Adjustable Belt And Chain Tensioning Torque For Slip-Efficiency Balance

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Solution Overview

Problem

Existing tensioning devices for belt or chain transmissions often experience excessive slippage due to insufficient tension or reduced efficiency due to excessive tension, making them unreliable and inefficient under changing operating conditions.

Innovation Solution

A tensioning device with adjustable clamping torque, featuring pivoting elements, restoring elements, and positioning aids that allow for manual or automatic adjustment of the clamping torque, enabling optimal belt or chain tension across various transmissions and power levels, ensuring reliable and efficient power transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the tensioning torque is increased to prevent slippage, then reliable power transmission is improved, but the gearbox efficiency is reduced due to excessive tension

Engineering Contradiction:
Improvepower transmission reliabilityVSAvoidgearbox efficiency
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The tensioning device employs pivoting elements that enable dynamic adjustment of the clamping force. The restoring element generates a tensioning torque that automatically adapts to changing operating conditions, allowing the system to maintain optimal tension without excessive force, thereby preventing both slippage and energy loss.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The device changes the parameter of tensioning torque through the pivoting mechanism. By allowing the pivoting elements to rotate about their respective axes, the effective lever arm and thus the tensioning torque can be adjusted dynamically, enabling the system to operate at optimal tension levels under varying conditions.

Inventive Principle:
Principle #35Parameter changes

2Loss of energy

If the tensioning torque is decreased to improve gearbox efficiency, then energy loss is reduced, but slippage occurs due to insufficient tension

Engineering Contradiction:
Improvegearbox efficiencyVSAvoidpower transmission reliability
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The dynamic pivoting mechanism allows the tensioning device to automatically increase tension when needed. The pivoting elements can rotate to adjust the effective lever arm, thereby increasing the tensioning torque dynamically in response to load variations, preventing slippage while maintaining efficiency during normal operation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The restoring element provides a feedback mechanism through its elastic properties. As the belt or chain tension changes, the restoring element's deformation changes, which in turn adjusts the tensioning torque automatically, ensuring sufficient tension is maintained to prevent slippage.

Inventive Principle:
Principle #23Feedback

3Device complexity

If the tensioning device is designed for fixed tension, then the structure is simple, but it cannot adapt to different operating conditions and power outputs

Engineering Contradiction:
Improvetensioning device structureVSAvoidapplication range
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The pivoting elements introduce a dynamic component to the tensioning device structure. This allows the device to adapt to different operating conditions and power outputs without requiring complete redesign, maintaining relatively simple construction while achieving versatility through the pivoting mechanism's ability to adjust tension dynamically.

Inventive Principle:
Principle #15Dynamics

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 tensioning device provides flexible and reliable power transmission by allowing for precise adjustment of clamping torque, maintaining optimal tension and efficiency regardless of operating conditions, thus enhancing the range of applications and longevity of the transmission system.

Implementation Method 1

The at least one return element is designed to generate a clamping torque acting at least partially around the pivot axis

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

The tensioning elements are designed to engage with or roll on the belt or chain by friction or positive locking

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3913256B1Tensioning device for a belt or chain transmission
Publication Date: 2022.12.28 GRIMME LANDMASCHINENFABRIK GMBH & CO KG
  • EP3913256B1 patent drawingFigure 1
  • EP3913256B1 patent drawingFigure 2
  • EP3913256B1 patent drawingFigure 3

AI summary

The invention relates to a tensioning device (2) for a belt or chain drive comprising at least a first pivoting element (4) on which a first tensioning element (6) is rotatably mounted about a first tensioning axis (8), and at least a second pivoting element (14) on which a second tensioning element (16) is rotatably mounted about a second tensioning axis (18) and which, in operation, is pivotably coupled to the first pivoting element (4) about at least one pivoting axis (10), and at least one return element (20) which is arranged between the first pivoting element (4) and the second pivoting element (14) to generate a tensioning torque (22) acting at least partially about the pivoting axis (10), wherein at least one adjusting device (30) for adjusting the tensioning torque (22) is provided. The invention further relates to a gearbox and a root crop harvester with such a tensioning device.