Plastic injected rigid splined shaft connection

An intermediate shaft assembly, comprising:

• a first shaft extending along an axis between a first end and a second end, said first shaft having a first tubular wall portion with an inner surface bounding a hollow bore extending into said first end, said inner surface having a plurality of radially inwardly extending female splines and said first tubular wall portion having at least one through opening;
• a second shaft extending along said axis between a coupling end and a connection end, said connection end having an outer surface sized for a clearance fit with said inner surface bounding said hollow bore of said first shaft, said outer surface having a plurality of radially outwardly extending male splines configured for an interdigitated fit with said female splines, said interdigitated fit establishing a clearance gap between said male splines and said female spines;
• and
• a polymeric material at least partially filling said clearance gap and extending into said at least one through opening,
• wherein said outer surface of said second shaft has at least one circumferentially extending groove, at least a portion of said first tubular wall portion of said first shaft extending into said at least one circumferentially extending groove.

An intermediate shaft assembly, comprising:

• a first shaft extending along an axis between a first end and a second end, said first shaft having a first tubular wall portion with an inner surface bounding a hollow bore extending into said first end, said inner surface having a plurality of radially inwardly extending female splines and said first tubular wall portion having at least one through opening;
• a second shaft extending along said axis between a coupling end and a connection end, said connection end having an outer surface sized for a clearance fit with said inner surface bounding said hollow bore of said first shaft, said outer surface having a plurality of radially outwardly extending male splines configured for an interdigitated fit with said female splines, said interdigitated fit establishing a clearance gap between said male splines and said female spines;
• a polymeric material at least partially filling said clearance gap and extending into said at least one through opening,
• wherein said first shaft has a second tubular wall portion with an inner surface bounding a hollow bore extending into said second end, said inner surface of said second tubular wall portion having a plurality of radially inwardly extending female splines extending generally parallel to said axis and said second tubular wall portion having at least one through opening, and further comprising:
• a third shaft extending along an axis between a coupling end and a connection end, said connection end of said third shaft having an outer surface sized for a clearance fit with said inner surface within said hollow bore of said second tubular wall portion, said outer surface of said third shaft having a plurality of radially outwardly extending male splines extending generally parallel to said axis, said male splines of said third shaft being configured for an interdigitated fit with said female splines of said second tubular wall portion, said interdigitated fit establishing a clearance gap between said male splines of said third shaft and said female spines of said second tubular wall portion;
• and
• a polymeric material filling said clearance gap between said male splines of said third shaft and said female spines of said second tubular wall portion and extending into said at least one through opening of said second tubular wall portion.

A method of assembling an intermediate shaft assembly, the method comprising:

• providing a first shaft extending along a first axis between a first end and a second end with the first shaft having a first tubular wall portion having an inner surface bounding a hollow bore extending into the first end, with the inner surface having a plurality of radially inwardly extending female splines extending generally parallel to the first axis and the first tubular wall portion having at least one through opening;
• providing a second shaft extending along a second axis between a coupling end and a connection end with the connection end having an outer surface having a plurality of radially outwardly extending male splines extending generally parallel to the second axis;
• and
• inserting the connection end of the second shaft in a clearance fit within the hollow bore of the first shaft and interdigitating the male splines with the female splines and establishing a clearance gap between the male splines and the female spines;
• filling at least a portion of the clearance gap with a polymeric material and causing the polymeric material to flow into the at least one through opening;
• and
• providing the outer surface of the second shaft having at least one circumferentially extending groove and deforming at least a portion of the first tubular wall portion of the first shaft to extend into the groove.

A method of assembling an intermediate shaft assembly, the method comprising:

• providing a first shaft extending along a first axis between a first end and a second end with the first shaft having a first tubular wall portion having an inner surface bounding a hollow bore extending into the first end, with the inner surface having a plurality of radially inwardly extending female splines extending generally parallel to the first axis and the first tubular wall portion having at least one through opening;
• providing a second shaft extending along a second axis between a coupling end and a connection end with the connection end having an outer surface having a plurality of radially outwardly extending male splines extending generally parallel to the second axis;
• and
• inserting the connection end of the second shaft in a clearance fit within the hollow bore of the first shaft and interdigitating the male splines with the female splines and establishing a clearance gap between the male splines and the female spines;
• filling at least a portion of the clearance gap with a polymeric material and causing the polymeric material to flow into the at least one through opening;
• providing the outer surface of the second shaft having an annular first groove and filling the first groove with the polymeric material;
• and
• further including causing the polymeric material to extend annularly about the outer surface of the connection end from the first annular groove outwardly from the hollow bore through the first end to seal off an annular seam between the first end and the outer surface of the connection end of the second shaft.