Telescopic shaft for steering vehicle and motor vehicle steering system

摘要

A telescopic shaft for steering vehicle includes: an inner shaft and a tubular outer shaft fitted with each other; at least three pairs of axial grooves formed on an outer periphery of the inner shaft and an inner periphery of the outer shaft; a rigid coupling element for rigidly connecting the inner shaft and the outer shaft in a circumferential direction of the inner shaft when a relative phase of the inner shaft and the outer shaft with respect to the circumferential direction exceeds a predetermined range; and a plurality of elongate resin rods as elastic coupling elements for elastically connecting the inner shaft and the outer shaft in the circumferential direction when the relative phase is in the predetermined range. Each of the plural resin rods is formed with a groove. A section of the groove is shaped like U opening toward the outside in a radial direction of the inner shaft.