The difference between a flat and V-belt drive

The difference between a flat and V-belt drive

Habasit has developed power transmission belts since 1946. We have extensive experience and knowledge about which applications will provide the most efficient utility for power transmission.

Today I will share some of my observations of the difference between flat and V-belt drive.

Two different transmission systems

Power transmission belts are used within any industry where something is operated with the aid of a transmission. Flat and V-belt drives are fundamentally different systems. The V-belt drive technology is based on the belt tracking in a mating groove in the belt pulley. The more power that is transmitted, the more belts and grooves in a row. The flat belt technology is based on the high friction of the belt against the crowned belt pulleys, and the transmission only contains one belt. Common flat belt applications are separators, grinders, wood planers, fans, roller conveyors, etc. The flat belt can also transmit power on both sides of the belt.

Construction

The flat belt traction layer consists of stabilized polyamide compositions, Polyester fabric or Aramid fabric. The friction surface usually consists of NBR rubber on one or both sides.

Efficiency and energy savings

Flat belts have only a small cross-section which makes them very flexible and require no wedging in and pulling out from grooves. Together with the smooth operation and the absence of wedging effects, there is a negligible energy loss. The efficiency is hence high: More than 98%. Thin and light flat belts also allow high belt speeds.

Service life

The flat belt is connected with the surface of the belt pulley via high friction, and the energy loss is minimal. The service life of a flat belt is measured by the amount of flexing and how small the diameter of the belt pulleys are. If this is favorable, the service life is theoretically endless.

The V-belt works by wedging, it is wedged in grooves and pulled out from grooves, which causes energy loss and high wear. The wear related to wedging limits the service life. The service life is even more limited if the work environment is dusty.

Noise and contamination

The flat belt is very quiet, and what noise is generated appears when air is pushed out between the belt and the pulley. Due to the way it works, the flat belt remains nearly completely clean during application and has limited wear.

The V-belt on the other hand emits a characteristic whistling noise when it is pushed into and pulled out of the grooves. This motion causes wear on both the belt and the grooves, thus limiting the service life. Contamination by black rubber dust is a consequence of this.

Installation and maintenance

The flat belt is installed with tension, that is, with an initial tension between 1% – 3% depending on the traction layer and the transmission configuration. This cannot be done by estimation, but must be calculated. The sign of a correctly installed flat belt is when it moves towards the center on both belt pulleys and tension has been reached. Thus a correctly installed flat belt does not need readjustment and is maintenance free.

V-belts are often installed by estimation and do have a certain error margin, however this affects the service life. V-belts must be tensed from time to time since their grooves wear down.

Design

At Habasit we manufacture flat belts customized to your needs. You do not need to stick to standard lengths or widths. We make it possible to design optimized operations from a technical, economical, and energy efficient perspective.

For anyone who wants to save energy and reduce electricity costs

If you want more efficient energy consumption, then Habasit’s HabaDRIVE flat belts are an excellent choice. You can save around 4% energy by switching from V-belts to flat belts. I hope this blog has been helpful in understanding the differences between belt types. Would you like to hear other examples or learn more about how our flat belts compare to our V-belts? Do not hesitate to contact us!

2017 November 21  |  Posted by

Sten-Göran Friberg is the Key Account Manager for Northern and Eastern Sweden. He has worked at Habasit for over 35 years and has extensive experience in drive belts, as well as webbing in most industries and applications. He is fluent in both Swedish and English.

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