Rotor Lamination with End Plates to Reduce Leakage Flux
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Solution Overview
Problem
Existing laminated stacks for rotors and stators of electric motors and generators are costly and unreliable in manufacturing, particularly due to issues with die-casting processes that lead to leakage flux and material intrusion into pockets.
Innovation Solution
Incorporating axially extending cavities between pockets that are closed at both ends with sheet metal laminations, preventing die-casting material from entering and allowing for post-die-casting magnet insertion, thereby reducing leakage flux and enabling cost-effective production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If axially extending cavities are provided between pockets to reduce leakage flux, then magnetic flux leakage is reduced, but die-casting material may enter the cavities and pockets during the die-casting process
Solution Approach 1:
End plates are预先 installed on the end faces of the lamellar package before the die-casting process to close the cavities. This preliminary action prevents die-casting material from entering the cavities and pockets during the high-pressure die-casting process, while still allowing the cavities to reduce leakage flux in the final product.
Solution Approach 2:
End plates serve as intermediary components that temporarily close the cavities during the die-casting process. These plates act as a barrier between the die-casting material and the cavities, preventing material intrusion while allowing the cavities to fulfill their magnetic shielding function in the completed rotor.
2Reliability
If the distance between pockets and starting cage is increased to prevent material intrusion, then die-casting material cannot enter pockets, but manufacturing complexity increases
Solution Approach 1:
End plates are预先 installed on the end faces of the lamellar package before the die-casting process to close the cavities. This preliminary action prevents die-casting material from entering the cavities and pockets during the high-pressure die-casting process, while still allowing the cavities to reduce leakage flux in the final product.
Solution Approach 2:
End plates serve as intermediary components that temporarily close the cavities during the die-casting process. These plates act as a barrier between the die-casting material and the cavities, preventing material intrusion while allowing the cavities to fulfill their magnetic shielding function in the completed rotor.
3Ease of manufacture
If magnets are inserted before die-casting, then magnet insertion is simpler, but die-casting material will enter and contaminate the magnets
Solution Approach 1:
End plates are预先 installed on the end faces of the lamellar package before the die-casting process to close the cavities. This preliminary action prevents die-casting material from entering the cavities and pockets during the high-pressure die-casting process, while still allowing the cavities to reduce leakage flux in the final product.
Solution Approach 2:
End plates serve as intermediary components that temporarily close the cavities during the die-casting process. These plates act as a barrier between the die-casting material and the cavities, preventing material intrusion while allowing the cavities to fulfill their magnetic shielding function in the completed rotor.
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 allows for efficient and reliable manufacturing of laminated stacks by reducing leakage flux and preventing material intrusion during the die-casting process, enabling the use of suitable die-casting materials like aluminum and copper alloys, and facilitating the insertion of magnets after the process.
Implementation Method 1
These cavities significantly reduce the magnetic flux leakage
Implementation Method 2
the starting cage is manufactured by die casting
Data Source
Figure 1~2
Figure 3
Figure 4~5
AI summary
The stack (2) has pockets (6) for retaining magnets, and axially running windows formed between the adjacent pockets, where two ends of the windows are closed by metal sheet slats (3a) or a plug-like end plate. Each metal sheet slat forms an end-side metal sheet slat of the stack. The windows exhibit a smaller radial distance from a starting cage (4) than the pockets. The metal sheet slats are made of magnetic or non-magnetic material. The pockets are filled with pressure casting material that is provided with conductance of greater than or equal to 58 millivolt per meter. An independent claim is also included for a method for manufacturing a rotor and a stator.