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What is a Chain?

•A series of connected links, usually made

of metal. •It is a reliable machine component, which

transmits power by means of tensile forces.

•Used primarily for power transmission and conveyance systems.

Leonardo da Vinci, who is famous for the "The Last Supper" mural in Milan,made a fairly accurate sketch of a structure that is now called the chain. This is said to be the beginning of the chain's history.

Medier Gal, a Frenchman, is the one who put it into practical use. Though he obtained a patent on bicycle chain in 1832, it turned out to be used not for bicycles but for load transmission. This chain is known now as "Gal chain".

HISTORY OF CHAINS

Features of Chain Drives

•Chain drives are the most economical way to transmit power to the rear wheel.

• They also convey the greatest percentage of engine power.

•Chain can accommodate long shaft-center distances (less than 4 m), and is more versatile.

•Speed reduction of up to seven to one.

• It is possible to use chain with multiple shafts or drives with both sides of the chain.

• It is easy to cut and connect chains.

The sprocket diameter for a chain system may be smaller than a belt pulley, while transmitting the same torque.

They also require the most maintenance, are dirty, and not as smooth as a shaft or belt drive.

Basic Structure of Power Transmission Chain

Conventional and bushingless chain

In the bushingless chain, the inner link plates are extruded so that the inner plates also serve as the bushings

Schematic Diagram of Bushingless Bicycle Chain

Bushingless Bicycle Chain Components

Bushingless chain

Roller chain

This type of chain is most commonly used for the transmission of mechanical power in bicycles, motorcycles, and industrial and agricultural machinery.

exploded view of all roller chain components

Chain is a series of journal bearings joined together, by side plates. This bearing is where the chain wear occurs and where lubrication is needed.

The o-rings fit into the gap between the rollers and the links that surround each roller and hold the entire chain together.

These rubber fixtures form a barrier that holds factory applied lubricating grease inside of the rollers while still applying sufficient lubrication to the chain body.

o-rings prevent dirt and other contaminants from entering the inside of the chain linkages, which causes significant wear.

These chains are most notably used in motorcycles

O-ring chains

Bicycle Chain

A bicycle chain is a roller chain that transfers power from the pedals to the drive-wheel of a bicycle, thus propelling it.

Most bicycle chains are made from plain carbon or alloy steel, but some are chrome-plated or stainless steel to prevent rust, or simply for aesthetics.

Application

Category Models of Bicycles

GeneralSports, small-tire, general-purpose, child's

Infant Infant's

Special Purpose

Road racing, heavy-duty carriage, track racing, mountain, tricycle, tandem

Nominal Number

PitchInner Link Width

Construction

Application

1/2 × 1/8 12.7 3.30Roller Chain

Simple driveGeneral purpose

1/2 × 3/32 12.7 2.38

Roller ChainBushingless Chain

With derailleurSportsRacing

Motorcycle Chain

Motorcycles are high-speed applications that operate in tough conditions—rain, dirt, sand, and high shock loads. These specially developed chains are used as the part of the drive train to transmit the motor power to the back wheel

Motorcycle Chain in Action

Why for chains???Motorcycle Chains are superior to gears,

which are in the crank cases, by the ease in adjusting the shaft center distance and the number of teeth of the sprocket.

one can freely design the motorcycle's reduction ratio taking into account the specifications and the working conditions.

In the case of a racing motorcycle, for example, the engine power may be 180 hp, and the chain speed is 1,500 m/min.

Construction

40 Class 50 Class 60 Class

Chain Number

Inside Width (mm)

Chain Number

Inside Width (mm)

Chain Number

Inside Width (mm)

420 6.35 520 6.35 630 9.53

425 7.95 525 7.95    

428 7.95 530 9.53

Motorcycle Chains have the same basic construction and sizes (numbers 40, 50, and 60) as Standard Roller Chains. But they have a special width of inner links, because of the very demanding working conditions

Features

StrengthQuad-staked riveting on the pin head helps to retain the link plate on the pin. Connecting links are press fit. Link plates are thicker (heavy) and the rollers are seamless.

Wear lifeSpecial coated pins, sintered bushings that are oil impregnated, and seamless bushings with O-rings are used to extend the wear life of the chain.

Resistance to dirt, sand, or mud -O-rings are used to seal the chains.

AppearanceThese chains may have special coloring, plating, (gold or silver), or glossy finish on the plate

Selection and Handling•Usually the specifications differ for each motorcycle or application, even with the same-sized chains.

•Failure of Motorcycle Chains may result in injury or death. Care must be exercised when connecting or aligning the chains.

•Chains wear rapidly if the O-rings fall off or if the oil in the sintered bushings is depleted.In this case,the chain must be replaced.

•The life of O-ring chain is usually determined by the durability of the O-ring. To improve the durability, there should be an oil film on the O-ring at all times.

Chain durabilityChain durability is affected by riding stylegear choicewhether the bicycle is ridden in rain or

snowtype of soil in the local terraintype of lubricant, lubrication techniquesthe size and condition of the bicycle's

sprockets.

Chain problemsChain stretchChain skippingImproper lubricationBroken pins

Shaft driven bicycle

Shaft driven motorcycle

Shaft drives operate at a very consistent rate of efficiency and performance, without adjustments or maintenance,though lower than that of a properly adjusted and lubricated chain.

Shaft drives are typically more complex to disassemble when repairing flat rear tires.

The manufacturing cost is typically higher.They are heavier than the chain drives.

Conclusions To keep up with the design enhancements of bicycles, chains are being developed in several ways: Lighter weight Higher rust and weather resistance Attractive appearance Guarding Lower noise at engagement.

Motorcycles are getting faster and more powerful. Therefore, Motorcycle Chains must have greater durability lighter and smaller. Manufacturers are working on new

materials, sizes, and heat treatments to improve the performance of the chain.

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