Combined Roller Sleeve Stud-and-Weld Structure for Casting Defect Reduction
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Solution Overview
Problem
Large-sized roller sleeves in industries such as cement, mining, electric power, and chemicals suffer from casting defects like gas porosity, shrinkage, looseness, and cracks, leading to high scrap rates and increased production costs, with combined roller sleeves experiencing issues in bonding stability and wear resistance due to gaps and stress concentration.
Innovation Solution
A combined roller sleeve design with separately formed first and second roller sleeves connected via notches, embedded hard studs, and metallic surfacing layers, where the studs and layers are made of hard alloys and high manganese steel, enhancing wear resistance and stability through surfacing welding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If large-sized roller sleeves are manufactured through casting, then production efficiency is maintained, but casting defects (gas porosity, shrinkage, looseness, cracks) occur frequently leading to high scrap rates
Solution Approach 1:
The roller sleeve is divided into multiple smaller segments (first roller sleeve and second roller sleeve) that are cast separately and then connected together. This segmentation allows each segment to be cast within a smaller, more controllable mold size, significantly reducing the frequency of casting defects while maintaining the ability to produce large overall roller sleeve dimensions.
2Reliability
If combined roller sleeves are used to reduce casting defects, then quality improves, but bonding stability deteriorates due to gaps and stress concentration at connections
Solution Approach 1:
The connection structure uses a composite design combining hard studs (made of wear-resistant material) embedded in metallic surfacing layers (welded material) within the roller sleeve body. This composite structure provides both mechanical interlocking through the studs and metallurgical bonding through the welded layers, eliminating gaps and preventing material penetration while distributing stress evenly across the connection zone.
3Ease of manufacture
If combined roller sleeves are connected by retaining rings, then assembly is simplified, but wear resistance deteriorates due to lack of metallurgical bonding and gaps between sleeves
Solution Approach 1:
The connection method merges multiple functions into a single integrated structure: the hard studs provide mechanical anchoring, the metallic surfacing layers provide metallurgical bonding through welding, and the combined structure eliminates gaps between segments. This unified approach achieves both strong bonding and wear resistance while maintaining ease of assembly through the embedded stud design.
4Productivity
If roller sleeves are made larger to meet industrial demands, then processing capacity increases, but casting defects increase leading to higher scrap rates
Solution Approach 1:
The roller sleeve is divided into multiple smaller segments that are cast separately and then connected together. This segmentation allows each segment to be cast within a smaller, more controllable mold size, significantly reducing the frequency of casting defects while maintaining the ability to produce large overall roller sleeve dimensions. The connected segments achieve the required large processing capacity without the material waste associated with defect-prone large-scale casting.
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
The design reduces casting defects and improves wear resistance and stability of the combined roller sleeve, extending its service life and reducing material waste.
Implementation Method 1
Gaps between the first hard studs and between each of the first hard studs and a wall of the groove are filled with metallic surfacing layers
Implementation Method 2
Wear-resistant alloy layers are formed on the first hard studs, the second hard studs, and roller surfaces between the first hard studs and the second hard studs through surfacing welding
Data Source
AI summary
Provided are a combined roller sleeve, a method for preparing the combined roller sleeve, and a press roller. The combined roller sleeve includes a first roller sleeve and a second roller sleeve that are separately formed and connected to each other. Connected end surfaces of the first roller sleeve and the second roller sleeve each have a notch in a circumferential direction. The notches are formed as a groove at a connection between the first roller sleeve and the second roller sleeve. First hard studs are embedded in the groove. Gaps between the first hard studs and between each of the first hard studs and a wall of the groove are filled with metallic surfacing layers.