Page 255 - Practical Machinery Management for Process Plants Major Process Equipment Maintenance and Repair

Power Transmission Gears 237

Figure 6-12. Straight roller bearing with inner race sken out of bearing assembly. Nc 2
roller shape.

2. Straight Roller Bearing-Highest radial load capacity for the
space used. Limited allowable shaft deflection through bearing-sel-
dom used for thrust. (See Figure 6-12.)
3. Spherical Roller Bearing-Very common in large drives where
large misalignment capability or medium thrust capacity or a combi-
nation of both is required. Often applied as a combination radial and
thrust bearing. (See Figure 6-13.)
4. Tapered Roller Bearing-Very common in all gear drives. High
radial and thrust capacity. Often supplied as a pure thrust bearing.
(See Figures 6-14 and 6-15.)
5. Plain Journal BearingAliding type of bearing. Works on either thin
film or hydrodynumicJilm lubrication. Usually made from bronze, zinc,
or babbitt-lined steel or bronze and may be either solid cylindrical or
split shell. The rolled insert type is also common. (See Figure 6-16.)
6. Modified Plain Journal Bearing-Can be modiJied for high speed
stability by cutting in a pressure dam, making an elliptical bore, or
cutting in longitudinal grooves. (See Figure 6-1 7.)