Two-Speed Vehicle Drive Gear Layout for Shorter Output Shafts

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Solution Overview

Problem

Existing vehicle drive apparatuses face challenges in reducing the axial-direction dimension of the output shaft when incorporating a high/low two-speed gear shifting mechanism directly coupled with the output shaft, leading to increased axial dimension and deteriorated vehicle mounting properties.

Innovation Solution

The vehicle drive apparatus distributes the shifting clutch across two shafts, allowing the drive gear secured to the input shaft to be used for continuous power generation, reducing the number of elements aligned on each shaft and thereby minimizing the axial-direction dimension of the output shaft.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a high/low two-speed gear shifting mechanism is directly coupled with the output shaft, then the power transmission efficiency is improved, but the axial-direction dimension of the output shaft increases

Engineering Contradiction:
Improvepower transmission efficiencyVSAvoidaxial-direction dimension of output shaft
Core Design Contradiction:
ProductivityVSLength of moving object

Solution Approach 1:

The shifting clutch is segmented into two separate parts: a first shifting clutch arranged on the input shaft and a second shifting clutch arranged on the countershaft. This segmentation allows the gear shifting mechanism to be distributed across different shafts, reducing the axial dimension requirements on any single shaft while maintaining power transmission efficiency.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from a single-shaft arrangement to a multi-shaft arrangement by placing clutch components on both the input shaft and countershaft. This dimensional redistribution in the shaft arrangement space reduces the axial-direction dimension of the output shaft while preserving the high/low speed gear shifting functionality.

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

2Adaptability or versatility

If multiple gear trains are arranged on a single shaft, then the gear shifting function is achieved, but the number of elements aligned on the shaft increases

Engineering Contradiction:
Improvegear shifting functionVSAvoidnumber of elements aligned on shaft
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The gear shifting mechanism is segmented across two shafts (input shaft and countershaft) with separate clutch components on each. This distributes the mechanical elements across multiple shafts, reducing the number of elements that must be aligned on any single shaft while maintaining the high/low speed gear shifting capability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The input shaft serves dual functions by accommodating both the first shifting clutch for gear shifting and the drive gear for continuous power generation. This multi-functionality reduces the need for separate dedicated components on each shaft, thereby reducing overall element count while maintaining gear shifting versatility.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Use of energy by moving object

If the drive gear is used for continuous power generation, then the power generation efficiency is improved, but the number of elements on the input shaft increases

Engineering Contradiction:
Improvepower generation efficiencyVSAvoidnumber of elements on input shaft
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The drive gear on the input shaft is designed to serve dual purposes: it engages with the first shifting clutch for gear shifting operations and simultaneously functions as a continuous drive gear for power generation. This multi-functionality allows the system to maintain power generation efficiency while avoiding the need for separate dedicated components, thereby reducing the overall number of elements on the input shaft.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP3992006B1Vehicle drive apparatus
Publication Date: 2024.05.22 NISSAN MOTOR CO LTD
  • EP3992006B1 patent drawingFigure 1
  • EP3992006B1 patent drawingFigure 2
  • EP3992006B1 patent drawingFigure 3

AI summary

An electric-power-generating-motor gear train 7 and a driven gear 13a2 are arranged on a first plane P1; a drive gear 12a1, a driven gear 12a2, and a differential 10 are arranged on a second plane P2; and a low clutch 15 and a high clutch 14 are arranged on a third plane P3.