Hybrid Power Transmission via Direct Planetary Gear Meshing
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Solution Overview
Problem
Conventional power transmission systems for hybrid vehicles are heavy and bulky due to complex gear engagement mechanisms, which detract from fuel efficiency and complicate the installation and removal of components like generators and motors.
Innovation Solution
A compact and lightweight power transmission system that directly engages the first and second planetary gear sets without a conventional power transmission unit, using a first and second motor/generator unit connected to the respective shafts, with external gear meshing and a differential unit connected to the second shaft, allowing for reduced size and weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a conventional power transmission unit with multiple gears is used to transfer power from the engine to the wheels, then power transmission function is achieved, but the system becomes heavy and bulky
Solution Approach 1:
The patent merges the functions of the first and second planetary gear sets by directly engaging their external gear teeth (first ring gear with second ring gear), eliminating the need for a separate power transmission unit with multiple gears. This integration reduces the number of components, decreases weight and bulk, while maintaining the power transmission function from the engine through the first shaft to the second shaft and finally to the wheels.
2Power
If a conventional power transmission unit with complex gear engagement mechanisms is used, then power transmission is achieved, but installation and removal of generator and motor become difficult
Solution Approach 1:
The patent segments the power transmission system into modular components (first planetary gear set, second planetary gear set, differential unit) that can be independently installed and removed. By eliminating the complex interconnected power transmission unit, the generator and motor can be accessed and serviced more easily, as they are no longer constrained by multiple engaged gears that require disassembly for component replacement.
3Power
If a conventional power transmission unit is used in hybrid vehicles, then power routing from engine to wheels is achieved, but fuel efficiency is reduced due to heavy and bulky construction
Solution Approach 1:
By merging the first and second planetary gear sets through direct external gear engagement, the patent eliminates the heavy power transmission unit that would otherwise be required. This reduction in transmission system weight and size decreases the energy required to move the vehicle, thereby improving fuel efficiency while maintaining the complete power routing function from engine through both shafts to the wheels.
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 design enhances fuel efficiency and simplifies the installation and removal of components by eliminating the need for a conventional power transmission unit, resulting in a more compact and efficient power transmission system for hybrid vehicles.
Implementation Method 1
The second planetary gear set, which includes a second ring gear, a second pinion gear, a second sun gear, and a second carrier, is disposed on the second shaft and is externally gear meshed with the first planetary gear set; i.e. the teeth of the outer edge of the second planetary gear set and the teeth of the outer edge of the first planetary gear set are directly engaged with each other.
Data Source
AI summary
The present invention relates to a power transmission for a hybrid vehicle with a more compact and lightweight design. The power transmission of the invention includes: an engine; a first shaft; a first planetary gear set disposed on the first shaft; a first motor/generator unit connected to the first planetary gear set; a second shaft disposed in parallel with the first shaft, the second shaft having a mediate gear; a second planetary gear set disposed on the second shaft; a second motor/generator unit connected to the second shaft; and a differential unit having a final gear connected to the mediate gear of the second shaft. In this manner, power is transmitted through the power transmission system by virtue of the external intermeshing of the first and second ring gears.