A V-belt is a wedge-shaped belt manufactured out of a rubber compound, reinforced with a tensile cord specifically engineered to transmit power into movement. V-belts can be found in driving mechanisms, such as engines in air compressors, fans, and pumps. They are available in a variety of sizes and materials to meet the needs of particular applications.
V-Belt Product Types
There are several possible types of V-belts available:
- Light Duty - Suitable for light-duty applications normally using fractional horsepower motors.
- Classical Heavy Duty - Wide range of sizes.
- Molded Cogged - Cogs allow the use of smaller diameter pulleys and provide heat dissipation; Raw Edge Sidewalls prevent slippage.
- Wedge - Narrower, deeper profile with higher power capacity than classical v-belt; allows for smaller, more compact drives.
- Wedge Cogged - Same properties as Wedge, but cogged for greater flexibility and heat dissipation.
- Banded – Two or more v-belts joined to form a single belt allowing the belts to function as a single belt with equal load distribution and wear.
How to Identify a V-Belt?
Belts with Branding
If the branding on the v-belt is still intact, the easiest way to identify it is to simply read the part number. Unfortunately, after hours of use, the brand is often worn off and not legible. In this case, it becomes necessary to take note of the dimensions of the belt.
Belts without Branding
You then need to find the measurements for your V-belt. The following steps will allow you to do so:
Step 1: Determine Belt Cross Section
V-belt cross sections are categorized based on their top width and depth measurements. Each width/depth combination is labelled using a letter of the alphabet. For example, v-belts with 21/32 in. width and 7/16 in. depth are labelled a "B" belt. Specially designed Browning V-Belt Rules are also available with a gauge to help you select the correct belt type.
Step 2: Identify Belt Construction
V-belts are available in either wrapped or raw edge styles. A conventional wrapped v-belt will have an envelope of rubberized fabric covering the belt. A raw edge cogged v-belt will have exposed rubber sidewalls and moulded cogs on the bottom that resemble teeth. The following characteristics may also be present, depending on the construction type:
- Rubberized fabric cover – Cover envelopes the entire belt and protects the belt core.
- Top fabric – Provides heat and oil resistance.
- Load carrying section – Cords (also known as tensile members) give the ability to transmit power and ensure uniform load distribution.
- Compression section – Elastomer resists compression fatigue and dissipates internal heat build-up, providing firm lateral pressure against the sheave/pulley sidewall and distributing the load to the cords.
- Precision molded cogs – Provide additional flexibility, allowing for the use of smaller pulley diameters, and aiding in heat dissipation.
Step 3: Measure V-belt length
The most difficult part of identifying a v-belt is measuring the length. There is no precise method that is practical to perform in the field for v-belt measurement. Precise measurement requires a measuring fixture with pulleys of prescribed dimension and the ability to apply a specific tension to the belt according to ARPM (Association for Rubber Product Manufacturers) standards for the given belt section.
Additionally, there are several terms used in the industry to describe length (e.g. inside length, outside length, pitch length, effective length) making it very confusing.
Some belt providers instruct end users to utilize tapes to measure outside length. While this method can approximate belt length, it can still be off by inches. If the drive has ample installation and take-up range, using a tape can yield a belt that will fit the drive in many cases, however, there is no guarantee it is the optimum length designed for the drive.
Contact Megadyne Application Engineering, who will work with you to perform the drive analysis and ensure the belts we deliver are the best choice for your application.
Step 4: Label the Drive
Finally, to avoid the issue of identifying the v-belt each time it needs to be replaced, a good maintenance practice is to properly label the drive with the correct belt part number. Use an adhesive sticker or any type of permanent signage where you can easily read the belt part number, making it easy to obtain belts in the future. Recording the date when the belts were installed can also enhance your maintenance program with increased uptime by knowing when to replace belts before they fail.
Quality V-Belts From Megadyne
Megadyne is pleased to offer a variety of v-belts, including rubber-wrapped, rubber raw edge, banded, and linked v-belts, to meet the needs of a wide range of applications. We are proud to provide quality rubber and synthetic v-belts for automotive and tire applications, commercial and domestic appliances, and construction and industrial equipment. To learn more about Megadyne's extensive selection of v-belts, contact us today.