| 摘要 |
<p>The spacer unit has front sides (17, 19) provided at a distance from each other and accommodating pressure, where the distance defines an axial length of the spacer unit. A cylindrical enclosure surface extends between circumferences of the front sides parallel to an axial direction. Compression struts (13) are made of hard foam material, where the compression struts extend in the axial direction. The compression struts are formed from phenolic resin plates, where the compression struts have larger pressure resistance than that of the foam material.</p> |
