Proceedings of SerbiaTrib '13

different types of motion, the robot uses a DryLin®linear guide system and iglide® plastic selflubricating plain bearings. The linear guidesfacilitate translational motion of the positioningmodule, which provides gross positioning for therobot’s needle driver. The needle driver is a vitalpart of the system, as it enables the rotation andtranslational movement of the “needle cannula”: aflexible tube inserted into the patient’s body cavityfor MRI-guided diagnosis and therapy (Figure 7).loads in dry conditions, such also in the presence ofmany lubricants (water, acids, alkali, oils, hydraulicliquids).- This kind of bearing can be used on softershafting, even anodized aluminium, which hasexcellent corrosion resistance and is usually lessexpensive and easier to machine than case hardenedmaterial or stainless steel.This paper is just a part of preview andintroduction in further researches of plasticbearings subjected to make simpler machinemaintenance and better energy efficiency. Becauseof great expansion and clear explained advantagesof plastic bearings application in several branchesof industry, not only investigations of new polymermaterials, but also deformation behaviour analysisin dry and conditions under different lubricantsused to be done.AKNOWLEDGEMENTFigure 7. Plastic bearings in magnetic resonance robotTwo plastic plain bearings are used in the frontand rear of the driver to constrain the needle guide.The bearings enable the robot’s motor to rotate theneedle using the mechanism by way of a timingbelt. This rotating needle would reduce tissuedamage while enhance targeting accuracy. Another10 plain bearings were used to create a revolutejoint, also known as a “pin joint” or “hinge joint”,to provide single-axis rotation.CONCLUSIONAn actual scientific and practical problem couldbeen solved concerning the development andapplication of high strength antifriction polymermaterials in machine building. According to manyresearches following by experience in lot of typicalapplications [8], we could summarize the mainbenefits of plastic bearings:- No maintenance- Oil free, dry-running;- Corrosion resistant;- Cost less than ball and other bearings;- Handle contamination well and often do notrequire seals or scrapers;- High damping characteristics for vibrations,ability to reliably work under static or dynamicThis work has been performed within theprojects TR-35021 and TR-35011. Those projectsare supported by the Republic of Serbia, Ministryof Education, Science and TechnologicalDevelopment, which financial help is gratefullyacknowledged.REFERENCES[1] Mat Mowry: The Thrue Cost of BearingLubrication, igus White Paper, igus inc.USA, 2012.[2] Momčilo R Janković: Exploitation Performances ofPlastic Radial Sliding Bearings made in Yugoslavia,Master Thesis, Mechanical Engineering FacultyUniversity of Belgrade, Belgrade, 1976.[3] S. P. Zakharychev and D. V. Otmakhov: UsingPolymer Adhesive Compositions in Design of SliderBearings, Polymer Science, Series D. Glues andSealing Materials, Vol. 4, No. 4, pp. 314–316.Pleiades Publishing Ltd. 2011.[4] Igus Bearings Catalogue, Igus inc.USA.[5] CSB Bi-metallic Composite Bearings, CSB France.[6] ISB Technical Catalogue, Italcuscinetti Group,Italia.[7] A. V. Anisimov, V. E. Bakhareva, and G. I.Nikolaev: Antifriction Carbon Plastics in MachineBuilding, Journal of Friction and Wear, Vol. 28, No.6, pp. 541–545, Allerton Press, Inc., 2007.[8] T.A. Osman: Effect of lubricant non Newtonianbehaviour and elastic deformation on the dynamicperformance of finite journal plastic bearings,Tribology Letters, Vol. 17, No. 1, pp. 31–40,Springer, 2004.250 13 th International Conference on Tribology – Serbiatrib’13