Hybrid Transmission Additional Electric Machine Torque Segmentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Hybrid vehicle transmissions face limitations in autonomy due to the sizing and mass constraints of electric machines and batteries, which impact driving range and performance, particularly when the electric machine must recharge the battery while stationary.
Innovation Solution
The introduction of an additional shaft linked to a second electric machine that can supply driving or resisting torque, along with three coupling means allowing various torque combinations and modes, enhances the transmission's efficiency and flexibility by enabling additional torque distribution and recharge capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the electric machine is sized to provide sufficient driving torque, then the vehicle's performance is improved, but the mass of the electric machine and battery increases, reducing autonomy
Solution Approach 1:
The patent divides the electric machine system into two separate machines: a first electric machine (7) connected to the hollow primary shaft (6) and a second electric machine (18) connected to the additional shaft (17). This segmentation allows each machine to be optimized for specific functions - the first for primary propulsion and the second for boosting and regenerative braking - thereby improving overall system efficiency and autonomy without requiring a single oversized machine
Solution Approach 2:
The second electric machine (18) is designed with multi-functionality, serving both as a boosting motor during acceleration and as a generator during regenerative braking. The control system (24) manages the second electric machine's dual role, allowing it to supply additional driving torque when needed and recover energy during deceleration, thereby extending autonomy without proportionally increasing battery capacity
2Loss of energy
If the electric machine operates as a generator to recharge the battery, then energy recovery is improved, but the driving torque available for propulsion is reduced
Solution Approach 1:
The patent separates the propulsion and energy recovery functions into two different electric machines. The first electric machine (7) remains dedicated to propulsion, while the second electric machine (18) handles regenerative braking. This allows the vehicle to recover energy during deceleration without compromising the primary electric machine's ability to provide full driving torque when needed
Solution Approach 2:
The second electric machine (18) acts as an intermediary between the drivetrain and the battery during regenerative braking. It captures kinetic energy that would otherwise be lost, converts it to electrical energy, and stores it in the battery, thereby reducing energy loss without interfering with the primary propulsion system's torque delivery capability
3Device complexity
If the transmission system is simplified with fewer components, then device complexity is reduced, but the ability to optimize torque distribution and extend autonomy is limited
Solution Approach 1:
The patent introduces an additional shaft (17) with a second electric machine (18) to segment the torque delivery system. This allows independent control of two electric machines, enabling optimized torque distribution strategies that extend autonomy. The segmentation is managed through a control system (24) that coordinates the operation of both machines based on driving conditions
Solution Approach 2:
The transmission system employs dynamic coupling mechanisms (third coupling means 22) that can connect or disconnect the additional shaft (17) from the primary shafts based on operating conditions. This dynamic reconfiguration allows the system to adapt torque distribution in real-time, optimizing autonomy without requiring a permanently complex mechanical structure
Data Source
Figure 1~2
Figure 3~4
Figure 5~6A
AI summary
The invention relates to a hybrid transmission for a motor vehicle provided with a heat engine (1) and an electric driving machine (7), comprising: - two concentric primary shafts (1, 6), a first coupling means (5) between the two primary shafts (1, 6) able to occupy at least three positions in which the heat engine (1) is uncoupled from the kinematic chain connecting the electric driving machine (7) to the wheels, the heat engine (1) drives the wheel with or without extra contribution from the electric driving machine (7), and the heat engine (1) and the electric driving machine (7) are coupled so as to add their torques toward the wheels, and - a secondary shaft (10) connected to the wheels of the vehicle, supporting a second coupling means (13) capable of connecting either of the two secondary pinions (11, 12) on that shaft. This transmission is characterized in that it comprises an additional shaft (17) connected to an additional electric machine (18), able to supply an engine torque or a resisting torque to the transmission.