Unitized seal with integral spacer

Abstract

A unitized seal assembly is provided for installation between linkages of a chain drive designed for tracked vehicles. The seal assembly facilitates field preventative maintenance on the drive chain by utilizing an integral spacer that holds the critical sealing surfaces together at all times, and has a seal head that can be easily removed from the outer link bore of a chain link. Removal of the seal head from the outer link bore causes as-installed clearance passageways between the seal head and seat portions and the spacer to forcefully close and prevent abrasive particles from getting inside the seal and reaching the interior interface junction of the dynamic sealing surfaces during seal maintenance. The seal assembly also includes additional sealing features that provide improved performance.

1 . A seal assembly, comprising: 
 a spacer sleeve;    a first seal member slidably disposed at a first end of said spacer sleeve; and    a second seal member disposed at a second end of said spacer sleeve, wherein said first seal member is biased in an axial direction relative to said second seal member.    
   
   
       2 . The seal assembly according to  claim 1 , wherein said first seal member includes an axially extending seal boot portion.  
   
   
       3 . The seal assembly according to  claim 2 , wherein said second seal member includes a plurality of sealing ribs on an outer surface thereof.  
   
   
       4 . The seal assembly according to  claim 2 , further comprising a spring seat engaging a portion of said seal boot portion, wherein a spring is disposed against said spring seat for biasing said spring seat relative to said second seal.  
   
   
       5 . The seal assembly according to  claim 1 , wherein said second seal member is disposed on a seal seat member slidably mounted on said spacer sleeve.  
   
   
       6 . The seal assembly according to  claim 5 , wherein said first seal member is mounted to a seal washer that is disposed adjacent to said seal seat member.  
   
   
       7 . The seal assembly according to  claim 6 , wherein said second seal member includes a seal lip engaging said seal washer.  
   
   
       8 . A seal assembly, comprising: 
 a spacer sleeve;    a seal seat member disposed on a first end of said spacer sleeve;    a first seal member disposed on said seal seat;    a seal washer disposed on said spacer sleeve adjacent said seal seat member;    an second seal member disposed on said seal washer;    a spring seat disposed on a second end of said spacer sleeve; and    a spring disposed between said spring seat and said seal washer.    
   
   
       9 . The seal assembly according to  claim 8 , wherein a portion of said second seal member is an elastomeric boot member which has a portion thereof supported by said spring seat.  
   
   
       10 . The seal assembly according to  claim 8 , further comprising a pair of end retaining members press fit on each end of said spacer sleeve.  
   
   
       11 . The seal assembly according to  claim 9 , wherein said elastomeric boot member includes a radially extending seal lip.  
   
   
       12 . The seal assembly according to  claim 8 , wherein said first seal member further includes a sealing portion engaging said seal washer.  
   
   
       13 . The seal assembly according to  claim 12 , wherein said sealing portion of said first seal member includes a lip seal.  
   
   
       14 . A drive chain assembly, comprising: 
 a plurality of pins;    a plurality of bushings each rotatably supported on a respective one of said pins;    a plurality of links each including an inner end mounted to a respective one of said bushings and an outer end mounted to a respective one of said pins;    a plurality of seal assemblies including a seal head portion disposed in a bore in said outer end of a respective one of said plurality of links and a seal seat portion disposed in a bore of a respective one of said bushings, wherein a spring is provided for biasing said seal head portion axially relative to said seal seat portion.    
   
   
       15 . The drive chain assembly according to  claim 14 , wherein said seal assemblies include a spacer sleeve mounted on a respective one of said pins and said seal head portion and said seal seat portion are mounted on said spacer sleeve.  
   
   
       16 . The drive chain assembly according to  claim 15 , wherein said seal head portion include a seal boot mounted at one end to a seal washer and mounted at a second end to a spring seat and further including a spring member disposed between said spring seat and said seal washer.  
   
   
       17 . The drive chain assembly according to  claim 16 , wherein said seal seat portion includes a seal seat ring slidably mounted on said spacer sleeve and an elastomeric grommet mounted on said seal seat ring, said elastomeric grommet further including a seal portion engaging said seal washer.  
   
   
       18 . The drive chain assembly according to  claim 15 , wherein said seal seat portion includes a seal seat ring slidably mounted on said spacer sleeve and an elastomeric grommet mounted on said seal seat ring.  
   
   
       19 . The drive chain assembly according to  claim 18 , wherein said elastomeric grommet includes at least one sealing rib engaging said respective one of said bushings.  
   
   
       20 . The drive chain assembly according to  claim 19 , wherein said elastomeric grommet includes a seal portion engaging said seal head portion.