Steering wheel rotational angle detecting apparatus

Abstract

In a steering wheel rotational angle detecting apparatus, an engaging pin protrudes radially from a projected part of one of a steering wheel and an annular rotating member and includes a spherical portion. An engaging groove is formed at a position on the other of the steering wheel and the annular rotating member of a rotational angle detector corresponding to the position of the engaging pin. The engaging groove is configured to receive and hold the spherical portion of the engaging pin on two sides while allowing the spherical portion to move within the engaging groove. When the steering wheel is turned, the engaging pin or groove immediately transmits torque to the engaging groove or pin, respectively, thus enabling the rotational angle detector to detect rotational angle with high precision in either of the rotational directions of the steering wheel. The movable engagement of the spherical portion and the engaging groove compensates for eccentric mounting of the steering wheel and the annular rotating member, and also a deviation of their rotational axes from each other, as the spherical portion relatively moves within the engaging groove to absorb or release twist stress, thus ensuring smooth rotation of the annular rotating member.

Dependencies are inferred from the claim text.