Linear Motor Cogging Reduction via Bridge Elements
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Solution Overview
Problem
Electromagnetic linear motors face challenges in optimizing cogging force across both straight and curved sections, as existing techniques often worsen cogging performance in one topology while improving it in the other, leading to inefficiencies and mechanical complexity.
Innovation Solution
Bridging the slots between stator teeth with magnetically permeable materials reduces air gap reluctance variation, thereby minimizing cogging force across both straight and curved sections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional linear motor designs are used with distinct straight and curved sections, then the motor can handle different path topologies, but cogging force varies significantly between sections making optimization difficult
Solution Approach 1:
The patent applies different slot opening dimensions to different sections of the stator. Straight sections have one slot opening dimension while curved sections have a different slot opening dimension. This local differentiation allows each section to be optimized for its specific topology while reducing cogging force variation across the entire motor.
Solution Approach 2:
The stator is divided into multiple sections (straight sections and curved sections) with distinct slot opening characteristics. This segmentation allows independent optimization of each section's slot opening to minimize cogging force for that specific section's topology.
2Object-generated harmful factors
If slot opening is minimized to reduce air gap reluctance variation, then cogging force is reduced, but motor force output may be compromised
Solution Approach 1:
Different slot opening dimensions are used in different sections. Straight sections use one dimension that optimizes for both cogging reduction and force output, while curved sections use another dimension optimized for their specific requirements. This local optimization allows cogging reduction without sacrificing overall motor force capability.
Solution Approach 2:
The slot opening dimension parameter is changed between different sections of the stator. By varying this geometric parameter locally, the motor achieves reduced cogging force while maintaining adequate force output through optimized parameters for each section's operating conditions.
3Adaptability or versatility
If different motor topologies are used for straight and curved sections, then each section can be optimized for its topology, but device complexity increases
Solution Approach 1:
The patent maintains a unified stator structure but introduces local variations in slot opening dimensions. This approach achieves topology-specific optimization without the complexity of completely separate motor designs for straight and curved sections, reducing overall device complexity while maintaining optimization benefits.
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 significantly reduces cogging force by up to 50% while maintaining motor performance, offering a balanced reduction in cogging and force loss, allowing for improved motion control and reduced mechanical complexity.
Implementation Method 1
bridge elements made of a material having a magnetic permeability of at least 5.0 x 10-3 H/m, wherein the bridge elements reduce cogging effects
Data Source
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AI summary
A linear controlled motion system includes a track having at least one mover mounted to the track and effective for receiving articles at one location and transporting the articles to another location. The system includes at least one magnetic linear motion motor for providing a magnetic field effective for moving each mover in a controlled motion along the track. To reduce the cogging effect of the magnetic linear motion motor, at least one bridge element is disposed between the teeth of the motor. For example, slots may be formed in the top portions of each tooth, and individual bridge elements may be slid into the slots. The bridge elements may be made of a material having a relatively high magnetic permeability to reduce the cogging effects of the motor.