Spreader Roll Tube Bending With an Eccentric Tension Element
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Solution Overview
Problem
Existing roll devices with rotating hollow tubes used in paper machines face challenges in achieving consistent sagging to smooth material webs without complex segment mounting and require additional support for bending, which complicates the design and functionality.
Innovation Solution
A roll device with a rotating hollow tube that uses a tension/compression element (TC element) to bend by exerting tension or pressure, eliminating the need for internal supports and allowing for adjustable curvature, and incorporates rotary bearings and axial bearings for torque-free operation and precise bending control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If multiple roll tube segments are used to achieve sagging, then the material web can be smoothed, but the mounting complexity of each individual roll tube segment increases
Solution Approach 1:
The roll tube is divided into multiple segments that can be mounted on a roll core, with each segment contributing to the overall sagging shape. The segments are arranged to create the desired bow shape while simplifying the mounting process through standardized interfaces.
Solution Approach 2:
The roll tube design allows for adjustable sagging by modifying the arrangement or shape of individual segments, enabling dynamic adjustment of the bow shape to optimize material web smoothing for different operating conditions.
2Shape
If a support structure is added to ensure roll tube bending, then bending control is improved, but the device complexity increases
Solution Approach 1:
The roll tube is designed to bend and maintain its sagging shape through its own structural properties and the arrangement of its segments, without requiring additional external support structures. The segments themselves provide the necessary structural support for bending control.
3Productivity
If the roll tube is designed to rotate rapidly, then productivity is improved, but maintaining consistent sagging becomes more difficult
Solution Approach 1:
The roll tube segments are constructed from materials with appropriate mechanical properties that maintain structural integrity and consistent sagging shape even during rapid rotation. The composite structure of segments allows for optimized weight and stiffness characteristics.
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 solution enables efficient bending of the roll tube without external forces or torques, allowing for precise deflection and sagging control, simplifying the design and reducing material fatigue, while maintaining stability and minimizing rotational complexity.
Implementation Method 1
the TC element as a pure tension element is contracted, or shortened, respectively, and pulls at the ends of the roll tube
Implementation Method 2
exerting tension or advantageously pressure on the roll tube
Implementation Method 3
incorporates rotary bearings and axial bearings for torque-free operation
Data Source
AI summary
A roll device as a spreader roll has a rotating hollow roll tube which at the ends thereof is rotatably mounted by means of bearing ends which are mounted in rotary bearings. The roll device has a tension element which runs so as to be eccentric to the central longitudinal axis of the roll tube through the roll tube and by internal tension toward the ends of the roll tube is impinged by a force with pressure. As a result, the roll tube is capable of being bent by way of an impingement of the tension element with a force, the deflection being transversely away from the longitudinal extent of said roll tube, if the tension element is tensioned in relation to the roll tube in an axial direction.