Linear Motor Thermal Barrier for Precise Positioning Repeatability
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Solution Overview
Problem
Moving magnet type linear motors face challenges in achieving precise positioning and repeatability due to heat generated by coils, which affects transport speed and inclination, and are prone to dust generation and cable disconnection issues in precision manufacturing environments.
Innovation Solution
Incorporating a heat conduction reduction portion between the excitation and acting units of the linear motor, using thermal insulation materials to minimize heat transfer and separate the coil and permanent magnet components, and configuring the transport apparatus to eliminate the need for cableveyors, thereby reducing dust generation and cable disconnection risks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If coils are arranged closer to permanent magnets to achieve compact structure, then device complexity is reduced, but heat conduction from coils to permanent magnets increases causing positioning accuracy degradation
Solution Approach 1:
The patent introduces a heat conduction reduction portion (thermal barrier) between the coil and the permanent magnet. This intermediary component blocks heat transfer from the coil to the permanent magnet while allowing the compact arrangement to be maintained, thus resolving the contradiction between structural compactness and positioning accuracy
Solution Approach 2:
The patent divides the motor structure into distinct functional segments: the coil assembly, the heat conduction reduction portion, and the permanent magnet assembly. This segmentation allows each component to be optimized independently - the coil can be positioned close to the magnet for compactness while the thermal barrier prevents heat transfer that would degrade positioning accuracy
2Volume of moving object
If coils are arranged closer to permanent magnets, then device size is reduced, but temperature stability of permanent magnets deteriorates affecting positioning repeatability
Solution Approach 1:
The heat conduction reduction portion serves as a thermal intermediary that physically separates the heat-generating coil from the temperature-sensitive permanent magnet. This allows the motor to maintain a compact volume while the permanent magnet remains thermally stable, ensuring positioning repeatability
Solution Approach 2:
The patent applies local thermal insulation specifically at the interface between the coil and permanent magnet, where heat transfer is most problematic. This localized approach maintains overall motor compactness while providing targeted temperature stability where needed for positioning repeatability
3Ease of operation
If cableveyor is used for connection cable in circulation type transport apparatus, then ease of operation is improved, but dust generation and cable disconnection occur due to sliding and bending
Solution Approach 1:
The patent extracts the cableveyor mechanism from the circulation type transport apparatus. By removing this component, the source of dust generation from cable sliding and bending is eliminated, while the connection cable can still be properly connected and secured through alternative means
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 effectively suppresses the influence of heat on positioning accuracy, enhances repeatability, and prevents dust and cable issues, making the linear motor and transport apparatus suitable for precision manufacturing applications.
Implementation Method 1
an airgap or a heat conduction reduction portion between the excitation unit and the acting unit, wherein the heat conduction reduction portion reduces heat conduction from the excitation unit to the acting unit more than in a case where the excitation unit and the acting unit are in direct contact with each other
Implementation Method 2
the coils supplied with current in driving generate heat due to Joule heat
Implementation Method 3
a movable element including a permanent magnet and configured to move using electromagnetic force applied from the stator as driving force
Data Source
AI summary
The disclosed linear motor includes a stator having a plurality of cores and coils that excite the plurality of cores, respectively, and a movable element having a permanent magnet and configured to move using electromagnetic force applied from the stator as driving force, each of the plurality of cores has an excitation unit wound with the coil and an acting unit configured to be magnetically coupled to the excitation unit and cause a magnetic flux applied from the excitation unit to work on the permanent magnet of the movable element, and the linear motor includes an airgap or a heat conduction reduction portion between the excitation unit and the acting unit, and the heat conduction reduction portion reduces heat conduction from the excitation unit to the acting unit more than in a case where the excitation unit and the acting unit are in direct contact with each other.