Hybrid Drive Gearbox Layout for Compact Multi-Gear Packaging
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Solution Overview
Problem
Existing hybrid drive systems for motor vehicles are not optimized for space efficiency, leading to increased installation space requirements, weight, and higher costs.
Innovation Solution
A hybrid drive system with a specific configuration of planetary gear sets, spur gear stages, and switching elements that allow for a compact design, utilizing two planetary gear sets and multiple switching elements to achieve a multi-gear capability and efficient torque transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional hybrid drive systems are used, then multi-gear capability is achieved, but installation space requirements increase
Solution Approach 1:
The patent implements nesting by placing the electric machine (22) and its rotor (26) within the hollow interior space of the planetary gear sets (50, 52), specifically positioning the rotor between the two planetary gear sets in a coaxial arrangement. This allows the electric machine to occupy the central void space of the planetary gear structure, achieving compact integration without increasing overall installation space.
Solution Approach 2:
The patent transitions from a conventional axial arrangement of components to a radial/coaxial dimension by positioning the electric machine's rotor concentrically within the planetary gear sets. The rotor rotates about the same axis as the planetary gear sets, utilizing the radial space efficiently and reducing the axial length required for the hybrid drive system.
2Adaptability or versatility
If conventional hybrid drive systems are used, then drive functionality is achieved, but weight increases
Solution Approach 1:
The patent merges the electric machine (22) with the planetary gear sets (50, 52) into a single integrated assembly where the rotor is positioned within the hollow space of the planetary gears. This combining of previously separate components (electric machine and transmission) into one unified structure reduces overall system weight by eliminating redundant housings and mounting structures.
Solution Approach 2:
The integrated assembly serves multiple functions simultaneously: the planetary gear sets provide mechanical gear reduction and torque multiplication, while the electric machine provides electric propulsion and can also function as a generator during regenerative braking. The switching elements enable the same physical assembly to operate in different drive modes (electric-only, hybrid, combustion-only), maximizing functionality without adding separate dedicated systems.
3Adaptability or versatility
If conventional hybrid drive systems are used, then drive capability is achieved, but costs increase
Solution Approach 1:
The patent segments the transmission into two partial gearboxes (46, 48) with distinct functions: the first partial gearbox (46) contains the planetary gear sets (50, 52) for hybrid operation, while the second partial gearbox (48) contains spur gear stages (70, 86) for additional gear ratios. This segmentation allows each module to be optimized and manufactured separately, then assembled together, reducing overall manufacturing complexity and cost compared to a single complex transmission housing.
Solution Approach 2:
The patent employs switching elements (80-96) that dynamically reconfigure the torque transmission paths within the integrated assembly. These switching elements allow the same physical hardware to operate in multiple drive modes (electric-only, hybrid parallel, combustion-only) by selectively engaging or disengaging torque paths, eliminating the need for multiple dedicated transmission systems and reducing manufacturing costs.
Data Source
AI summary
A hybrid drive system for a motor vehicle has an internal combustion engine having a drive shaft via which first drive torques can be supplied by the internal combustion engine to drive the motor vehicle. The system also has an electric machine having a rotor via which second drive torques can be supplied by the electric machine to drive the motor vehicle. The system further has an axle drive having an axle drive input gear via which the axle drive can be driven and a gearbox having a first partial gearbox and a second partial gearbox. The first partial gearbox has a first planetary gear set having a first element, a second element, and a third element, as well as a second planetary gear set having a fourth element and a fifth element connected permanently in a rotationally fixed manner to the first element, and a sixth element.