| 摘要 |
<p>An actuation device uses, for the active element, a flexible bellows operated by a pressurized fluid (usually, but not necessarily, at a pressure higher than the ambient one). The bellows is housed, for the most part of its length, inside a cylindrical cavity having the inner diameter slightly larger than the outer diameter of the bellows, so that the bellows is free to vary its length, but is restrained to bend sideways and therefore can be operated by high pressure.</p> |
