Slew Bearing Segmented Raceway for Roller Access
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Solution Overview
Problem
Maintenance and refurbishment of slew bearings in hoisting cranes require disassembly, leading to complex processes and significant downtime, as existing solutions do not allow for in-situ access or replacement of axial load rollers without disassembling the crane.
Innovation Solution
A hoisting crane design with a slew bearing that includes top and side entry ports allowing direct access and replacement of axial load rollers without disassembly, using removable raceway segments and roller cages, enabling maintenance and refurbishment while the crane is operational.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the slew bearing is designed as a conventional closed structure, then the structural integrity and load transmission are improved, but the maintenance complexity and downtime increase due to required disassembly
Solution Approach 1:
The slew bearing structure is divided into separable segments: the bearing rings are split into multiple sections that can be independently removed, and the raceways are divided into modular segments. This segmentation allows maintenance personnel to access and replace axial load rollers without disassembling the entire crane structure, thereby maintaining structural integrity while improving maintenance accessibility.
Solution Approach 2:
Entry ports are provided in the bearing rings that allow direct extraction of axial load rollers from the closed structure. The raceway segments can be removed to provide access to the rollers, enabling taking out the components that need maintenance without taking apart the entire bearing assembly or crane.
2Loss of time
If the slew bearing allows direct access for maintenance, then the downtime and maintenance complexity are reduced, but the structural complexity increases due to entry ports and removable segments
Solution Approach 1:
The bearing structure is segmented into modular components including separable bearing rings and divided raceways. These segments are designed with standardized connection interfaces that simplify assembly and disassembly operations, reducing the time required for maintenance while the added structural elements remain relatively simple in design.
Solution Approach 2:
The slew bearing transitions from a static closed structure to a dynamic structure with movable components. Entry ports can be opened or closed, and raceway segments can be removed or installed as needed, allowing the structure to adapt between operational integrity and maintenance accessibility states.
3Productivity
If axial load rollers are replaced without disassembly, then the productivity and operational efficiency are improved, but the ease of manufacture decreases due to specialized entry ports and removable segments
Solution Approach 1:
The bearing components are manufactured as separate modular segments that can be produced using standard manufacturing processes. The entry ports and removable raceway segments are designed as discrete components that can be manufactured independently and then assembled, maintaining ease of manufacture while enabling rapid roller replacement that improves productivity.
4Reliability
If the slew bearing uses a closed structure without entry ports, then the reliability and load transmission are improved, but the ease of operation for maintenance decreases
Solution Approach 1:
Entry ports and removable raceway segments are pre-configured in the bearing structure during manufacturing. These features are built in advance to facilitate future maintenance operations, allowing axial load rollers to be accessed and replaced without requiring complex disassembly procedures, thereby improving ease of operation while maintaining reliability.
Data Source
AI summary
A hoisting crane includes a slew bearing. The slew bearing includes a top bearing ring, a bottom bearing ring, a first row of axial load rollers and a second row of axial load rollers, which rows of axial load rollers are provided between a corresponding top roller raceway and bottom roller raceway. The top bearing ring has a top wall which extends above the first row of axial load rollers and in which at least one top entry port is provided. Furthermore, the top roller raceway of the first row of axial load rollers includes a removable raceway segment releasable attached in the top entry port. The removable raceway segment can be removed to enable access via the top entry port to the first row of axial load rollers to remove axial load rollers in a substantially vertical direction.