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CAUTION: WHEN HANDLING BEARINGS WHICH ARE CLEANED AND NOT OILED, WEAR EITHER SYNTHETIC RUBBER GLOVES OR NYLON MESH GLOVES WITH POLYETHYLENE PALMS AND FINGERS. IF NOT AVAILABLE, CLEAN COTTON GLOVES SHALL BE WORN.
(2)
Place bearings in a covered container or plastic bag while awaiting inspection to minimize contamination.
NOTE: To reduce the chance of damage, minimize handling bearings and bearing components.
(3)
Identify the following bearing functional surfaces to be inspected:
.
Total raceway width of straight-through (non-flanged) races of roller bearings.
.
Load paths on flanged raceways of roller bearings.
.
Roller OD load path.
.
Roller corner radius to end face intersection (see Figure 301).
.
Roller bearing raceway guide flange inner surface.
.
Cage pilot land surface.
.
Balls and ball bearing outer raceway.
.
Ball bearing loaded raceway half for split inner rings.
(4)
Visually inspect the bearing functional surfaces. Refer to Table 301 for explanation and definition of defect terms used in determining the condition of the bearing or bearing component being inspected.
NOTE: Visual inspections should be performed using suitable lighting and an instrument capable of magnifying the bearing surfaces ten times (10-power magnification).
Visual inspection may be supplemented by hand tracing using a precision stylus as descried in Step (5).
(5) Inspect the bearing functional surfaces using a precision stylus.
NOTE: When a stylus is used it shall have a tip radius as specified in Table 302 and Table 304. The stylus shall be held perpendicular to the surface being examined, and the only pressure exerted should be the weight of the stylus.
Surface blemishes of acceptable bearings must not exceed the requirements specified in Table 302, Table 303, Table 304, and Table 305.
Inspection
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(6) Determine if the bearings surface conditions are severe enough to reject the bearing for reuse.
NOTE: Components (races, rollers, cage, etc) of each bearing should be separated from components of other bearings. Each reassembled bearing must contain only original components and be oriented the same as the bearing drawing requires.
(a)
Bearings that exhibit surface conditions that exceed the limits specified in Table 302, Table 303, Table 304 and Table 305, or other damage that renders them inoperable, are to be rejected for reuse.
(b)
Bearings that have surface conditions no worse than those shown in illustrations are identified as acceptable and may be reused.
(c)
Roller bearings that have a half-complement of rollers with the rollers assembled in alternate cage pockets may be reassembled with the rollers in the unused cage pockets as long as the cage does not have any defects which would be cause for rejection.
Inspection
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Table 301. Bearing Component Inspection Criteria Definitions and Limits
Term Definition (Description of Defect)
Arced Round pit shaped cavity in a surface from which metal has been removed by an electrical arc, causing a temper change (softer) in the metal around the pit shaped cavity. Arced condition is cause for rejection.
Brinelling (True) True brinelling is plastic flow of metal characterized by smooth, shiny bottomed indentations in raceways and rolling elements usually equally spaced corresponding to rolling element spacing as shown in Figure 302. (Refer to Table 302 and Table 303 for limits.)
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