Thermal expansion compensation shock absorber

Abstract

The present invention provides the art with a shock absorber which is capable of compensating for the differing thermal expansion between two materials. The shock absorber in its various embodiments includes a free floating pressure tube that is able to expand or contract axially without breaking a seal, a hybrid piston rod with a shaft of one material that compensates for differing thermal expansions and a cap of another material that absorbs axial forces, a unique rod guide assembly with a biasing member that compensates for differing thermal expansions, and a unique cylinder end assembly with a biasing member made from springs, a rubber block, or pressurized gas.

1 . A shock absorber which compensates for thermal expansion, said shock absorber comprising: 
 a rod guide;    a pressure tube forming a compression chamber, said pressure tube slidingly engaging said rod guide;    a piston slidably disposed within said compression chamber;    a piston rod connected to said piston;    a reserve tube disposed around said pressure tube, said reserve tube and said pressure tube defining a fluid reservoir; and    a cylinder end assembly disposed between said compression chamber and said fluid reservoir for controlling the flow of fluid between said compression chamber and said fluid reservoir, said pressure tube slidingly engaging said cylinder end assembly:    said floating pressure tube being able to move freely relative to said rod guide and said cylinder between a first position engaging said rod guide and a second position engaging said cylinder end assembly.    
     
     
         2 . The shock absorber according to  claim 1 , wherein said pressure tube slidingly engages said cylinder end assembly.  
     
     
         3 . The shock absorber according to  claim 1 , wherein said pressure tube slidingly engages said rod guide assembly.  
     
     
         4 . The shock absorber according to  claim 3 , wherein said pressure tube slidingly engages said cylinder end assembly.  
     
     
         5 . A shock absorber which compensates for thermal expansion, said shock absorber comprising: 
 a pressure tube forming a compression chamber;    a piston slidably disposed within said compression chamber;    a piston rod connected to said piston;    a reserve tube disposed around said pressure tube, said reserve tube and said pressure tube defining a fluid reservoir;    a base valve assembly disposed between said compression chamber and said fluid reservoir for controlling the flow of fluid between said compression chamber and said fluid reservoir; and    a biasing member disposed between said pressure tube and said base valve assembly for urging said pressure tube away from said base valve assembly.    
     
     
         6 . The shock absorber according to  claim 5 , wherein said biasing member is a Belleville spring.  
     
     
         7 . The shock absorber according to  claim 6 , wherein said Belleville spring is secured to said base valve assembly by a circle-clip.  
     
     
         8 . The shock absorber according to  claim 6 , wherein said spring is secured to said base valve assembly by a spring retainer.  
     
     
         9 . The shock absorber according to  claim 6 , wherein said spring is disposed between two radial retainers secured to the base valve assembly.  
     
     
         10 . The shock absorber according to  claim 5 , wherein said base valve assembly has two portions, a top portion connected to said pressure tube and a bottom portion connected to said reserve tube, said top portion slidingly engaging said bottom portion.  
     
     
         11 . The shock absorber according to  claim 10 , wherein said biasing member is disposed between said top portion and said bottom portion.  
     
     
         12 . The shock absorber according to  claim 5 , wherein said biasing member and one end of said pressure tube are disposed within said base valve assembly.  
     
     
         13 . A shock absorber which compensates for thermal expansion, said shock absorber comprising: 
 a pressure tube forming a compression chamber;    a piston slidably disposed within said compression chamber;    a piston rod connected to said piston;    a reserve tube disposed around said pressure tube, said reserve tube and said pressure tube defining a fluid reservoir;    a base valve assembly disposed between said compression chamber and said fluid reservoir for controlling the flow of fluid between said compression chamber and said fluid reservoir;    a base plate slidingly engaging said reserve tube adjacent said base valve assembly; and    a biasing member disposed between said base plate and an end of said reserve tube for urging said base plate away from said end of said reserve tube.    
     
     
         14 . The shock absorber according to  claim 13 , wherein said biasing member is a Belleville spring.  
     
     
         15 . The shock absorber according to  claim 13 , wherein said biasing member is an elastomeric block.  
     
     
         16 . The shock absorber according to  claim 13 , wherein said biasing member is a pressurized gas.