How to correctly identify a V-belt?

V-belts (single, independent) are one of the most used elements of mechanical transmissions for transferring rotational motion and thus mechanical energy from one shaft to another. They are relatively inexpensive, lightweight and the vast majority of sizes are available in our stock. Due to design developments, there are several groups of profiles that differ from each other mainly in the magnitude of the power transmitted.

Basic division of V-belts:

By profile type

The difference between a classic V-belt and a narrow V-belt lies in their profile. The main difference can be seen at a glance by the height of the wedge (the narrow profile has a wedge that is much higher than the classic profile).

Classic V-belts are the first types of profiles that were developed for the transmission of traction force. These belts are more affordable and are mainly used in older and classic applications with common power transmission requirements.

Narrow V-belts are capable of transmitting up to 100% more power compared to conventional profiles due to the higher key. The narrow design replaces conventional profiles without the need to replace pulleys.

Examples of possible replacements: 10/Z = SPZ, 13/A = SPA, 17/B = SPB, 22/C = SPC

According to the design and production technology

Wrapped V-belts are historically older designs with a rubberized canvas-wrapped surface, suitable for a wide range of industrial applications. Example markings: Z(10), A(13), B(17), C(22), D(32), SPZ(9,5), SPA(12,5), SPB(16), SPC(21).

Cut V-belts, of newer design, often replace coated belts. They have uncovered ground sides on which the tensile textile elements are visible. These belts have a longer service life, increased power transmission and allow a higher circumferential speed compared to coated belts. They also have better temperature resistance and can be used on smaller pulley diameters. Example markings: ZX(10), AX(12), BX(17), XPZ(9,5), XPA(12,5), XPB(16), XPC(21), etc.

Special V-belts - POLYURETHANE 60° designed for high-speed machines and tools (machining, medical, textile machines, hand tools). The 60° side angle ensures good tension distribution, moreover in a small space and at high circumferential speeds. The belts are wear and ozone resistant. It is possible to use single V-belts as well as multiple belts, which can be cut from the sleeve to a given number of ribs according to customer requirements. Example markings: 3M, 5M, 7M and 11M.

By use and shape

As a result of design developments, there are several groups of V-belt profiles that differ primarily in the power transmitted. Furthermore, the basic design of single V-belts has led to variants in multiple, double-sided, ribbed and variator designs.

How to determine the correct V-belt size?

The first step is to measure the width of the V-belt, then the height and finally the length, either internal or external.

1. Correct measurement of height, width and length: Before you start selecting a V-belt, it is essential to measure the height, width and section of the existing belt if you have one. Length measurements should be taken accurately, ideally using a string and tape measure or a professional belt gauge.
   An incorrectly chosen dimension can cause a reduction in performance and shorten the life of the belt.

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   The height and width can be used to determine the profile of the V-belt.

   If the belt is side-circled (wear from service), the profile can also be determined from the height of the V-belt.

   There is a fixed length difference between Lw, La and Li for each profile, regardless of the belt length. For example, for profile 13/A the difference is: Li + 30 = Lw, Lw + 20 = La.

   

2. Consideration of the V-belt type: there are several types of V-belts, where each type is designed for a specific application and has different characteristics. When selecting a belt, it is important to consider the required power, speed and the environment in which the belt will be used.
3. Material quality: V-belts are made from a variety of materials including rubber, neoprene and polyurethane. The quality of the material has a direct impact on resistance to wear and temperature changes. When selecting, it is important to choose a belt made of a quality material that can withstand a variety of operating conditions.
4. Brand and reliability: when choosing a V-belt, it is always a good idea to choose a reputable brand. Quality manufacturers usually supply belts with high durability and reliability. Read reviews and experiences of other users to get an idea of the reliability of a particular brand.
5. Manufacturer's Instructions: always follow the recommendations and instructions from the manufacturer of the machine or equipment on which the V-belt will be used. Each machine may have specific requirements for the type and dimensions of the V-belt.

1. Tip:
   On the outer surface of each new belt you will find information about its dimensions and manufacturer.
   It is also advisable to record this information as soon as possible, for example in the instruction manual.

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