Motor Vehicle Auxiliary Unit Integral Stator Grounding
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Solution Overview
Problem
Existing motor vehicle auxiliary units, such as electric gas pumps, face challenges in achieving good electromagnetic compatibility (EMC) and are difficult to assemble due to the need for precise alignment and separate mounting of additional contact elements to minimize electromagnetic interference radiation.
Innovation Solution
A motor vehicle auxiliary unit with an electronically commutated electric motor and a unit connector plug featuring an integral stator body contact element that provides a direct low-resistive electric connection between the stator body, motor electronics, and external ground potential, eliminating the need for separate contact elements and simplifying assembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a separate stator body contact element is used to provide direct electric connection between stator body and motor electronics, then electromagnetic compatibility (EMC) characteristics are improved, but assembly complexity increases due to precise alignment requirements
Solution Approach 1:
The patent combines the stator body contact element with the connector plug into a single integrated component. The contact element is formed as an integral part of the connector plug body, eliminating the need for separate mounting and alignment operations. This merging resolves the contradiction by maintaining the EMC benefits of direct stator body connection while removing the assembly complexity of separate contact elements.
Solution Approach 2:
The connector plug is designed to perform multiple functions simultaneously: it provides electrical connection for power and control signals, and integrates the stator body contact element for EMC grounding. This multi-functionality allows a single component to address both connectivity and electromagnetic compatibility requirements, simplifying the overall assembly process while maintaining reliability.
2Reliability
If multiple separate contact elements and junctions are used to connect stator body with ground, then electrical connection reliability is improved, but total resistance increases
Solution Approach 1:
The patent merges multiple electrical connection paths into a single integrated low-resistive connection. The stator body contact element is directly integrated with the connector plug's ground terminal, creating a direct electrical path that eliminates intermediate junctions. This reduces the total resistance of the grounding path while maintaining connection reliability through the direct integral connection.
3Object-generated harmful factors
If separate stator body contact element is mounted additionally, then electromagnetic interference radiation is minimized, but manufacturing complexity increases
Solution Approach 1:
The stator body contact element is merged with the connector plug into a single manufactured component. This integration allows the entire assembly to be manufactured as one piece or pre-assembled unit, reducing the number of separate manufacturing processes and quality checks required. The EMC benefit of direct stator body connection is maintained while manufacturing complexity is reduced.
Solution Approach 2:
The contact element is pre-integrated into the connector plug during manufacturing, before final assembly with the motor. This preliminary action ensures proper alignment and connection is built-in from the start, eliminating the need for complex alignment procedures during final assembly and reducing overall manufacturing 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
The solution ensures good EMC characteristics and simplifies the assembly process by reducing the number of electrical junctions and total resistance in the connection, while maintaining reliable electrical contact and alignment.
Implementation Method 1
the external-ground connector lug is internally directly connected with the motor electronics ground terminal for electrically connecting the motor electronics ground terminal with the external vehicle ground potential
Implementation Method 2
the externally commutated electric motor of the motor vehicle auxiliary unit generates electromagnetic interference radiation
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
The invention is directed to a motor vehicle auxiliary unit (10) comprising - an electronically commutated electric motor (12) with • a permanent magnetic motor rotor (20) • a motor stator (22) with a ferromagnetic stator body (24) and at least one stator coil (26), and • a motor electronics (28) with a ground terminal (44), and - a unit connector plug (18) with at least an external-ground connector lug (36) being directly electrically connected with the motor electronics ground terminal (44), - wherein the external-ground connector lug (36) is provided with an integral stator body contact element (42;42';42") providing a direct electric connection with the stator body (24). The unit connector plug (18) with the integrated stator body contact element (42;42';42") ensures good EMC characteristics of the motor vehicle auxiliary unit (10) and allows a simple assembling of the motor vehicle auxiliary unit (10).