Segmented Drive Motor Offset for Electric Vehicle Wheel

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Sports type electric vehicles face challenges in achieving high motor output while maintaining maneuverability and cost-effectiveness, as large drive motors are costly and heavy, and existing configurations require additional elements like idle shafts for driving the wheel.

Innovation Solution

A sports type electric vehicle with a drive motor composed of multiple unit motors arranged coaxially and adjacently in the vehicle width direction, with a drive sprocket for power transmission to the rear wheel, and an offset center to facilitate a simple wheel drive system, allowing for the use of existing motors and enhancing cooling and power distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If a large-type motor for exclusive use is installed to achieve high output, then the motor output is improved, but the cost rises

Engineering Contradiction:
Improvemotor outputVSAvoidcost
Core Design Contradiction:
PowerVSEase of manufacture

Solution Approach 1:

The drive motor is divided into multiple unit motors (first unit motor and second unit motor) that are arranged adjacently in the vehicle width direction. These unit motors can be integrated to achieve the required high output while using commercially available, cost-effective components instead of expensive custom-built large motors.

Inventive Principle:
Principle #1Segmentation

2Power

If a high-output drive motor is used, then the motor output is improved, but the weight increases

Engineering Contradiction:
Improvemotor outputVSAvoiddrive motor weight
Core Design Contradiction:
PowerVSWeight of moving object

Solution Approach 1:

The drive motor is segmented into multiple unit motors arranged adjacently. This segmentation allows the use of lighter, commercially available motor units rather than a single heavy custom-built high-output motor, thereby reducing overall weight while maintaining required power output.

Inventive Principle:
Principle #1Segmentation

3Adaptability or versatility

If additional elements like idle shafts are used for driving the wheel, then the drive system is more flexible, but the system complexity increases

Engineering Contradiction:
Improvedrive system flexibilityVSAvoidsystem complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The invention eliminates the idle shaft from the drive system. The drive shaft of the drive motor directly transmits power to the drive sprocket, removing the unnecessary intermediate element and simplifying the overall drive system while maintaining functional flexibility.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The functions of the drive shaft and the power transmission mechanism are merged into a more direct configuration. The drive shaft directly connects to the drive sprocket, combining what were previously separate functional elements into a streamlined integrated system.

Inventive Principle:
Principle #5Merging (Combining)

4Device complexity

If the drive motor center is offset to facilitate simple wheel drive, then the drive system is simplified, but the motor positioning becomes more complex

Engineering Contradiction:
Improvedrive system complexityVSAvoidmotor positioning
Core Design Contradiction:
Device complexityVSShape

Solution Approach 1:

The drive motor is positioned with an asymmetric offset in the vehicle width direction, with the center located toward one side rather than at the vehicle centerline. This asymmetric positioning allows the drive sprocket to be directly connected to the drive shaft, simplifying the drive system while the offset is accommodated in the motor mounting design.

Inventive Principle:
Principle #4Asymmetry

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 provides a high-output, cost-effective drive motor solution that minimizes system losses and enhances drivability and mileage by using existing motors without additional elements, while improving cooling and power transmission efficiency.

Implementation Method 1

a driving force is transmitted from the drive shaft (39) to the driving wheel (4) through only a chain type transmission mechanism (58) including the drive sprocket (58a)

Methodology Applied
Scientific EffectChain type transmission mechanism: Chain

Data Source

PatentEP2484581B1Sports type, saddle type electric vehicle
Publication Date: 2015.04.29 HONDA MOTOR CO LTD
  • EP2484581B1 patent drawingFigure 1
  • EP2484581B1 patent drawingFigure 2
  • EP2484581B1 patent drawingFigure 3

AI summary

In a sports type, saddle type electric vehicle, to a drive wheel (4) is enabled to be driven without intermediation by an additional element, such as an idle shaft, while achieving a reduction in cost by making use of a plurality of existing motors. A drive motor (3) as a drive source for traveling has a plurality of motor bodies (3a, 3b) arranged coaxially with and adjacently to each other in the vehicle width direction to permit integral driving thereof, and is disposed forwardly of a pivot for a swing arm supporting the driving wheel. One end in the vehicle width direction of a drive shaft (39) of the drive motor (3) is made to be an output end for output to the driving wheel, and a drive sprocket (58a) for power transmission to the driving wheel is provided at the output end. The center (center line MCL) of the drive motor (3) in the vehicle width direction is disposed with an offset to the side opposite to the side of the drive sprocket (58a) with reference to the vehicle body center (center line CL).