| 摘要 |
PURPOSE:To reduce frictional resistance and to contrive miniaturization of the capacity of a motor making expansible and contractive motions by constituting these motions in such a way as to be operated by means of both balls and a spiral groove into which the balls are fitted in the construction of an expansion and contraction section of the subject device. CONSTITUTION:In a device wherein an upper shaft 2 at the steering wheel 1 side is fixed on one end section while a lower shaft 5 is coupled with the other end section thereof by means of spline connection, furthermore a shaft tube 6 into which the lower shaft 5 is inserted is rotatably coupled with a telescopic tube 9, a circular body 13 is outwardly coupled with the other end of the telescopic tube 9 while being fixed thereon. A plurality of balls 17 is embedded in the outer circumference of the aforesaid circular body 13 formed in a spiral form so as to be coupled within a sleeve 30 which is rotatably supported for letting each ball 17 be engaged with a spiral groove 32 formed along the inner circumference of it. It is constituted that an electric motor 36 allows the aforesaid sleeve 30 to be rotated via gear trains 35, 34, 33 and 31 to move the telescopic tube 9 in its axial direction. |
