Mechanical Belt Fastening Systems: Types and Peculiarities

Mechanical Belt Fastening Systems: Types and Peculiarities

The advantages of mechanical fasteners for a conveyor belt were highly evaluated in the most complicated parts, splicing of conveyor belts by means of hot or cold vulcanization causes many difficulties. We can speak about complicated technology, quality and it will be impossible to quickly fasten the conveyor belt as the downtime will last for 24-72 hours. However, mechanical conveyor belt fasteners have their disadvantages too.

Types of Conveyor Belt Mechanical Fastening: Pluses and Minuses

A method of conveyor belt fastening primarily consisted in sewing transversal cuts in the cloth. The lengthwise cuts were sewn with patches, the edges were glued and such repairs significantly influenced the durability (technical characteristics) of the conveyor belt.

The threads and cables were gradually substituted by more advanced variants, from which the main methods to restore a conveyor are still used.

Swing fastening

 It is possible to distinguish swing-rivet fastening (solid) and swing bolt fastening, in the foundation of which is fixing of a metal conveyor belt fastener to the belt butt ends, between which a pin joint is placed. It is a rod, a special construction lock, that helps the joint to turn, when a drum passes.

  • The main disadvantage with a big width of a conveyor belt is an increased waste of a drum and of the rolls
  • This joint is not recommended to be used, when the cargoes on the belt are big, high temperatures (burning of the belt) and for the conditions, when periodic belt cleaning is require

Solid Conveyor Belt Fastener

A joining element, the assembly of which requires eliminating the restored part of the belt, while doing he following repairs, means to install solid fasteners. The task of this joining is to minimize the waste of a drum and rolls and it has two types:

  1. A clamping or clinching fastener, the analogue of which is tepler, with the screw joints, which are cut
  2. Solid belt fastening that increases reliability of hot and cold vulcanization.

For your information! Besides rivets, it is recommended to use clamps, pressed into the fabric cord of the conveyor belt and the method of “breaking” rubber cloth of the belt by means of clamps. A disadvantage of this type is that it is impossible to repair the defected part of the belt without any additional prolongation of the belt in case of a repeated damage.

Besides this fact, solid fasteners significantly increase cylinder and waste of rollers. Technically, flexible fasteners that are placed in accordance with the drum radius and that allow the belt to support high cargoes, do not have such disadvantages.

Flexible fasteners are a breakthrough that substituted hot vulcanization

Elastic locks refer to a mechanical type, but are a piece of a belt from a material with analogical characteristics. Fastening is made in two ways:

  1. The cloth being repaired connects the ends without any protrusions, forming a smooth surface. It is used for the places, where it is necessary to use scrappers for servicing a conveyor.
  2. Fastening is made overlapping and a small ledge is formed. This fastening is considered to be very high and is often used by professionals.

In any case choosing a correct method of restoring a transporter is treated very seriously, preparing materials and equipment, needed for repairs beforehand.

How to Choose Mechanical Fasteners for a Conveyor Belt

There are options for any case in a range of PWS fasteners, but it is worth considering the general principles of a correct choice.

  • Belt material is rubber cloth or rubber cable
  • Width of the belt is 8-20 mm
  • Belt resistance is more than 500 kN/m
  • Depending on the lock type, it is necessary to calculate the number of elements for repairs. The producer usually indicates the peculiarities of the goods and if you have any difficulties, Odessa Coal Company specialists will give you assistance with some recommendations. This fact specifically concerns the materials, from which the fasteners are made.

From What Materials Conveyor Belt Fasteners are Made

With the purpose to decrease the production cost, numerous enterprises use usual steel, less often alloy steel. However, the application of these materials is limited for certain companies, especially dangerous types of them. The priority is given to special steels and alloys without any limitations in their application:

  • PWS fasteners are made of alloys, which are not subject to corrosion, prolonging their service time
  • Fasteners made of anti-magnetic alloys can be used for the lines with magnetic catchers
  • Sparkless PWS-1 fasteners are allowed for repairing conveyor belts for production companies with an elevated risk of flaming, because of sparks

What Defects Fastening of Rubber Cloth by Incorrect Fasteners may Bring

In the dynamics of the conveyor belt movement, passing through a transmission drum (shank end) is especially important. The belt is working with bending here and being subject to maximal cargoes, that is why the diameter of a drum is a basic parameter for calculations here. Elastic rubber turns the drum around without any problems, but adding of the fasteners significantly increases the resistance of the repaired part. If fasteners are chosen incorrectly, both the belt and the drum will suffer from an increased waste. When a lock of a too big size is installed, the belt will over slip and the surface of the drum will have some additional impulsive loads. That is why the lower the size of the driving drum is, the lower the sizes of the locks should be.

How Conveyor Belt Fastening is Performed

The technology is well-prepared, you will not have to stop the production process for a long time or dismantle the conveyor.

  • The damaged part is marked and cut in a strict perpendicular manner across the cloth
  • The first step is marked and cut on the cloth until the necessary cord is reached ( it is required to do it to preserve a smooth surface of the belt). Depending on the width of the belt and loading of such steps, it is necessary to make up to three of them from both sides
  • After putting one end on the other we receive the same width of the repaired part as the main belt has.
  • Drill the required number of holes and a fastener is put into each of them (from above and in the lower part), tightening them with a belt fastener bolt
  • Elastic rubber makes it possible to place the washers at the same level with the belt that will include the drum waste. Some extra threads from the lower part of the belt are eliminated by the breaker, and the repairs are over.

For your information! Some minute differences in repairs depend on the peculiarities of the fasteners.

We hope that the article will help you to solve the problem of quick repairs.