Method of making a sealing element

摘要

A seal for rock bits having a Belleville type spring and a lock-ring embedded in rubber is made in a process where the spring and the lock-ring are plasma etched before the metal parts are embedded in a partially cured rubber composition. The rubber is cured in a mold to provide a seal having significantly strengthened rubber-to-metal bonding. Preferably, highly saturated nitrile rubber is used for the seal, and the rubber composition preferably also includes lubricating agents which reduce friction between the rubber seal and rotating metal parts of the rock bits.