Hybrid Powertrain Planetary Gear Set for Stable Engine Operation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Hybrid vehicles face challenges in achieving optimal fuel efficiency and cost-effectiveness due to complex configurations required for varying driving conditions, which complicate the implementation of efficient engine modes.
Innovation Solution
A powertrain configuration featuring a planetary gear set, motor-generators, clutches, and drive gears allows for a simple implementation of various operation modes, including a fixed gear ratio engine mode, enhancing fuel efficiency and reducing vehicle costs by stabilizing engine operation at high vehicle speeds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a complex powertrain configuration is used to achieve optimal fuel efficiency across varying driving conditions, then fuel efficiency is improved, but device complexity increases
Solution Approach 1:
The planetary gear set serves multiple functions: it provides continuous variable ratio transmission for fuel-efficient engine operation, enables fixed gear ratio modes for high-speed efficiency, and integrates motor-generator connections for hybrid operation. This multi-functionality allows a single configuration to address various driving conditions without requiring multiple separate systems
Solution Approach 2:
The system dynamically switches between different operational modes (continuous variable ratio, fixed gear ratio, different clutch engagement states) to optimize fuel efficiency. The clutches enable dynamic reconfiguration of the powertrain to match driving conditions, allowing the engine to operate in highly efficient regions across different speed ranges
2Device complexity
If a simple powertrain configuration is used to reduce vehicle costs, then device complexity is reduced, but the ability to implement efficient engine modes is limited
Solution Approach 1:
The planetary gear set with integrated motor-generator connections performs multiple functions within a single compact structure: CVR transmission, fixed gear ratio engagement, and hybrid power synthesis. This eliminates the need for separate systems while maintaining fuel efficiency capabilities
Solution Approach 2:
The patent merges the CVR transmission system and fixed gear ratio system into a single planetary gear set configuration. The clutches enable both operational modes to coexist in one structure, reducing overall system complexity while preserving fuel efficiency benefits
3Power
If the engine operates at high vehicle speeds to meet driving demands, then power output is improved, but fuel efficiency deteriorates due to operation outside highly efficient region
Solution Approach 1:
The system dynamically adjusts the gear ratio through clutch engagement to keep the engine operating in its highly efficient region across different vehicle speeds. At high vehicle speeds, the fixed gear ratio mode maintains optimal engine RPM for efficiency while still delivering required power through the gear multiplication effect
Data Source
AI summary
A powertrain for a hybrid vehicle may include a planetary gear set; a first motor-generator connected to one rotation element of the planetary gear set and an engine connected to the first motor-generator; a second motor-generator connected to another rotation element of the planetary gear set; a second clutch connected to the other rotation element of the planetary gear set and a second drive gear connected to the second clutch; a first clutch connected to the rotation element to which the first motor-generator is connected and a first drive gear connected to the first clutch; and an output shaft having a first driven gear and a second driven gear engaged in the first drive gear and the second drive gear, respectively.