Laboratory Device for Checking the Functionality of the Elevator Rope Sensors

Leopold Hrabovsky,David Borovsky

doi:10.2478/mspe-2021-0008

Abstract

Abstract The paper describes the structural design of a laboratory device that allows for presenting operation, simulating work procedures and checking functionality of the elevator “rope sensors” when equalizing different tensile forces in partial ropes of a rope system of traction elevators. The laboratory device is modified for checking operations of commonly used rope sensors. In an overwhelming number of cases, elevator technicians use them for setting up the unequally distributed tensile forces in elevator ropes. The device is equipped with three, mutually attached pulleys, over which the rope is installed. The unknown tensile force in the rope is determined by an “indirect method”, i.e. from the resultant of the forces of the rope bent over the pulleys, which have an effect on the force sensor. The tensile force along the rope axis can be determined numerically, but also experimentally, from the inclination angle of the rope installed on the pulleys, diameter of the pulleys, diameter of the rope and the force detected by the force sensor of the stretched rope. The paper presents experimentally obtained tensile force values at the rope sensor, deduced from stretching the rope. The paper also describes the procedure for determining the measured load in the rope by rope sensors of the SWR, SWK and RMT-1 types based on the variable axial force in the rope.

Highlights

Elevators used in high rise and highspeed applications are sensitive to uneven rope tensions [24], suffering from unnecessary wear, excessive vibrations, and unwelcome noise as a result [9]
Referred to as traction elevators, have a cabin suspended from a system of ropes
As the load-bearing capacity of the elevator increases, the required number of load-bearing ropes increases, especially in the case where small diameter ropes are used in traction elevators

Summary

Introduction

Elevators used in high rise and highspeed applications are sensitive to uneven rope tensions [24], suffering from unnecessary wear, excessive vibrations, and unwelcome noise as a result [9]. The balance must be checked by an installer who manually evaluates the ropes. These checks are not necessarily based on skill or training, making the process guesswork rather than a science. “equalize”) tensile forces in individual ropes of traction elevator rope systems [29, 31, 32, 33] Both systems can be characterized by the same advantage, which consists of the possibility to detect tensile forces by a nondestructive method. It means that the tensile force along the longitudinal axis of the rope can be determined without the need to break the rope length

Methods

Results

Discussion

Conclusion