| 摘要 |
<p>In order to avoid excessive wear between a sealing ring and a shaft, the sealing ring is provided with a biased sealing lip which is moved against the shaft by a pressure medium flowing into an infeed channel of the shaft. When not in use, the sealing lips are spaced from the shaft and serve to close off the pressure medium chambers of the feed device. In order to exhaust air, the flow of pressure medium is shut off to the feed device so that the sealing lips are sprung back against a projection of the device in spaced relation to the shaft. This permits the pressure medium to exhaust from the shaft through a gap between the shaft and the feed device.</p> |
