Automated Gearbox Shift Rod Mounting Sleeve Assembly

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing automated manual transmission shifting devices require high assembly effort and have limited load-bearing capacity due to complex and time-consuming assembly processes of the actuating piston and shift rod connection.

Innovation Solution

The actuating piston is equipped with a mounting sleeve for pre-mounting the retaining ring and support disk, and the cylinder shaft has an outer assembly cone for the pre-assembled locking ring and support disk, allowing for easier and more reliable assembly by inserting the pre-assembled components onto the shift rod, with features like centering grooves and captive retention to prevent jamming and enhance load-bearing capacity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the actuating piston is fastened to the shift rod using a self-locking nut or circlip with support disk, then the connection can be securely fixed, but the assembly effort and time increase significantly

Engineering Contradiction:
Improveconnection reliabilityVSAvoidassembly productivity
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The mounting sleeve is pre-assembled onto the actuating piston before installation, with the locking groove and sealing elements already in position. This preliminary preparation eliminates the need for complex step-by-step assembly during final installation, allowing the entire actuating piston assembly to be mounted as a single unit onto the shift rod, thereby significantly reducing assembly time while maintaining secure connection

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The mounting sleeve integrates multiple functions into a single component: it provides sealing, positioning, and locking features all in one element. The sealing groove, locking groove, and mounting features are combined in the mounting sleeve, eliminating the need for separate sealing elements and locking mechanisms, thus simplifying the assembly process while ensuring reliable connection

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If individual components like retaining ring and support disk are fitted separately after the actuating piston is pushed onto the cylinder shaft, then the connection can be secured, but the assembly work becomes comparatively high

Engineering Contradiction:
Improvefastening reliabilityVSAvoidassembly complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The mounting sleeve combines the functions of the retaining ring and support disk into a single integrated component. The locking groove provides the retaining function while the sleeve body provides the support function, eliminating the need for separate retaining rings and support disks. This integration reduces assembly complexity while maintaining secure fastening

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The mounting sleeve is pre-configured with the locking groove and sealing features before installation. This preliminary preparation ensures that all necessary components are in place before the actuating piston is mounted onto the shift rod, eliminating the need for subsequent fitting operations and reducing overall assembly complexity

Inventive Principle:
Principle #10Preliminary action

3Ease of manufacture

If a standard stamped circlip is used for fixing the actuating piston, then the design is simple and cost-effective, but the load-bearing capacity is limited

Engineering Contradiction:
Improvemanufacturing easeVSAvoidload-bearing capacity
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The mounting sleeve is constructed as a composite structure combining different material properties and structural features. The sleeve integrates sealing elements, locking features, and structural support in a single component, creating a hybrid solution that exceeds the capabilities of simple stamped circlips while remaining manufacturable. This composite design provides enhanced load-bearing capacity through the integrated structure

Inventive Principle:
Principle #40Composite materials

Data Source

PatentEP2481957B1Shifting device of an automated gearbox
Publication Date: 2013.03.13 ZF FRIEDRICHSHAFEN AG
  • EP2481957B1 patent drawingFigure 1
  • EP2481957B1 patent drawingFigure 2

AI summary

The switching device (1) has an axially displaceable shift rod (2), where an actuating piston (3) of a hydraulic or pneumatic actuating cylinder (4) is fixed on an end side of the shift rod. The actuating piston is provided with a mounting sleeve (12) for pre-installation of a safety ring (9) and a supporting disk (11), where the mounting sleeve is axially arranged externally on the actuating piston.