BELT AND BELT DRIVES; UNDERSTANDING THE TRANSMISSION OF POWER ON ENGINES

We all talk about engines and how they move and rotate converting one form of energy to another. Just like the crank shaft converts linear motion to rotational motion of the flywheel. But have you ever wondered or asked how this rotational motion is transmitted to other engine parts for kinetic motion of your vehicle? or how your alternator moves relatively with your engine movement?

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BELT

Well according to a Wikipedia belts are known to be a piece of clothing or flexible material usually worn round a piece of clothing (trouser).

Of course, we are not talking about belt used for clothing’s although they are both black and rugged but they do different things. We are talking about the mechanical belts used in engines. Wikipedia defines this belt as a loop made of flexible transmission that can link two or more rotating shafts together for the sole puropose of power transmission.

I am very sure most of us see this black thick thing that rotates along with your engine either in your vehicle bonnet or generator engine (if you run an alternator engine). Especially in the Nigerian homes some of us have been whipped with this strong black thing which is very strong and painful.

I know you have an idea of what this thig does as when it slips or falls away the other part stops working. Therefore, this endless circular black substance is called a belt and you are right basically to a layman the belt transmit motion in form of power from one part of the engine to another. Belts are usually placed on pulleys which are wheels on a shaft or axle.

THE MATERIAL COMPOSITION OF BELT DRIVES

The materials used in making mechanical belts should have certain characteristics some of which are flexibility, durability, and reliability. Therefore, certain materials which have these qualities are leather, cotton, rubber and plastic. The application of these belts determine what material type of belt should be used.

TYPES OF BELTS

There are several types of belts used for several purpose and application in the engineering world. Some of which include;

• Flat belts
• V-belts
• Flat belts
• Multi grooved belts
• Ribbed belts

FLAT BELTS

Flat belts are usually designed for light transmission of power. They are one o the earliest forms of belts and are used for small pulley with a large central distance. They have high transmission efficiency, cost effective and usually easy to install.

^{flat belt from Wikimedia under CCO license}

V-BELTS

This type of belts is usually triangular or trapezoidal in shape used for transmission of power. They are used where speed ratio is not critical. They are used for very high-speed transmission of power.

MULTI GROOVED BELTS

A multi groove belt usually consists of several v-belts joined together. It is much more flexible and wider which results inn more efficiency and more power transmission that the v-belts.

RIBBED BELTS

These belt types operate by contact between the rib of the belt and the grooves of the pulley. They are used for even distribution across pulley width where belt is in contact. They are used where there is high speed ratio such as in washing machines, lawn mowers.

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BELT DRIVES

We have talked severally about belts now, but belts don’t move themselves as they are mounted on something called pulley once mounted on a pulley it results in what is known as a belt drive as they are responsible for how the belts move the speed and the power at which the belt transmits. There is a driver pulley and a driven pulley the pulley that owns or causes the motion is called the driver pulley while the driven pulley lacks motion, or it is the stationary pulley that you need power in.

^{belt drive from Wikipedia under CCO license}

TYPES OF BELT DRIVES

There are two types of belt drives which depend on how the belt operate or behave which are the open and the crossed belt drives.

OPEN BELT DRIVES

Open belt drives are used to rotate the driven pulley in the same direction as the driver pulley. When motion across this belt drive occurs, one side of the pulley is more tightened compared to the other.

^{open belt drive from Wikimedia under CCO license}

CROSSED BELT DRIVES

Crossed belt drives rotate the driven pulley in opposite direction to the driving pulley. The wrap around this kind of drive must be great for more power to be transmitted when compared to open belt drives.

^{cross belt drive from Wikimedia under CCO license}

APPLICATION OF BELTS

Belt drives are used in several devices and equipment’s where noise is not needed, and friction needs to be overcome some of these applications are In conveyor belts, escalators, mowers, vehicles, generators and anywhere power is needed to be transferred.

ADVANTAGES OF BELT DRIVES

• Belt drives simply saves you enough money as they are economical.
• Belt drives do not require parallel shafts.
• Most belt drives are provided with overload and jam protection.
• Reduced noise or noiseless operation are one of the best characteristics of belt drives as they increase machine life.
• They require little or no maintenance operation as they do not need lubrication.
• They have high efficiency.

DISADVANTAGES OF BELT DRIVES

• The velocity ratio of belt drives is not equal or constant due to slippage or stretching of belts
• Heat occurs as we all know friction acts against movement which causes heat.
• Operations are usually restricted to certain temperatures due to the material.
• Adjustments of center distance are done for comprehension of the stretching and belt wearing.

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CONCLUSION

The importance of belt drives is felt in many engineering equipment’s as transmission of power is essential in mechanical engineering. Belts are endless and usually of low maintenance with little or no operation or lubrication. Belts are made up of several materials whose application depends on the selections. Belts are usually mounted on pulleys and are called drives which may be open or closed. The importance of belt is very essential as without these your equipment or tool might just have a part working with the other useless there by costing you more to move all parts together.
In the event of all that has happened in the steemSTEM community, as an engineer I belong to them I say we all come out to support and stand by them and engage in the comment and on discord. Help your fellow scientists, engineers technologist and mathematicians. Build a connection and make friends most of all don’t forget to have fun.

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REFERENCES
For further reading please use any of these books or read the links.

• the-material-used-in-belt-drive
• Belt
• v_belts
• belt-drives
• belt-and-chain-drives
• a text book on machine design by R.S Khumi.
• flat_belts

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