| 摘要 |
<p>PROBLEM TO BE SOLVED: To improve baffling function of a hub by specifying a diameter of a hub center hole, a radius from the center of the hub center hole to a tip of a hub claw, a radius of a case hub hole and lengths of respective locking pieces in a specific sizing relation and also by making an angle made by adjacent locking pieces specific. SOLUTION: A relation among a radius r2 of a hub center hole B, a radius r1 from the center of the hub center hole B to a tip of a hub claw, and a radius r3 of a case hub hole F with respect to lengths a, b, c of respective locking pieces 91 , 92 , 93 is specified as b>a>c, r3 >b>r2 >r1 >a>c, preferably a+b≈r1 +r2 . In addition, anglesθ2 ,θ3 ,θ1 made between adjacent locking pieces 91 92 , 92 93 , 93 91 are made to be angles which are not multiples of 60 degrees and radially provided to satisfy 120 deg.<θ2 <180 deg. andθ1 +θ2 +θ3 =360 deg.. Further, a relation among anglesα,β,γof inclined rims at an upper end of the respective locking pieces 91 , 92 , 93 is structured to beβ<γ<α.</p> |
