Hybrid Electric Vehicle Steering Gearbox Layout

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Solution Overview

Problem

In hybrid electric vehicles, space constraints in the engine compartment prevent the steering gearbox from being located on the front side of the drive shafts, compromising driving stability, steering feeling, and noise and vibration performance.

Innovation Solution

The hybrid electric vehicle configures the internal combustion engine and motor-generator with a steering gearbox positioned between them, allowing the steering gearbox to be placed on the front side of the drive shafts, thereby optimizing the layout to enhance stability, steering, and reducing noise and vibration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If the steering gearbox is located behind the drive shafts due to space constraints in the engine compartment, then the space utilization is improved, but the driving stability, steering feeling, and noise and vibration performance deteriorate

Engineering Contradiction:
Improveengine compartment space utilizationVSAvoiddriving stability
Core Design Contradiction:
Area of stationary objectVSStability of the object's composition

Solution Approach 1:

The patent relocates the steering gearbox from the conventional position behind the drive shafts to a position in front of the drive shafts, utilizing previously underutilized space in the front engine compartment. This spatial reconfiguration in the longitudinal dimension resolves the contradiction by achieving both compact space utilization and optimal steering performance.

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

2Adaptability or versatility

If the steering gearbox is located behind the drive shafts, then the layout flexibility is improved, but the steering feeling and noise and vibration performance deteriorate

Engineering Contradiction:
Improvelayout flexibilityVSAvoidnoise and vibration
Core Design Contradiction:
Adaptability or versatilityVSObject-generated harmful factors

Solution Approach 1:

By repositioning the steering gearbox to the front of the drive shafts, the patent creates an optimized layout that reduces the length of tie rods and improves steering geometry. This dimensional change in component arrangement simultaneously enhances steering feeling and reduces noise and vibration while maintaining layout flexibility.

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

Data Source

PatentEP3978287B1Hybrid electric vehicle
Publication Date: 2023.06.14 NISSAN MOTOR CO LTD
  • EP3978287B1 patent drawingFigure 1
  • EP3978287B1 patent drawingFigure 2
  • EP3978287B1 patent drawingFigure 3

AI summary

An hybrid electric vehicle (HEV) 1 drives front wheels 9 by a motor-generator 4 via drive shafts 10 by use of electricity generated by an internal combustion engine (ICE) 2. A lower portion of the internal combustion engine 2 is located on a front side of a lower portion of the motor-generator 4 in the vehicle body with being distanced therefrom. A steering gearbox 7 is placed between the internal combustion engine 2 and the motor-generator 4 and located on a front side of the drive shafts 10. According to this configuration, driving stability, steering feeling, and noise and vibration can be balanced at a high level.