Sliding Sleeve Assembly for Low-Friction Operating Feedback

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Solution Overview

Problem

Existing operating units in agricultural vehicles experience high inner mechanical friction due to components like pre-loaded springs, which complicate integration and increase friction during use, necessitating stronger user feedback forces to overcome typical vibrations and jerking.

Innovation Solution

A sliding sleeve composed of two cylindrical sleeve portions with connection means, such as pins and sockets, that are rotationally fixed and axially positioned to reduce friction, allowing for easy assembly and reduced component complexity, and incorporating torsion springs for adjustable restoring forces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If pre-loaded springs and complex assemblies are used in operating units, then user feedback force is provided, but inner mechanical friction increases and device complexity increases

Engineering Contradiction:
Improveuser feedback forceVSAvoidassembly complexity
Core Design Contradiction:
ForceVSDevice complexity

Solution Approach 1:

The operating unit is divided into modular components: a control adapter that pivots independently, a sliding sleeve with receiving regions, and separate restoring means. This segmentation allows each component to perform its function with minimal interference, reducing overall assembly complexity while maintaining feedback force capability

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The complex pre-loaded spring assembly is extracted and replaced with a simpler configuration using torsion springs that rest against the sliding sleeve's receiving regions. This extraction eliminates the need for complicated pre-loading mechanisms while preserving the restoring force function

Inventive Principle:
Principle #2Taking out (Extraction)

2Force

If pre-loaded springs are used in operating units, then restoring force is provided, but inner mechanical friction increases during use

Engineering Contradiction:
Improverestoring forceVSAvoidmechanical friction
Core Design Contradiction:
ForceVSObject-generated harmful factors

Solution Approach 1:

The sliding sleeve acts as an intermediary component between the control adapter and the restoring means. Its cylindrical geometry with receiving regions allows the torsion springs to engage smoothly, minimizing friction during the pivoting motion while still providing the necessary restoring force

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The design changes the physical parameters of the restoring mechanism by using torsion springs with specific spring rates that can be adjusted to provide the required restoring force. The sliding sleeve's receiving regions are dimensioned to accommodate these springs with optimal clearance, reducing friction while maintaining force capability

Inventive Principle:
Principle #35Parameter changes

3Force

If complex operating unit assemblies are used, then user feedback is provided, but manufacturing costs and integration complexity increase

Engineering Contradiction:
Improvefeedback forceVSAvoidintegration ease
Core Design Contradiction:
ForceVSEase of manufacture

Solution Approach 1:

The sliding sleeve serves multiple functions simultaneously: it guides the control adapter's pivoting motion, provides receiving regions for the restoring means, and acts as a structural connector between components. This multi-functionality reduces the total number of parts needed, simplifying both manufacturing and integration while maintaining feedback force 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 solution reduces manufacturing costs and complexity while providing clear user feedback through adjustable restoring forces, enhancing the operating unit's reliability and ease of assembly.

Implementation Method 1

restoring means, wherein the restoring means generate a restoring force when the control adapter is relatively pivoted

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP4579375A1Sliding sleeve, operating unit and method for manufacturing an operating unit
Publication Date: 2025.07.02 ELOBAU GMBH & CO KG
  • EP4579375A1 patent drawingFigure 1~2
  • EP4579375A1 patent drawingFigure 3
  • EP4579375A1 patent drawing

AI summary

A sliding sleeve (1) comprising two substantially cylindrical sleeve portions (2), wherein the two sleeve portions each have a first axial end (3), a second axial end (4) and an outwardly directed receiving region (5) between the first axial end and the second axial end, wherein the second axial end or the first and the second axial ends have a larger outer diameter than the receiving region, wherein an axial extension of the receiving region is limited at least on one side by at least the second axial end, wherein connection means (6) are formed at the first axial ends to connect the two sleeve portions coaxially and rotationally fixed to one another, an operating unit (10) comprising a control adapter (13), a sliding sleeve (1), especially a sliding sleeve according to the invention, restoring means (12) and a housing (11) and a method for manufacturing an operating unit.