US Patent 7922593 Driveshaft assembly

A driveshaft with a hollow shaft, a pair of caps and a universal joint. The hollow shaft is rotatable about an axis and has an annular wall member that defines an outer surface, an inner surface and a pair of opposite ends. At least one of the outer surface and the inner surface includes a plurality of longitudinally extending splines. The caps are fixedly coupled to the opposite ends of the hollow shaft to at least substantially close the opposite ends of the hollow shaft. The universal joint is coupled to one of the caps. The splines extend the length of the hollow shaft.