| 摘要 |
The sealing device (10) is mounted on the rotating part (2) and has two sealing lips pressing respectively on first (56) and second (52) bearing surfaces on the fixed part. The first sealing lip (11) is between the drilling material and a cavity (40) forming the grease reservoir and the second sealing lip (13) is between the pressure compensation system outlet and the cavity. Rock drill head with cones, where each cone has a fixed part and a part which rotates about an axis, and a dynamic sealing device (10) between the fixed and rotating parts (2) to prevent drilling material entering. The fixed part (2) has a pressure compensation system which produces at its outlet a grease at a desired counter-pressure. The first lip (11) is oriented so it presses on the first bearing surface under pressure and the second lip (13) is oriented so it presses on the second bearing (52) surface under the counter-pressure, so the cavity can be refilled and pressure compensation in the cavity carried out. The first bearing surface (56) is a ring about the axis and the second bearing surface is a cylinder about the axis. The two sealing lips are made of elastomer. The second lip (13) is an annular cushion with double bevel to form a secure seal. At least one lip includes a loading spring, preferably with preloaded coils to form a toroidal ring. |
