floating”) bearing system (e)
Fig. 7
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