Eccentric Suction Wheel for Sheet Feeder
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Solution Overview
Problem
Existing suction wheels in sheet feeders face challenges in reliably gripping the top sheet from a stack due to a constant distance between the suction wheel and the stack, leading to suction problems such as double sheet feeding and inadequate air cushion generation.
Innovation Solution
A non-circular suction wheel with varying radius segments, each serving a specific function: a larger radius for suction, a smaller radius for holding, and a reduced suction effect for release, allowing precise sheet gripping and air cushion creation between sheets.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the distance between the suction wheel and the top edge of the stack is kept constant and small (4-6mm), then the suction wheel can grip the top sheet securely, but a separating air cushion cannot be generated between the top sheet and the sheet below
Solution Approach 1:
The suction wheel body is designed with a non-circular cross-section, causing the distance between the suction surface and the sheet stack to vary dynamically during rotation. During the suction phase, the wheel surface approaches the stack closely for secure gripping, then moves away during the release phase to allow separating air to form an air cushion between sheets, preventing double feeding.
Solution Approach 2:
The suction wheel body is divided into distinct functional segments: a suction area with higher suction effect for gripping the top sheet, and a release area with lower suction effect where separating air is introduced to create an air cushion. This segmentation allows different regions of the wheel to perform different functions at different rotational positions.
2Object-generated harmful factors
If the distance between the suction wheel and the top edge of the stack is increased, then separating air can be blown under the sheet to form an air cushion, but the point in time at which the uppermost sheet is gripped by the suction wheel cannot be specified exactly
Solution Approach 1:
The varying distance created by the non-circular suction wheel body allows the system to achieve both precise sheet gripping and air cushion formation. When the suction surface is close to the stack, the gripping point is precisely defined by the mechanical contact. When the wheel rotates and the distance increases, separating air can be effectively introduced to form an air cushion, resolving the timing precision issue.
3Device complexity
If the suction wheel body is circular with constant radius, then the structure is simple, but the suction wheel cannot reliably grip the top sheet while allowing air cushion formation
Solution Approach 1:
The suction wheel body is designed with a non-circular, asymmetric cross-section where the radius varies around the rotation axis. This asymmetry creates distinct zones: areas where the wheel surface is close to the sheet stack for reliable gripping, and areas where the distance is larger to allow separating air to form an air cushion. This asymmetric design resolves the sheet separation reliability issue while maintaining reasonable structural complexity.
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
Ensures reliable and defined sheet gripping, reduces stress on sheets, and enhances sheet processing efficiency by preventing double feeding and improving fold quality without increasing sheet speed.
Implementation Method 1
The suction wheel body is provided with a large number of suction openings on its outer surface for sucking in and transporting sheets
Implementation Method 2
periods when there is a large distance when separating air can be easily blown between the uppermost sheet and the underlying sheet to form an air cushion between the two arcs
Data Source
Figure 1a~1b
Figure 2a
Figure 2b
AI summary
The invention relates to a suction wheel (1) with a suction wheel body (20) rotatable about a pivot axis (29), wherein the suction wheel body (20) is provided on its outer surface (28) with a plurality of suction openings (27) for suctioning and transporting sheets (1000). According to the invention, the suction wheel body (20) is non-circular. In particular, the suction wheel (1) has a suction area (24) for suctioning a sheet (1000), a holding area (25) for holding and conveying a sheet (1000), and a release area (26) for releasing a sheet (1000). The invention also relates to a sheet feeder (10) with such a suction wheel (1).