Research On Measurement Method Of Braking Torque For Mine Hoist Disc Brake

The brake is an important part of the hoist.The braking performance is directly related to the safety and reliability of the hoist.The brake must provide suitable braking torque to ensure deceleration and safe stopping of the hoist.Excessive braking torque will cause a large inertial impact on the equipment and may also cause a broken rope in the sports car.If the braking torque is too small,over-rolling and over-discharge accidents may occur.Accurately measuring the braking torque of the hoist and mastering the working status of the brake are crucial to the safe production of the mine.This paper summarizes the existing braking torque measurement method for mine hoist disc brakes,and proposes a braking torque measurement method based on bearing strain and fiber grating for the lack of existing measurement methods.Take TP-63 type disc brake as research object,establish the three-dimensional model of the brake bearing,import the model into ANSYS Workbench for finite element analysis,set the material characteristic parameters,select the appropriate grid type,according to the stress situation of hoist braking bearing,setting the boundary conditions and applying the load,carrying out the static structural analysis,according to the simulation results,determine the position where the bearing strain is greatest.By loading different sizes of braking torque,the functional relationship between strain and braking torque is established.The fiber Bragg gratings suitable for the measurement of small strains are selected as the sensing elements.They are installed in the position where the strain of the bearing is the largest,and the braking torque is measured by measuring the strain size.The paper analyzes the strain sensing characteristics of fiber Bragg gratings.Based on the established strain and braking torque functions,a functional relationship between the center wavelength variation of the fiber grating and the braking torque is established.The paper compares the strain transfer characteristics of the patch type fiber Bragg grating strain gage and the bare grating on the surface of the steel structure through experimental comparison,determines the structure type of the fiber grating,and installs fiber Bragg grating sensors by epoxy bonding and spot welding.By comparison and analysis,the brake torque is measured by installing the patch type fiber Bragg grating strain gauge on the brake bearing by spot welding.By means of equivalent substitution experiments,the measured values of the fiber grating sensor,the finite element simulation values and the theoretical calculation values are compared and analyzed under the force loading to verify the feasibility of the method based on bearing strain and fiber grating measurement braking torque.The results show that the proposed measurement method and the selected FBG sensor can realize the braking torque measurement.