| 摘要 |
<p>In a feed screw device (1) according to the present invention, a coil member (3) is disposed on the outer periphery of a rotary shaft member (2). The coil member (3) is formed of an elastic body such as a priece of piano wire. The coil member (3) is mounted at least partially on the shaft member (2) so as to have at least a portion remaining in a free state. The coil member (3) is used to engage a nut placed on the outer periphery of the shaft member. When the shaft member is rotated, the coil member (3) is also rotated together with the shaft member (2), so that the nut is moved in the axial direction of the feed screw (1). When the nut is brought into contact with a stopper by a driving force, the nut impactively strikes the stopper. However, since the coil member (3) can be elastically deformed in the axial direction, the coil member (3) is elastically deformed to absorb its impact. Also, the "spring back" effect enabled by the deformable coil member (3) serves as a contribution to the initiation of movement of the nut in the reverse direction. Thus, when the direction of the driving force is reversed, the nut can immediately be moved in the reserve direction by a slight driving force.</p> |
