Crane Gantry and Boom Force Cancellation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional cranes face challenges in minimizing loading and bending moments on the upperstructure, leading to increased mass and size requirements due to horizontal forces from the boom and gantry, which are not efficiently managed by traditional rectangular shapes.
Innovation Solution
The innovative mounting of a gantry and boom to an upperstructure with inclined front gantry legs that counteract horizontal forces from the boom, allowing for a circular turret design that reduces structural mass and enhances torque resistance by eliminating net horizontal forces at attachment points, transforming the upperstructure into a more efficient, compact, and mass-efficient circular shape.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If traditional rectangular upperstructure design is used with conventional boom and gantry mounting, then structural strength is maintained, but mass and size increase due to horizontal forces requiring extensive internal bracing
Solution Approach 1:
The inclined front gantry legs are positioned and angled to generate horizontal force components that counteract the horizontal forces from the boom. This creates a balanced force system where the gantry's horizontal forces oppose and reduce the net horizontal loading on the upperstructure, eliminating the need for extensive internal bracing and reducing overall mass.
Solution Approach 2:
The patent transitions from a traditional rectangular upperstructure to a circular turret design. This curved geometry provides superior torsional resistance and more efficient force distribution around the circumference, allowing the structure to handle combined vertical and horizontal loads with reduced mass compared to rectangular designs requiring extensive bracing.
2Volume of moving object
If conventional boom and gantry mounting is used, then structural stability is maintained, but upperstructure size increases due to bending moments requiring reinforcement
Solution Approach 1:
The inclined front gantry legs create horizontal force components that counteract boom-induced horizontal forces, significantly reducing net bending moments on the upperstructure. This force cancellation allows for a more compact upperstructure volume while maintaining stability under combined loading conditions.
Solution Approach 2:
The circular turret geometry inherently resists bending moments and torsional loads more efficiently than rectangular shapes. The curved structure distributes stresses more uniformly around the circumference, reducing peak bending moments and allowing for reduced cross-sectional dimensions while maintaining structural stability.
3Ease of manufacture
If rectangular upperstructure shape is used, then manufacturing simplicity is maintained, but torque resistance efficiency decreases requiring more material
Solution Approach 1:
The circular turret design provides superior torque resistance due to the curved geometry that distributes rotational stresses uniformly around the circumference. This curved shape is inherently more efficient at resisting torsional loads than rectangular shapes, reducing the material required while maintaining or improving torque capacity.
Data Source
AI summary
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.