Automotive Alternator Rectifier Axial Compactness
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Solution Overview
Problem
Conventional automotive alternator rectifying apparatuses face reduced cooling efficiency due to obstructed cooling airflow and increased pressure loss, and higher manufacturing costs due to the need for bending rectifying element leading electrodes, which also compromises reliability.
Innovation Solution
The design includes a circuit board positioned between heatsinks with rectifying elements, allowing axial extension of leading electrodes without bending, reducing axial dimensions, and optimizing airflow channels to enhance cooling efficiency by minimizing pressure loss and increasing airflow rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If wiring is disposed radially inside the cooling fins to connect rectifying elements, then the connection pathway is shortened, but the cooling airflow is obstructed and pressure loss is increased
Solution Approach 1:
The patent changes the wiring arrangement from a radial position (inside cooling fins) to an axial position (between heatsinks in the axial direction). This dimensional change allows the wiring to connect rectifying elements effectively while avoiding obstruction of the radial cooling airflow paths, thus reducing pressure loss while maintaining connection efficiency.
2Length of stationary object
If cooling fins are disposed to overlap in the rotating shaft direction, then the axial dimension is reduced, but the cooling airflow rate is reduced due to deflection at downstream fins
Solution Approach 1:
The patent segments the cooling fin structure into two separate heatsinks (first heatsink and second heatsink) positioned at different axial locations. This segmentation allows each heatsink to have its own cooling fins that do not overlap in the rotating shaft direction, preventing airflow deflection and pressure loss while still achieving a compact overall axial dimension through optimized spacing.
3Length of stationary object
If leading electrodes are bent perpendicularly to reduce axial dimensions, then the axial dimension is reduced, but the reliability of rectifying elements is reduced
Solution Approach 1:
Instead of bending the leading electrodes perpendicularly (conventional approach), the patent inverts the approach by extending the leading electrodes axially between the first and second heatsinks. This inversion eliminates the need for perpendicular bending, maintaining the mechanical strength and reliability of the rectifying elements while still achieving reduced axial dimensions through the compact heatsink arrangement.
4Reliability
If leading electrodes are extended axially without bending, then the reliability is improved and manufacturing is simplified, but the axial dimension increases
Solution Approach 1:
The patent merges the first and second heatsinks into a closely integrated assembly with minimal axial spacing between them. This merging allows the leading electrodes to be extended axially between the heatsinks without significantly increasing the overall axial dimension, while maintaining the reliability benefits of non-bent electrode connections.
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 reduces axial dimensions, increases reliability by eliminating electrode bending, lowers manufacturing costs, and enhances cooling efficiency by improving airflow and heat dissipation.
Implementation Method 1
a flow channel that causes cooling air to flow axially into the protective cover through the suction aperture due to rotation of the fan
Implementation Method 2
a plurality of first radially inner cooling fins that are formed on a radially inner side of the first rectifying element holding portion
Implementation Method 3
cooling air flows into the protective cover through the suction aperture due to rotation of the fan, cools the rectifying apparatus
Data Source
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AI summary
The present invention provides an automotive alternator that can reduce axial dimensions of a rectifying apparatus while suppressing reductions in reliability of rectifying elements and cooling of the alternator. In the present rectifying apparatus, a circuit board is disposed between a first rectifying element holding portion and a second rectifying element holding portion, first rectifying elements that are held by the first rectifying element holding portion are connected to a first rectifying element connecting portion of the circuit board by extending a first leading electrode axially, second rectifying elements that are held by the second rectifying element holding portion are connected to a second rectifying element connecting portion of the circuit board by extending a second leading electrode axially, the circuit board is configured such that only a housing linking portion, a stator winding connecting portion, and a voltage regulator connecting portion protrude from the first rectifying element holding portion and the second rectifying element holding portion when viewed from an axial direction, a plurality of first radially inner fins are formed on a radially inner side of the first rectifying element holding portion, and a plurality of second radially outer fins are formed on a radially outer side of the second rectifying element holding portion.