Angular Arch Dragline Bucket Arm Reduces Weld Stress
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Solution Overview
Problem
The existing dragline buckets with arched front ring assemblies face issues with load transfer, leading to weld cracking due to fatigue and higher weld stress at cheek plate joints.
Innovation Solution
The dragline bucket design incorporates an angular arch arm with a planar base portion, first and second extensions with connection interfaces, and a dump anchor with planar front and rear edges welded to the base portion, improving load distribution and reducing weld stress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If an arched front ring assembly is used in the dragline bucket, then the bucket can be manufactured with standard curved fabrication processes, but the attachment does not suitably fit to the arched surface leading to weld cracking due to fatigue load
Solution Approach 1:
The patent applies local quality by providing a planar base portion at the specific location where the dump anchor attaches, while the rest of the front ring assembly maintains its arched configuration. This localized planar surface allows the attachment to fit properly and distribute loads evenly, preventing weld cracking in the critical attachment zone while preserving the overall arched structure for manufacturability.
2Device complexity
If cheek plate joints take direct loading from the attachment, then the attachment can be simply connected, but this results in higher weld stress and potential failure
Solution Approach 1:
The patent introduces a planar base portion as an intermediary element between the attachment and the arched front ring assembly. This base portion acts as a load-distributing mediator that receives forces from the attachment and disperses them across a wider area of the front ring, reducing the stress concentration at the cheek plate joints and preventing weld failure.
3Device complexity
If the attachment is directly welded to the curved arched surface, then the assembly is simple, but load transfer causes weld cracking due to fatigue
Solution Approach 1:
The patent applies local quality by providing a planar base portion at the specific location where the dump anchor attaches, while the rest of the front ring assembly maintains its arched configuration. This localized planar surface allows the attachment to fit properly and distribute loads evenly, preventing weld cracking in the critical attachment zone while preserving the overall arched structure for manufacturability.
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 design enhances stress accommodation and reduces weld stress by up to 25-30%, improving the durability and reliability of the dragline bucket.
Implementation Method 1
The front edge and the rear edge of the dump anchor, which are planar, are welded to the upper surface of the base portion of the angular arch arm
Data Source
AI summary
A dragline bucket can comprise: a bottom wall; a first sidewall portion extending from the bottom wall and defining a first upper edge portion; a second sidewall portion extending from the bottom wall and defining a second upper edge portion; a lip assembly at a front side of the bottom wall; an arm having a base portion, a first extension extending from the base portion to the first sidewall portion, and a second extension extending from the base portion to the second sidewall portion, the first and second extensions each having a connection interface, and the base portion having an upper surface that is planar; and a dump anchor fixedly coupled to the upper surface of the base portion of the arm.