Rotary Electric Machine Heat-Sink Layout for Solder-Free Assembly
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Solution Overview
Problem
Existing rotary electric machines have limitations in heat dissipation and assemblability due to the arrangement of the heat-sink between the substrate and housing, and the soldering process for terminal connections.
Innovation Solution
A rotary electric machine design featuring a heat-sink that closes the housing, a substrate arranged perpendicular to the heat-sink, and a connector assembly with press-fitting terminals, along with positioning holes and a guide portion for improved alignment and assembly, enhancing heat dissipation and assemblability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a heat-sink is arranged between the substrate and the housing and covered with a cover, then the structure is compact, but the heat dissipation effect is insufficient
Solution Approach 1:
The heat-sink is repositioned from an internal arrangement between the substrate and housing to an external arrangement on the housing side, utilizing the radial dimension for heat dissipation. This dimensional reconfiguration allows the heat-sink to access external airflow and space, dramatically improving heat dissipation effectiveness without increasing internal structural complexity.
2Reliability
If the heat-sink and substrate are assembled to the housing with terminal connections by soldering, then the connection is reliable, but the assembly process is complex and time-consuming
Solution Approach 1:
The soldering process is replaced with a press-fit mechanical connection system. The connection terminal includes a press-fit portion that mechanically engages with the bus bar through elastic deformation, eliminating the need for thermal soldering processes while maintaining reliable electrical and mechanical connections.
Solution Approach 2:
The connection terminal is segmented into distinct functional portions: a press-fit portion for mechanical connection with the bus bar, a terminal portion for electrical connection with the substrate, and a holding portion for structural support. This segmentation enables specialized design of each portion to optimize both connection reliability and assembly simplicity.
3Temperature
If the heat-sink is repositioned to close the housing opening with exposed surface, then heat dissipation is improved, but the assembly sequence becomes more complex
Solution Approach 1:
The heat-sink is merged with the housing structure, where the heat-sink serves both as a thermal management component and as a closure for the housing opening. This merging eliminates the need for separate cover components and simplifies the assembly sequence by reducing the number of parts and assembly steps.
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 design improves heat dissipation efficiency and simplifies the assembly process by allowing efficient heat transfer and secure, solder-free connection of the bus bar to the terminal, thereby enhancing the overall performance and reliability of the rotary electric machine.
Implementation Method 1
a heat-sink that closes the opening of the housing
Implementation Method 2
enhancing the heat dissipation effect of the heat-sink
Implementation Method 3
having a press-fitting portion that is press-fitted and fixed to the bus bar of the motor portion
Implementation Method 4
press-fitted and fixed to the bus bar
Data Source
AI summary
Improving the assemblability while improving the heat dissipation effect of the heat-sink.In the rotary electric machine, the ECU unit has the heat-sink that closes the opening of the housing of the motor portion, the circuit board fixed to the lower side of the heat-sink, and the connector assembly fixed to the upper side of the heat-sink with a part of the heat-sink exposed. Thus, the heat of the electronic components of the circuit board can be dissipated to the outside of the rotary electric machine by the heat-sink. Moreover, a connection terminal is provided on the lower surface of the circuit board, and the bus bar terminal portion of the motor portion is press-fitted into the connection terminal. Therefore, the bus bar terminal portion can be connected to the circuit board without being soldered to the circuit board. Therefore, the assemblability of the rotary electric machine can be improved.