A slew bearing includes a stationary bearing ring to be fixed to a base, and 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 raised 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, and 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 raised 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 crane for lifting and transporting loads includes a base frame for transferring the loads of the crane onto a support surface by a plurality of wheels. The wheels are capable of rotating relative to the base frame so as to change the camber angle of the wheels.

A crane for lifting and transporting loads includes a base frame for transferring the loads of the crane onto a support surface by a plurality of wheels. The wheels are capable of rotating relative to the base frame so as to change the camber angle of the wheels.

A control device equipped with a first acquisition unit for acquiring information pertaining to the location of the center of gravity of cargo transported by a work machine, a second acquisition unit for acquiring information pertaining to the location of a first section of the cargo which differs from the location of the center of gravity thereof, and a calculation unit for calculating information pertaining to the orientation of the cargo on the basis of the information pertaining to the location of the center of gravity of the cargo and the information pertaining to the location of the first section.

Provided is a handrail device in first and second unit booms adjacent to each other, having high strength. The handrail device includes: a pair of first poles; a pair of second poles; a first main rope stretched between the pair of first poles; a second safety line stretched between the pair of second poles; a first pole support member and a second pole support member that support the first poles and the second poles, respectively; first and second connection member; a first stay rope stretched between the first pole and the second connection member; and a second stay rope stretched between the second pole and the first connection member. The first pole support member and the first connection member are fixed to a common first fixation member, and a second pole support member and the second connection member are fixed to a common second fixation member.

Provided is a handrail device in first and second unit booms adjacent to each other, having high strength. The handrail device includes: a pair of first poles; a pair of second poles; a first main rope stretched between the pair of first poles; a second safety line stretched between the pair of second poles; a first pole support member and a second pole support member that support the first poles and the second poles, respectively; first and second connection member; a first stay rope stretched between the first pole and the second connection member; and a second stay rope stretched between the second pole and the first connection member. The first pole support member and the first connection member are fixed to a common first fixation member, and a second pole support member and the second connection member are fixed to a common second fixation member.

A hoisting machinery comprises a steering wheel and wheels, wherein the active steering system comprises an active steering device, a hydraulic power steering gear and a hydraulic power steering system, the active steering device is arranged between the steering wheel and a pitman arm of the hoisting machinery, so as to adjust a steering ratio of the steering wheel to the pitman arm according to a driving cycle of the hoisting machinery, and the hydraulic power steering gear is arranged between the steering wheel and the pitman arm, so as to control the hydraulic power steering system to drive steering of the wheels. In the active steering system of the present invention, a hydraulic power steering system is adopted to drive steering of wheels, which can improve capability of overcoming steering resistance and can be applicable to multiple chassis of cranes, thereby enlarging application ranges of the active steering system.

A hoisting machinery comprises a steering wheel and wheels, wherein the active steering system comprises an active steering device, a hydraulic power steering gear and a hydraulic power steering system, the active steering device is arranged between the steering wheel and a pitman arm of the hoisting machinery, so as to adjust a steering ratio of the steering wheel to the pitman arm according to a driving cycle of the hoisting machinery, and the hydraulic power steering gear is arranged between the steering wheel and the pitman arm, so as to control the hydraulic power steering system to drive steering of the wheels. In the active steering system of the present invention, a hydraulic power steering system is adopted to drive steering of wheels, which can improve capability of overcoming steering resistance and can be applicable to multiple chassis of cranes, thereby enlarging application ranges of the active steering system.

A kit of parts for use in demountably configuring a variety of structural assemblies. A kit may comprise a plurality of cylindrical structural components configured for engagement with various types of male connector components along the sides or at the ends of the cylindrical structural components, there provided for demountable engagement of a female-end socket component at the end of another cylindrical structural component. The kit may additionally comprise components for one or more of roller carriage assemblies and/or one or more of sliding carriage assemblies configured for rolling or sliding movement along rail assemblies comprising a plurality of cylindrical, square, rectangular, or octagonal track components. The rail assemblies may be supported by bases comprising the cylindrical structural components and other components such as weight components, as well as threaded foot components or threaded caster components on which the rail assemblies can be adjustably levelled.