V Belts Selection Guide: Types, Features, Applications

Construction

Three common designs of v belts include:

Fabric ply belts consist of several plies or layers that are made of cotton or synthetic fiber, with or without rubber impregnation. The number of plies determines the belt thickness that will help determine the minimum pulley diameter for the drive.

Fabric cord belts are constructed with multiple cords made from cotton or synthetic fibers such as rayon, nylon, plastic, or Kevlar. They are incased in rubber and covered with a fabric/runner covering. This type is generally classed as a heavy-duty v belt, used for high speeds, small pulley diameters, and shock loads. Steel cables can also be used as they have higher capacity and lower stretch than fabric cord v belts.

Synthetic v belts are made from nylon. Nylon offers flexibility, extremely high tensile strength, and operates effectively at high rim speeds. The belts are thin and they may consist of several plies of thin nylon bonded together to form a tough but flexible v belt.

Specifications

Specifications that are important to consider include: belt type, belt width, and initial elongation. If any of these factors change, the belt must be recalculated.

Power transmission belt material types include polyester, aramide, and polyamide.

Polyester is the most common material due to it price-to-value ratio. It supplies a versatile belt that can be used in a wide range of operating temperatures with low energy consumption, high flexibility, and reliable performance.

Aramide is a strong choice for long belts due to the short take-up and high accuracy for number of revolutions (RPM) and belt speed. It is highly flexible, simple to join, has a high E-modulus, and low energy consumption.

Polyamide is reliable and has a long service life. It can work in a variety of conditions and functions well in extreme environments with intermittent overload and high temperatures. Polyamide is shock resistant and grooves enable high grip.

Belt width is simply the width of the belt. The tensile force for 1% elongation per unit of width after running-in (N/mm), k1% a.r.i., is the decisive value for calculating the required belt width and the resulting shaft load after belt relaxation

Applications

The power transmission v belt can be used in many forms of power transmission. It is known as a two pulley drive, consisting of a driving pulley, a driven pulley, and the belt. Below are examples of pulley design variations.

This article comes from globalspec edit released