Battery Pack Double-Shear Connection for Stable Tool Coupling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing battery packs for cordless tools and electrical devices often lack a secure and efficient mechanism for coupling and decoupling, which can lead to instability and reduced performance during use and charging.
Innovation Solution
A battery pack design featuring a battery cell carrier with connector screw bosses and a housing with aligned outer and inner screw bosses, creating a double shear condition, along with a terminal block for electrical communication, ensures secure coupling and efficient power transfer to the device.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a conventional single shear connection is used to attach the battery cell carrier to the housing, then the device complexity is reduced, but the connection strength and stability deteriorate
Solution Approach 1:
The connection structure is segmented into multiple components: outer screw bosses on the housing, inner screw bosses on the battery cell carrier, and threaded fasteners that pass through both. This segmentation allows the creation of a double shear condition where the fastener passes through the housing, carrier, and back through the housing, distributing loads across multiple interfaces and significantly increasing connection strength while maintaining a manageable structural complexity
Solution Approach 2:
The connection is enhanced by adding a dimensional aspect - the fasteners extend through the housing portion twice, creating a three-dimensional path that establishes a double shear condition. This dimensional approach transforms a simple single-plane connection into a multi-plane structural attachment, improving strength without proportionally increasing complexity
2Stability of the object's composition
If the battery pack uses a secure double shear connection mechanism, then the connection stability is improved, but the manufacturing precision requirements increase
Solution Approach 1:
The screw bosses (both outer and inner) are pre-formed on the housing and battery cell carrier during manufacturing, establishing precise alignment features before assembly. This preliminary action ensures that when the threaded fasteners are installed, they naturally follow the pre-established alignment paths, reducing the need for high-precision manual alignment during final assembly while maintaining connection stability
Solution Approach 2:
The threaded fasteners act as intermediaries that bridge the outer screw bosses and inner screw bosses. These fasteners accommodate minor variations in alignment by providing threaded engagement, which allows for self-centering and load distribution, thereby maintaining connection stability even when perfect alignment is not achieved
Data Source
AI summary
A battery pack is configured to be coupled to an electrical device. The battery pack includes a plurality of battery cells, a battery cell carrier to support the battery cells, a housing having an upper housing portion. The battery cell carrier having a plurality of connector screw bosses. The upper housing portion having an outer screw boss on each lateral side and a respective inner screw boss formed on an inner surface of the upper housing portion. The upper housing portion is connected to the battery cell carrier with a plurality of threaded fasteners each extending through one of the outer screw bosses, a respective one of the plurality of connector screw bosses, and a respective inner screw boss creating a double shear condition on each side of the respective connector screw boss.