Nested Hybrid Transmission with Electric Machine Integration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing hybrid vehicle transmissions with multiple planetary gear sets and electric machines face challenges in achieving compact design, low component loads, and efficient gearing while supporting various operating modes, including purely electric driving and hybrid driving.
Innovation Solution
A transmission design incorporating a compact configuration with multiple planetary gear sets, shift elements, and an electric machine connected to a second input shaft, allowing for selective engagement of shift elements to create different power paths and gear ratios, enabling efficient operation in various modes by integrating the electric machine with the prime mover.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple planetary gear sets and shift elements are integrated into the transmission, then different operating modes (purely electric driving, hybrid driving) can be implemented, but the device complexity increases
Solution Approach 1:
The patent combines multiple planetary gear sets (first, second, and third planetary gear sets) into a single integrated transmission structure that shares common components such as the output shaft and housing. This merging approach allows the transmission to achieve multiple operating modes (purely electric driving, hybrid driving, mechanical driving) while reducing overall structural complexity compared to separate independent gear systems.
Solution Approach 2:
The transmission design incorporates multiple shift elements (first through sixth shift elements) that can selectively engage different planetary gear sets to provide universal functionality across multiple operating modes. The same transmission structure serves both purely electric driving operations and hybrid driving operations, as well as mechanical driving, making the system multi-functional and adaptable.
2Adaptability or versatility
If the electric machine is integrated into the transmission with multiple planetary gear sets, then various operating modes can be achieved, but the volume of the transmission increases
Solution Approach 1:
The patent arranges the planetary gear sets in a nested configuration where the first planetary gear set, second planetary gear set, and third planetary gear set are positioned concentrically around a common output shaft. The electric machine is integrated within this nested structure, with its rotor connected to the second input shaft. This nesting approach minimizes the overall volume of the transmission while accommodating multiple gear sets and the electric machine.
Solution Approach 2:
The transmission utilizes radial arrangement of the planetary gear sets around the output shaft, transitioning from a linear sequential layout to a two-dimensional radial configuration. This dimensional change allows multiple gear sets to occupy the same axial space, significantly reducing the transmission's overall volume while maintaining the capability for multiple operating modes.
3Productivity
If shift elements are actuated to change gear ratios, then different gears can be formed, but the loss of time during gear shifts increases
Solution Approach 1:
The transmission design pre-positions all six shift elements in a ready state, with each shift element continuously engaged or disengaged based on the current operating mode. When a gear shift is required, the system transitions by actuating only the specific shift element that needs to change state, rather than reconfiguring the entire gear train. This preliminary positioning of shift elements enables rapid gear shifts with minimal time loss.
Solution Approach 2:
The transmission employs dynamic shift elements that can be rapidly actuated between engaged and disengaged states. The shift elements are designed to allow quick transitions without requiring complex mechanical reconfiguration, enabling the transmission to adapt dynamically to changing operating conditions and achieve high productivity in gear shifting operations.
Data Source
AI summary
A transmission (G) for a motor vehicle includes an electric machine (EM1), a first input shaft (GW1), a second input shaft (GW2), an output shaft (GWA), two planetary gear sets (P1, P2, P3), and at least six shift elements (A, B, C, D, E, F). Different gears are implementable by selectively actuating the at least six shift elements (A, B, C, D, E, F) and, in addition, in interaction with the electric machine (EM1), different operating modes are implementable. A drive train for a motor vehicle with such transmission (G) and a method for operating such transmission (G) are also provided.