Features to increase efficiency elevator winches of a traditional construction

Boyko А. A., Semeniuk V. F., Sokolov Y. A., Zubak V. V.
Hoisting and transport equipment, 2020, №1(62)
The article discusses the issues of increasing the efficiency of elevator winches of a traditional construction, which include a worm gear, a two-speed asynchronous motor. The control is carried out by an unregulated relay contactor control system. It is noted that elevators with similar winches minimally satisfy the conditions of typical optimal movement diagrams. Similar winches are widely used in residential buildings in Ukraine, despite their inefficiency and unsatisfactory dynamic indicators. A number of researchers propose a way to increase their efficiency - replacing control systems with closed, adjustable ones without changing the construction of the elevator winches. It is assumed that this can lead to the occurrence of oscillatory processes the inability to configure control systems and the disruption of the normal functioning of elevator mechanisms. To confirm or refute this, the article analyzes the dynamic properties of a typical elevator with a winch of a traditional construction. In the analysis, the block diagram of the electromechanical elevator system is used, where the control moment is the winch engine moment, and the disturbing moment is the mass resistance moments of the elevator lifting mechanism. Adjustable variables are speeds of mass, the scheme include the force of internal viscous friction and the moment of elasticity. The analysis shows that the influence of the magnitude of the logarithmic attenuation decrement, when it changes, leads to a slight change in the magnitude of the resonant peak. The presence of an undamped resonance at the frequency of free oscillations indicates a significant effect of electromechanical communication in the system. It is shown that an elevator electromechanical system with a traditional gear winch is predisposed to the occurrence of oscillatory phenomena, which is based on an analysis of the values of the electromechanical coupling coefficient and dynamic coefficient. When applying an adjustable control system, taking into account the specified criteria for optimal regulation, there is a need to increase the damping properties of the elements of the lifting mechanism, which is only possible by reducing the rigidity of the mechanical characteristics of the winch motor. The need to replace a two-speed asynchronous motor contradicts the idea of increasing the efficiency of traditional elevator winches only by introducing adjustable control systems without changing the structural part of the winch.
winch, lifting mechanism, elevator, control system, analysis of dynamic properties.
Download article