Crane and method for weathervaning such a crane
AssigneeLiebherr-Werk Biberach GmbH
InventorChristoph Eiwan
Life of this patent
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Abstract
The present invention relates to a method for weathervaning of a crane which has a boom which can rotate about a vertical axis, a slewing gear motor and a slewing gear service brake for securing the boom in a rotational position with a securing torque in the crane mode, wherein in the case of a crane which has been out-of-operation, the boom is braked against rotation with an out-of-operation mode braking torque which is less than said securing torque in the crane mode. In this respect, the invention also relates to such a crane itself, in particular in the form of a revolving tower crane. In accordance with the invention, the out-of-operation mode braking torque is kept at least approximately constant over the range of the speed of rotation and over the range of the angle of rotation of the boom.
Claims17
A revolving tower crane comprising:
- a boom configured to rotate about a vertical axis;
- a slewing gear;
- a drive train of the slewing gear comprising:
- a slewing gear motor for rotating the boom about the vertical axis;
- and
- a slewing gear brake for braking the rotation of the boom,
- wherein the slewing gear brake is adjustably configured in its braking torque so that braking torques of different magnitudes can be provided, further comprising an out-of-operation control apparatus for adjusting the slewing gear brake to an out-of-operation mode braking torque which is smaller than a securing torque provided to a crane mode,
- wherein the slewing gear brake is configured to be spring-actuated and has a spring device adjustable in its spring force for applying braking forces of different magnitudes, and
- wherein the out-of-operation control apparatus is configured to adjust a spring preload of the spring device so that the spring device provides a lower spring force in the case of a crane that has been set out of operation compared to when the crane is in a default crane mode.
A revolving tower crane comprising:
- a boom configured to rotate about a vertical axis;
- a slewing gear;
- a drive train of the slewing gear comprising:
- a slewing gear motor for rotating the boom about the vertical axis;
- a slewing gear brake for braking the rotation of the boom;
- and
- a torque limiting coupling comprises a hysteresis clutch between the slewing gear motor and the slewing gear brake or between the slewing gear motor and an output gear engaged with a slewing ring connected to the boom,
- wherein the drive train does not comprise an out-of-operation brake in addition to the slewing gear brake,
- wherein the slewing gear brake is preloaded into a braking position to fix a rotary position of the boom in an out-of-operation mode of the revolving tower crane,
- wherein the hysteresis clutch is integrated into the drive train of the slewing gear such that the hysteresis clutch transmits usual torques of the drive train when the revolving tower crane is in operation,
- wherein when the hysteresis clutch is switched into a crane operation mode and the crane is in operation, the hysteresis clutch provides a high slip torque which is higher than a securing torque of the slewing gear brake for support, and
- wherein when the hysteresis clutch is switched into an out-of-operation mode and the crane is out of operation, the hysteresis clutch provides a low slip torque smaller than the securing torque of the slewing gear brake.
Dependencies are inferred from the claim text.