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Innovative sealing and sensing technologies for extended life of lubricated elements.

Periodic Reporting for period 2 - ISSELUB (Innovative sealing and sensing technologies for extended life of lubricated elements.)

Reporting period: 2017-07-01 to 2018-12-31

The overall goal of the project is focused on incrementing the efficiency of Electro-Mechanical and Electro-Hydrostatic systems in terms of extending the life and improving the reliability and enhancing the performance of the maintenance activities of wing actuation systems. It means to investigate and improve innovative sealing and sensor solutions, combined with health monitoring technologies, able to monitor the actuation systems and to detect and predict failures at an early stage in order to avoid a catastrophic fault. With this objective in mind, the activities within the project have been oriented to the following goals:

Innovative and alternative sealing solutions that are able to reduce the friction, wear and leakage at high level of deformation monitored in accelerated seal tests. To increase lifetime to thermal cycles of the seals.

Innovative and alternative lubricant solutions that are able to reduce friction and wear and to increase extreme pressure properties, increasing the temperature limit and time to a fixed temperature in relation to reference lubricants. The best lubricating alternatives will be tested in order to quantify their capacity to extend their lifetime.

New oil sensing systems to monitor the status of the lubricant (chemical and physical parameters along with inspection of solid particles) with a twofold aim: identify faulty conditions and extend the life of the lubricant.

The lifetime control (friction, wear) of the selected gears materials and lubricants was performed by means of accelerated simulated tests monitoring in parallel both vibrations and wear, in order to create the right knowledge for conditions monitoring.

Develop, implement and integrate Health Monitoring algorithms to predict failures before affecting the actuator output in a critical way.

Conclusions

There have been 3 main conclusions, that impact the three pillars of the project.

Extension of the life of seals: Different seal/lubricant pairs were be selected and tested in order to find sealing solutions providing a longer service life. The validation of the performance of the different new proposed sealing systems and lubricants was performed through simulated tests at lab scale and the most promising tribo-systems were validated using the advanced test rig TESSA, were aeronautical working conditions were simulated in an electro hydraulic actuator. The information gathered will impact the design of future electro hydraulic actuators, improving the life of the seal-hydraulic par.

On-line monitorization of the hydraulic fluid: In ISSELUB it was decided to adapt and modify the oil health and oil-wear sensors (oil quality and wear debris sensor) for the working conditions of electro-hydraulic actuators. A new line of Oilhealhtand Oilwear sensors is being developed, bringing to the market the product of the research done in the project. On the other hand the monitoring of some of the EHA parts has given insight of the degradation process. This valuable information will be used in future designs.

Health monitoring of mechanical components: ISSELUB advanced the state-of-the-art in health monitoring by developing, implementing and validating a health monitoring solution for actuators. It was targeted to develop technologies to efficiently exploit the information of sensors for failure detection and diagnostics. The tests and the health algorithm developed have an impact in future designs, as they will be safer and more efficient.
A state of the art was carried out.
The main basis in lubricant degradation, identifying parameters of interests, degradation processes and main monitoring technologies were studied.

The sealing test bench TESSA was adapted to the testing of EHAs. Compatibility and characterization tests were performed among seals and fluids.
OilWear-PICO sensor was redesigned, and some of the components were changed. This sensors were installed in LIEBHERR to monitor hydraulic fluids and mechanical components.
The requirements for health monitoring system in EHA and EMA were studied.

The testing methodology for the hydraulic fluids characterization was studied.
EHA monitoring by hydraulic oil monitoring and particle counting was performed. Samples of the fluids tested were be collected and sent to be analysed in IK4-Tekniker’s laboratory, to benchmark results with the ones measured by the sensor.
A design of experiments for the mechanical component requirements in EHAs and EMAs was done.
The tests of the gears were performed in the FZG test rig. A signal acquisition system, and the needed sensors were added. A fatigue test was performed.
Concerning the screwball tests, the objective of the test is to ensure the capabilities of the screwball in an endurance test and to develop a health and usage monitoring algorithm. For such a fast degradation test was performed.
A design of experiments was done with the objective in mind. A test bench was designed and manufactured for this purpose.

The information recorded in WP 4 was analyzed and a solution for the enlargement of the life of seals, gears and pumps in EHA's and EMA's.

The solution obtained in WP5 was tested and an improvement of it was designed and tested.

Overview of results of exploitation and dissemination

A version of Oilwear and Oilhealht sensors adapted for working conditions and fluids of aeronautics was designed and built.

A test bench for EMA's was designed and built, and services of testing were offered.

An algorithm for the monitorization of EMA's was developed.

The TESSA test rig was adapted to work in conditions simulating aeronautical needs, and this is now part of the catalogue of services of Tekniker.

As part of the dissemination effort, several articles were published especially in spanish speaking media, reinforcing the image of Tekniker for aeronautical projects.

Scientific articles were published and presented in international specialized congresses. Contacts were made among the scientific and industrial community, potentially opening for future research in the aeronautical sector.
The aim of ISSELUB is to extend the service life of EMAs and EHAs.

The extension of life was done in three main areas:

Extension of the life of seals: Different seal/lubricant pairs were be selected and tested in order to find sealing solutions providing a longer service life. The validation of the performance of the different new proposed sealing systems and lubricants was performed through simulated tests at lab scale and the most promising tribo-systems were validated using the advanced test rig TESSA, were aeronautical working conditions were simulated in an electro hydraulic actuator.

On-line monitorization of the hydraulic fluid: In ISSELUB it was decided to adapt and modify the oil health and oil-wear sensors (oil quality and wear debris sensor) for the working conditions of electro-hydraulic actuators.

Health monitoring of mechanical components: ISSELUB advanced the state-of-the-art in health monitoring by developing, implementing and validating a health monitoring solution for actuators. It was targeted to develop technologies to efficiently exploit the information of sensors for failure detection and diagnostics.