Analytical mathematical model of the pumping unit of machine water lifting systems K. G. Abidov, Sh.O. Zaripova, N.B. Khamudkhanova, S.A. Dusmukhamedova, M.O. Gafurova and H. Baratov E3S Web Conf., 289 (2021) 07004 Published online: 13 July 2021 DOI: 10.1051/e3sconf/202128907004