| 摘要 |
PROBLEM TO BE SOLVED: To suppress the displacement of a moving shaft resulted from a radial load to satisfactorily keep the engagement state with a feed ring and to stably perform a motion conversion from rotating motion to linear motion or the reverse motion conversion. SOLUTION: Of four feed rings R1-R4 held within a rotating cylinder A and engaged with a screw shaft S, the engagement positions al and a2 of the two feed rings R1 and R2 are set to radially opposed positions, and the engagement positions a3 and a4 of the remaining two feed rings R3 and R4 are set to positions radially opposed to each other but shifted circumferentially by a prescribed angle to the engagement positions a1 and a2 of the first set. |
