Nested Gearbox Shift Shafts for Hybrid-Friendly Gear Selection

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Solution Overview

Problem

Current control solutions for X-Y type gearbox operating systems are cumbersome and difficult to install in three-axis gearboxes, and the integration of electrical machines with linear or rotary actuators is problematic, especially in hybridization applications.

Innovation Solution

A compact gearbox operating system with a hollow first shaft and a non-circular inner shaft, featuring separate actuator assemblies for axial and rotational movements, allowing for independent control of gear selection and engagement, enabling the installation of electrical machines for mild hybridization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If linear or rotary actuators are coupled to the case of the operating system or gearbox, then the gearbox can achieve gear selection and engagement, but the system becomes extremely problematic for hybridization with electrical machines

Engineering Contradiction:
Improvehybridization capabilityVSAvoidactuator integration complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The operating system is segmented into two independent shafts (first shaft for selection, second shaft for engagement) that can be controlled by separate actuator assemblies. This segmentation allows the system to avoid complex integration of linear or rotary actuators with the gearbox case, while still achieving full gear selection and engagement functionality, thereby enabling hybridization with electrical machines.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The first shaft is designed with dual functionality: it performs both selection movement (axial translation) and engagement movement (rotation) through its two independent actuator assemblies. This multi-functionality eliminates the need for separate dedicated actuators for each function, reducing overall system complexity and improving adaptability for hybridization applications.

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

2Volume of moving object

If a hollow first shaft fitted on a second shaft is used with separate actuator assemblies, then the system becomes compact and easy to install, but the structural complexity of the shaft arrangement increases

Engineering Contradiction:
Improveoperating system sizeVSAvoidshaft arrangement complexity
Core Design Contradiction:
Volume of moving objectVSDevice complexity

Solution Approach 1:

The first shaft is designed as a hollow shaft that is fitted on the second shaft, creating a nested configuration where one shaft is placed inside the other. This nesting arrangement significantly reduces the overall volume of the operating system and simplifies installation, while the functional independence of each shaft maintains operational simplicity despite the increased structural complexity of the nested arrangement.

Inventive Principle:
Principle #7Nested doll (Nesting)

Data Source

PatentEP3825582B1A system for operation of a gearbox for a motor vehicle
Publication Date: 2024.04.10 STELLANTIS EUROPE SPA
  • EP3825582B1 patent drawingFigure 1
  • EP3825582B1 patent drawingFigure 2
  • EP3825582B1 patent drawingFigure 3

AI summary

Described herein is a system (1) for operating a gearbox (100), comprising: - a first shaft (2) having a first longitudinal axis (X2); - a first actuator assembly (4) operatively connected to the first shaft (2); - a second shaft (6) having a second longitudinal axis (X6) ; - a second actuator assembly (8) operatively connected to the second shaft (6); and - a plurality of engagement elements (10, 12, 14) connected in rotation to said second shaft (6); The first shaft (2) is hollow, is fitted on said second shaft (6), and is axially movable relative to the second shaft (6), and said plurality of engagement elements (10, 12, 14) are moreover connected in translation to said first shaft (2) and are axially movable therewith along said first longitudinal axis (X2) and relative to the second shaft (X6). The first and second shafts can be operated independently of one another for execution of the movements of selection and engagement of the gears of a gearbox (100).