9 ) ' ~ n s ~ $ c t t%s % & r i n g r e c w a y s . In case of s e p a r a b l e b ~ a r i n g s , it 5s p a c s l b l s t o i n s p e c t t h e r a c e v a y t ,%roughly , Look f o r r e c f n ~ s s on t h e r+cEway. I P t h ~ r e is o a v i n s s s on t h ~ raceuay, it w i l l n o t l ook **niFormly b r i g h t .

1 ~ ) Ax.-.-o c h f c k t h e r o l f i p g E I E E E ~ ~ S a s f a r a s p o s s i b ~ e I T ~ E I ' E Liius't n o t b~ a n y s c r a t c h , n i c k o r r u s t mark.

-. 1 3 ) t ' 7 ~ c k th i . r a d i a l c ; c * i i - ~ ~ of + t h e b ~ a r i n g s u h e r s

p3;sible. I n C ~ E E o f t ~ a r i n g s l i k s s p h ~ r i c a 1 o r cy::ndrizal r o l l e r , it can b s e a s i l y d o n s by f ~ ~ l ~ r g a u q ~ . Thf R.C. suet b~ a s p ~ r I.S.O.

12) R o t z t e t b ~ b e a r i n g b y >and and t r y t o EEL from EXFET~E!?CE i f t h e r t . t ~ a i i ) n is f r E e t

?3! Cook f o r g r i n d i n g or t b r n i n g n a r k s , Also c h ~ c k i f t h e r f 2% a n y mark l s f t from ho ld ing t h e b e a r i n g s l o r m c h i n i n g . Look f o r p r o c ~ s s i n g t r a c s s w i t h E m r y p2QET.

-. , n c i k s C s r ~ d portLon of t h e o u t ~ r rirrg s i d ~ s shou ld t-5 t l a c k a s t h ~ s f pcrtions do n o t u - ~ d ~ x g o g r i n d i n g after hsat t r ~ ~ t a ~ i ~ t . Rad i i of b o t h i n n ~ r and o u t e r rzngs s n d a l s o l u b r i c a t i Tkese c o u l d sonsticf 0 s d t f i ~ i t r l y btz unground,

Yocr = s i n C ~ U E is, i f thE b s a r i l g l o o k s v e r y b r i g h t , it must b~ c h ~ ; k ~ d tho rough ly e n d e n y d i s c r a p a n c y n-%iced s h o u l d b e r e f s z r ~ 2 $0 s a n u f a c t u r s r s .

C icck - 2 g ~ d s s i g n - S ~ E E ~ and b r a ~ s / ~ r o n g t y p e o r F ~ V E E t y p ~ - I t s h o u l d b e as PET F A G P ~ b l i ~ a t i i 3 n .

C r : ~ r i r :%at t b ~ r s a r e no a r ~ l d i n g s p o t s niEar t h e s t a n p i n g ,

Thsck t b s t chamf&r nn b a t h She s i d s s L.F t h e r i n g a r e L7.iFcr&e

i n c a s e o f c y l i n d r i c a l PoIEer b ~ a r l n g s , t r a c k d i a m e t e r s h o u l d b e as per t h s ca t e logue ,

/

Loair f o r i d ~ n t i f i c a t i o n on m ~ t a l l i c s h i e l d or R u b b ~ r Z e a l . I t s h o u l d be as G E ~ ; e r anufac tu re rqs d ~ s i g n .

*.srinting marks e n B o r ~ or O.D. is a n i n d i c a t i a n o f USE^ S ~ ~ r i n g .

FAG Precision Bearings Limited

I)

CNARACTERISTlCS AND ADVANTAGES OF 'TVPB' CAGES f GLASS FiBRE REINFORCED POLYAMID& 66 J

1. Density of Material :-

The density of high strength ~ ~ ! , a m i d ~ materials used for the cages is only about 15 of the density of steel or bress Shoa time changes of speed due fo acceier~tions or retardations of roliers and t;-bcs may result in slippage between rollers and raceways. This slippage increases with :';e mass of the rotating parts Under such 0per;:rng corditions a low cage weigh? 8s fsvourable. .

2. Precise shaping of the high si,e?gth polyamide material (InjecPion moulding) :-

The shape of the injection m o ~ l d e d high strength polyamide cage can be much better adapted to special requirements than the pressed or machined metel cage. This applies to shaping of lubrication pockets a s well as t o application of resilient holding devices e. g. for holding the rollers in the cage and for timitating the cage movements relaf've to the bearing ring.

3. Good sliding and dry running properties :-

The sliding properties and the wear resistants of pofyamide combined with steel or other po!yamide parts are excellent. These assets mainly become effective in case of sliding without lubrication or sparse lubrication. For example, deep groove ball beaitngs with high strength polyamide cages have proven out well whei? highly stressed on the crank shaft of two-stroke engines known by their unfavourabie lubricating conditions due to the fuel-oil mixture. The cran3 shaft speed of racer e@ies may reach more than t 4 . W rpm. In this case maximum temperatures of more than 1 W C were ascertained.

4. Advantages of the material elasticity in (deep groove ball bearing) :- . The cage is particularly highly stressed when the inner ring is tined relative t o the outer ring due t o a moment, e. g. in case of important shaft deflections. The batls will then run siower or faster than the cage once per fotation (continuous changing of the wntact angle bal!jraceway once per cage rotation). The stiffer the cage the greater the reaction between rolling element and cage pocket and thus the higher the cage wear and eventually even the raceway wear. In this case the high elasticity of the high strength polyamide cage proves profitable.

5.- Higher reliability in case of in gress of solid contaminants into the bearings :-

Here the cage design is of great importance. Due t o a possible q m u l a t b r ! of f ~ i e i g n matter (e. g. Coal. Stone. Powder, etc.) in the cage pockets the rolling elements tend to be locked which leads to elevated temperature. In this case the polyamide cage whose elasticity prevents locking of the batls in the cage pockets would Be profitably put t o use.

6. Optimum utilisation of the bearing cross section by high strength polyamide cagrs :. The FAG Spherical Roller Bearings E-type enabled on increase of load ratiag. By rsmirdng the center lip and applying a high strength polyamide cage, it was possible 20 fully use the bearing section (larger rollers, increased number of rollers, raceways without recessss).