Electric Motor Contact Lug Segmentation for Vibration Resistance
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Solution Overview
Problem
Mechanical stresses in electric motor vehicle auxiliary units cause the fixation of contact lugs in the plastic base body to loosen over time, leading to loose or broken connections between motor coils and connecting cables.
Innovation Solution
The contact lugs are designed with a flat plug-in body featuring teeth on both sides, where the distance from the center line decreases towards the distal end, creating an angled virtual crest line greater than 0.5°, and are radially aligned with a line pocket for secure motor coil connection lines, ensuring a robust and secure mechanical and electrical connection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If contact lugs are fixed in the plastic base body using a friction fit, then the assembly process is simple, but the mechanical connection loosens over time due to mechanical stress
Solution Approach 1:
The contact lug is segmented into multiple teeth along its length, transforming a single rigid connection point into multiple distributed fixation points. This segmentation allows the connection to better distribute mechanical stresses and prevents loosening while maintaining assembly simplicity.
Solution Approach 2:
The teeth are designed with asymmetric dimensions - the tooth width and spacing vary along the length of the contact lug. This asymmetric design creates varying friction forces at different positions, enhancing the overall mechanical interlocking with the plastic base body while preserving ease of assembly.
2Strength
If the contact lugs are securely fixed in the base body, then the mechanical strength improves, but the complexity of the contact lug design increases
Solution Approach 1:
By dividing the contact lug into multiple teeth segments, the design achieves enhanced mechanical strength through distributed stress absorption. The segmentation provides multiple engagement points with the plastic base body, significantly improving fixation strength without requiring complex additional components.
Solution Approach 2:
The contact lug with multiple teeth serves multiple functions simultaneously: it provides electrical conduction, mechanical fixation through friction, and stress distribution. This multi-functionality achieves strong fixation without adding separate complex fixation mechanisms, thereby limiting the increase in design complexity.
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
This design significantly improves the mechanical strength of the contact lug fixation within the plastic base body, preventing loosening and ensuring a secure connection under mechanical stress, such as vibrations and impacts.
Implementation Method 1
the slightly elastic plastic of the base body protrudes slightly into the valleys between two teeth after assembly
Data Source
Figure 1~2
Figure 3
AI summary
The invention relates to an electric vehicle auxiliary unit (10) with an electric drive motor (20) and a drive element (12) driven by the drive motor (20), wherein the drive motor (20) has a motor rotor (22) and a motor stator (30), the motor stator (30) has an electrically non-conductive plastic base body (40) which carries several stator coils (42) and into which several electrically conductive contact lugs (32) are inserted, the contact lugs (32) are electrically connected to an electronic motor control (24) and to connecting leads (43) of the motor coils (42), each contact lug (32) has a flat toothed plug body (34) which has several teeth (361-367) on each of its two lateral narrow sides, and the two virtual vertex lines (37) which each connect the tooth tips (38) of the teeth (361-367) are at an angle to each other. a greater than 1.0°.