| 摘要 |
A roller bit comprises a plurality of legs each of which has a longitudinally extending pin. A cutting cone is rotatably mounted on each of the pins and a prefabricated sealing insert is fixedly connected at a longitudinally inner end of each of the pins. A sealing element is positioned between the cone and a sealing surface of the insert. The insert is formed of a material having a hardness greater than a core hardness of the pin. |
