TELESCOPIC SHAFT

PROBLEM TO BE SOLVED: To provide a telescopic shaft for preventing rattling between an inner shaft and an outer shaft with no trouble by reducing relative moving resistance between the inner shaft and the outer shaft in the axial direction. SOLUTION: An intermediate shaft 5 as the telescopic shaft has the inner shaft 16 and the cylindrical outer shaft 17 fitted to each other to be relatively movable in an axial direction S1 and torque-transmissive to each other. A plurality of balls 22 are laid between each of axial grooves 19A, 19B, 19C in an outer peripheral face 18 of the inner shaft 16 and each of axial grooves 21A, 21B, 21C in an inner peripheral face 20 of the outer shaft 17 for transmitting torque between the inner shaft 16 and the outer shaft 17. To an outer peripheral face 23 of the outer shaft 17, a ring spring 24 for giving preload is fitted in the balls 22. The preload given to the balls 22 by the ring spring 24 prevents rattling between the inner shaft 16 and the outer shaft 17. The rolling of the balls 22 is utilized for reducing relative moving resistance between the outer shaft 17 and the inner shaft 16. COPYRIGHT: (C)2007,JPO&INPIT