Research of the Lifetime and Lubricant Properties of Greases for Rolling Bearings Operating in Space Conditions
Tóm tắt
In this study, the lubricating properties and relative service life of plastic lubricants for work in space were studied. Grease relative lifetime and lubricity test methods and testing equipment were developed. Commercially available VNII NP-274, AMETIST, NIKA, IZUMRUD, and EFELE SG-394 greases are tested. The test procedure is based on testing the rolling bearing with a limited amount of lubricant. Lubricity is evaluated by the value of the friction coefficient. The grease relative lifetime is assessed by the bearing operation time before the friction coefficient sharply increases divided by the lubricant mass. Tests are carried out in both normal climatic conditions and conditions close to those in space (vacuum of <10–4 bar and at a high temperature of 100°С). The bearing load is 2800 N and rotation frequency is 50 rpm. The test results show that VNII NP-274, NIKA, and EFELE SG-394 greases have a low friction coefficient and a high relative lifetime under normal climatic conditions. When tested in conditions close to space (in vacuum and at high temperatures), NIKA and EFELE SG-394 greases have a low friction coefficient and the highest relative lifetime. The relative lifetime of the studied greases decreases 6–20-fold (for VNII NP-274, up to 200-fold) during the transition from normal climatic to space conditions. The lifetime decrease is associated with the lubricant accelerated destruction in vacuum and during heating.
Tài liệu tham khảo
Bronovets, M.A., Tribology problems in space, Proc. 5th World Tribology Congr. (WTC 2013), Turin, 2013, vol. 4, pp. 2951–2954.
Bronovets, M.A., Analysis of in-orbit friction and wear test schemes, Trudy VI Mezhdunarodnoi nauchnoi konferentsii “Fundamental’nye issledovaniya i innovatsionnye tekhnologii v mahsinostroenii” (Proc. VI Int. Sci. Conf. “Fundamental Studies and Innovative Technologies in Machine Engineering”), Moscow, 2019, pp. 78–80.
Myshkin, N.K., Grigor’ev, A.Ya., Basinyuk, V.L., Mardosevich, E.I., Koval’chuk, G.F., Papina, S.S., Kovaleva, I.N., and Kudritskii, V.G., Space tribology: the states and prospects, Mekh. Mash., Mekh. Mater., 2012, nos. 3–4 (20–21), pp. 126–130.
Prozhega, M.V., Albagachiev, A.Yu., Smirnov, N.I., and Smirnov, N.N., Lubricating Materials for Mechanisms Operating in Space, J. Frict. Wear, 2018, vol. 39, no. 4, pp. 335–340.
TRIBOKOSMOS. https://tsniimash.ru/science/scientific-experiments-onboard-the-is-rs/cnts/experiments/tribokosmos/. Cited July 26, 2021.
Luo, J. and Zhou, X., Superlubricitive engineering—future industry nearly getting rid of wear and frictional energy consumption, Friction, 2020, vol. 8, pp. 643–665. https://doi.org/10.1007/s40544-020-0393-0
Zhuang, W., Fan, X., Li, W., Li, H., Zhang, L., Peng, J., Cai, Z., Mo, J., Zhang, G., and Zhu, M., Comparing space adaptability of diamond-like carbon and molybdenum disulfide films toward synergistic lubrication, Carbon, 2018, vol. 134, pp. 163–173. https://doi.org/10.1016/j.carbon.2018.03.059
De Laurentis, N., Kadiric, A., Lugt, P., and Cann, P., The influence of bearing grease composition on friction in rolling/sliding concentrated contacts, Tribol. Int., 2016, vol. 94, pp. 624–632. https://doi.org/10.1016/j.triboint.2015.10.012
Ghezzi, I., Tonazzi, D., Rovere, M., Le Coeur, C., Berthier, Y., and Massi, F., Frictional behaviour of a greased contact under low sliding velocity condition, Tribol. Int., 2021, vol. 155, art. ID 106788, https://doi.org/10.1016/j.triboint.2020.106788
Vengudusamy, B., Enekes, C., and Spallek, R., On the film forming and friction behaviour of greases in rolling/sliding contacts, Tribol. Int., 2019, vol. 129, pp. 323–337. https://doi.org/10.1016/j.triboint.2018.08.026
Gonçalves, D., Graça, B., Campos, A.V., and Seabra, J., On the friction behavior of polymer greases, Tribol. Int., 2016, vol. 93, pp. 399–410. https://doi.org/10.1016/j.triboint.2015.09.027
Albagachiev, A.Y., Buyanovskii, I.A., Samusenko, V.D., et al., Temperature resistance of Russian vacuum lubricants, Russ. Eng. Res., 2019, vol. 39, no. 12, pp. 1011–1013. https://doi.org/10.3103/S1068798X19120037
Pepper, S.V. and Kingsbury, E.P., Spiral orbit tribometry—Part I: Description of the tribometer, Tribol. Trans., 2003, vol. 46, no. 1, pp. 57–64. https://doi.org/10.1080/10402000308982600
Novikov, A.V., Prozhega, M.V., Smirnov, N.I., Smir-nov, N.N., and Nazarov, A.N., Study of the lifetime and lubricity of greases for rolling bearings, IOP Conf. Ser.: Mater. Sci. Eng., 2020, vol. 747, art. ID 012039. https://doi.org/10.1088/1757-899X/747/1/012039
Prozhega, M.V., Reschikov, E.O., Shirshov, A.D., and Yakovenko, N.G., Frictional properties of 3D printing polymers in vacuum, J. Frict. Wear, 2020, vol. 41, no. 6, pp. 565–570. https://doi.org/10.3103/S1068366620060173
Gonçalves, D., Cousseau, T., Gama, A., Campos, A.V., and Seabra, J.H.O., Friction torque in thrust roller bearings lubricated with greases, their base oils and bleed-oils, Tribol. Int., 2017, vol. 107, pp. 306–319. https://doi.org/10.1016/j.triboint.2016.11.041
Gonçalves, D., Pinho, S., Graça, B., Campos, A.V., and Seabra, J.H.O., Friction torque in thrust ball bearings lubricated with polymer greases of different thickener content, Tribol. Int., 2016, vol. 96, pp. 87–96. https://doi.org/10.1016/j.triboint.2015.12.017
Cousseau, T., Graça, B.M., Campos, A.V., and Seabra, J.H.O., Influence of grease rheology on thrust ball bearings friction torque, Tribol. Int., 2012, vol. 46, no. 1, pp. 106–113. https://doi.org/10.1016/j.triboint.2011.06.010
Cousseau, T., Graça, B., Campos, A., and Seabra, J., Friction torque in grease lubricated thrust ball bearings, Tribol. Int., 2011, vol. 44, no. 5, pp. 523–531. https://doi.org/10.1016/j.triboint.2010.06.013