Complaint “c”
wrong type of grease or oil Consult reliable lubricant manufacturer for proper type of lubricant.
causing break-down of lubricant. Check SKF Catalog instructions to determine if oil or grease should be used.
-
Low oil level. Loss of lubricant Oil level should be at center of lowest ball or roller in bearing.
2 through seal.
Insufficient grease in housing. Using grease, lower half of pillow block should be ‘/2 to $$ full.
See Illzi~t~ation-Complaint “A”, Condition
Bearings selected with inade-quate internal clearance for
con-ditions where external heat is Replacemen t bearing should have identical marking as original
conducted thru shaf+, thereby bearing for proper internal clearance. Check with SKF if bearing
expanding excessively the in- markings have become indistinct.
ner ring.
Foreign matter (dirt, sand, car
5 bon, etc.) entering into bearing Clean out bearing housing. Replace worn-out seals or improve
housing. seal design to obtain adequate protection of bearing.
Corrosive agents (water, acids,
6 paints, etc.) entering the beor- Additio n of a shroud and Ior) flinger to throw ofF the foreign matter.
ing housing.
Housing bore ou t of round. Check and scrape housing bore to relieve pinching of bearing.
7-8-9 Housing warped. Excessive dis- Be sure pedestal surface is flat, and shims cover entire area of
11-51 tortion of housing. Undersized pillow block base.
housing bore. See Ihtration-Com plaiaint “A”, Conditions 7-8-9-4 I-5
Failure to remove chips, dirt,
10 etc. from bearing housing be. Carefully clean housing, and use fresh lubricant.
fore assembling bearing un it.
25
CODE 10 TYPICAL ONDITION
REPLACEM ENTS ARE TOO FREQUENT - C~mploint “C” (Continued)
REASON FOR CONDITION PRACTICAL SOLUTION
Oil leakage resulting from air
11 flow over bearings. (Example:
forced draft fan with air inlet Provide proper baffles to. divert direction of air flow.
over bearings.)
15 Opposed mounting. Insert gasket between housing and cover flange to relieve axial
pre-loading of bearing.
See Illustration-Comp laint “A”, Condition IS
16 Two “held” bearings on one Back of covers in one of the housings, using shims to obtain
ade-23-24 shaft. Excessive shaft expansion. quote clearance of outer ring, to permit free axial b earing motion.
See Illustration-Comp laint “A”, Conditions 16-23-24
17 ,* Shaft diameter too small. Metallize shaft and regrind to obtain proper fit.
Adapter insufficiently tightened. Retighten adapter to get firm grip on shaft.
See Illustration-Comp laint “B”, Conditions I 7- I
19 Adapter tightened excessively. Loosen locknut and sleeve assembly. Retighten sufficiently to clamp
sleeve on shaft but be sure bearing turns freely.
See Illustration-Comp laint “A”, Condition 19
“UCVLHMFACES
If not severe, use thin layer of --l
20 Jxcessive Oil leakage loss at of housing lubrica nt. split. gasket cemen t. Don’t use shims.
Replace housing if necessary.
L!I!QL
OR .OR
I P’s i; ‘P
21-52 Unbalanced lood. l-lousing bore Rebalance machine. Replace housing with one having proper bore.
too large. See Illustration-Comp laint “A”, Con ditions 2 I -52
Unequa l load distribution an Rework shaft, housing, or both, to
25 26
bearing. obtain proper fit. May require
new shaft and housing.
27 Inadequate shoulder support Remachine shaft fillet to relieve
causing bendin g of shaft. stress. May require shoulder collar.
29 Inadequate support in housing Remachine housing fillet to relieve
causing cocking of outer ring. stress. May require shoulder collar.
28 Rubbing of shaft shoulder Remachine shaft shoulder to clear seal.
against bearing seals. See Illustration-Comp laint “A”, Condition 28
30 Distortion of bearing seals. Remachine housing shoulder to clear seal.
See Illustration-Comp laint “B”, Condition 30
26
REPL ACEM ENTS ARE TOO FREQUEN T - CornplaIn, “C” (Continued)
Remach ine shaft fillet to obtain neven expansion
Distortion of housin
stationary parts.
sing fillet to obtain
earance of rotating seal to elimina te rubbing.
The oil level at standstill must not exceed the center of the lowermost ball or roller. Locate cup with rotation of bearing. Replace constant level oiler with sight gage.
Incorrect method of mounti
Hamme r blows on bearing. when mountin
Excessively worn leathe r (or Replace seals after thoroughly 44 composition), or labyrinth seals.
Result: lubricant loss; dirt
get-ting in to bearing. fresh lubricant.
47
Shaft and housing shoulders and
face of locknut out-of-square Remach ine parts to obtain squareness with bearing seat.
50
Bearing seat diameter machined
oversize, caus ing excessive ex- Grind shaft to get proper fit between inner ring of bearing pansion of bearing inner ring, and shaft.
thus reducing clearance in
bearing.
53
“Pounding-out” of housing bore due to soft metal. Result:
en-larged bore . . . causing spin- bushing to correct size.
ning of outer ring in housing.
VIBRATION
Complaint “D”
Foreign matter [dirt, sand,
car-bon, etc.) entering bearing Clean out bearing housing. Replace worn-out seals or improve seal
housing. design to obtain ad equate protection of bearing.
27
VIBRATION - Comp lafnf W” (Continued)
REASON FOR CONDITION PRACTICAL SOLUTION
Corrosive agents (water, acids,
6 points, etc.) entering the bear- Addition of a shroud and (or) flinger to throw off foreign matter.
ing housing.
Housing bore out of round. Check and scrape housing bore to relieve pinc hing of bearing.
7-8 Housing warped. Excessive dis- Be sure pedestal surface is flat, and shims cover entire area of
9-41 tortion of housing. Undersized pillow block base.
housing bore. See Ihtration-Corn/hint “A”, Conditions 7-8-P-41 -SI
Failure to remove chips, dirt,
10 etc. from bearing housing be- Carefully clean housing, and use fresh lubricant.
fore assembling bearing unit.
Shaft diometer too small. Metallize shaft and regrind to obtain proper fit.
17-l 8 Adapter not tightened sufi- Retighten adapter to get firm grip on shaft.
ciently. See Ihtration-Com plaint “B”, Conditions 17-l
21-52 Unbalanced load. Housing bore Rebalance machine. Replace hous ing with one having proper bore.
too’ large. See Ibstration-Com plaint “A”, Conditions 21-52
22 Flat on ball or roller due to Carefully examine balls or rollers, looking for fiat spots on the
skidding. (Result of fast starting.9 surface. Replace bearing,
25-26 Unequa l load distribution on Rework shaft, hous ing, or both, to obtain proper fit. May requir
bearing. new shaft and housing.
See Illustration-Complaint “C”, Conditions 25-26
27 __ Inadequate shoulder support Remachine shaft fillet to relieve stress. May require shoulder collar.
causirig bending of shaft. See Illustration-Compiaint “C”, Condition 27
29
Remachine housing fillet to relieve stress. May require shoulder
Inadequate support in housing collar
causing cocking of outer ring. See iliustration-Complaint “C”, Condition 29
Distortion of shaft and inner
31 ring. Uneven expansion of bear- Remachine shaft fillet to obtain proper support.
ing inner ring. See Mustration -Comp laint “C”, Condition 3
32 Distortion of housing and outer Remachine housing fillet to obtain proper support.
ring. Pinching of bearing. See Ihstration-Com plaint “C”, Condition 32
Incorrect linear or angular align- Correct alignme nt by shimming pillow blocks. Be sure shafts are
35-36 ment of two or more coupled coupled in straight line--especially when three or more bearings
shafts with two or more bearings. operate on one shaft.
See Ihstration-Com plaint “A”, Conditions 35-36
42 Incorrect method of mounting. Replace with new bearing. Don’t hammer any part of bearing
Hammer blows on bearing. when mounting.
45 Excessive clearance in bearing,
resulting in vibration. Use bearings with recommended internal clearances.
46 Vibration of machine. Check balance of rotating ports. Rebalance machine.
“Pounding-out” of housing bore 53
Rebore housing and press steel bushing in bore. Machine bore of
du t0 Soft metal. Result: en- bushing to correct size
larged bore . . . causing spin-ning of outer ring in housing.