Compact Hybrid Drive Unit for Narrow Motorcycle Width

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Solution Overview

Problem

Conventional hybrid vehicles with a large vehicle width cannot accommodate a hybrid-type drive unit on motorcycles due to space constraints, leading to a protruding drive unit when attempted to be mounted on smaller vehicles.

Innovation Solution

A straddle-type vehicle design with a hybrid-type drive unit where the power distributing device, generator, and motor are aligned rearwardly and in parallel to the crankshaft, using a chain to transmit drive force between the generator and motor, allowing for a compact configuration that does not project in the vehicle width direction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the engine, generator, switching mechanism, and motor are arranged in series on the same axis in the vehicle width direction, then the hybrid-type drive unit can be provided on conventional four-wheelers, but such a configuration cannot be mounted on motorcycles having a small vehicle width and causes the drive unit to project considerably in the vehicle width direction

Engineering Contradiction:
Improveadaptability to different vehicle typesVSAvoidvehicle width
Core Design Contradiction:
Adaptability or versatilityVSArea of stationary object

Solution Approach 1:

The patent reconfigures the arrangement of the power distributing device, generator, and motor from a longitudinal alignment (in the vehicle width direction) to a transverse alignment (in the vehicle length direction). This dimensional change allows the components to be arranged along the longitudinal axis of the motorcycle, significantly reducing the vehicle width occupation while maintaining all necessary functional connections between components.

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

Solution Approach 2:

The patent employs a nested arrangement where the power distributing device is positioned between the generator and motor along the longitudinal axis. The components are integrated in a compact sequence where the output of one component directly connects to the next, creating a space-efficient configuration that minimizes the overall footprint in the vehicle width direction while accommodating all necessary mechanical and electrical connections.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Area of stationary object

If the power distributing device, generator, and motor are aligned on an axis rearwardly separate from and in parallel to the crankshaft, then the configuration becomes compact in the vehicle width direction, but the drive force transmission path becomes more complex

Engineering Contradiction:
Improvevehicle widthVSAvoiddrive force transmission path
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

The patent introduces a chain as an intermediary transmission element that connects the power distributing device to the reduction device. This chain transmission serves as a mediator that efficiently transmits drive force from the longitudinally arranged power distributing device to the rear wheel reduction device, simplifying the overall transmission path while maintaining the compact transverse alignment of components.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent utilizes the longitudinal dimension of the vehicle to arrange the power distributing device, generator, and motor in sequence along the vehicle length direction. This spatial reconfiguration separates the components in the longitudinal dimension while keeping them compact in the width dimension, and the chain transmission bridges the gap created by this dimensional arrangement.

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

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

Enables the mounting of a hybrid-type drive unit on motorcycles with limited vehicle width without increasing the vehicle's width, achieving a compact and efficient power transmission system that simplifies the drive-wheel transmission device's journaling and enhances structural stiffness and strength.

Implementation Method 1

the drive force is transmitted from the power distributing device to the reduction device by a chain disposed in a portion between the generator and the motor in a vehicle width direction

Methodology Applied
Scientific EffectMechanical force transmission: Mechanical Force

Implementation Method 2

a generator to generate electrical power

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 3

a drive motor driven by electrical power

Methodology Applied
Scientific EffectElectromagnetic force: Lorentz Force

Implementation Method 4

to drive the rear wheel through a reduction device

Methodology Applied
Scientific EffectMechanical advantage: Mechanical Advantage

Data Source

PatentEP1820682B1Straddle-type vehicle
Publication Date: 2009.08.26 YAMAHA MOTOR CO LTD
  • EP1820682B1 patent drawingFigure 1
  • EP1820682B1 patent drawingFigure 2
  • EP1820682B1 patent drawingFigure 3

AI summary

The present invention relates to a straddle-type vehicle having a hybrid-type drive unit, said drive unit comprising an engine (20) arranged with a crank shaft (24) directed in a vehicle width direction, a generator (40) to generate electrical power, a drive motor (50) driven by electrical power, a power distributing device (30) distributing a drive force, which is generated by the engine (20), to drive the rear wheel through a reduction device (60), and to actuate the generator (40) to generate electrical power, wherein the power distributing device (30), the generator (40), and the motor (50) are aligned on an axis rearwardly separate from and in parallel to the crank shaft (24) of the engine (20).