Research on the Relations Between Strip Tension and Loads of Electric Drives of a Tension Leveller on a Continuous Pickling Line

Abstract
Download PDF DOI: 10.18503/1995-2732-2020-18-3-69-78 Abstract Problem statement (Relevance): The electric drive of the tension leveller (TL) of the continuous pickling line is multi-motor using planetary gears. Such a drive design leads to two types of relations between them: through a mechanical part - a complex chain of cylindrical and planetary gears, and also through a technological process - treated strips in a state of elastic-plastic deformation. Objectives: To ensure a trouble-free operation of TL by setting correct electric drive torques and speeds for a various product range of strips. Methods Applied: Experimental data on the distribution of strip tension in TL and adjacent tension stations were collected and processed by oscillography of drive torques and speeds; mathematical modeling of speed and power parameters on drive shafts of TL. Originality: It lies in the development of a mathematical description that establishes the relations between torques of the electric drives of TL and the strip tension created by rollers of the tension stations. Findings: It was found that due to the planetary gear between the second and third rollers of TL, energy of rear tension created by the elongation drive was transmitted forward by a mechanical transmission and converted into forward tension through the third roller. As a result, the main drive only adds front tension, but its main part is created by the elongation drive and rear tension mechanically transmitted forward. Based on the analysis of changes in the rear and front strip tension as a function of load of the main drive motors and the elongation drive, formulas are obtained for calculating the strip tension in the TL section. It was found that the load of the elongation drive directly determines the strip tension in front of TL. Practical relevance: The obtained dependences to calculate the load conditions make it possible to correct set values of speeds and torques of the TL electric drives to prevent elongation drive overloads and excessive loads on the planetary gear, thereby increasing its service life and stability. Keywords Continuous pickling line, tension leveller, strip tension, electric drive, mathematical model, elongation drive, tension station. For citation Kornilov G.P., Filatov A.M., Filatova O.A., Khramshin T.R., Khramshin R.R. Research on the Relations Between Strip Tension and Loads of Electric Drives of a Tension Leveller on a Continuous Pickling Line. Vestnik Magnitogorskogo Gosudarstvennogo Tekhnicheskogo Universiteta im. G.I. Nosova [Vestnik of Nosov Magnitogorsk State Technical University]. 2020, vol. 18, no. 3, pp. 69–78. https://doi.org/10.18503/1995-2732-2020-18-3-69-78