Rotating Drum Feed Fin Geometry to Prevent Workpiece Trapping

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Solution Overview

Problem

Conventional rotating drums for workpiece conveyance face issues such as workpieces getting trapped in internal corners and inefficient washing liquid flow, leading to conveyance failures and reduced washing efficiency, especially with lightweight materials and when multiple workpieces are conveyed.

Innovation Solution

The rotating drum design features a helically extending feed fin with obtuse internal corners (110° to 130°) and a tapered shape to prevent trapping, along with a liquid passable and impassable section configuration using porous materials and inclined edge portions to control washing liquid flow from downstream to upstream, ensuring efficient conveyance and washing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional feed fin with right angle internal corner is used, then the structure is simple, but workpieces get trapped in the internal corner causing conveyance failure

Engineering Contradiction:
Improveconveyance reliabilityVSAvoidfeed fin structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The internal corner angle of the feed fin is changed from 90 degrees to an obtuse angle (110-130 degrees). This parameter change prevents workpieces from getting trapped in the internal corner while being conveyed, thereby improving conveyance reliability without significantly increasing structural complexity

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The feed fin is designed with asymmetric geometry where the internal corner angle differs from the external corner angle. The internal corner has an obtuse angle (110-130 degrees) to prevent trapping, while the external corner maintains a different configuration for efficient workpiece engagement and conveyance

Inventive Principle:
Principle #4Asymmetry

2Productivity

If multiple workpieces are conveyed simultaneously, then productivity increases, but workpieces get trapped between adjacent fin sections

Engineering Contradiction:
Improveworkpiece conveyance capacityVSAvoidconveyance reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The internal corner angle of the feed fin is changed to an obtuse angle (110-130 degrees), which prevents workpieces from getting trapped between adjacent fin sections during simultaneous conveyance of multiple workpieces, thereby maintaining conveyance reliability while enabling high productivity

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The helical feed fin creates segmented flow paths between adjacent fin sections. The obtuse internal corner angle ensures that these segments do not trap workpieces, allowing multiple workpieces to be conveyed simultaneously through the segmented channels created by the helical fins

Inventive Principle:
Principle #1Segmentation

3Adaptability or versatility

If lightweight workpieces are conveyed, then material versatility improves, but workpieces get nipped or stacked in the internal corner

Engineering Contradiction:
Improvematerial handling capabilityVSAvoidconveyance reliability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The internal corner angle is changed to an obtuse angle (110-130 degrees), which prevents lightweight workpieces from being nipped or stacked in the internal corner. This parameter change enables reliable conveyance of lightweight materials while maintaining versatility in handling different workpiece types

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The asymmetric design with obtuse internal corner angle provides sufficient clearance for lightweight workpieces to pass through without being trapped, while the external geometry maintains effective engagement for conveying various material types including lightweight plastics and rubbers

Inventive Principle:
Principle #4Asymmetry

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 effectively prevents workpiece trapping and ensures reliable conveyance while maintaining washing efficiency by directing washing liquid flow to prevent dirty liquid from entering the downstream direction, enhancing the overall cleaning process.

Implementation Method 1

a liquid passable section made from a porous material

Methodology Applied
Scientific EffectPermeation: Permeation

Data Source

PatentEP3281712B1Workpiece cleaning device comprising a rotating drum for workpiece conveyance
Publication Date: 2022.05.04 HIRAIDE PRECISION CO LTD
  • EP3281712B1 patent drawingFigure 1
  • EP3281712B1 patent drawingFigure 2(a)~2(d)
  • EP3281712B1 patent drawingFigure 3(a)~3(d)

AI summary

A rotating drum (7) of a rotating drum-type workpiece cleaning device is provided with feed fins (13) that extend helically along the inner circumferential surface (11a) of the drum body (11). The feed fins (13) are, for example, fins in which metal sheets have been folded. On both sides of the feed fins (13), the angle (θ) of the internal corner (64) between the feed fin (13) and the inner circumferential surface (11a) of the drum body (11) is an obtuse angle, for example, about 120 degrees. It is possible to prevent or limit the trapping of conveyed workpiece (w) in the internal corner (64) and trapping between adjacent fin sections (13a, 13b).