Dual-Motor Electric Axle Layout for Differential-Free Torque Vectoring
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Solution Overview
Problem
Current electrified vehicle axles are bulky, costly, and inefficient, with limited ability to incorporate dynamic torque vectoring, particularly in systems without a wheel differential.
Innovation Solution
An electric axle assembly with two motor-generator assemblies and a compact 'banjo' style housing that eliminates the need for a differential, using spiral bevel gears for power transfer and allowing for dynamic torque vectoring through motor control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multi-stage helical gear or planetary drive is used for dynamic torque vectoring, then torque vectoring capability is improved, but device complexity and packaging difficulty increase
Solution Approach 1:
The patent extracts the differential function entirely from the system by using two independent motor-generator assemblies, one for each wheel. This eliminates the need for complex multi-stage helical gears or planetary drives while maintaining torque vectoring capability through independent motor control.
Solution Approach 2:
The patent replaces the mechanical differential and gear-based torque vectoring system with an electric control system. Two independent motor-generator assemblies provide torque control through electrical means rather than mechanical gear arrangements, simplifying the overall system architecture.
2Adaptability or versatility
If dual friction clutch and helical gear or planetary drives are used, then torque vectoring is achieved, but manufacturing cost increases
Solution Approach 1:
The patent removes the dual friction clutch and planetary drive components from the system. Instead, it uses two independent motor-generator assemblies that can be manufactured using standard electric motor production techniques, reducing manufacturing complexity and cost.
Solution Approach 2:
The motor-generator assemblies serve multiple functions: they provide propulsion, enable torque vectoring, and can operate independently. This multi-functionality eliminates the need for separate differential and clutch mechanisms, reducing overall system cost.
3Adaptability or versatility
If single motor with dual friction clutch and shift system is used, then part-time torque vectoring is achieved, but device complexity and packaging difficulty increase
Solution Approach 1:
The patent extracts the shift system and single-motor architecture entirely, replacing them with two independent motor-generator assemblies. This eliminates the need for complex shifting mechanisms while providing continuous torque vectoring capability.
Solution Approach 2:
The patent segments the powertrain into two independent motor-generator assemblies, one for each wheel. This segmentation eliminates the need for a single motor with complex shifting mechanisms, as each motor independently controls its respective wheel's torque.
4Power
If traditional electrified vehicle axle design is used, then power transmission is achieved, but weight and cost increase
Solution Approach 1:
The patent merges the motor, generator, differential, and axle functions into an integrated electric axle assembly. The two motor-generator assemblies are directly mounted to the axle housing, eliminating the need for separate differential cases and reducing overall weight.
Solution Approach 2:
The patent extracts the traditional differential mechanism from the axle assembly. By using two independent motor-generator assemblies, the system eliminates the heavy differential case and associated gears, reducing axle weight while maintaining power transmission capability.
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
The solution enables efficient dynamic torque vectoring in a compact package, reducing weight and cost while maintaining torque vectoring capabilities, suitable for hybrid and electric vehicles.
Implementation Method 1
a first motor-generator assembly (104), a second motor generator assembly (106)
Data Source
AI summary
Provided herein is an electric axle assembly including a first motor-generator assembly, a second motor generator assembly, an axle housing, a first axle half shaft drivingly connected to the first motor-generator assembly and a second axle half shaft drivingly connected to the second motor-generator assembly. The first and second motor-generator assemblies each include a motor-generator and a housing and gear carrier portion. The axle housing includes a first axle tube portion, a second axle tube portion, a center portion, and an opening extending through the center portion of the axle housing, wherein the first axle tube portion and the second axle tube portion are disposed on axial opposite sides of the central portion. The first and second half shafts extended into the opening of the axle housing, and the first motor-generator assembly and the second motor-generator assembly are connected to the axle housing assembly.