| 摘要 |
PURPOSE:To obtain the damping effect of a large capacity with no increase in the mass of an inertia body, by increasing the rotational speed of a recirculating ball member with the use of a differential gear speed-up mechanism. CONSTITUTION:A screw rod 3 rotates a ball recirculating member 4 when a relative displacement between a main casing and a subcasting 2 with a low acceleration is brought about due to thermal deformation or the like. The rotation of the member 4 is transmitted to a resilient member 8 through a differential gear speed-up mechanism comprising gears 6, 7, 9. Since an acceleration in the rotation of the recirculating ball member 4 is small, it is transmitted to an inertia body 11 through balls 12, and therefore, a friction member 10 rotates with a gap being defined between the friction member 10 and a main case annular friction member 1e so that an object to be damped is permitted to be slowly displaced, smoothly. A relative rotation comes about between the inertia body 11 and the resilient member 8 when a relative displacement with a high acceleration is brought about therebetween, resulting in a positional shifting between recesses 8b, 11a, and therefore, the balls 12 roll up on a slant surface so that the friction member 10 is engaged with the annular friction member 1e. Thereby the damping operation is carried out. |
