Universal Joint Spider Temperature Sensing for Early Wear Detection

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Solution Overview

Problem

Existing methods for detecting impending wear in universal joints of cardan shafts, used in agricultural machinery, are not reliable or compact, and fail to effectively identify wear issues early on.

Innovation Solution

A spider with integrated temperature sensors, positioned on each pin of the universal joint, measures the temperature of the material and lubricant to detect increased friction and misalignments, which indicate wear, with a logic unit processing signals to generate an output indicating fault conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If temperature sensors are integrated into the spider base or pins to detect wear through temperature changes, then wear detection reliability is improved, but device complexity increases due to additional sensor elements and signal processing requirements

Engineering Contradiction:
Improvewear detection reliabilityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The temperature sensor elements are integrated directly into the spider base or pin structures, merging the sensing function with the mechanical components. This integration approach improves reliability by eliminating separate monitoring systems while managing complexity through unified component design.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent uses temperature sensors as intermediary elements that indirectly detect wear conditions through temperature changes caused by friction and power loss. This intermediary approach allows reliable wear detection without requiring direct mechanical contact sensors, balancing reliability improvement with acceptable device complexity.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If multiple sensor elements are distributed across different pins to monitor individual temperatures, then measurement precision is improved, but device complexity increases due to multiple data lines and processing logic

Engineering Contradiction:
Improvetemperature measurement precisionVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The monitoring system is segmented into multiple independent sensor elements, each assigned to specific pins. This segmentation enables precise local temperature measurement at each pin while allowing modular data collection and processing, improving measurement precision without overwhelming system complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the spider (base or pins) are equipped with temperature sensors based on their specific functional requirements and thermal characteristics. This local quality approach ensures that each critical area is monitored with appropriate precision while avoiding unnecessary sensors in less critical regions, balancing measurement precision with device complexity.

Inventive Principle:
Principle #3Local quality

3Measurement precision

If sensor elements are positioned close to the pin centers where friction heat is generated, then temperature detection accuracy is improved, but manufacturing precision requirements increase due to precise positioning needs

Engineering Contradiction:
Improvetemperature detection accuracyVSAvoidsensor positioning precision
Core Design Contradiction:
Measurement precisionVSManufacturing precision

Solution Approach 1:

The sensor elements are pre-positioned in optimized locations within the spider base or pins during manufacturing, before final assembly. This preliminary positioning action allows for controlled placement that achieves accurate temperature detection while managing manufacturing precision requirements through planned fixture and tooling designs.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent employs standardized sensor element designs that can be replicated across multiple pins using consistent manufacturing processes. This copying approach reduces the impact of positioning precision requirements by ensuring uniform sensor placement and characteristics, improving temperature detection accuracy while simplifying manufacturing constraints.

Inventive Principle:
Principle #26Copying

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

This solution allows for early detection of wear in universal joints, independent of external temperature, by monitoring temperature differences and power loss, enabling timely maintenance and reducing operational inefficiencies.

Implementation Method 1

The temperature sensor according to the present invention directly detects the temperature of the spider. The temperature sensor usually detects the current temperature of the material forming the spider or of a lubricant (usually grease) contained in the base of the spider.

Methodology Applied
Scientific EffectTemperature detection:

Implementation Method 2

Wearing bearings usually have increased coefficients of friction. Misalignments of individual components of the spider that move relative to one another can also lead to increased power loss in the spider, which increases the temperature.

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3696435B1Universal joint spider with a temperature sensor and universal joint with such a spider
Publication Date: 2021.11.10 OFF HIGHWAY POWERTRAIN SERVICES GERMANY GMBH
  • EP3696435B1 patent drawingFigure 1~3

AI summary

The present invention lies in the field of drive technology and proposes a space-saving method for the early detection of wear of the universal joint with four pins (6) projecting from a base (14). The pin cross (8) is provided with a temperature sensor (18) for this purpose.