Composite Linear Guide With Metal Running Sheets for Bearing Wear

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing linear guides made of metal materials face issues with thermal stability, rigidity, weight, and compatibility with bearings due to the hardness difference between composite materials and traditional bearings, leading to rapid wear and delamination problems during manufacturing.

Innovation Solution

A linear guide comprising tubular elements made of composite material with integrated thin metal sheets, where rolling bearings slide on these sheets, and a manufacturing process involving photogravure engraving and co-molding to ensure precise positioning and prevent delamination, using thermosetting resins and fibrous reinforcement for enhanced bonding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If metal materials are used for linear guides, then mechanical resistance is improved, but thermal stability and rigidity deteriorate

Engineering Contradiction:
Improvemechanical resistanceVSAvoidthermal stability
Core Design Contradiction:
StrengthVSStability of the object's composition

Solution Approach 1:

The patent applies composite materials consisting of a thermosetting resin matrix and fibrous reinforcement (such as carbon fibers, glass fibers, or basalt fibers) to manufacture the track and slide. This composite structure provides both high mechanical resistance and excellent thermal stability, resolving the contradiction between strength and thermal stability that plagues traditional metal linear guides.

Inventive Principle:
Principle #40Composite materials

2Stability of the object's composition

If composite materials are used for track and slide, then thermal stability and rigidity are improved, but hardness deteriorates

Engineering Contradiction:
Improvethermal stabilityVSAvoidhardness
Core Design Contradiction:
Stability of the object's compositionVSStrength

Solution Approach 1:

The patent applies local quality by integrating thin metal sheets (0.5-3mm thick) specifically at the contact surfaces where bearings slide, while the main body remains composite material. This creates a localized hard surface (50-60 HRC) for bearing compatibility while maintaining the overall thermal stability and low weight of composite materials.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent creates a hybrid composite structure combining composite material (for thermal stability and low weight) with metal sheets (for hardness and bearing compatibility). This multi-material composite approach resolves the contradiction between thermal stability and surface hardness.

Inventive Principle:
Principle #40Composite materials

3Strength

If metal sheets are glued to composite surfaces, then hardness is improved, but positioning accuracy and bonding durability deteriorate

Engineering Contradiction:
ImprovehardnessVSAvoidpositioning accuracy
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The patent merges the metal sheet integration process with the composite molding process into a single co-molding operation. The metal sheets are positioned and bonded simultaneously with composite material curing, eliminating separate gluing steps and achieving both high positioning accuracy and bonding durability through the integrated process.

Inventive Principle:
Principle #5Merging (Combining)

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 provides a lightweight, mechanically resistant, and thermally stable linear guide with high rigidity, preventing quick wear and malfunction, while maintaining cost-effectiveness and precision in manufacturing.

Implementation Method 1

b) engraving a surface of each thin sheet by means of photogravure

Methodology Applied
Scientific EffectPhotogravure:

Implementation Method 2

c) co-molding the first thin sheets to the inner tubular element and the second thin sheets to the outer tubular element

Methodology Applied
Scientific EffectCo-molding:

Implementation Method 3

due to the significant difference in the thermal dilation coefficient between the composite material and the metal material. In fact, the cooling, which follows the molding, needed for the hardening of the composite resin, creates thermal tensioning for the interface between the two materials

Methodology Applied
Scientific EffectThermal dilation: Thermal Expansion

Implementation Method 4

a means is interposed for reducing friction, such as ball cages, rolling pins, or other types of bearings

Methodology Applied
Scientific EffectRolling friction: Friction

Data Source

PatentEP3594515B1Linear guide and process to produce such a linear guide
Publication Date: 2021.08.25 JOFA SRL
  • EP3594515B1 patent drawingFigure 1a~2b
  • EP3594515B1 patent drawingFigure 3~4
  • EP3594515B1 patent drawingFigure 5

AI summary

The present invention relates to a linear guide (1) comprising an outer tubular element (2), an inner tubular element (3), adapted to slide telescopically in said outer tubular element (2), and friction reduction means interposed between said inner tubular element (3) and said outer tubular element (2), said friction reduction means comprising n rolling bearings (4), wherein n ≥ 1, each rolling bearing (4) being provided with rolling elements, wherein the outer tubular element (2) and the inner tubular element (3) are made of a composite material and wherein said rolling elements slide on two thin sheets (6a, 6b), a first thin sheet (6a) positioned on an outer face of the inner tubular element (3) and a second thin sheet (6b) positioned on a corresponding inner face of the outer tubular element (2). The present invention also relates to a process of manufacturing such a linear guide (1), and more generally, to a method of manufacturing an element made of a composite material provided with at least one thin sheet at at least an outer surface thereof.