在设计要求用 O 型密封圈的密封件时,你并不一定对密封圈的尺寸总有广泛的选择机会。大直径的 O 形密封圈尤其如此。此外,O 形密封圈总得装在一个窄槽内以避免与其它零件相干涉。在这些条件下,只要遵守一些设计约束,则较小的 O 形密封圈可以被拉伸使用。O 形密封圈不应拉伸得超过适当的极限(大约为其原直径的15～20%)。如果超过这一界限,其体积将发生变化。O 形圈在被拉伸使用时应满足这样的要求:当使其放松 When designing seals that require O-ring seals, you do not always have a wide choice of seal sizes. This is especially true for large diameter O-rings. In addition, the O-ring is always housed in a narrow slot to avoid interference with other parts. Under these conditions, smaller O-rings can be stretched as long as some design constraints are observed. O-rings should not be stretched beyond the proper limits (about 15-20% of their original diameter). If this limit is exceeded, the volume will change. The O-ring, when used in tension, should fulfill the requirement that it be relaxed