THE INFLUENCE OF SELECTED FACTORS ON AXIAL FORCE AND FRICTION TORQUE IN A THRUST BEARING LUBRICATED WITH MAGNETORHEOLOGICAL FLUID
Journal Title: Tribologia - Year 2016, Vol 269, Issue 5
Abstract
Magnetic fluids belong to the class of materials in which rheological properties can be controlled by magnetic fields. Magnetic fluids are suspensions of ferromagnetic particles in a carrier fluid, and the magnetic field can change their internal structure. This phenomenon is fully reversible, almost instantaneously. The test results of a hydrostatic bearing lubricated by magnetic fluid are shown in the publication [L. 7]. It has been shown that the use of MR fluids as a lubricant allows high stiffness of the bearing to be obtained regardless of the height of the bearing gap. The publication [L. 8] presents the results of a thrust bearing lubricated by magnetic fluid with no external feed pump. The load capacity of the bearing was achieved by a self-sealing effect. This effect is associated with the ability to hold a magnetic fluid in a predetermined position through the magnetic field. This is caused by the appropriate geometry of the bearing surface. This effect retains the flow of the magnetic fluid out of the bearing gap as a result of the occurrence of a magnetic barrier, which counteracts the movement of the magnetic fluid. This barrier is a result of a local increase or decrease in magnetic induction similar to magnetic fluid seals. Another phenomenon highlighted in [L. 9, 10, 11] is the generation in the magnetic fluid of additional pressure due to the interaction of the magnetic field gradient. The result is an additional buoyancy force. When selecting a magnetic fluid for application in the thrust bearing, a number of factors should be taken into account. In addition to the parameters describing the typical lubricant, such as lubricity, corrosion properties, and work at high temperatures, the magnetic fluid used in the friction zone should allow a wide range of the rheological properties to be obtained due to changes in the magnetic field intensity. It is also important that the magnetic fluids have the ability to generate the appropriate value of the normal force due to the magnetic field.<br/><br/>
Authors and Affiliations
Wojciech HORAK, Józef SALWIŃSKI, Marcin SZCZĘCH
TRIBOLOGICAL PROPERTIES OF GRAPHENE OXIDE-METAL-CARBON COMPOSITES
Cu-C composites are materials used for the production of brushes, contacts, and pressing shoes for electric machines due to their mechanical and wear properties. These characteristics include good thermal and electrical...
Modele tribologiczne współpracy skojarzenia tłok-pierścienie tłokowe-tuleja cylindrowa silnika spalinowego
Przedstawiono modele tribologiczne współpracy skojarzenia tłok–tuleja– –pierścienie tłokowe silnika spalinowego w aspekcie poprawy współpracy elementów silnika oraz zmniejszenia ich zużycia. Wykorzystując ablacyjną mikro...
STATIC AND DYNAMIC FRICTION CHARACTERISTICS OF POLYMER COMPOSITES INTENDED FOR REGENERATION OF TOOL GUIDES
The paper presents the results of static and dynamic friction force measurements for chemo-setting metal-polymer composites, made from epoxy resin. The composites are intended for the regeneration of the sliding guides i...
CHARAKTERYSTYKA NOWEGO STANOWISKA ORAZ METODYKA PULSACYJNEGO BADANIA WYTRZYMAŁOŚCI ZMĘCZENIOWEJ ZĘBÓW KÓŁ ZĘBATYCH NA ZŁAMANIE
Złamanie zęba u podstawy jest najbardziej niebezpieczną formą zużycia kół zębatych wykluczającą je z dalszej eksploatacji. W celu przeciwdziałania wystąpieniu tego rodzaju uszkodzenia bardzo istotne jest właściwe zaproje...
TRIBOLOGICAL PROPERTIES OF CRC+CRN TYPE HYBRID LAYERS PRODUCED IN COMBINED VACUUM CHROMIZING PROCESS AND PVD TREATMENT
Tribological properties of the CrC+CrN type hybrid layers, produced on X210Cr12 steel in vacuum chromizing process combined with arc evaporation PVD treatment, have been investigated. A comparison of the CrC+CrN type hyb...