Lamella Pack Positioning Structure for Low-Loss Electric Drives
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Solution Overview
Problem
Existing electric drive systems experience increased power losses and reduced holding forces due to the damage of insulation during the stacking of sheet metal lamellas, which is caused by the common stamping method used to connect them.
Innovation Solution
A disk pack design featuring a circular base body with radially extending grooves and rotationally symmetric positioning elements, including recesses, deformation sections, and compensating elements, which allows for reduced contact interruptions and enhanced holding forces while minimizing power losses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If punch-stack joining is used to secure laminations to one another, then the laminations are firmly connected, but the insulation between laminations is compromised resulting in increased eddy current losses
Solution Approach 1:
The patent introduces an intermediate element (the deformation section acting as a mechanical intermediary) that transmits the connecting force without requiring direct metal-to-metal contact between laminations. The deformation section deforms plastically to create a mechanical lock while the insulating varnish layer remains intact, thus mediating between the need for strong connection and the need to preserve electrical insulation.
Solution Approach 2:
The patent extracts the connection function from the direct lamination contact interface and relocates it to the deformation section. By taking out the punching action from the final lamination and creating a deformation section that engages with the opening in the preceding lamination, the connection is achieved through a dedicated structural feature rather than direct penetration of multiple laminations.
2Loss of energy
If the number of connection points is reduced to minimize insulation damage, then eddy current losses are reduced, but the holding forces between laminations are insufficient
Solution Approach 1:
The patent applies preliminary action by pre-forming the deformation section in the lamination before stacking. The deformation section is created with a specific geometry that is designed to engage with the opening in the preceding lamination, ensuring that the connection is established in advance rather than requiring forceful insertion during assembly. This preliminary preparation allows for fewer connection points while maintaining adequate holding force.
3Loss of energy
If empty laminations are inserted to reduce contact between laminations, then power losses are reduced, but the manufacturing robustness is reduced due to longer insertion path and reduced holding forces
Solution Approach 1:
The patent segments the lamination stack into alternating patterns of laminations with deformation sections and laminations with openings. This segmentation creates a structured sequence where each lamination with a deformation section engages with the preceding lamination having an opening. The segmentation allows for reduced contact interruptions while maintaining manufacturing robustness through a systematic, repeatable stacking pattern that does not require long insertion paths.
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 design effectively reduces power losses and increases holding forces in electric drive systems by allowing for easier assembly and reduced contact between lamellas, thereby improving the efficiency and robustness of the electric drive.
Implementation Method 1
one of which has a deformation section and the other has an opening accommodating the deformation section
Data Source
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AI summary
The invention relates to a lamella (10) for a lamella pack (12) of an electric drive (14) for a motor vehicle (44), comprising a circular base body (16) with a centrally arranged annular opening (18), an outer edge region (20) and an inner edge region (22), wherein a plurality of radially extending grooves (24) are arranged in the outer edge region (20).It is proposed that at least three positioning elements (26) are provided in the inner edge region (22) and/or the outer edge region (20), wherein the at least three positioning elements (26) are rotationally symmetric, at an angle (α) to each other and at the same distance (A) from a center point (M) of the circular base body (16) around the center point (M), wherein of the at least three positioning elements (26) at least one positioning element forms a recess (28), at least one positioning element forms a deformation section (30) and at least one positioning element forms a compensation element (32).