Flywheel-Differential Layout for Reduced Driveline NVH

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Solution Overview

Problem

Existing vehicle power systems experience degraded noise, vibration, and harshness (NVH) performance and reduced handling stability due to the presence of numerous transmission components.

Innovation Solution

A power system design featuring a reduction shaft, differential, and flywheel, where the reduction shaft and differential are positioned on the same side of the flywheel, with specific gear connections and arrangements to disperse weight and reduce rotational speed, improving balance and noise/vibration performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a large number of transmission components are used to transmit power from the power source to the output mechanism, then power transmission is achieved, but NVH performance and handling stability deteriorate

Engineering Contradiction:
Improvepower transmission capabilityVSAvoidNVH performance and handling stability
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent combines the reduction shaft and differential into a compact integrated arrangement positioned on the same side of the flywheel. The reduction shaft includes a first section connected to the driving motor and flywheel, and a second section connected to the differential, forming a unified power transmission assembly that reduces the number of separate transmission components while maintaining effective power transmission capability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent repositions the differential and reduction shaft to be disposed on the same side of the flywheel in a compact layout, with the orthographic projection of the differential housing within the orthographic projection of the flywheel. This spatial reconfiguration in a different dimensional arrangement reduces the overall transmission component footprint and improves weight distribution, thereby enhancing NVH performance and handling stability while preserving power transmission function.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Productivity

If transmission components are arranged in a conventional configuration, then power transmission is efficient, but weight distribution is unbalanced causing vibration and noise

Engineering Contradiction:
Improvepower transmission efficiencyVSAvoidweight balance and vibration control
Core Design Contradiction:
ProductivityVSStability of the object's composition

Solution Approach 1:

The patent employs an asymmetric configuration where the reduction shaft and differential are positioned on the same side of the flywheel rather than in a symmetric or conventional balanced layout. The first section of the reduction shaft is farther from the driving motor than the second section, creating an asymmetric weight distribution pattern that disperses mass more effectively and reduces rotational imbalance, thereby minimizing vibration and noise while maintaining power transmission efficiency.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The reduction shaft is divided into a first section and a second section with different functional connections - the first section connects to the driving motor and flywheel while the second section connects to the differential. This segmentation allows for optimized weight distribution and balance, with each section positioned to minimize vibration and noise while preserving efficient power transmission through the segmented structure.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP4699839A1Power system and automobile
Publication Date: 2026.02.25 CHERY AUTOMOBILE CO LTD
  • EP4699839A1 patent drawingFigure 1
  • EP4699839A1 patent drawingFigure 2
  • EP4699839A1 patent drawingFigure 3

AI summary

The present application relates to the technical field of automobile power, and discloses a power system and an automobile. The power system comprises a reduction axle, a differential, a flywheel, and a driving motor. The reduction axle and the differential are located on the same side of the flywheel. The reduction axle comprises a first section and a second section, the first section is connected to the second section, the driving motor and the flywheel each are transmittingly connected to the first section, and the first section is farther away from the driving motor than the second section. The differential comprises a first output gear and a housing, the first output gear is transmittingly connected to the housing and the second section, the orthographic projection of one end of the housing on a first projection plane is located in the orthographic projection of the flywheel on the first projection plane, and the first projection plane is a plane perpendicular to the length direction of the housing. In the power system of the present application, by arranging one end of the housing of the differential at the position where the first projection plane coincides with the flywheel, the difference in distance between two ends of the housing and respective wheels is reduced, that is, the lengths of two half shafts are close, thus reducing abnormal noise and vibration generated during operating.