Plastic Guide Component With Convex Sliding Surface

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Solution Overview

Problem

Existing guide components for endless chains in chain drives often fail to provide stable and long-lasting guidance due to vibrations and temperature variations, leading to uneven contact and potential loss of contact, which results in vibrations and noise.

Innovation Solution

A guide component with a T-shaped cross section, featuring a convex sliding surface and a stiffening rib, is designed to maintain homogeneous contact and stability under high loads and temperature changes, ensuring reliable chain guidance over long periods with reduced noise.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a plastic guide component is used for guiding an endless chain, then the guide component is lightweight and easy to manufacture, but it lacks sufficient rigidity and resistance to distortions under high loads and temperature variations

Engineering Contradiction:
Improveease of manufactureVSAvoidrigidity
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The guide component is made from a composite material consisting of polyamide 6.6 and 15% glass fiber. The glass fiber reinforcement significantly enhances the rigidity and dimensional stability of the plastic material, allowing it to resist distortions under high loads and temperature variations while maintaining the ease of injection molding manufacturing process.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The sliding surface is designed with a convex curvature instead of a flat surface. This convex shape allows the sliding surface to maintain homogeneous contact with the endless chain even when subjected to temperature variations and thermal expansion, preventing loss of contact and ensuring stable guidance under varying operating conditions.

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Stability of the object's composition

If the sliding surface is designed with convex shape, then homogeneous contact is maintained under temperature variations, but manufacturing precision requirements increase

Engineering Contradiction:
Improvecontact stabilityVSAvoidmanufacturing precision
Core Design Contradiction:
Stability of the object's compositionVSManufacturing precision

Solution Approach 1:

The sliding surface is designed with a specific convex radius of curvature (R1 = 2-5 mm) that optimizes the balance between maintaining homogeneous contact and facilitating manufacturability. This parameter optimization ensures that the convex shape compensates for thermal expansion and maintains stable contact without requiring excessively tight manufacturing tolerances.

Inventive Principle:
Principle #35Parameter changes

3Ease of operation

If side walls are designed to protrude beyond the box profile, then lateral guidance is provided, but contact area with the chain increases leading to more friction and wear

Engineering Contradiction:
Improvelateral guidanceVSAvoidfriction
Core Design Contradiction:
Ease of operationVSLoss of energy

Solution Approach 1:

The side walls are designed with selective contact features: they protrude beyond the box profile to provide lateral guidance and positioning, but only specific localized areas of the side walls are designed to contact the endless chain. This selective contact provides necessary lateral stability while minimizing the overall contact area and associated friction losses.

Inventive Principle:
Principle #3Local quality

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 guide component ensures perfect guidance of the endless chain over long operating times and a wide temperature range, maintaining low-noise operation from -30°C to +150°C, with enhanced rigidity and resistance to distortions.

Implementation Method 1

The guide rail (12) has an overall T-shaped cross section and has a convex sliding surface (16)

Methodology Applied
Scientific EffectGeometric shape: Geometry

Implementation Method 2

The web (18) of the T forms a stiffening rib running in the longitudinal direction of the guide rail (14), which increases the flexural rigidity about a transverse axis

Methodology Applied
Scientific EffectStructural reinforcement:

Implementation Method 3

ensures perfect guidance of the endless chain over long operating times and a wide temperature range... maintaining low-noise operation from -30°C to +150°C, with enhanced rigidity and resistance to distortions

Methodology Applied
Scientific EffectThermal expansion resistance: Thermal Expansion

Data Source

PatentEP2505876B1Plastic guide component for guiding an endless chain of a chain drive
Publication Date: 2015.07.29 BAYERISCHE MOTOREN WERKE AG
  • EP2505876B1 patent drawingFigure 1~3
  • EP2505876B1 patent drawingFigure 4~6

AI summary

The component has a guide rail (12) comprising a T-shaped cross-section, where an upper side of a top portion (14) of the cross-section forms a convex sliding surface (16) for an endless chain. A base (18) of the cross-section increases flexural rigidity of the rail, where longitudinal sides of the surface are limited by respective side walls (20). Passage areas between the top portion and the walls are formed with bulges (22) extending along side edges of the surface. Ends of the top portion are connected with one another, where the component is designed as an injection molding component.