| 摘要 |
This invention relates to a hoisting crane comprising a jib, a jib connection member which is disposed on the column and to which the jib is connected pivotably. The crane further comprises an annular bearing structure extending around the column guiding and carrying the jib connection member rotatable about the column. The annular bearing structure comprises one or more column bearing parts comprising column bearing surfaces associated with the vertical column and one or more jib bearing parts comprising jib bearing surfaces associated with the jib connection member, whereby the column bearing surfaces and the jib bearing surfaces are arranged opposite from each other. A first column bearing surface is oriented substantially vertically and is arranged in a radial direction more inwards than the opposed first jib bearing surface, to support radially inwards directed horizontal loads from the jib connection member to the column. A second column bearing surface is oriented substantially horizontally and is arranged below the opposed second jib bearing surface, to support downwardly directed vertical loads from the jib connection member to the column. According to a first aspect of the invention, a third column bearing surface is oriented substantially vertically and is arranged in a radial direction more outwards than the opposed third jib bearing surface. According to a second aspect of the invention the first substantially vertical jib bearing surface has circumferentially uniformly been pre-stressed in a radially inward direction. |
