| 摘要 |
An evacuation type retainer according to the present invention is designed so as to relatively move an annular outer member and an inner member inserted thereinto in one or both of the axial and circumferential directions thereof or fix them with respect to each other by supplying and discharging a high pressure fluid to and from these members. A conventional retainer of this kind had to be manufactered with a high processing accuracy and a high measurement accuracy so as to secure a smooth and safe operation thereof, so that it cost high. According to the present invention, these problems are solved by unitarily forming on one of the outer and inner circumferential surfaces of each of the above-mentioned inner and outer members, which are adjacent to each other, a metal layer the hardness of which is different by a predetermined level from that of the material of the other surface. The retainer according to the present invention has high operational reliability and safety, and can be used advantageously for fixing and retaining the operational positions of relatively moving structures and regulating the moving speeds thereof in a crane, a rocket launcher, a hopper, a dam gate, a lifter, nuclear installations, a crusher and various kinds of testing machines. |
