Proceedings of SerbiaTrib '13

Table 3: Data of the test gear pair [6]ParametersDataCentre distance30 mmModule1.252 mmTransmission ratio 40Pressure angle 20Wheel materialFe1.5Cr0.2MoWorm material16MnCr5Speed 1500 – 10000 min -1Torque12-36 NmSynthetic oil Klüber GH6 1500Mineral oil Optigear BM 1500Grease: Klübersynth G34-130Figure 2. Viscosity-temperature behaviour for usedlubricants4.2 Mineral oilCastrol Optigear BM 1500 was used in theexperiment as the mineral oil with the sameviscosity as Klübersynth GH6 1500. Highperformance gear oil Castrol Optigear BM containsthe mineral oil-based additive packageMICROFLUX Trans (MFT). This combination ofload-active agents and additives adjusts to varyingloads and actively prevents wear. Difficulties in therun-in phase can be reduced and problems withwear, material fatigue on surfaces (pitting) andmicropitting can be avoided.Table 4: Data of lubricants4. LUBRICATIONFigure 1. Test benchFor the sake of comparison, lubrications testswere done under same parameters and withdifferent lubricants: synthetic oil, mineral oil andgrease.4.1. Synthethic oilSynthetic oil made by Klüber company(Klübersynth GH6 15000) was used in tests. Thisoil can withstand high scuffing load capacity andhas good wear protection. Furthermore, the oilreduces friction and has a flat viscosity-temperaturebehaviour. This oil is based on polyglycol and it ismainly used in transmissions with the materialcombination of steel/steel.The additive GH6 reduces the frictioncoefficient and wear, especially for worm gearswith the material combination steel/bronze. Verylow wear intensities for worm gears can beachieved with this oil. Klübersynth GH6 oil with aviscosity of 40 = 1500 mm 2 /s was used for testing.Table 4 shows the characteristics of used lubricants.Parameter GH6 1500 BM 1500 G34-130Temperature Range [°C] -20 to 160 -10 to 90 -30 to 130Density (20 o C) [g/cm 3 ] 1.08 0.93 0.87Kin. base oil viscos. DIN51562 ν 40 [mm 2 /s]1500 1507 150Kin. base oil viscos. DIN51562 ν 100 [mm 2 /s]231 75.6 16Consistency class DIN 51818, NLGI (grease) 04.3 GreaseKlübersynth G34-130 grease for small gears wasused in the grease tests. Klübersynth G34-130 isgrease based on synthetic hydrocarbon oil. Otheringredients are mineral oil and lithium soap asspecial polyureas, which serve as consistencyfactors. The grease has good anti-wear propertiesand can be used with the combination of steel andplastic.Figure 2 presents the dependence of kinematicviscosity on temperature for the selected lubricants.The oils Klüber GH6 1500 and Castrol OptigearBM 1500 have the same viscosity at thetemperature of 40 o C. At higher temperatures, theviscosity of mineral oil Castrol Optigear BM 1500is smaller than the synthetic oil Klüber GH6 1500.Lubricants dependence on the viscosity is veryimportant at low temperatures. They should still be322 13 th International Conference on Tribology – Serbiatrib’13