| 摘要 |
<p>A bridge breaker has balls (4) between a casing (1) and an inner ring (2) for supporting the inner ring (2) such that it is rotatable without independent ball bearings for easiness and downsizing of costs. There are provided seal rings (6, 7) having square-shaped sections and being laid on same horizontal-level surfaces of the casing (1) and the inner ring (2) and being depressed by air pressure for preventing powder from entering into the device and frequent exchange of packing. There is also provided a blade (3) being fixed to the inner ring (2) by a connection through a shaft (3a) and a hole (2c) for preventing trouble caused by looseness or releasing of connecting bolts.</p> |
