| 摘要 |
A bridge breaker includes a casing and an inner ring. Balls are provided between the casing and the inner ring for rotatably supporting the inner ring, without independent ball bearings, so as to make for easy and cost-effective machining. Seal rings having a square shape section are laid on same horizontal level surfaces of the casing and the inner ring, and are depressed by air pressure for preventing powder from entering into the device and to avoid frequent exchange of packing. A blade having a shaft is fixed to the inner ring through a hole of the inner ring, to prevent problems caused by looseness or releasing of connecting bolts. |
