Rotary Electric Machine Unit Sound Absorbing Member
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Solution Overview
Problem
Conventional rotary electric machine units in electric vehicles experience amplified radiation sound due to resonance between the case and power control unit, leading to noise issues and increased weight and cost.
Innovation Solution
A rotary electric machine unit with a power control unit directly mounted on a case, featuring a sound absorbing member between the case and power control unit, comprising a resin partition cover and a sound absorbing body to suppress radiation sound resonance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If the power control unit is directly mounted on the case accommodating the rotary electric machine, then weight and cost are reduced and the number of components is decreased, but radiation sound of the rotary electric machine resonates between the case and power control unit, causing noise amplification
Solution Approach 1:
A sound absorbing member is introduced as an intermediary component between the case and the power control unit. This mediator absorbs radiation sound from the rotary electric machine, preventing resonance while maintaining the direct mounting configuration. The sound absorbing member achieves this without adding significant weight or complexity to the system.
Solution Approach 2:
The sound absorbing member utilizes porous material properties to absorb radiation sound effectively. The porous structure allows the material to trap and dissipate sound energy, reducing resonance between the case and power control unit while maintaining a compact design that doesn't significantly increase overall system weight.
2Device complexity
If the power control unit is directly mounted on the case, then the number of components is reduced and assembly is simplified, but resonance occurs between the case and power control unit bottom surface
Solution Approach 1:
The sound absorbing member serves as a mediator that eliminates resonance noise without requiring additional mounting frames or complex assembly structures. It is simply placed between the case and power control unit, maintaining component simplicity while solving the resonance problem.
3Ease of manufacture
If the power control unit is directly mounted on the case, then attaching frames and three-phase cables are eliminated, but radiation sound resonates and is amplified
Solution Approach 1:
The sound absorbing member is integrated into the direct mounting arrangement as a simple intermediary element. It can be easily installed between the case and power control unit during assembly, maintaining the simplicity of direct mounting while effectively suppressing resonance noise.
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 effectively reduces radiation sound amplification and eliminates the need for additional attaching frames and cables, thereby minimizing noise and weight while maintaining efficient power control.
Implementation Method 1
a sound absorbing member provided between the upper surface of the case and the bottom surface of the power control unit
Data Source
AI summary
A rotary electric machine unit includes a rotary electric machine, a case accommodating the rotary electric machine, a power control unit configured to control the rotary electric machine and mounted on the case by directly connecting a unit-side connector provided on a bottom surface of the power control unit to a case-side connector provided on an upper surface of the case; and a sound absorbing member provided between the upper surface of the case and the bottom surface of the power control unit.