| 摘要 |
Improvement to reduction bushings (10, 30, 30), along with particulars of the use thereof, and to systems for sealing to the casing (15, 42), that are considerably different from those so far in use. Instead of O-rings, the seal between the bushing (10, 20, 30) and the casing (15, 42) is achieved by arc-welding (16) done at the tips thereof or by threading the bushing into the top of the casing. |
