| 摘要 |
<P>PROBLEM TO BE SOLVED: To enhance fatigue strength of a male spline part of a power transmission shaft by easing both of tensile stress and shear stress in the male spline part, and also to enhance fatigue strength in a small diameter cylinder part. <P>SOLUTION: The male spline part Sm is formed along an outer periphery of both shaft ends of the power transmission shaft. A diameter enlarged part 21b of which outside diameter dimension is gradually enlarged to an anti-shaft end side is provided on the anti-shaft end side part of a valley part 21 of the male spline part Sm. A round part 21b1 having an arc shaped cross section is provided on circumferential both sides of the diameter enlarged part 21b, and a radius of curvature of the round part 21b1 is gradually increased toward the anti-shaft end side. When a surface area of a small diameter cylinder part having the smallest outside diameter dimension in a region between the male spline parts on both shaft ends is A, and a cross sectional area is A<SB>0</SB>, 0<A/A<SB>0</SB>≤25. <P>COPYRIGHT: (C)2009,JPO&INPIT |
