Slip-between-center propeller shaft assembly

1. A propeller shaft assembly for a vehicle including:

a first shaft extending along an axis between a proximal end and a distal end;

a joint coupled with said proximal end of said first shaft and defining a plurality of bolt holes arranged in a bolt circle having a bolt circle diameter for receiving fasteners to connect the joint to a vehicle component;

said first shaft having an externally splined region having a spline region outside diameter and disposed adjacent to said distal end, and a cylindrical region having a cylindrical region outside diameter extending axially from said externally splined region toward said proximal end;

a second shaft extending axially between a base end and a terminal end and including an internally splined sleeve region extending from said terminal end receiving said externally splined region of said first shaft for providing relative axial movement between said first and second shafts while rotationally fixing said first and second shafts to one another;

said second shaft including a tube portion having a tube outside diameter extending between said base end and said internally splined sleeve region and an inner tube diameter, wherein said inner tube diameter is larger than said spline region outside diameter;

said cylindrical region outside diameter of said first shaft being less than or equal to 50% of said bolt circle diameter and greater than or equal to 30% of said tube outside diameter of said tube portion of said second shaft to provide for bending stiffness of said propeller shaft assembly while providing tool access to the bolt holes; and

said distal end of said first shaft moveable into said tube portion of said second shaft.

2. The propeller shaft assembly of claim 1 , wherein said first shaft is hollow along said cylindrical region and said externally splined region and defines an inside diameter being greater than or equal to 40% of said cylindrical region outside diameter to provide bending stiffness and reduced mass of said propeller shaft assembly.

3. The propeller shaft assembly of claim 1 , wherein a distance between said terminal end of said second shaft and said proximal end of said first shaft is greater than or equal to 70 mm when said first and second shafts are axially aligned in a normal position to provide for both operational and crash telescoping of said first shaft relative to said second shaft and for allowing said first shaft to extend into said tube portion of said second shaft in the event of a vehicle crash; wherein in said normal position, said distal end of said first shaft is axially aligned with a transition region of said second shaft located axially between said sleeve region and said tube region of said second shaft.

4. The propeller shaft assembly for a vehicle as set forth in claim 1 , wherein said internally splined sleeve region of said second shaft includes a plurality of internal splines to define a spline inside diameter, and wherein said cylindrical region outside diameter is less than or equal to said spline inside diameter for a length of at least 60 mm between said between said externally splined region and said proximal end of said first shaft to allow said first shaft to axially move into said tube portion of said second shaft during a crash event.

5. The propeller shaft assembly of claim 1 , wherein said first shaft is comprised of cast ductile iron.

6. The propeller shaft assembly of claim 1 , wherein said tube and internally splined sleeve regions of said second shaft are comprised of aluminum material to allow said tube and internally splined sleeve regions to be welded to one another.

7. A propeller shaft assembly for a vehicle including:

a first shaft extending along an axis between a proximal end and a distal end;

a joint coupled with said proximal end of said first shaft and defining a plurality of bolt holes arranged in a bolt circle having a bolt circle diameter for receiving fasteners to connect the joint to a vehicle component;

said first shaft having an externally splined region having a spline region outside diameter and disposed adjacent to said distal end, and a cylindrical region having a cylindrical region outside diameter extending axially from said externally splined region toward said proximal end, and said first shaft being hollow and having an inside diameter;

a second shaft extending axially between a base end and a terminal end and including an internally splined sleeve region extending from said terminal end and receiving said externally splined region of said first shaft for providing relative axial movement between said first and second shafts while rotationally fixing said first and second shafts to one another;

said second shaft including a tube portion having an inner tube diameter, wherein said inner tube diameter is larger than said spline region outside diameter; and

said cylindrical region outside diameter being less than or equal to 50% of said bolt circle diameter, and said inside diameter of said first shaft being greater than or equal to 40% of said cylindrical region outside diameter to provide bending stiffness and reduced mass of said propeller shaft assembly while providing tool access to the bolt holes;

said distal end of said first shaft moveable into said tube portion of said second shaft.

8. The propeller shaft assembly for a vehicle of claim 7 , wherein said tube portion of said second shaft has a tube outside diameter, and wherein said cylindrical region outside diameter of said first shaft is greater than or equal to 30% of said tube outside diameter to provide for bending stiffness of said propeller shaft assembly.

9. The propeller shaft assembly of claim 7 , wherein a distance between said terminal end of said second shaft and said proximal end of said first shaft is greater than or equal to 70 mm when said first and second shafts are axially aligned in a normal position to provide for both operational and crash telescoping of said first shaft relative to said second shaft and for allowing said first shaft to enter said tube portion of said second shaft in the event of a vehicle crash; wherein in said normal position, said distal end of said first shaft is axially aligned with a transition region of said second shaft located axially between said sleeve region and said tube region of said second shaft.

10. The propeller shaft assembly for a vehicle as set forth in claim 7 , wherein said internally splined sleeve region of said second shaft includes a plurality of internal splines to define a spline inside diameter, and wherein said cylindrical region outside diameter is less than or equal to said spline inside diameter for a length of at least 60 mm between said between said externally splined region and said proximal end of said first shaft to allow said first shaft to axially move into said tube portion of said second shaft during a crash event.

11. The propeller shaft assembly of claim 7 , wherein said first shaft is of a cast ductile iron.

12. A propeller shaft assembly for a vehicle including:

a first shaft extending along an axis between a proximal end and a distal end;

said first shaft having an externally splined region having a spline region outside diameter and disposed adjacent to said distal end, and a cylindrical region having a cylindrical region outside diameter extending axially from said externally splined region toward said proximal end;

wherein said first shaft is hollow and defines an inside diameter being greater than or equal to 40% of said cylindrical region outside diameter to provide for bending stiffness and reduced mass of said propeller shaft assembly;

a second shaft extending axially between a base end and a terminal end and including an internally splined sleeve region extending from said terminal end and receiving said externally splined region of said first shaft for providing relative axial movement between said first and second shafts while rotationally fixing said first and second shafts to one another, said sleeve portion having an internal wall defining a first axial bore for receiving said distal end of said first shaft;

said second shaft including a tube portion having an internal wall defining a second axial bore having an inner tube diameter being fluidly connected to said first axial bore, and wherein said inner tube diameter is larger than said spline region outside diameter; and

said distal end of said first shaft moveable into said tube portion of said second shaft;

wherein a distance between said terminal end of said second shaft and said proximal end of said first shaft is greater than or equal to 70 mm when said first and second shafts are axially aligned in a normal position for continuous operation to provide for both operational and crash telescoping of said first shaft relative to said second shaft and for allowing said first shaft to enter said second axial bore in the event of a vehicle crash;

wherein said internally splined sleeve region of said second shaft includes a plurality of internal splines to define a spline inside diameter, and wherein said cylindrical region outside diameter of said first shaft is less than or equal to said spline inside diameter for a length of at least 60 mm between said externally splined region and said proximal end of said first shaft to allow said first shaft to axially move into said tube portion of said second shaft during a crash event;

wherein said cylindrical region outside diameter of said first shaft is greater than or equal to 30% of said tube outside diameter of said tube portion of said second shaft to provide for bending stiffness of said propeller shaft assembly.

13. The propeller shaft assembly for a vehicle as set forth in claim 12 wherein said distance between said terminal end of said second shaft and said proximal end of said first shaft is greater than or equal to 85 mm when said first and second shafts are axially aligned in the normal position.

14. The propeller shaft assembly for a vehicle as set forth in claim 12 wherein said distance between said terminal end of said second shaft and said proximal end of said first shaft is greater than or equal to 100 mm when said first and second shafts are axially aligned in the normal position.

15. The propeller shaft assembly for a vehicle as set forth in claim 12 wherein said distance between said terminal end of said second shaft and said proximal end of said first shaft is greater than or equal to 120 mm when said first and second shafts are axially aligned in the normal position.