Rotating Electrical Machine Fuse Reliability via Notch Separation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In controller-integrated rotary electric machines, the fuse function is not reliably achieved due to the fuse portion melting and re-establishing contact with the electric power interconnecting part during overcurrent events, leading to ineffective current interruption.
Innovation Solution
The fuse portion and electric power interconnecting part are separated, with the fuse portion located on the power module terminals and the interconnecting part having a notch around the terminal placement area, extending to the cooling member side, preventing re-contact and allowing cooling to reduce temperature and thermal expansion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the fuse portion is formed in the power module terminals to interrupt overcurrent, then the fuse function is provided, but the blown fuse portion may melt and re-establish electrical contact with the electric power interconnecting part, causing the fuse function to fail
Solution Approach 1:
The electric power interconnecting part is extracted from the immediate vicinity of the fuse portion by introducing a notch that creates separation. This removes the harmful proximity that allows re-contact after fuse blowout, while maintaining the fuse's current-interrupting function.
Solution Approach 2:
The notch acts as an intermediary barrier between the fuse portion and the electric power interconnecting part. This intermediate structure prevents direct re-contact of molten fuse material with the interconnecting part, ensuring reliable current interruption.
2Volume of moving object
If the fuse portion and electric power interconnecting part are placed close together to reduce device size, then device compactness is improved, but thermal expansion during overcurrent may cause re-contact and fuse function failure
Solution Approach 1:
The notch introduces a dimensional separation in the radial direction between the fuse portion and the electric power interconnecting part. This radial separation prevents thermal expansion from causing re-contact, while maintaining compact overall device dimensions through efficient space utilization.
Solution Approach 2:
The notch creates a localized separation zone specifically where thermal expansion and re-contact risk occur, while other areas of the device maintain compact integration. This targeted approach ensures reliability without compromising overall device compactness.
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 configuration ensures reliable overcurrent interruption and prevents re-contact between the fuse and interconnecting parts, enhancing the fuse function even in high-temperature environments, such as internal combustion engine rooms.
Implementation Method 1
the part in which the plurality of terminals of the power module are not placed extends to the cooling member side
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Provided is a controller-integrated rotary electric machine, the controller includes a cooling member, and the power circuit portion includes the power module and the electric power interconnecting part. The power module includes the switching element. The electric power interconnecting part includes the conductor to be connected to the plurality of terminals of the power module. At least one of the plurality of terminals of the power module has the fuse portion. The fuse portion and the electric power interconnecting part are separated from each other. The electric power interconnecting part has the notch formed in the portion around which the plurality of terminals of the power module are placed. The part in which the plurality of terminals of the power module are not placed extends to the cooling member side.