Hybrid Electric Variable Transmission for AWD Off-Road Torque Demand
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Solution Overview
Problem
Existing electronically variable transmissions (EVTs) in hybrid electric vehicles face challenges in providing increased efficiency and lower emissions while meeting performance demands, particularly in all-wheel drive vehicles.
Innovation Solution
An electrified powertrain system incorporating two planetary gear sets, clutches, and a motor speed reducer to enhance torque transmission, including a first electric motor, a second electric motor, an internal combustion engine, and a final drive ratio, designed for all-wheel drive vehicles to handle high torque requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If fixed gear assemblies are used in electrified drive modules, then the vehicle can deliver drive torque effectively, but the vehicle cannot achieve improved efficiency and lower emissions through infinite ratio variations
Solution Approach 1:
The patent applies dynamics by transitioning from fixed gear assemblies to a continuously variable transmission (CVT) system using planetary gear sets. The CVT enables infinite ratio variations through continuous adjustment of gear ratios, allowing the transmission system to adapt dynamically to different driving conditions and optimize energy efficiency throughout the vehicle's operation.
Solution Approach 2:
The patent implements parameter changes by varying the gear ratio continuously rather than through discrete steps. The planetary gear sets allow the transmission ratio to be adjusted continuously between minimum and maximum values, enabling optimal matching of engine operating point to vehicle demand and thereby improving energy efficiency.
2Object-generated harmful factors
If electronically variable transmissions are used for improved efficiency, then emissions are reduced, but performance demands in all-wheel drive off-road conditions cannot be met
Solution Approach 1:
The patent applies segmentation by dividing the transmission system into multiple planetary gear sets (first and second planetary gear sets) with distinct functions. The first planetary gear set handles torque multiplication for off-road conditions, while the second planetary gear set provides continuous variable ratio adjustment for efficiency optimization, allowing the system to meet both performance and emissions requirements.
Solution Approach 2:
The patent implements multi-functionality by designing a transmission system that can simultaneously handle high torque multiplication needs for off-road performance and continuous ratio variation for fuel efficiency. The combined planetary gear system serves multiple functions: torque multiplication, ratio variation, and all-wheel drive power distribution, making it universally capable of meeting diverse driving demands.
3Force
If torque multiplication is increased for off-road conditions, then the vehicle can handle high torque demands, but the transmission system complexity increases
Solution Approach 1:
The patent applies the nested doll principle by nesting planetary gear sets within each other. The first planetary gear set is positioned within or adjacent to the second planetary gear set, with the sun gear of one set serving as a component of the other. This nested arrangement achieves high torque multiplication through combined gear ratios while minimizing the overall size and complexity of the transmission system.
Solution Approach 2:
The patent implements merging by combining multiple planetary gear sets into a single integrated transmission system. The first and second planetary gear sets work together as a unified mechanism, sharing common components such as the sun gear and carrier, to achieve the required torque multiplication for off-road conditions without requiring separate gearbox assemblies.
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 system achieves enhanced torque multiplication and efficiency, supporting high torque demands for off-road conditions, with improved performance and reduced emissions.
Implementation Method 1
The first planetary gear set includes a first sun gear, a first carrier and a first ring gear. The first sun gear is coupled to the first electric motor output. The first ring gear is coupled to the second electric motor output and the first carrier is selectively coupled to the ICE output.
Implementation Method 2
The system achieves enhanced torque multiplication and efficiency, supporting high torque demands for off-road conditions
Implementation Method 3
The first clutch selectively fixes the second ring gear from rotating. The second clutch selectively fixes the first and second ring gear for rotating together.
Data Source
AI summary
An electrified powertrain that generates and transfers drive torque to a driveline of a hybrid vehicle includes a first electric motor, a second electric motor, an internal combustion engine (ICE), a first and second planetary gear set, and a first and a second clutch. The first planetary gear set includes a first sun gear, a first carrier and a first ring gear. The first sun gear is coupled to the first electric motor output. The first ring gear is coupled to the second electric motor output and the first carrier is selectively coupled to the ICE output. The second planetary gear set includes a second sun gear, a second carrier and a second ring gear. The second sun gear is coupled to the first ring gear. The second carrier is coupled to the driveline. The first clutch selectively fixes the second ring gear from rotating.