| 摘要 |
A cup seal (21) of the invention includes an intermediate lip portion (21d), positioned between an inner lip portion (21b) and an outer lip portion (21c), provided in a base portion (21a). The intermediate lip portion (21d) is configured in such a way that first intermediate lip portions (21d1), communication passages (21d3), second intermediate lip portions (21d2), whose axial direction length is less than that of the first intermediate lip portions (21d1), and the communication passages (21d3), which have no lip portion, are cyclically disposed, in this order, in the peripheral direction. An easy elastic deformation portion of the base portion (21a) which elastically deforms easily is formed by the second intermediate lip portions (21d2) and communication passages (21d3) and, by the easy elastic deformation portion elastically deforming easily when supplying liquid, a flow passage with a larger passage area is formed.
|
