Twin Bushing Track Chain Cartridge

Abstract

A cartridge assembly for a track chain is disclosed. The cartridge assembly includes a pin that has a lubricant channel therein. The pin is accommodated in an inner bushing that also has a channel extending therethrough for accommodating the pin. The pin extends beyond either end of the inner bushing. The pin and inner bushing are partially disposed in an outer bushing that also has a channel for accommodating the pin in inner bushing. The ends of the inner bushing and pin extend beyond the ends of the outer bushing. First and second inserts are disposed at either end of the inner bushing. The first and second inserts are disposed between the outer bushing and a pair of opposing collars which are disposed on the ends of the pin beyond the inserts and beyond the ends of the inner bushing. The inserts and collars each include seals. The seals of the collars are supported by one or more thrust rings as opposed to the inserts or partially by the inserts.

1 . A cartridge assembly for a track chain, comprising:
 a pin defining a longitudinal axis and having a lubricant channel, the pin including first and second opposing ends;   an inner bushing having first and second ends and a channel extending therethrough for rotatably accommodating a portion of the pin disposed between the first and second opposing ends of the pin;   an outer bushing having first and second opposing ends and a channel extending therethrough for accommodating a portion of the inner bushing disposed between the first and second opposing ends of the inner bushing;   first and second inserts, each having a channel extending therethrough for accommodating opposing portions of the inner bushing that extend beyond the outer bushing, the first insert engaging the first end of the outer bushing, the second insert engaging the second end of the outer bushing;   first and second collars, each having a channel extending therethrough for accommodating portions of the pin that extend beyond the inner bushing; and   first and second thrust rings, the first thrust ring disposed between the first collar and the first insert, the second thrust ring disposed between the second collar and the second insert.   
     
     
         2 . The cartridge assembly of  claim 1  further including a first seal disposed between the first collar and first insert and a second seal disposed between the second collar and second insert. 
     
     
         3 . The cartridge assembly of  claim 1  wherein the first thrust ring includes a pair of first thrust rings, one disposed inside the other and the second thrust ring includes a pair of second thrust rings, one disposed inside the other. 
     
     
         4 . The cartridge assembly of  claim 1  wherein the first and second thrust rings are disposed on top of the inner bushing. 
     
     
         5 . The cartridge assembly of  claim 1  wherein the first and second thrust rings each include opposing ends, one end of the first thrust ring engaging the first end of the inner bushing and one end of the second thrust ring engaging the second end of the inner bushing. 
     
     
         6 . The cartridge assembly of  claim 5  wherein the other end of the first thrust ring engages the first collar and the other end of the second thrust ring engages the second collar. 
     
     
         7 . The cartridge assembly of  claim 1  wherein the first and second thrust rings each include opposing ends, one end of the first thrust ring engaging the first insert and the other end of the first thrust ring engaging the first collar, and one end of the second thrust ring engaging the second insert and the other end of the second thrust ring engaging the second collar. 
     
     
         8 . The cartridge assembly of  claim 1  wherein the first and second opposing ends of the pin each accommodate a plug. 
     
     
         9 . The cartridge assembly of  claim 1  further including a first seal axially sandwiched between the first collar and the first insert and a second seal axially sandwiched between the second collar and the second insert, the first seal being radially sandwiched between the first collar and the first thrust ring, the second seal being radially sandwiched between the second collar and the second thrust ring. 
     
     
         10 . The cartridge assembly of  claim 1  further including a first seal axially sandwiched between the first collar and the first insert and a second seal axially sandwiched between the second collar and the second insert, the first seal being radially sandwiched between the first collar and the inner bushing, the second seal being radially sandwiched between the second collar and the inner bushing. 
     
     
         11 . The cartridge assembly of  claim 1  wherein the first collar has an axially facing inner face with at least one recess for accommodating a first seal and the first thrust ring, and the second collar has an axially facing inner face with at least one recess for accommodating a second seal and the second thrust ring. 
     
     
         12 . The cartridge assembly of  claim 1  wherein the first collar has an axially facing inner face with at least one recess for accommodating a first seal, the first thrust ring and the first end of the inner bushing, and the second collar has an axially facing inner face with at least one recess for accommodating a second seal, the second thrust ring and the second end of the inner bushing. 
     
     
         13 . The cartridge assembly of  claim 1  further including first and second seals axially sandwiched between the first and second collars and first and second inserts respectively, the first and second seals each including an inner radial surface that does not engage the first and second inserts respectively. 
     
     
         14 . The cartridge assembly of  claim 1  further including first and second seals axially sandwiched between the first and second collars and inserts respectively, the first and second seals each including an inner radial surface that engages one of the first and second thrust rings respectively. 
     
     
         15 . A track chain comprising:
 a plurality of cartridge assemblies, each including
 a pin defining a longitudinal axis and having a lubricant channel, the pin including first and second opposing ends; 
 an inner bushing having first and second opposing ends and a channel extending therethrough for rotatably accommodating a portion of the pin disposed between the first and second opposing ends of the pin; 
 an outer bushing having first and second opposing ends and a channel extending therethrough for accommodating a portion of the inner bushing disposed between the first and second opposing ends of the inner bushing; 
 first and second inserts, each having a channel extending therethrough for accommodating opposing portions of the inner bushing that extend beyond the outer bushing, the first insert engaging the first end of the outer bushing, the second insert engaging the second end of the outer bushing; 
 first and second collars, each having a channel extending therethrough for accommodating portions of the pin that extend beyond the inner bushing; and 
 first and second thrust rings, the first thrust ring disposed between the first collar and the first insert, the second thrust ring disposed between the second collar and the second insert, wherein the first and second thrust rings each include inner and outer radial faces, the outer radial faces of the first and second thrust rings supporting first and second seals respectively, the inner radial faces of the first and second thrust rings engaging one of the pin or the inner bushing; and 
   the first collar being accommodated in a first link, the second collar being accommodated in a second link, the first insert being accommodated in a third link and the second insert being accommodated in a fourth link.   
     
     
         16 . The track chain of  claim 15  further including a first seal axially sandwiched between the first collar and the first insert and a second seal axially sandwiched between the second collar and the second insert, the first seal being radially sandwiched between the first collar and the first thrust ring, the second seal being radially sandwiched between the second collar and the second thrust ring. 
     
     
         17 . The track chain of  claim 15  further including a first seal axially sandwiched between the first collar and the first insert and a second seal axially sandwiched between the second collar and the second insert, the first seal being radially sandwiched between the first collar and the inner bushing, the second seal being radially sandwiched between the second collar and the inner bushing. 
     
     
         18 . The track chain of  claim 15  further including first and second seals axially sandwiched between the first and second collars and inserts respectively, the first and second seals each including an inner radial surface that does not engage the first and second inserts respectively. 
     
     
         19 . The track chain of  claim 1  further including first and second seals axially sandwiched between the first and second collars and inserts respectively, the first and second seals each including an inner radial surface that engages one of the first and second thrust rings respectively. 
     
     
         20 . A method for providing stiffness to a cartridge assembly of a track chain, the method comprising:
 providing a pin defining a longitudinal axis and having a lubricant channel, the pin including first and second opposing ends;   inserting the pin into an inner bushing having first and second opposing ends and a channel extending therethrough for rotatably accommodating a portion of the pin with the first and second opposing ends of the pin extending beyond the first and second opposing ends of the inner bushing respectively;   inserting the pin and inner bushing into an outer bushing having first and second opposing ends and a channel extending therethrough for accommodating a portion of the inner bushing with the pin and with the inner bushing extending beyond the first and second opposing ends of the outer bushing;   coupling first and second inserts over opposing portions of the inner bushing that extend beyond the outer bushing and coupling the first insert to the first end of the outer bushing and coupling the second insert to the second end of the outer bushing;   coupling a first thrust ring to the pin and the first end of the inner bushing and coupling a second thrust ring to the pin and the second end of the inner bushing;   coupling first and second collars to the first and second thrust rings respectively and to portions of the pin that extend beyond the inner bushing.