Boot for constant velocity universal joint, and constant velocity universal joint

摘要

A boot has a bellows section that includes three or more peak portions and three or more valley portions. A radially outer portion of each of the peak portions in vertical cross-section of the boot is formed into a round shape. A curvature radius of the radially outer portion of a peak portion being positioned at a central portion between a large diameter section and a small diameter section is set to be larger than curvature radii of the radially outer portions of the other peak portions.