Hybrid Powertrain Dynamic Clutch Split Mode Operation
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Solution Overview
Problem
Existing powertrain systems for hybrid vehicles face inefficiencies in energy management and torque distribution, particularly in high-speed operations and regenerative braking, leading to energy loss and performance deterioration.
Innovation Solution
A powertrain system incorporating dynamic and static clutches that selectively couple electric machines to the drivetrain and gearset, allowing for compound and split modes of operation, enhancing kinetic energy recovery and fuel efficiency by maintaining high rotational speeds and independent operation of electric machines.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the generator is connected to the planetary gear in existing hybrid vehicles, then torque assist can be provided, but follow-up loss occurs when the engine stops and the vehicle travels with the motor alone
Solution Approach 1:
The powertrain is segmented into two independent power paths: one through the planetary gearset for torque assist operations, and another direct path from the engine to the drivetrain gear for high-speed operations. The dynamic clutch enables selective engagement/disengagement of the generator from the drivetrain, allowing the system to operate in compound mode (both paths engaged) or split mode (direct path only), thereby eliminating follow-up loss during high-speed travel while preserving torque assist capability when needed.
2Power
If the generator remains connected during high-speed running, then torque assist is available, but electric energy is consumed to stop the generator rotation
Solution Approach 1:
The system dynamically adjusts the generator connection status based on operating conditions. The dynamic clutch enables real-time switching between compound mode (generator connected for torque assist) and split mode (generator disconnected to eliminate energy consumption). This dynamic reconfiguration allows the system to consume electric energy only when the generator provides beneficial torque assist, rather than continuously consuming energy to stop generator rotation during high-speed operations.
3Power
If the planetary gear constraints are applied, then torque assist by the generator is enabled, but torque assist is restricted in high-speed operations
Solution Approach 1:
The powertrain is divided into two independent power paths that can operate separately or together. The first path through the planetary gearset provides torque assist with its inherent constraints, while the second direct path from engine to drivetrain gear operates independently without planetary gear constraints. The dynamic clutch enables selective engagement of these paths, allowing the system to overcome planetary gear constraints during high-speed operations by routing power directly, while still utilizing torque assist when operating conditions are suitable.
4Loss of energy
If dynamic clutches are added to enable compound and split modes, then energy management and torque distribution are improved, but device complexity increases
Solution Approach 1:
The generator connection to the drivetrain is extracted as a separately controllable element through the dynamic clutch. This allows the generator to be selectively engaged or disengaged from the drivetrain independent of the planetary gearset connection. By extracting this control capability, the system achieves superior energy management and torque distribution flexibility without requiring complete redesign of the entire powertrain architecture, thereby limiting the increase in device complexity to a manageable addition.
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 improves acceleration performance, enhances kinetic energy recovery across a wide range of vehicle speeds, and minimizes energy loss, thereby improving fuel economy and reliability by optimizing energy use and component life.
Implementation Method 1
a second electric machine, and at least one dynamic clutch selectively coupling the second electric machine to the drivetrain gear and the gearset
Implementation Method 2
The first and second electric machines are operable independently as an electric motor and electric generators
Data Source
AI summary
A powertrain system for a vehicle is provided, including an internal combustion engine, a drivetrain gear for connection to a drivetrain of the vehicle, a gearset connecting the internal combustion engine to the drivetrain gear, a first electric machine connected to the gearset, a second electric machine, and at least one dynamic clutch selectively coupling the second electric machine to the drivetrain gear and the gearset. In a compound mode of operation, the at least one dynamic clutch couples the second electric machine and the gearset. In a split mode of operation, the at least one dynamic clutch couples the second electric machine and the drivetrain gear.