Patent ID: 7264129

Claim:
A device for slewing a column of a crane, comprising: a fastenable crane base defined by a housing ( 1 ) that is open at the top and at the bottom and having a lower tubular part that is adapted to rotatably receive a crane column, a power source ( 21 ) that is connectable to the crane column via a power transmission in order to provide for a powered slewing of the crane column around a center line of the crane base, said power transmission including an eccentric gear ( 10 ), which is integrated with the housing ( 1 ) and located in an annular space ( 6 ) in the housing ( 1 ), and a bearing that includes two axially separated radial force absorbing bearings ( 7 , 8 ) and an axial force absorbing bearing ( 9 ), wherein the eccentric gear ( 10 ) comprises an eccentric sleeve ( 11 ) rotated by means of the power source ( 21 ) and having rotary symmetric out—and insides, the symmetry axes of which are eccentrically displaced in relation to each other and have a mutual angular displacement so that they converge in an apex point (P) within the crane base and adjacent to or on the center line of the crane base.