Gearshift Transmission With Countershaft For Direct Shifting

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Solution Overview

Problem

Conventional dual-clutch transmissions have limited flexibility and increased component loads due to the requirement for multiple sub-transmissions and shifting elements, restricting gear shifting sequences and efficiency.

Innovation Solution

The implementation of a triple powershift clutch unit with an additional countershaft gear that can be engaged via a third powershift clutch, allowing for reduced wheel planes, synchronizing clutches, and gear selectors, enabling more gear stages and direct gear shifts without preselection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a conventional dual-clutch transmission with two sub-transmissions is used, then power shift operations can be performed, but the number of wheel planes and shifting elements increases, leading to higher device complexity and component loads

Engineering Contradiction:
Improvegear shifting flexibilityVSAvoidnumber of wheel planes and shifting elements
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The countershaft is designed to serve multiple functions: it acts as an intermediate transmission for direct gear shifts (enabling 1st to 3rd gear without preselection), provides additional gear reduction stages, and can be selectively engaged or disengaged. This multi-functional design allows the transmission to achieve greater gear shifting flexibility without proportionally increasing the number of wheel planes and shifting elements

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

Solution Approach 2:

The countershaft functions as an intermediary transmission element between the input shaft and output shaft. By introducing this intermediate stage with gear pairs, the system enables direct gear shifts and additional reduction stages without requiring separate sub-transmissions for each gear stage, thereby reducing overall device complexity while maintaining versatility

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If multiple sub-transmissions are used to enable direct gear shifts, then gear shifting flexibility improves, but component loads and stress increase

Engineering Contradiction:
Improvegear shifting sequence freedomVSAvoidcomponent loads on clutches
Core Design Contradiction:
Adaptability or versatilityVSStress or pressure

Solution Approach 1:

The countershaft serves as a mediator that distributes and reduces component loads. By providing an intermediate transmission stage with gear pairs, it allows power to be transferred through alternative paths during gear shifts, preventing excessive stress concentration on individual clutches and enabling more flexible gear shifting sequences

Inventive Principle:
Principle #24Intermediary (Mediator)

3Quantity of substance

If a triple powershift clutch unit with countershaft is implemented, then the number of gear sets and synchronizer clutches is reduced, but the initial device complexity increases

Engineering Contradiction:
Improvenumber of gear sets and synchronizer clutchesVSAvoidstructure of powershift unit
Core Design Contradiction:
Quantity of substanceVSDevice complexity

Solution Approach 1:

The countershaft transmission is integrated directly into the existing powershift unit structure, merging the intermediate transmission function with the clutch assembly. This consolidation allows the system to reduce the number of separate gear sets and synchronizer clutches while the compact integration minimizes the increase in overall device complexity

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP3126710B1Gearshift transmission for a motor vehicle
Publication Date: 2020.01.08 AUDI AG
  • EP3126710B1 patent drawingFigure 1~2
  • EP3126710B1 patent drawingFigure 3~4
  • EP3126710B1 patent drawingFigure 5a~6

AI summary

The invention relates to a gearshift transmission for a motor vehicle, comprising shiftable gear wheel sets that are associated with a first and a second partial transmission, each of which includes one input shaft and a common output shaft, the input shafts being alternatingly activatable by separate powershift clutches. In order to create a structurally and functionally advantageous transmission, an auxiliary transmission (VG) which causes a gear change and can be alternatingly connected by a third powershift clutch (K3) is associated with one of the partial transmissions (B).