Transmission Shift Selector Layout for Compact Gear Selection

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Solution Overview

Problem

Existing gearbox shifting mechanisms in manual transmissions require significant installation space due to the parallel arrangement of shift gates and actuators, which is becoming scarce in modern vehicle designs, especially in commercial vehicles.

Innovation Solution

A shifting mechanism with a shift actuation unit and selector unit that allows the selector element to move in a direction perpendicular to the shift actuation axis, using a conversion unit to convert linear motion into rotary motion, reducing the need for multiple shift rods and minimizing installation space.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If shift gates are arranged parallel to transmission shafts and gate selection actuator is arranged perpendicular to transmission shafts, then gear selection function is achieved, but installation space requirement increases

Engineering Contradiction:
Improvegear selection functionVSAvoidinstallation space
Core Design Contradiction:
Ease of operationVSVolume of moving object

Solution Approach 1:

The patent merges the gate selection actuator and the gear selection actuator into a single integrated actuator that performs both functions. This eliminates the need for separate actuators arranged in perpendicular directions, thereby reducing the installation space while maintaining both gate selection and gear selection functionalities.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single actuator is designed to perform multiple functions: it serves as both the gate selection actuator (selecting shift gates) and the gear selection actuator (selecting gears). This multi-functional design allows the system to achieve the same operational capabilities with reduced component count and smaller installation footprint.

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

2Adaptability or versatility

If multiple shift rods are used to operate multiple shift forks, then each shift fork can be independently actuated, but device complexity and installation space increase

Engineering Contradiction:
Improveindependent shift fork actuationVSAvoidnumber of shift rods
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The single shift rod is segmented with multiple actuation points along its length. Each actuation point can independently engage with different shift forks, allowing the segmented rod to provide independent actuation for multiple shift forks while maintaining a unified, space-efficient structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The single shift rod serves multiple functions by engaging with multiple shift forks at different locations. This multi-functional design eliminates the need for separate shift rods for each shift fork, reducing device complexity and installation space while maintaining independent actuation capability.

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

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The mechanism achieves a compact design by allowing a single shift rod to operate multiple shift forks, saving space and enabling precise gear selection with reduced actuator power requirements.

Implementation Method 1

a conversion unit that can be connected to the switching actuator and configured to convert the linear motion of the switching actuator into a rotary motion of the selector element

Methodology Applied
Scientific EffectLinear motion to rotary motion conversion:

Data Source

PatentEP3830452B1Gear-shifting device for a transmission
Publication Date: 2022.09.07 KNORR BREMSE SYSTEME FUER NUTZFAHIZEUGE GMBH
  • EP3830452B1 patent drawingFigure 1
  • EP3830452B1 patent drawingFigure 2

AI summary

The invention relates to a gear-shifting mechanism (1) for a transmission. The gear-shifting mechanism (1) comprises a gear-shifting actuating unit (2) having a gear-shifting actuator (3) that can be moved along a gear-shifting actuating axis (4), and a selection unit (5) that can be connected to the gear-shifting actuator (3). The selection unit (5) comprises a selection element (6) which is designed to adopt different positions in a direction that is non-parallel to the gear-shifting actuating axis (4), in order to be able to connect to different selector forks (19, 19') in the different positions, for moving transmission components for shifting gears, and a switching actuator (8) having a switching actuator axis (9) that defines a switching movement of the switching actuator (8) for moving the selection element (6) into the different positions. The switching actuator axis (9) and the gear-shifting actuating axis (4) are oriented such that they are parallel to each other.