Hybrid composite drive shaft and a method of making

Abstract

A drive shaft for transferring torque including a tubular insert extending along an axis and defining a first layer of the drive shaft including at least one straight portion and at least one undulation, wherein the tubular insert includes a first material having a first deformation temperature, and a polymeric tubular covering defining a second layer of the drive shaft surrounding the tubular insert including a second material having a deformation temperature lower than the deformation temperature of the first material, wherein the covering includes at least one straight portion adjacent to the straight portion of the tubular insert and at least one undulation adjacent to the at least one undulation of the tubular insert.

What is claimed is: 
     
         1 . A drive shaft for transferring torque comprising:
 a tubular insert extending along an axis and defining a first layer of the drive shaft including at least one undulation, wherein the tubular insert includes a first material having a first deformation temperature; and   a polymeric fiber reinforced composite covering defining a second layer of the drive shaft surrounding the tubular insert including a second material having a deformation temperature lower than the deformation temperature of the first material, wherein at least one undulation adjacent to the at least one undulation of the tubular insert.   
     
     
         2 . The drive shaft of  claim 1 , further comprising an adhesive between the insert and the covering. 
     
     
         3 . The drive shaft of  claim 1 , wherein the insert is thinner than the covering in a radial direction relative to the axis. 
     
     
         4 . The drive shaft of  claim 1 , wherein the first material includes a thermoplastic polymer material, or thermoplastic polymer matrix composite material. 
     
     
         5 . The drive shaft of  claim 1 , wherein the deformation temperature of the first material is higher than the deformation temperature of the second material. 
     
     
         6 . The drive shaft of  claim 1 , wherein the insert material includes fiber reinforcement. 
     
     
         7 . The drive shaft of  claim 1 , wherein the second material includes a fiber reinforced thermoset polymer composite material, or a fiber reinforced thermoplastic polymer matrix material. 
     
     
         8 . The drive shaft of  claim 7 , wherein the fiber reinforcement includes continuous or large discontinuous or short fibers. 
     
     
         9 . The drive shaft of  claim 7 , wherein the fiber includes carbon, aramid polymer, other organic materials, glass, or other inorganic materials. 
     
     
         10 . The drive shaft of  claim 1 , wherein the insert includes at least one straight portion. 
     
     
         11 . The drive shaft of  claim 10 , wherein the covering includes at least one straight portion adjacent to the straight portion of the insert. 
     
     
         12 . A method of forming a composite drive shaft comprising:
 forming a tubular insert to define a first layer of the drive shaft including forming at least one undulation, wherein the tubular insert includes a first material having a first deformation temperature;   surrounding the tubular insert with a polymeric tubular covering defining a second layer of the drive shaft including a second material having a deformation temperature lower than the deformation temperature of the first material by surrounding the tubular insert; and   forming at least one undulation within the polymeric covering radially of the at least one undulation of the tubular insert.   
     
     
         13 . The method of  claim 12 , wherein the at least one undulation of the tubular insert is formed by expanding an initial tubular insert against an external mold. 
     
     
         14 . The method of  claim 12 , wherein the at least one undulation of the tubular insert is formed by compression from a heated mold. 
     
     
         15 . The method of  claim 12 , further comprising joining the insert and the covering with an adhesive layer. 
     
     
         16 . The method of  claim 15 , wherein the joining includes applying the adhesive layer onto the tubular insert. 
     
     
         17 . The method of  claim 12 , further comprising cooling the covering to solidify the drive shaft. 
     
     
         18 . The method of  claim 12 , further comprising curing the insert and the covering at temperature below the first deformation temperature and above the second deformation temperature. 
     
     
         19 . The method of  claim 12 , wherein surrounding includes applying a non-cured or partially cured thermoset polymer matrix composite covering and subsequently curing said applied covering at a temperature below the first deformation temperature. 
     
     
         20 . The method of  claim 12 , wherein forming the at least one undulation of the covering includes compression by a heated mold.