Workpiece Carrier Transfer Device Positioning Accuracy
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Solution Overview
Problem
Existing transfer devices using toothed belts for workpiece carriers suffer from inaccuracies due to elasticity and manufacturing tolerances, resulting in positioning deviations of up to 0.1 mm, especially when reversing direction.
Innovation Solution
A transfer device with a position sensor on each drive to detect the exact position of the workpiece carrier, combined with a high-resolution position sensor in the target area, eliminating the influence of toothed belt elasticity and play, allowing for precise positioning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If toothed belts are used for driving workpiece carriers, then the device is inexpensive and easy to manufacture, but positioning accuracy deteriorates due to elasticity and manufacturing tolerances
Solution Approach 1:
The patent replaces the mechanical toothed belt drive system with a direct drive system where the workpiece carrier is driven directly by the drive mechanism without intermediate elastic elements. This substitution eliminates the elastic deformation and manufacturing tolerances of toothed belts, achieving positioning accuracy of 5 μm while maintaining ease of manufacture through the direct coupling design
Solution Approach 2:
The patent introduces a coupling mechanism as an intermediary between the drive and the workpiece carrier. This coupling serves as a precision interface that eliminates the need for toothed belts while maintaining the drive's ease of manufacture. The coupling directly transmits motion without elastic deformation, resolving the contradiction between ease of manufacture and positioning accuracy
2Device complexity
If toothed belts are used for driving workpiece carriers, then the structure is simple, but positioning accuracy deteriorates due to play and elasticity
Solution Approach 1:
The patent replaces the complex toothed belt system with a direct drive mechanism that eliminates elastic elements and play. The direct coupling between drive and workpiece carrier simplifies the overall structure while achieving 5 μm positioning accuracy by removing the problematic intermediate components
Solution Approach 2:
The patent extracts and removes the toothed belt component from the drive system entirely. By taking out the elastic intermediary element, the system achieves both structural simplicity and high positioning accuracy, as the direct drive eliminates the sources of error without adding complex compensation mechanisms
3Device complexity
If motor position sensor is used during transfer, then the system is simple, but positioning accuracy deteriorates in the target area
Solution Approach 1:
The patent implements a feedback mechanism where the position sensor continuously monitors the workpiece carrier's position and provides real-time data to the control system. This feedback enables dynamic adjustment of the drive to achieve 5 μm positioning accuracy in the target area, maintaining system simplicity while dramatically improving precision through closed-loop control
4Manufacturing precision
If high-resolution position sensor is introduced in target area, then positioning accuracy improves, but device complexity increases
Solution Approach 1:
The patent applies the high-resolution position sensor only in the target area where precise positioning is critical, rather than throughout the entire transfer path. This localized application achieves 5 μm positioning accuracy where needed while minimizing overall device complexity by using lower-resolution or no sensors in other areas
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
Enables dynamic and precise transfer of workpieces with improved accuracy, reducing positioning errors to around 5 μm, independent of toothed belt influences.
Implementation Method 1
each drive being provided with a position sensor which detects the exact position of the workpiece carrier
Implementation Method 2
at least one drive being provided which linearly moves the workpiece carrier
Data Source
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AI summary
The transfer device (1) for workpieces (2) that for the purpose of processing are feedable by a workpiece carrier (3) to a workstation. A driver (8) is provided which moves the workpiece carriers linearly. A position emitter is associated with the driver for registering a position of the workpiece carrier. The position emitter (20) has a stationary sensor that detects a code of a code carrier that is arranged on the workpiece carrier. An independent claim is included for a method for transferring workpieces.