Electric Drive Unit Test Rig With Gearbox Acoustic Decoupling
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Solution Overview
Problem
Conventional test rigs for electric drive units in electric vehicles fail to effectively isolate noise emissions from output motors, leading to inaccurate NVH measurements due to direct mechanical coupling, which includes motor vibrations, affecting the quality assessment of the drive units.
Innovation Solution
The testing device employs a gearbox, specifically a belt drive, to couple output motors with output shafts, allowing for acoustic decoupling and improved noise filtration, enabling separate NVH measurements of the electric drive unit by filtering out motor noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If output motors are directly coupled to output shafts, then mechanical connection is simple and robust, but noise emissions from output motors are transmitted to the electric drive unit, degrading NVH measurement accuracy
Solution Approach 1:
A gearbox is introduced as an intermediary component between the output motor and the output shaft. The gearbox transmits mechanical power while acoustically decoupling the output motor from the electric drive unit, allowing NVH measurements to capture only the electric drive unit's noise emissions without contamination from output motor vibrations.
2Measurement precision
If a gearbox is introduced to decouple output motors, then NVH measurement accuracy is improved, but device complexity increases
Solution Approach 1:
The gearbox serves as a standard mechanical intermediary component that provides both power transmission and acoustic decoupling functions. By using a conventional gearbox design rather than custom-built decoupling mechanisms, the solution achieves measurement accuracy improvement while minimizing the increase in device complexity.
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 enhances the accuracy of NVH measurements by isolating motor noise, identifies structural faults, and reduces the need for test fixtures, resulting in cost savings and efficient use of resources.
Implementation Method 1
a belt drive (22) is provided, by means of which the output motor (20) is coupled to the output shaft (16)
Data Source
Figure 1
AI summary
The invention relates to a testing device (10) for electric drive units, comprising a receptacle (12a, b) for an electric drive unit (14) and two output shafts (16) which can be coupled to an electric drive unit (14) at either end, wherein the two output shafts (16) are each coupled to a separate output motor (20) which can drive the electric drive unit (14) in motor operation and/or load it in generator operation, characterized in that each output motor (20) is coupled to the associated output shaft (16) via a gear (22).