A crane includes a base, an upperstructure rotationally mounted on the base, a boom, and a gantry. The boom is pivotally attached to the upperstructure at a front attachment location and supports a load line operable to raise a payload. The gantry is mounted on the upperstructure and supports a boom line coupled to the boom. The gantry includes at least one front leg mechanically coupled to the front attachment location and inclined away from the boom to apply, to the front attachment location, a horizontal force component towards the boom opposed by a horizontal force component applied by the boom towards the front leg. The upperstructure includes a frustoconical turret forming an upper circle and a lower circle. The front attachment location is aligned over the upper circle of the frustoconical turret.

The present disclosure relates to an apparatus and to a method for controlling a crane slewing gear. The apparatus comprises a hydraulic motor for driving the slewing gear and for braking the slewing gear from a rotational movement. The slewing gear is kept stationary via a holding brake. A hydraulic brake circuit for controlling the holding brake, a load sensing device for measuring a load instantaneously taken up by the crane, and an orientation sensing device for measuring an instantaneous orientation of the crane and/or of at least one crane component are furthermore provided. In accordance with the disclosure, a hydraulic limitation circuit is provided by means of which a hydraulic pressure applied to the motor can be limited to a specific limit value. A control unit is furthermore provided that determines a maximum permitted torque and/or a parameter derived therefrom for a current slewing gear movement.

The present disclosure relates to an apparatus and to a method for controlling a crane slewing gear. The apparatus comprises a hydraulic motor for driving the slewing gear and for braking the slewing gear from a rotational movement. The slewing gear is kept stationary via a holding brake. A hydraulic brake circuit for controlling the holding brake, a load sensing device for measuring a load instantaneously taken up by the crane, and an orientation sensing device for measuring an instantaneous orientation of the crane and/or of at least one crane component are furthermore provided. In accordance with the disclosure, a hydraulic limitation circuit is provided by means of which a hydraulic pressure applied to the motor can be limited to a specific limit value. A control unit is furthermore provided that determines a maximum permitted torque and/or a parameter derived therefrom for a current slewing gear movement.

The present disclosure relates to a support for a crane, in particular for a mobile crane, having at least two first support beams and two second support beams that are each arranged pairwise at mutually oppositely disposed sides of the support.

The present disclosure relates to a support for a crane, in particular for a mobile crane, having at least two first support beams and two second support beams that are each arranged pairwise at mutually oppositely disposed sides of the support.

A slew bearing includes a stationary bearing ring to be fixed to a base, a moveable bearing ring to be fixed to a moveable object, wherein the stationary bearing ring and the moveable bearing ring are configured to enable rotation of the moveable bearing ring relative to the stationary bearing ring about a rotation axis. A main axial bearing and an auxiliary bearing are provided between the stationary bearing ring and the moveable bearing ring, wherein the moveable bearing ring includes one or more main portions and one or more auxiliary portions, which one or more main portions are moveable relative to the one or more auxiliary portions between an operational position, in which the main axial bearing transfers the axial loads between moveable bearing ring and stationary bearing ring, and a maintenance position, in which the auxiliary axial bearing transfers the axial loads between moveable bearing ring and stationary bearing ring and the main bearing is allowed to be inspected and/or maintained so that the slew bearing during inspection and/or maintenance is still operational.

A slew bearing includes a stationary bearing ring to be fixed to a base, a moveable bearing ring to be fixed to a moveable object, wherein the stationary bearing ring and the moveable bearing ring are configured to enable rotation of the moveable bearing ring relative to the stationary bearing ring about a rotation axis. A main axial bearing and an auxiliary bearing are provided between the stationary bearing ring and the moveable bearing ring, wherein the moveable bearing ring includes one or more main portions and one or more auxiliary portions, which one or more main portions are moveable relative to the one or more auxiliary portions between an operational position, in which the main axial bearing transfers the axial loads between moveable bearing ring and stationary bearing ring, and a maintenance position, in which the auxiliary axial bearing transfers the axial loads between moveable bearing ring and stationary bearing ring and the main bearing is allowed to be inspected and/or maintained so that the slew bearing during inspection and/or maintenance is still operational.

Lifting performance of a work machine is increased while suppressing an increase in a vehicle weight. When a slewing frame is seen from a side, a first reinforcement member is provided from a boom foot section to a front side part of a slewing bearing, a second reinforcement member is provided from the boom foot section to a mast foot section, and a third reinforcement member is provided from the mast foot section to a rear side part of the slewing bearing. Furthermore, a fourth reinforcement member is provided from a middle region (M) located at an upper end portion of the slewing frame and above a rear portion of the slewing bearing to the front side part of the slewing bearing, and a fifth reinforcement member is provided from the middle region (M) to the rear side part of the slewing bearing.

Lifting performance of a work machine is increased while suppressing an increase in a vehicle weight. When a slewing frame is seen from a side, a first reinforcement member is provided from a boom foot section to a front side part of a slewing bearing, a second reinforcement member is provided from the boom foot section to a mast foot section, and a third reinforcement member is provided from the mast foot section to a rear side part of the slewing bearing. Furthermore, a fourth reinforcement member is provided from a middle region (M) located at an upper end portion of the slewing frame and above a rear portion of the slewing bearing to the front side part of the slewing bearing, and a fifth reinforcement member is provided from the middle region (M) to the rear side part of the slewing bearing.

There is provided a mobile crane including an undercarriage, turning body turnably supported by the undercarriage, a boom derrickably supported by the turning body, a derricking unit that causes the boom to perform a derricking operation, a derricking force measurement unit that measures a derricking force by which the derricking unit causes the boom to perform the derricking operation, a ground angle acquisition unit that acquires a boom-to-ground angle which is an angle of the boom relative to a ground where the undercarriage is disposed, and an actually suspended load calculation unit that calculates an actually suspended load, based on the derricking force and the boom-to-ground angle.