The main technical results achieved are:
• Efficient running in by the low temperature use of graphitized glycerol fluids (suspensions of graphite in recovered glycerol)
• Longer lubricants service life (+20%) due to increased thermal stabilit
• Higher corrosion protection during stocking, due to better adhe- sion to the metal
• Final protective oil impregnation step not needed
• Pre-heating of lubricants allows to have the proper viscosity val- ues during fluxing
• Energy recovery from the transmissions under fluxing
• Lower lubricant losses due to lower volatility of bio lubricants and excellent high tem- perature stability of graphite in inert gas
1) All the sub-systems, i.e. pumps, filters, heating and cooling systems, and lubricant distribution manifold were assembled on the transmission flushing pilot system.
2) Practical flushing tests on transmission units with various power ratings (80-120 HP) using the new lubricants (graphitized glycerol and bio-lubricant) have provided satisfactory results, since the flushed transmissions were cleansed in an excellent way.
3) Chemical analyses of the properties of the new lubricants during the different flushing stages have provided indicators allowing us to confirm that these new lubricants last longer than mineral oils, especially at high operating temperatures.
4) Tractors were fitted with transmissions flushed in the new pilot system for the purpose of performing practical tests to compare values obtained from the conventional mineral oil flushing process with those of the new system, using graphitized glycerol and bio-lubricant.
1) The two biolubricant tanks, equipped with silver ion treated aluminium alloy inserts hanging inside them in a precise layout, have been finished and installed. The purpose is to keep the oil in contact with these inserts as long as possible when the fluid is mixed and recirculated.
The fluid dynamics of the installation are maintained in a valid condition thanks to the circuits designed for the tanks.
Laboratory tests show that the properties of the biolubricant remain stable (viscosity, without bacterial loads or fungi).
2) The filtering and heating subsystems of the two lubricants (graphitized glycerol and biolubricant) have been fully completed and provide excellent results as to filtering in general and separation of the metal particles.
The commitment towards determining the filter able to retain these particles, comprising various types of metal, is worthy of mention.
Filters with the right sort of magnetic separators featuring high magnetic fields, were only adopted after numerous tests.
3) The preheating system for the biolubricant oil and graphitized glycerol has been designed.
The two tanks for heating the fluids are currently being installed, with a solar panel that powers a heat converter.
This step will be completed in May and will be followed by practical tests to make sure that enough solar energy is supplied (therefore without installing a further electric heating element in the tanks).
1) The work performed to find the right mixture of biolubricants was successfully concluded at the end of December 2012. This result was achieved in several steps:
– Definition of the best size for the particles of graphite powder;
– Definition of the conditions required for maintaining a state of fluidization as the transmissions are flushed;
– Assessment of the residues that remain on the transmission components after the first tests;
– Definition of three biolubricant compounds fit for the three different transmission power ranges in question.
Laboratory tests were performed to assess the stability of the biolubricant when subjected to high temperatures and dynamic centrifugation at different speeds, and its effect on the rubber components currently used in the transmissions was analyzed. The results showed that these components would have to be replaced with other, more resistant ones, in teflon-coated rubber.
To do all this, we had to build a reduced-size test line, which allowed us to overcome the technical problems that had led to slight delays in completing the action without, however, affecting the outcome of the project.
Collaboration with the University of Modena and Reggio Emilia and with “CURA” of Padua allowed us to attain all our objectives and define the experimental oil, which was called “FLUXOIL-BIO”.
2) The tasks for designing and building a tank for the biolubricant began in a regular way, but work slowed down to a slight extent during the summer owing to the earthquakes that occurred at that time. Thus the tasks required in order to design the tank were defined and planned at the beginning of October. This work is currently in progress and excellent results have been obtained: definition of the fluid dynamics of the tank, design engineering of the tank especially with regard to the diameter of the pipes, the types of pump and the heating system. The action is proceeding rapidly and in a regular way and its successful conclusion is forecast within next March.
3) Future actions: construction of the auxiliary separation and heating systems is imminent. The tank will be completed and tests will begin within the next few months.
Research into bio-lubricants is in progress, as is the construction of a miniature system that simulates how gears are treated with glycerol and graphite:
1) The purpose of the laboratory work is to assess the percentages of vegetable feedstock the lubricant oil must comprise. We are continuing the chemical and physical reaction tests on the rubber and Teflon seals used in the tractors by keeping them in contact with bio-lubricant based oil. The tests are performed at high and low temperatures, after which the changes in the elasticity of the products are assessed along with the structural deformations.
2) The type of system in which the transmission assemblies are to be subjected to tests with the new glycerol – graphite mixture has been defined in the project. Structural components such as the fluid reservoirs, application of electric motors, the transmission gear turning control and pipe network for transferring and blending products in the reservoirs have all been built.