Crane Hoisting Arrangement Rope Drum Orientation
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Solution Overview
Problem
The existing hoisting arrangements in cranes struggle to maximize the hoisting height while maintaining economical and reliable rope systems, particularly at upper positions where increased rope forces and the risk of the hoisting hook and pulley tipping are concerns.
Innovation Solution
The hoisting arrangement features a rope drum with a first end for winding the hoisting rope at the upper position and a second end for unwinding at the lower position, with pulleys and sheaves positioned to maintain the rope's disengagement and attachment points in the same vertical plane, allowing for efficient use of space and minimizing lateral errors, thus reducing wear and the risk of tipping.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If the hoisting arrangement uses a conventional rope system, then the structure is simple and easy to manufacture, but the hoisting height is limited and rope forces increase at upper positions
Solution Approach 1:
The patent repositions the rope drum so its axle is parallel to the main support structure, and arranges the disengagement point, sheave attachment point, and hoisting rope attachment point in the same vertical plane. This spatial reconfiguration allows the hoisting rope to engage with the first rope pulley at a point further from the second end than the first end of the rope drum, effectively utilizing the length of the rope drum in the horizontal dimension to reduce vertical height requirements while maintaining mechanical advantage.
2Length of moving object
If the hoisting arrangement maximizes hoisting height, then the available free height is utilized efficiently, but the risk of hoisting hook and pulley tipping over increases
Solution Approach 1:
By arranging the disengagement point, sheave attachment point, and hoisting rope attachment point in the same vertical plane, and positioning the first rope pulley such that the release point is further from the second end than the first end of the rope drum, the patent creates a more stable geometric configuration. This arrangement improves the alignment and reduces lateral forces that could cause tipping, while still achieving maximum hoisting height.
3Length of moving object
If the rope drum axle is perpendicular to the main support structure, then the rope arrangement is conventional and easy to manufacture, but the height dimension increases and hoisting height is reduced
Solution Approach 1:
The patent rotates the rope drum 90 degrees so that its axle is parallel to the main support structure instead of perpendicular. This dimensional change allows the rope to wrap around the drum in a different orientation, enabling the disengagement point to be positioned optimally in the vertical plane with the sheave and hoisting rope attachment point, thereby maximizing hoisting height without significantly increasing manufacturing complexity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration allows for a compact hoisting arrangement that maximizes the hoisting height, reduces wear on the rope and pulleys, and minimizes the risk of the hoisting hook and pulley tipping, enabling the use of conventional ropes and maintaining structural stability even at upper positions.
Implementation Method 1
a hoisting mechanism that has a rope drum for a hoisting rope, a rope pulley arrangement which has upper sheave arrangements and lower rope pulley arrangements and through which the hoisting rope may be guided from the rope drum to a attachment point
Data Source
AI summary
The hoisting arrangement of a hoist of a of a crane, includes a trolley arranged to move along a main support structure of the crane, whereby the trolley includes a support frame structure; bearing wheels which are fastened to the support frame structure and by means of which the trolley is arranged to move along said main support structure; a hoisting mechanism that has a rope drum for a hoisting rope, a rope pulley arrangement which has upper sheave arrangements and lower rope pulley arrangements and through which the hoisting rope may be guided from the rope drum to an attachment point, and a hoisting member in cooperation with the hoisting rope for hoisting a load; whereby the rope drum is supported to the support frame structure of the trolley so that the axle of the rope drum is parallel to the main support structure. In the hoisting arrangement, the disengagement point of the hoisting rope from the rope drum, the attachment point of the sheave, and the attachment point of the first end of hoisting rope are arranged on the same vertical plane of the hoisting arrangement. The rope drum has a first end towards which the hoisting rope is wound in the hoisting member's upper position, and a second end towards which the hoisting rope is unwound in the hoisting member's lower position. The first rope pulley of the rope pulley arrangement is so placed that the release point of the hoisting rope from the first rope pulley to the first sheave is, in the axle direction of the rope drum, further from the second end than the first end of the rope drum.