Hybrid Drive Transmission With Four-Shaft Planetary Gear Integration

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Solution Overview

Problem

Existing hybrid drive systems for motor vehicles are not optimized for a space-saving and cost-effective design, which limits their efficiency and integration into vehicles.

Innovation Solution

A hybrid drive system incorporating a four-shaft first planetary gear set, a second planetary gear set, and multiple switching elements to create a compact, multi-speed transmission that integrates an internal combustion engine and an electric machine, allowing for efficient torque distribution and reduced component count.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a conventional hybrid drive system with separate planetary gear sets is used, then the transmission can provide multiple gear ratios, but the system occupies excessive space and increases installation complexity

Engineering Contradiction:
Improvemulti-speed transmission capabilityVSAvoidinstallation space
Core Design Contradiction:
Adaptability or versatilityVSArea of stationary object

Solution Approach 1:

The patent merges two separate planetary gear sets into a single integrated four-shaft planetary gear set. This unified structure combines the functions of both gear sets, allowing multiple gear ratios to be achieved through a compact design with shared components, thereby reducing the overall space occupation while maintaining multi-speed transmission capability

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The four-shaft planetary gear set is designed to perform multiple functions simultaneously - it provides both the first and second gear ratios needed for hybrid operation, serves as both a reduction gear mechanism and a torque distribution system, and integrates the electric machine connection directly into the gear set structure, eliminating the need for separate dedicated gear sets

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If multiple separate planetary gear sets are used to achieve multi-speed transmission, then various gear ratios can be obtained, but the component count and system complexity increase

Engineering Contradiction:
Improvegear ratio variabilityVSAvoidnumber of components
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent combines multiple planetary gear sets into a single four-shaft planetary gear set with integrated components. The sun gears, planet carriers, and ring gears are shared across different gear ratio pathways, reducing the total number of components while maintaining the ability to provide multiple gear ratios through different engagement configurations

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The planetary gear set is segmented into four functional shafts (first sun gear shaft, second sun gear shaft, planet carrier shaft, and ring gear shaft) that can be independently controlled and engaged. This segmentation allows flexible combination of components to achieve different gear ratios without requiring separate complete planetary gear sets for each ratio

Inventive Principle:
Principle #1Segmentation

3Area of stationary object

If a compact hybrid drive system is designed, then space usage is optimized, but manufacturing and assembly costs may increase

Engineering Contradiction:
Improvespace utilizationVSAvoidmanufacturing complexity
Core Design Contradiction:
Area of stationary objectVSEase of manufacture

Solution Approach 1:

By merging multiple planetary gear sets into a single four-shaft design with shared components, the patent reduces the total number of parts that need to be manufactured and assembled. The integrated structure allows for standardized manufacturing processes and reduces assembly steps, thereby lowering manufacturing costs despite the compact design

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP4323218B1Hybrid drive system for a motor vehicle, and motor vehicle
Publication Date: 2024.10.30 MERCEDES BENZ GROUP AG
  • EP4323218B1 patent drawingFigure 1
  • EP4323218B1 patent drawingFigure 2
  • EP4323218B1 patent drawingFigure 3

AI summary

The invention relates to a hybrid drive system (16) for a motor vehicle, with an internal combustion engine (18) which has a first output shaft (24), with an electric machine (28) which has a rotor (32) with a rotor shaft (34) as second output shaft, and with a transmission (38) which has a four-shaft, first planetary set (40), a second planetary set (44), a first shifting element (46a), a second shifting element (46b), a third shifting element (46c) and a third output shaft (62), wherein the four-shaft, first planetary set (40) has a first shaft (42a), a second shaft (42b), a third shaft (42c) and a fourth shaft (42d), the second planetary set (44) has a first element (48), a second element (50) and a third element (52), the first shaft (42a), the second shaft (42b), the third shaft (42c) and the fourth shaft (42d) can be rotated relative to one another and can be connected to one another fixedly for conjoint rotation by means of the second shifting element (46b), the first output shaft (24) is coupled or can be coupled fixedly to the first shaft (42a) for conjoint rotation, the rotor shaft (34) is coupled or can be coupled to the second shaft (42b) in such a way that torques which emanate from the rotor shaft (34) can be introduced via the second shaft (42b) into the transmission (38), the third shaft (42c) can be connected fixedly to the third output shaft (62) for conjoint rotation by means of the first shifting element (46a), the fourth shaft (42d) is connected or can be connected fixedly to the first element (48) of the second planetary set (44) for conjoint rotation, the first shaft (42a) comprises a first sun gear (76) of the first planetary set (40), and the third shaft (42c) comprises a second sun gear (78) of the first planetary set (40).