Webwatch A s s i g n e e : The Torrington Company {
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Figure 6. The seal p o s i t i o n s i t s e l f correctly, r e g a r d l e s s o f i m p r o p e r centering. c e n t r i n g of t h e s u p p o r t e l e m e n t relative to the :zxis o1 t h e valve. C o n s e q u e n l l y , a n y e r r o r s of perpendicularity between the s u r f a c e of the ei~gine h e a d a n d t h e axis of t h e valve do llOt aflect t h e s e a l i n g of t h e v~llve s e a l s .
Seal for a spherical plain bearing Patent number: US5573336 Date o f p u b l i c a t i o n : 1 2 t h November 1996 Inventor: M i c h a e l M a r o n e y
S p h e r i c a l p l a i n b e a r i n g s a r e u s e d in g i m b a l m e c h a n i s m s , t r a c k drives lbr b u l l d o z e r s , s u p p o r t s lor b a c k h o e shovels, a n d o t h e r a r t i c u l a t i n g m e c h a n i s m s . In s u c h a p p l i c a t i o n s , eflective s e a l s m a y e x t e n d t h e life of the ball a n d s o c k e t (outer ring or b e a r i n g housing} b y r e t a i n i n g lubricant within the bearings, e x c l u d i n g d e b r i s from the b e a r i n g s , a n d r e d u c i n g r u s t on the s p h e r i c a l m e m b e r a n d o u t e r ring. Various s e a l i n g r i n g s h a v e b e e n p r o p o s e d for s p h e r i c a l p l a i n bearings such as a simple e l a s t o m e r i c w i p e r r i n g m o u n t e d on t h e o u t e r ring a t t h e j u n c t u r e w i t h the s p h e r i c a l m e m b e r . However, s u c h s e a l i n g r i n g s p r o v i d e little s p a c e lot l u b r i c a n t r e t e n t i o n , are not b i a s e d n o r m a l to the s p h e r i c a l m e m b e r ' s s u r f a c e , allow little m i s a l i g n m e n t of t h e s p h e r i c a l member, and may require a s e p a r a t e p r o t e c t i v e m e t a l c a p over t h e s e a l i n g ring. O v e r c o m i n g t h e s e p r o b l e m s is a c c o m p l i s h e d in this i n v e n t i o n by p r o v i d i n g a seal, 10 F i g u r e 7, for a spherical plain bearing with a s p h e r i c a l m e m b e r a n d a n o u t e r ring or b e a r i n g h o u s i n g . The seal c o m p r i s e s a n a n n u l a r metallic s u p p o r t m e m b e r with a c y l i n d r i c a l s u r f a c e a n d a c o n i c a l s u r f a c e . An
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Figure 7. The seal t o l e r a t e s significant misalignment. a n n u l a r e l a s t o m e r i c seal lip is m o u n t e d on t h e c o n i c a l s u r l a c e of the m e t a l l i c s u p p o r t m e m b e r , a n d a n e l a s t o m e r i c s e a t b o d y is m o u n t e d on t h e c o n i c a l s u r f a c e of the m e t a l l i c s u p p o r t m e m b e r , a x i a l l y i n w a r d oI l he e l a s t o m e r i c seal lip. T h e c y l i n d r i c a l s u r f a c e is m o u n t a b l e withi!l a b o r e of t h e o u t e r ring or b e a r i n K h o u s i n g so t h a t t h e elastom,~ric s e a t lip a n d e l a s t o m e r i c s e a l b o d y c o n t a c t the spherical member. T h e s e a l p e r m i t s a large a m o u n t of m i s a l i g n m e n t of a s h a f t m o u n t e d in t h e bore. G r o o v e s a r e a l s o incorporated within the elastomeric seal body, w h i c h e x t e n d a l o n g t h e s p h e r i c a l s u r f a c e Io facilitate lubrication.
Webwatch Alumina Ceranics
The MeNally I n s t i t u t e
http: / /www.ceran~ics.com/aci
http: / / w w w . m c n a l l y i n s t i t u t e . c o m
A l u m i n a C e r a m i c s , p a r t of t h e C o o r s C e r a m i c C o m p a n y , m a k e s w e a r p a r t s from t e c h n i c a l c e r a m i c s : a l u m i n i u m oxide, silicon c a r b i d e , silicon n i t r i d e a n d t u n g s t e n c a r b i d e . T e c h n i c a l s p e c i f i c a t i o n s for e a c h of t h e m a t e r i a l s a r e offered, a n d s e n s i b l y , s e p a r a t e a d d r e s s e s a r e p r o v i d e d for g e n e r a l a n d q u o t a t i o n i n q u i r i e s - e l e c t r o n i c d r a w i n g files c a n be a t t a c h e d .
P r o c l a i m i n g itself "the only c e n t r i f u g a l p u m p a n d m e c h a n i c a l s e a l URL y o u will ever need", t h e McNally I n s t i t u t e ' s h o m e p a g e is a d m i t t e d l y o u t s t a n d i n g . E s s e n t i a l l y t h i s is a n e n t i r e r e f e r e n c e h a n d b o o k in e l e c t r o n i c form, w i t h over 100 p a p e r s on a b e w i l d e r i n g a r r a y of r e l a t e d topics. A l t h o u g h l a c k i n g a n y a p p a r e n t e x p l a n a t o r y d i a g r a m s , t h i s is easily t h e F i n d Of The M o n t h .
Rotary Industrial Components http: //www.rotarylt d.com
Wriason Seals http: //www.wriason. com
RIC a t t r i b u t e s m a n y p a c k i n g f a i l u r e s to i n c o r r e c t fitting, a n d so its w e b s i t e i n c l u d e s a c o m p r e h e n s i v e g u i d e to p a c k i n g t y p e s a n d i n s t a l l a t i o n p r o c e d u r e s . T h e c o m p a n y a c t s a s a d i s t r i b u t o r for F l e x - A - S e a l c a r t r i d g e s e a l s a n d t h e full r a n g e is profiled. An S I / I m p e r i a l c o n v e r s i o n tool is a l s o p r o v i d e d .
Sealing Technology No. 40
A s o u r c e of s e a l s a n d s e a l k i t s for J a p a n e s e m e t r i c h y d r a u l i c c y l i n d e r s Rod, p i s t o n a n d b u f f e r s e a l s , b u s h i n g s , U - c u p s , O - r i n g s a n d w e a r r i n g s are covered in a 22 p a g e guide, a n d a s i m p l e s c h e m a t i c i n d e x of t h e a s s e m b l y d e m o n s t r a t e s w h e r e e a c h of t h e s e u n i t s fits in.
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