Figure 2-6. Locked anti-friction bearing.

(5) P r e l o a d . Preload is an initial force placed

clean paper. Do not unwrap new bearings until

o n the bearing at the time of assembly. Determine

time of install ation.

from

clearance

the

end

preload or

(c) The life of an anti-friction bearing will be

SPECIFICATIONS, Care should be exercised in

s h o r t e n e d if not properly lubricated.

applying preload. Misapplication of preload to

bearings requiring end clearance can result in

bearing

failure.

(6) S l e e v e b e a r i n g s . D O N O T I N S T A L L

SLEEVE BEARINGS WITH A HAMMER. Use

a press if possible and apply the pressure directly in

iine with the bore. If it is necessary to drive on a

bearing use a driver or a bar with a smooth flat end.

If a sleeve bearing has an oil hole, align it with the

o i l hoie in the mating part.

k. Gaskets. Be sure the holes in the gaskets

correspond with the lubricant passages in the

m a t i n g parts. If it is necessary to make gaskets,

s e l e c t stock of the proper type and thickness. Be

Figure 2-6. Locked anti-friction bearing.

sure to cut holes properly. Blank gaskets can cause

(2) Double row, tapered roller. D o u b l e r o w ,

serious damage.

tapered roller bearings are precision fit during

l. Seals.

manufacture and the components are not in-

(1) F l o a t i n g s e a l s .

terchangeable. The cups, cones and spacers are

(a) Floating ring seals have highly finished

usually etched with the same serial number and

surfaces and are held together by toric sealing rings.

letter designator. If no letter designators are found,

T h e flexibility of the toric sealing rings makes the

wire the components together to assure correct

floating ring seals self aligning and compensates for

installation. Reusable bearing components should

w e a r on the metal faces.

b e installed in their original positions,

(b) During disassembly, tape the metal

(3) Heating b e a r i n g s . B e a r i n g s w h i c h r e q u i r e

floating ring seals together so they will be kept in

e x p a n s i o n for installation should be heated in oil

matched sets. Always install the metal floating ring

not to exceed 250F. (121 C). When more than

seals in pairs; that is, two new seals together or two

one part is heated to aid in assembly, they must be

seals that have previously run together. Never

a l l o w e d to cool and then pressed together again.

r e i n s t a l l a used toric sealing ring.

P a r t s often separate as they cool and shrink.

(4) I n s t a l l a t i o n , L u b r i c a t e n e w o r u s e d

checked, the metal floating ring seal (2), the rubber

bearings before installation. Bearings that are to be

toric sealing ring (3) and the toric sealing ring

p r e l o a d e d must have a film of oil over the entire

retainer (4). The dimension must be uniform

assembly to obtain accurate preloading. When

around the entire circumference of the floating ring

installing a bearing, spacer or washer against a

seal. Check the dimension at 90 intervals.

s h o u l d e r on a shaft, be sure the chamfered side is

toward the shoulder (fig. 2 - 7 ) . W h e n p r e s s i n g

b e a r i n g s into a retainer or bore, apply pressure to

the outer race, If the bearing is pressed on the shaft,

a p p l y pressure on the inner race.

Figure 2-8. Floating seal installation.

Figure 2-7. Chamfer on a shouldered shaft.

2-5