Motor Winding-to-PCB Converter Connection Without Junction Box
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Solution Overview
Problem
The existing electrical drive units for three-phase motors require complex wiring and separate junction boxes, leading to increased contact resistances and thermal management challenges due to numerous cables and connectors.
Innovation Solution
The electric drive unit integrates a converter onto a circuit board assembly, allowing direct connection of coil windings to terminal contacts on the board, eliminating the need for a separate junction box and simplifying electrical connections by using crimped or screwed connectors directly on the circuit board.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a separate junction box with numerous cables and connectors is used to connect coil windings to the converter, then the electrical connection can be established, but the wiring complexity increases and contact resistances increase
Solution Approach 1:
The patent merges the junction box function directly into the circuit board by integrating terminal contacts onto the board. The coil connectors are connected directly to terminal contacts on the circuit board, eliminating the separate junction box and reducing the number of connectors and cables required, thereby reducing wiring complexity while maintaining electrical connection reliability
2Reliability
If a separate junction box with numerous connectors is used, then the electrical connection can be established, but the contact resistances increase due to multiple connection points
Solution Approach 1:
The patent reduces the number of connection points by integrating terminal contacts directly onto the circuit board. This eliminates intermediate connectors and junction box connections, thereby reducing the cumulative contact resistances while maintaining reliable electrical connection between coil windings and the converter
3Temperature
If a separate junction box is used for thermal management of contacts, then the thermal management can be addressed, but the device complexity and space requirements increase
Solution Approach 1:
The patent integrates the thermal management function into the circuit board structure itself. The terminal contacts are mounted directly on the board, allowing heat dissipation through the board's thermal pathways and eliminating the need for a separate junction box structure, thereby reducing device complexity while maintaining thermal management capability
Solution Approach 2:
The patent extracts the junction box as a separate component and eliminates it entirely by integrating its functionality directly into the circuit board. This removes the need for separate thermal management structures while maintaining the necessary thermal dissipation through the board's inherent thermal pathways
Data Source
AI summary
An electric drive unit includes a three-phase motor having a rotor, a stator, and a motor housing, wherein the stator has three coil windings that each include one winding wire having two coil connectors. The electric drive unit further includes a converter that provides the three-phase motor with a three-phase alternating current and has three terminal contacts. The coil connectors are connected to the terminal contacts by way of a star circuit or a delta circuit. The converter is implemented in a circuit board assembly having at least one circuit board. The terminal contacts of the converter are on the circuit board, and the connections, provided in the context of the star circuit or delta circuit, between the coil connectors and the terminal contacts of the converter, are implemented in that the respective ends of the winding wires of the coil windings are connected directly to the circuit board.