Battery Pack Wedge Shim Compression for Tolerance Variation
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Solution Overview
Problem
Conventional traction battery packs face challenges in efficiently compressing and securing battery cells due to tolerance variations and the absence of array support structures, leading to assembly complexities and inconsistent compression forces.
Innovation Solution
A shim system incorporating wedge inserts is used to interface between the enclosure tray and cell matrix, translating draft angles and applying compressive loads normally to the cell stack, while addressing tolerance issues and securing the cell matrix without traditional array support structures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional array support structures are used to group and support battery cells, then structural support and cell grouping are achieved, but device complexity and assembly complexity increase
Solution Approach 1:
The patent removes conventional array support structures (frames, spacers, rails, walls, end plates, bindings) from the battery pack design. Instead of using these separate supporting components, the enclosure tray itself is designed to directly support and compress the cell stacks, simplifying the overall structure while maintaining structural integrity
Solution Approach 2:
The enclosure tray is designed to perform multiple functions simultaneously: it provides structural support for the cell stacks, applies compression forces to secure the cells, and defines the overall geometry of the battery pack. This multi-functional design eliminates the need for separate array support structures
2Stability of the object's composition
If conventional array support structures are used to secure battery cells, then cell positioning is achieved, but manufacturing precision and tolerance control become more difficult
Solution Approach 1:
The patent changes the compression parameter by applying force through the enclosure tray rather than through multiple discrete support structures. The compression force is distributed across the cell stacks through the tray walls, which compensates for tolerance variations in cell dimensions and positions, achieving stable cell positioning despite manufacturing variations
3Force
If array support structures are used to compress battery cells, then compression force is applied, but force consistency and compression efficiency decrease
Solution Approach 1:
The enclosure tray walls serve dual purposes: providing structural support and applying compression force to the cell stacks. The draft angles on the tray walls are specifically designed to translate into effective compression forces on the cells, making the compression process more efficient and consistent
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 shim system ensures consistent and efficient compression of battery cells, maintaining structural integrity and reducing assembly complexities by normalizing compressive forces, even in the absence of array support structures.
Implementation Method 1
a wedge insert that establishes an interface between a draft angle of a side wall of the enclosure tray and the cell matrix
Implementation Method 2
an adhesive is disposed between the first side face and the side wall and further between the second side face and the cell matrix
Data Source
AI summary
Traction battery packs are disclosed that include battery systems. A cell stack/cell matrix of the battery system may be positioned within an enclosure tray of the traction battery pack. A wedge insert may be positioned at an interface between the cell stack/cell matrix and a side wall of the enclosure tray. The side wall may include a draft angle. The wedge insert may be configured to translate the draft angle in order to apply a compressive load in a direction that is substantially normal to the cell stack/cell matrix.