Motor Vehicle Auxiliary Unit Connector Encapsulation
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Solution Overview
Problem
Existing electric motor vehicle auxiliary units face challenges in maintaining high electrical reliability due to potential moisture exposure and mechanical misalignment during assembly, which can lead to unreliable connections and reduced operational stability.
Innovation Solution
An electric motor vehicle auxiliary unit with an electronically commutated drive motor features a motor control circuit board partially encapsulated in a plastic potting body, where rigid metal pin bodies are soldered to the circuit board, forming a secure connector arrangement within a monolithic casting. This setup prevents moisture ingress and ensures a robust, gas-tight seal, while axial support lugs and sockets ensure precise assembly positioning, enhancing electrical reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the motor control circuit board is left exposed or partially protected, then the assembly process is simpler, but the electrical reliability deteriorates due to moisture exposure
Solution Approach 1:
The patent merges the circuit board protection function with the connector housing function into a single encapsulation body. The potting material simultaneously encapsulates the circuit board and forms the connector housing, eliminating the need for separate protection structures and achieving both moisture protection and structural integration.
Solution Approach 2:
The patent uses potting material (a composite material) that serves multiple functions: protecting the circuit board from moisture, providing mechanical support, and forming the connector housing. This composite material approach resolves the contradiction by providing comprehensive protection while maintaining assembly simplicity.
2Reliability
If multiple contact levels are used for electrical connection, then the connection flexibility is higher, but the electrical reliability deteriorates due to potential connection failures at each interface
Solution Approach 1:
The patent merges the circuit board, connector pins, and housing into a single encapsulated structure. The connector pins are directly embedded in the potting material that encapsulates the circuit board, eliminating intermediate connection interfaces and reducing the risk of connection failures.
Solution Approach 2:
The patent segments the connector pins from the housing structure while maintaining direct electrical connection to the circuit board. The pins are individually embedded in the potting material, allowing each pin to have its own direct connection path without relying on intermediate contact levels.
3Reliability
If the connector pins are potted along with the circuit board, then the moisture protection is improved, but the mechanical alignment and assembly precision deteriorate
Solution Approach 1:
The patent performs preliminary positioning of the connector pins in the housing before applying the potting material. The pins are first mechanically positioned and secured, then the potting material is applied to provide moisture protection without disrupting the pre-established mechanical alignment.
Solution Approach 2:
The patent separates the mechanical positioning function (handled by the housing and pin arrangement) from the moisture protection function (handled by the potting material). This segmentation allows each function to be optimized independently: mechanical precision for alignment and chemical protection for moisture resistance.
4Reliability
If the circuit board is completely encapsulated, then the protection from environmental factors is improved, but the ease of repair and inspection deteriorates
Solution Approach 1:
The patent applies local quality by providing different levels of encapsulation: the critical circuit board and connector pins are fully encapsulated for maximum protection, while the connector housing and external interfaces remain accessible. This localized approach protects vulnerable components while maintaining repairability for external connections.
Data Source
Figure 1
Figure 2~3
AI summary
The invention relates to an electric motor vehicle secondary assembly (10) having an electronically commutated drive motor (14), a working means (18) driven by the drive motor (14), a peripheral connector arrangement (16) having at least two exposed connector pins (50), and a motor control circuit board (34) at least partly potted in a cast body (40), which is located in a motor transverse plane and has commutation electronics (80). The connector pins (50) are each formed by a single stiff pin element (51), which is directly electrically connected to the motor control circuit board (34). The cast body (40) has a connector core (48) that is integrally molded on in one piece and encloses the pin element (51) between the motor control board (34) and a connector base (49) formed by the connector core (48). The connector core (48) plugs into a housing opening (60) of a housing body (26), such that the connector base (49) closes the housing opening (60) completely, and the pin elements (51) project outward from the connector base (49) through the housing opening (60).