Series Hybrid Motorcycle Engine-Generator Layout for Compact Output

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Solution Overview

Problem

Series hybrid type straddled vehicles face a challenge in increasing output while minimizing size, as large engine and electric power generator components lead to increased dimensions, particularly in the up-down and front-back directions, affecting wheelbase and frame size.

Innovation Solution

The electric power generation engine and generator are arranged offset towards the center with overlap in the left-right direction, and supported by the frame body rather than the rear arm, allowing for a compact configuration that suppresses dimensional increases while maintaining output by optimizing the positional relationship and supporting structure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If the engine and electric power generator are made large to increase output, then the power output is improved, but the vehicle size increases particularly in the up-down and front-back directions

Engineering Contradiction:
ImproveoutputVSAvoidvehicle size
Core Design Contradiction:
PowerVSLength of stationary object

Solution Approach 1:

The patent applies dimensional reconfiguration by arranging the engine and electric power generator side-by-side in the left-right direction rather than stacking them in the up-down direction. This transforms the spatial arrangement from vertical stacking to horizontal placement, allowing the components to overlap when viewed from the left-right direction while suppressing dimensional increases in the up-down and front-back directions that would otherwise affect wheelbase and frame size.

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

2Length of stationary object

If the engine and electric power generator are arranged side by side in the left-right direction, then the increase in dimensional amount in up-down and front-back directions is suppressed, but the electric power generation engine may be arranged off-set from the center

Engineering Contradiction:
Improvedimensional amount in up-down and front-back directionsVSAvoidpositional arrangement
Core Design Contradiction:
Length of stationary objectVSShape

Solution Approach 1:

The patent accepts and utilizes the asymmetric arrangement of the electric power generation engine off-set from the vehicle center in the left-right direction. This asymmetric positioning is necessary to achieve the side-by-side configuration that suppresses dimensional increases in the up-down and front-back directions. The design prioritizes compactness in the vertical and longitudinal dimensions over symmetric weight distribution.

Inventive Principle:
Principle #4Asymmetry

3Length of stationary object

If the electric power generation engine and electric power generator are arranged to overlap in the left-right direction, then the vehicle size is reduced, but the positional relationship and supporting structure become more complex

Engineering Contradiction:
Improvevehicle sizeVSAvoidpositional relationship and supporting structure
Core Design Contradiction:
Length of stationary objectVSDevice complexity

Solution Approach 1:

The patent merges the electric power generation engine and electric power generator into a closely integrated assembly where the components overlap in the left-right direction. This merging reduces the overall vehicle size by eliminating gaps and optimizing spatial utilization. The supporting structure is designed to hold both components together as a unified power generation unit, simplifying the overall arrangement despite the overlapping configuration.

Inventive Principle:
Principle #5Merging (Combining)

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 enables increased output while keeping the vehicle size smaller compared to traditional designs, enhancing travel performance and maintaining structural rigidity and compactness.

Implementation Method 1

an electric power generation engine and an electric power generator, the electric power generation engine being arranged off-set toward a first direction from the center of the series hybrid type straddled vehicle with respect to a left-right direction of the series hybrid type straddled vehicle

Methodology Applied
Scientific EffectCombustion: Combustion

Implementation Method 2

the electric power generator being positioned farther in a second direction than the electric power generation engine and being arranged so as to have an overlap with the electric power generation engine when viewed in the left-right direction

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP3950476B1Series hybrid type straddled vehicle
Publication Date: 2024.12.11 YAMAHA MOTOR CO LTD
  • EP3950476B1 patent drawingFigure 1(a)~1(b)
  • EP3950476B1 patent drawingFigure 2
  • EP3950476B1 patent drawingFigure 3

AI summary

Provided is a series hybrid type straddled vehicle capable of increasing an output while suppressing a size increase. A series hybrid type straddled vehicle of the present teaching includes an electric power generation unit including an electric power generation engine and an electric power generator, the electric power generation engine being arranged off-set toward a first direction from the center of the straddled vehicle with respect to a left-right direction of the straddled vehicle, provided that the left-right direction is composed of the first direction and a second direction opposite to the first direction, the electric power generation engine being positioned so as not to overlap a drive motor when viewed in the left-right direction, the electric power generator being positioned farther in the second direction than the electric power generation engine, the electric power generator being arranged so as to have an overlap with the electric power generation engine when viewed in the left-right direction, the electric power generator being arranged so as not to overlap the drive motor when viewed in the left-right direction, the electric power generator being driven by the electric power generation engine to generate electric power for driving the drive motor, the electric power generation unit being not supported by a rear arm but supported by a frame body such that the electric power generation unit constitutes a frame structure or does not constitute the frame structure.