Evaluation of the Thermal Stability and Surface Characteristics of Thermoplastic Polyurethane V-Belt.

Piotr Krawiec,Leszek Różański,Dorota Czarnecka-Komorowska,Łukasz Warguła

doi:10.3390/ma13071502

Abstract

This article proposes thermography as a non-contact diagnostic tool for assessing drive reliability. The application of this technique during the operation of the belt transmission with a heat-welded thermoplastic polyurethane V-belt was presented. The V-belt temperature changes depending on the braking torque load at different values of the rotational speed of the active pulley, which were adopted as diagnostic characteristics. In this paper, the surface morphology of the polyurethane (PU) belts was assessed on the basis of microscopic and hardness tests. A surface roughness tester was used to evaluate the surface wear. The surface morphology and topography of the materials was determined by scanning electron microscopy (SEM) and optical microscopy. It was found that the most favorable operating conditions occurred when the temperature values of active and passive connectors were similar and the temperature difference between them was small. The mechanical and structure results indicate that the wear of the PU belt was slight, which provided stability and operational reliability for V-belt transmission. The microscopic images lacked clear traces of cracks and scratches on the surface, which was confirmed by the SEM observations.

Highlights

The application of belts in different types of cars, machines and device drives is known and well described in the literature in the field of mechanical engineering [1,2,3,4]
The direction of the rotation of the drive pulley was counterclockwise. During this time, using the camera, a temperature difference of 0.1 ◦ C was recorded between the temperature in the active connector of 29.1 ◦ C, and the temperature in the inactive connector of 29.2 ◦ C
The results indicate that an increasing of the load caused the temperature change had a linear behavior, and above this value, it quickly increased to a value of an increase in the temperature difference to approximately 8 ◦ C for a braking torque load of 13 Nm

Summary

Introduction

The application of belts in different types of cars, machines and device drives is known and well described in the literature in the field of mechanical engineering [1,2,3,4]. The condition for manufacturing belts made of this type of materials is their easy processing by extrusion at a temperature of about 200 ◦ C, followed by cooling to obtain the desired shape of the belt. The advantage of this solution is the ability to process belts multiple times. Heat-welded V-belts are made of thermoplastic materials, such as polyesters and polyurethanes, with a hardness from 85 to 100 Shore A [5,6,7] They are used both in classic drive technology and in Materials 2020, 13, 1502; doi:10.3390/ma13071502 www.mdpi.com/journal/materials

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Results

Conclusion