Hysteresis Magnetic Coupler Thermal Management
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing hysteresis magnetic couplers face issues with torque irregularity at varying speeds and significant heating due to poor thermal conductivity, leading to increased size and cost to manage temperature, which affects performance and efficiency.
Innovation Solution
A hysteresis magnetic coupler design featuring iron-chromium-cobalt magnetic alloys with high electrical resistivity and thermal conductivity, combined with radial slots to limit eddy currents and heat dissipation fins, along with a thermally conductive paste and stainless steel flanges for improved heat management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a molded paste containing hysteresis magnet particles and electrically insulating binder is used in the induced sub-assembly, then torque variations from eddy currents are reduced, but significant heating occurs due to poor thermal conductivity of the binder
Solution Approach 1:
A thermally conductive paste is introduced as an intermediary substance between the hysteresis magnets and the metal support disc. This intermediary material has high thermal conductivity to efficiently transfer heat away from the magnets, while the metal support disc serves as a heat sink with excellent thermal conductivity to dissipate the heat. This resolves the contradiction by adding a thermal management pathway without compromising torque regularity.
Solution Approach 2:
The invention changes the thermal conductivity parameter of the interface between hysteresis magnets and support structure. Instead of using the poor thermal conductivity binder alone, the system transitions to a high thermal conductivity paste (with thermal conductivity ≥ 1 W/m·K) in contact with a metal support disc, fundamentally improving heat dissipation capability while maintaining the hysteresis effect for torque regularity.
2Temperature
If the induced sub-assembly is sized generously to avoid excessive temperatures, then heating is controlled, but the device size and cost increase
Solution Approach 1:
The invention changes the thermal conductivity parameter of the interface materials (thermally conductive paste and metal support disc) to enable efficient heat dissipation from a compact induced sub-assembly. This allows the device to maintain acceptable temperature levels without requiring generous sizing, thus resolving the contradiction between temperature control and device compactness.
3Reliability
If radial slots are added to channel magnetic flux and attenuate eddy currents, then torque regularity improves, but manufacturing complexity increases
Solution Approach 1:
The induced element is segmented into discrete hysteresis magnets arranged in an annular pattern, with radial slots separating them. This segmentation serves multiple functions: it limits eddy current paths to improve torque regularity, provides thermal pathways for heat dissipation, and simplifies manufacturing by allowing individual magnets to be separately positioned and secured with simple retainers, rather than requiring complex integral structures.
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 ensures regular torque transmission across a wide range of speeds while minimizing heating and size, enhancing performance and reducing costs by effectively managing thermal expansion and conductivity.
Implementation Method 1
high electrical resistivity
Implementation Method 2
thermally conductive paste
Implementation Method 3
heat dissipation fins
Implementation Method 4
radial slots to limit eddy currents
Implementation Method 5
inductor developing an alternating magnetic-multipolar field
Data Source
Figure 1
Figure 2
AI summary
A magnetic coupler with hysteresis (1) comprises an inductor subassembly (2) and an armature subassembly (6) that are capable of rotating one with respect to the other. The inductor subassembly has a plurality of magnetic poles and the armature subassembly (6) has one or more armature permanent magnets with hysteresis (11, 12). The invention is notable in that the or each armature magnet is produced in the form of a ring of one piece in magnetic material with vertical hysteresis and has through-slots for attenuating radial currents each running in the direction of the circumferential spread of the ring. Application to limiting heating and reducing axial bulk.