Six-speed front-transverse double-clutch transmission with third counter shaft

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing dual clutch transmissions require significant axial installation space, limiting their suitability for compact applications such as front-transverse motor vehicle arrangements.

Innovation Solution

A transmission design featuring six shafts with coaxial and axially offset arrangements, along with nine switching elements, including frictional starting clutches and gear connections, allows for a compact axial layout by utilizing an additional shaft with an idler gear to maintain unchanged axial dimensions while reducing space requirements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If a dual-clutch transmission with six forward gears is implemented using conventional two-countershaft designs, then the gear functionality is achieved, but the axial installation space becomes excessively large

Engineering Contradiction:
Improveaxial installation spaceVSAvoidtransmission structure complexity
Core Design Contradiction:
Volume of moving objectVSDevice complexity

Solution Approach 1:

The patent implements a nested shaft arrangement where the third shaft is positioned coaxially inside the hollow second shaft, and the fourth shaft is positioned inside the fifth shaft. This nesting of shafts within shafts dramatically reduces the axial footprint of the transmission while maintaining all necessary gear pathways for six forward gears and reverse functionality.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The patent transitions from a conventional two-countershaft layout to a six-shaft arrangement that utilizes both axial and radial dimensions more efficiently. By distributing gears and shafts across multiple dimensions (coaxial arrangements, offset positions), the design achieves compact axial packaging while preserving all gear engagement pathways.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Length of stationary object

If the number of shafts is increased to six shafts with coaxial and offset arrangements, then the axial space is reduced, but the structural complexity increases

Engineering Contradiction:
Improveaxial dimensionVSAvoidshaft and gear arrangement complexity
Core Design Contradiction:
Length of stationary objectVSDevice complexity

Solution Approach 1:

The transmission is segmented into six distinct shafts, each with specific functions and gear arrangements. The shafts are divided into coaxial groups (first, second, and third shafts share a common axis; fourth and fifth shafts are offset from each other) which modularizes the complexity and allows for systematic gear engagement control through nine dedicated switching elements.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The third shaft acts as an intermediary component that provides additional gear engagement pathways without significantly increasing axial space. By positioning the third shaft coaxially within the hollow second shaft, it serves as a mediator that enables additional forward gears while maintaining compact axial dimensions.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Adaptability or versatility

If nine switching elements are implemented to control gear engagements, then all gear ratios and reverse functions are achieved, but the device complexity increases

Engineering Contradiction:
Improvegear ratio variabilityVSAvoidswitching element quantity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

Each switching element is designed to perform multiple functions: controlling engagement between different shafts, enabling various gear ratios, and facilitating reverse gear operation. The switching elements act as universal connectors that can establish rotational fixed connections between any combination of shafts, providing versatile gear control without requiring dedicated mechanisms for each function.

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

Data Source

PatentEP3894722B1Six-speed front-transverse double-clutch transmission with third counter shaft
Publication Date: 2023.11.15 ZF FRIEDRICHSHAFEN AG
  • EP3894722B1 patent drawingFigure 1
  • EP3894722B1 patent drawingFigure 2
  • EP3894722B1 patent drawingFigure 3

AI summary

The invention relates to a transmission (101, 201, 301) with a first shaft (W1), a second shaft (W2), a third shaft (W3), a fourth shaft (W4), a fifth shaft (W5), a sixth shaft (W6), a first shift element (K1), a second shift element (K2), a third shift element (A), a fourth shift element (B), a fifth shift element (C), a sixth shift element (D), a seventh shift element (E), an eighth shift element (F), a ninth shift element (G), and an output. The first shaft (W1) and the third shaft (W3) can be rotationally fixed to each other via the first shift element (K1); the first shaft (W1) and the second shaft (W2) can be rotationally fixed to each other via the second shift element (K2); the second shaft (W2) and the fourth shaft (W4) can be operatively connected together in a rotational manner via the third shift element (A); the third shaft (W3) and the fourth shaft (W4) can be rotationally fixed to each other via the fourth shift element (B) and the fifth shift element (C); the second shaft (W2) and the fifth shaft (W5) can be operatively connected together in a rotational manner via the sixth shift element (D); the fourth shaft (W4) and the fifth shaft (W5) can be operatively connected together in a rotational manner via the seventh shift element (E); the third shaft (W3) and the fifth shaft (W5) can be operatively connected together in a rotational manner via the eighth shift element (F); and a fixed gear (F4) of the fourth shaft (W4) and a fixed gear (F5) of the fifth shaft (W5) are each operatively connected to the output in a rotational manner. A first gear of the sixth shaft (W6) and a fixed gear of the second shaft (W2) mesh together; a second gear of the sixth shaft (W6) and a fixed gear of the third shaft (W3) mesh together; wherein the first gear is a movable gear (L6) of the sixth shaft (W6), the second gear is a fixed gear (F6) of the sixth shaft (W6) or the first gear is the fixed gear (F6) of the sixth shaft (W6), and the second gear is the movable gear (L6) of the sixth shaft (W6); and the movable gear (L6) of the sixth shaft (W6) and the sixth shaft (W6) can be rotationally fixed to each other via the ninth shift element (G).