SU978019A1 - Method of determination of friction coefficient in mine winder brake - Google Patents

Description

(B) METHOD FOR DETERMINING THE COEFFICIENT OF FRICTION IN THE BRAKE OF THE LIFTING MINE MACHINE

one

The invention relates to mechanical engineering, in particular, to methods for estimating the coefficient of friction in brakes of shaft-fed machines.

There is a method for determining the coefficient of friction in the brake of a mine machine, which is as follows. The lifting vessels into which the ore is loaded are set at predetermined heights in the shaft of the shaft, i.e. under actual operating conditions. The vessels are accelerated to a given speed along the shaft, the machine is braked using a brake, the kinematic and dynamic parameters of the machine and the process of braking are measured, from which the coefficient of friction is calculated. The measured mass, the force on the ropes, measured using strain gauge dynamometers and measuring acceleration 11

A significant disadvantage of the known method is that it has a comparatively low accuracy of determining the coefficient of friction in the brake of a mine machine. This is due to the fact that when using the brakes, it is necessary to measure the forces on the ropes during braking. The exact value of these efforts is difficult to determine due to the influence on the process of inhibiting vibrations and other factors. A significant mistake is made and T9 that

10, this method ignores the mass of the rope at a height equal to the difference in height between the under-lifting vessels when the vessels in the mine change.

The purpose of the invention is to improve the accuracy of determining the coefficient of friction in the brake of a mine machine.

Claims (1)

This goal is achieved. According to the method for determining the friction coefficient in the brake of an elevating mine machine, the principle is that the lifting vessels of the mine machine are set at predetermined heights in the shaft shaft, turn on the machine and accelerate the vessels to a certain speed, produce braking of vessels with the help of a brake, and determining the coefficient of friction, taking into account the reduced mass of moving parts of the machine and one of the variable kinematic parameters, when estimating the reduced mass, take into account the weight of the rope on the length, the corresponding difference in height between the lifting vessels, and the braking path is taken as the variable controlled parameter. The method is carried out as follows. Lifting vessels are installed in the shaft at a predetermined distance from each other along the height of the shaft, the movement of the shaft machine is driven and, when the desired speed is reached or braked, the brake is applied, the time and position of the vessels are fixed at the moment of the beginning and end of braking The braking distance is determined. The weight of the rope between the lifting vessels is determined by the difference between the heights of the vessels and the weight of the running meter of the rope. The coefficient of friction is calculated by the formula f. 2SSi H where m is the reduced mass of the moving parts of the machine; .. V is the speed) S is the stopping distance, P is the difference of static tensions in the branches of the rope (it is assumed that two vessels are suspended on one canal); Q is the weight of the brake drive; - gear ratio brake; 1 - brake efficiency factor. From the calculation formula it can be seen that to determine the coefficient of friction 9 4 It is necessary to measure the braking speed and the reduced mass. The steel parameters of the machine and the brake to be investigated are usually known. Using the proposed method allows to increase the accuracy of the coefficient of friction estimation, since the weight of the rope is taken into account, and the main variable controllable parameter is the braking distance, the value of which can be determined with higher accuracy than the amount of effort in the ropes during the operation of the mine machine The invention The method of determining the coefficient of friction in the brake of the lifting shaft machine, which consists in the fact that the lifting vessels Acht machines are set at predetermined heights in the shaft, turn on the machine and accelerate the vessels to a certain speed, brake the vessels with a brake and determine the friction coefficient, taking into account the reduced mass of the moving parts of the machine and one of the variable kinematic parameters that differs that, in order to improve the accuracy, when estimating the reduced mass, the weight of the kaiat on the length corresponding to the height difference between the lifting vessels is taken into account, and the braking path is taken as the variable parameter to be monitored augmentation. Sources of information taken during the examination 1, Safe operation of electromechanical equipment in coal mines. M., Nedra, N., t, 23 1975, p. 7 (prototype).