Planetary Gear Transmission with Electromechanical Control
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Solution Overview
Problem
Current automotive transmissions, particularly continuously variable transmissions (CVTs), face inefficiencies due to the need for multiple independent gears and clutches, leading to torque interruptions and energy loss through heat dissipation during gear shifts.
Innovation Solution
A single planetary gear set configuration with an electromechanical control system that eliminates the need for multiple gears and clutches, allowing for continuous torque output and infinite speed ratios by using a sprag clutch and motor/generator to manage torque and regeneration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple independent gears and clutches are used in CVT, then gear shifting capability is improved, but torque interruptions and energy loss increase
Solution Approach 1:
The patent merges multiple independent gears and clutches into a single planetary gear set with one clutch mechanism. The planetary gear set integrates multiple gear ratios (low, medium, high) within a unified structure, eliminating the need for separate gear trains and multiple clutches. This consolidation reduces the number of moving parts and potential failure points while maintaining continuous torque transmission, thereby reducing energy loss through heat dissipation.
Solution Approach 2:
The single planetary gear set is designed to perform multiple functions that previously required separate mechanisms. It provides low, medium, and high gear ratios simultaneously through its planetary configuration, and the single clutch can engage/disengage all gear ratios. This multi-functional design eliminates torque interruptions associated with sequential gear shifts in conventional multi-gear systems.
2Adaptability or versatility
If multiple independent gears and clutches are used in CVT, then speed ratio variability is improved, but device complexity increases
Solution Approach 1:
The patent consolidates multiple gear trains and clutch mechanisms into a single planetary gear set. The planetary configuration naturally provides multiple gear ratios through different engagement states of the sun gear, planet gears, and ring gear, eliminating the need for separate gear assemblies. This merging reduces structural complexity while preserving speed ratio variability.
Solution Approach 2:
The planetary gear set is segmented into functional zones (sun gear region, planet gear region, ring gear region) that can independently engage or disengage to provide different gear ratios. This segmentation allows the single planetary set to perform the work of multiple gear trains while maintaining a compact, integrated structure that is easier to manufacture and maintain.
3Adaptability or versatility
If conventional clutch activity is used for gear engagement, then gear shifting is achieved, but torque transmission efficiency decreases
Solution Approach 1:
The patent uses a single clutch mechanism to control engagement for all gear ratios within the planetary set, replacing multiple independent clutch operations. This unified clutch system maintains continuous torque transmission paths, avoiding the torque interruptions and efficiency losses associated with sequential clutch engagement in conventional multi-gear systems.
Solution Approach 2:
The planetary gear set with single clutch design ensures continuous torque transmission from input to output throughout all gear ratio changes. Unlike conventional systems where torque must be interrupted during clutch engagement/disengagement, this design maintains uninterrupted torque flow, improving reliability and transmission efficiency.
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 reduces torque interruptions and energy loss, achieving over 85% torque transmission efficiency by regenerating energy during deceleration and utilizing electromechanical controls to manage gear shifts, thereby enhancing hybrid electric vehicle performance.
Implementation Method 1
the residual torque can keep turning the carrier and rotor, regenerating current back to either a capacitor or battery
Implementation Method 2
The input sun gear is incorporated with a sprag clutch to disengage the transmission from the engine or prime mover
Data Source
AI summary
A transmission device 100 with an input 101 and output planetary set 102 connected by two co-axial shafts 110 and 111 such that the combination of a gear and speed ratio is possible without interrupting the torque path between the engine or prime mover and the wheel using an electromechanical control apparatus comprising of two motor generators 117 and 118 that also provides electric torque to complement the mechanical torque. The current powerflow is increased by the planetary configuration and continuous power regeneration during torque and inertia phases. Where the carrier 108 can engage the engine to the transmission 100 and where the hybrid torque is transmitted by engaging the vehicle load to the transmission.