Hollow Roller Journals for Printing Press Pressure Compensation
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Solution Overview
Problem
Inconsistent contact pressure and transmission behavior across the width of rollers due to deformation under line pressure, leading to uneven pressure distribution between the centers and edges of axially parallel rollers in printing press construction.
Innovation Solution
The solution involves inserting journals with varying diameters into a hollow roller, adjusting the insertion depth, and incorporating an elastic layer to compensate for pressure differences by altering the bending curve and stiffness, thereby decoupling the bending lines at the roller edges.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If two axially parallel rollers are pressed together, then line pressure is applied to transfer material or image, but the rollers deform under the pressure causing inhomogeneous pressure distribution across the width
Solution Approach 1:
The patent applies local quality by varying the journal insertion depth at different locations along the roller axis. The journals are inserted to different depths (e.g., deeper at edges, shallower at center) to create location-specific stiffness variations that compensate for the non-uniform pressure distribution caused by roller deformation under line pressure.
Solution Approach 2:
The patent implements dynamics by making the journal insertion depth adjustable rather than fixed. The journals can be inserted to variable depths allowing the system to adapt its stiffness characteristics dynamically to compensate for roller deformation and achieve more uniform pressure distribution during operation.
2Stress or pressure
If the journals are inserted deeper into the hollow roller, then the bending curve is altered to compensate for pressure differences, but the overall length and complexity of the journal structure must be adapted
Solution Approach 1:
The patent applies segmentation by dividing the journal into multiple sections along its length, where each section can have different insertion depths and diameters. This allows the journal structure to be segmented into functional zones that independently address pressure compensation requirements at different locations while maintaining overall structural integrity.
Solution Approach 2:
The patent implements nesting by placing the journal inside the hollow roller, utilizing the hollow space of the roller to accommodate the journal structure. The journal is nested within the roller's hollow cavity, allowing for variable insertion depths without increasing the external dimensions of the roller assembly.
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 approach reduces pressure differences between the roller centers and edges, improving print quality by flattening the bending line profile and reducing edge lubrication, enhancing the performance of printing presses.
Implementation Method 1
the rollers deform under line pressure along their central axes in such a way that the distance between the centers of the rollers is smaller at the roller edges than at the center
Implementation Method 2
A bending moment is exerted on the gravure printing cylinder, bending its axis, whereby the position, length and maximum deflection of the bending line are adapted to the desired change in the printed image
Implementation Method 3
The elastic layer can be made of a compliant material, such as rubber
Data Source
Figure 1~2
Figure 3~5
AI summary
The invention relates to a device, particularly for use in printing press construction, comprising at least two rollers (1, 2) rolling against each other, wherein at least one first roller (1) has at least two journals (3, 4), the first roller (1) being designed as a hollow roller. According to the invention, at least one of the two journals (3, 4) is inserted into the first roller (1), the journal (3) having at least two different diameters (5, 6). Furthermore, the invention also includes a method for compensating for pressure differences between rollers (1, 2).