Hybrid Vehicle Drive System AWD via Dual Motor Functionality

Solution Overview

Problem

Implementing all-wheel drive (AWD) in hybrid vehicles without increasing weight, size, and cost, as existing power-split hybrid vehicles require additional electric motors, which contribute to higher weight and expense.

Innovation Solution

A hybrid vehicle drive system utilizing a planetary gear mechanism, one pair of drive wheels, an internal combustion engine, a first electric motor, and a second electric motor, with inter-element clutches to switch between coupling and uncoupling configurations, allowing for efficient power distribution and regenerative operations to achieve AWD in HV modes without the need for a third electric motor.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If additional electric motors are added to existing power-split hybrid vehicles to implement all-wheel drive, then AWD capability is achieved, but weight and cost increase

Engineering Contradiction:

ImproveAWD capabilityVSAvoidvehicle weight

Core Design Contradiction:

Adaptability or versatilityVSWeight of moving object

Solution Approach 1:

The first electric motor is designed to perform multiple functions: it acts as a generator during power-split operation and as a drive motor for the second pair of drive wheels during AWD operation. This multi-functionality eliminates the need for a third dedicated electric motor, thereby reducing vehicle weight while maintaining AWD capability

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent combines the generator function and the second drive motor function into a single first electric motor unit. By merging these functions into one component rather than using separate components, the system reduces the total number of motors from three to two, directly addressing the weight and cost concerns

Inventive Principle:

Principle #5Merging (Combining)

2Adaptability or versatility

If additional electric motors are added to existing power-split hybrid vehicles to implement all-wheel drive, then AWD capability is achieved, but cost increases

Engineering Contradiction:

ImproveAWD capabilityVSAvoidmanufacturing cost

Core Design Contradiction:

Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The first electric motor is designed to perform multiple functions: it acts as a generator during power-split operation and as a drive motor for the second pair of drive wheels during AWD operation. This multi-functionality eliminates the need for a third dedicated electric motor, thereby reducing vehicle weight while maintaining AWD capability

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent combines the generator function and the second drive motor function into a single first electric motor unit. By merging these functions into one component rather than using separate components, the system reduces the total number of motors from three to two, directly addressing the weight and cost concerns

Inventive Principle:

Principle #5Merging (Combining)

3Device complexity

If the first electric motor is used for both power generation and driving second drive wheels, then component count is reduced, but operational complexity increases

Engineering Contradiction:

Improvenumber of electric motorsVSAvoidcontrol complexity

Core Design Contradiction:

Device complexityVSEase of operation

Solution Approach 1:

The system dynamically switches the operational mode of the first electric motor based on driving conditions. The control unit adjusts the motor's function in real-time, operating it as a generator during power-split mode and as a drive motor during AWD mode. This dynamic adaptability allows the system to manage operational complexity through intelligent control while maintaining a reduced component count

Inventive Principle:

Principle #15Dynamics

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 AWD in hybrid vehicles with improved efficiency and reduced weight, size, and cost by using existing power sources, maintaining enhanced energy efficiency and travel performance across various modes.

Implementation Method 1

a planetary gear mechanism configured to transmit motive power among a first rotary element, a second rotary element, and a third rotary element

Methodology Applied

Scientific EffectMechanical Advantage: Mechanical Advantage

Implementation Method 2

a second electric motor configured to perform power running operation using power generated by the first electric motor

Methodology Applied

Scientific EffectElectromagnetic Induction: Electromagnetic Induction

Data Source

PatentUS11498406B2Hybrid vehicle

Publication Date: 2022.11.15 SUBARU CORP

AI summary

A hybrid vehicle includes a planetary gear mechanism, a first electric motor, an internal combustion engine, first drive wheels, an inter-element clutch, a second electric motor, and second drive wheels. The planetary gear mechanism is configured to transmit motive power among first to third rotary elements. The first electric motor is coupled to the first rotary element in a power transmittable manner. The internal combustion engine is coupled to the second rotary element in a power transmittable manner. The first drive wheels are coupled to the third rotary element in a power transmittable manner. The inter-element clutch is configured to switch between coupling and uncoupling two of the first to third rotary elements. The second electric motor is configured to perform power running operation using power generated by the first electric motor. The second drive wheels are coupled to the second electric motor in a power transmittable manner.