UNDERSTANDING THE UNDERSTANDING THE FUNDAMENTALS OFFUNDAMENTALS OFCHAIN & SPROCKETCHAIN & SPROCKET

Submitted BySubmitted ByBalraj - 007Balraj - 007Devesh - 008Devesh - 008Debajyoti - 009Debajyoti - 009

ChainsChains Definition A chain is a reliable machine

component, which transmits power by means of tensile forces, and is used primarily for power transmission and and conveyance systems(for material handling purpose)..

As a transmission, chain drives can operate efficiently at high loads and they may be used where precise speed ratios are required.

Features of Chain DrivesFeatures of Chain Drives

Features of Chain Drives:Features of Chain Drives: Speed reduction/increase of up to seven to one can be Speed reduction/increase of up to seven to one can be

easily accommodated. easily accommodated. Chain can accommodate long shaft-center distances (less Chain can accommodate long shaft-center distances (less

than 4 m), and is more versatile. than 4 m), and is more versatile. It is possible to use chain with multiple shafts or drives with It is possible to use chain with multiple shafts or drives with

both sides of the chain. both sides of the chain. Standardization of chains under the American National Standardization of chains under the American National

Standards Institute (ANSI), the International Standardization Standards Institute (ANSI), the International Standardization Organization (ISO), and the Japanese Industrial Standards Organization (ISO), and the Japanese Industrial Standards (JIS) allow ease of selection. (JIS) allow ease of selection.

It is easy to cut and connect chains. It is easy to cut and connect chains. The sprocket diameter for a chain system may be smaller The sprocket diameter for a chain system may be smaller

than a belt pulley, while transmitting the same torque. than a belt pulley, while transmitting the same torque.

Types of chainsTypes of chains

Conveyorchains

InvertedToothchains

Chains

Roller chains

Roller Chains

A length of roller chain is made up from a number of links and each chain link comprise side plates, pins, bushes and rollers. The ends of a chain are joined together when in mesh with the drive and driven sprocket. As the sprocket teeth engage with the rollers, rolling rather than sliding contact occurs - thus making this a very efficient form of transmission element.

Roller chains are available in various standard forms, including stainless steel, plastic (for their self lubricating qualities) and various forms (especially for use on agricultural and conveying applications).

Components of roller chainComponents of roller chain A roller chain consists of a

number of inner link assemblies in which adjacent pairs are connected by outer links.

An inner link assembly is made up of a pair of inner plates connected by two riveted bushes spaced a set distance apart called the pitch. A roller is free to rotate on either bush.

The outer links comprise a pair of outer plates which are attached via a pair of riveted bearing pins which are spaced a pitch distance apart.

These pins are free to fit inside the inner link bushes and connect inner links as shown in Figure.

Conveyer ChainConveyer Chain Roller chains which are Roller chains which are

specifically manufactured for specifically manufactured for use on material handling and use on material handling and conveyor equipment are called conveyor equipment are called ‘Conveyer Chain’. ‘Conveyer Chain’.

Such chains are widely used in Such chains are widely used in the textile, food processing, the textile, food processing, mining and agricultural mining and agricultural industries, for escalators, industries, for escalators, elevators and also on modern elevators and also on modern machine tools.machine tools.

Inverted Tooth ChainInverted Tooth Chain

Inverted Tooth chain has teeth Inverted Tooth chain has teeth formed in the links and these formed in the links and these engage with the teeth in the engage with the teeth in the sprockets.sprockets.

Their sprockets can be likened to Their sprockets can be likened to gears but instead of meshing with gears but instead of meshing with each other they connect across a each other they connect across a greater centre distance by means greater centre distance by means of a chain.of a chain.

Due to the compliance of Due to the compliance of individual links, there is less individual links, there is less impact force when a link first impact force when a link first engages with sprocket teeth and engages with sprocket teeth and consequently an inverted tooth consequently an inverted tooth chain drive can operate more chain drive can operate more quietly and at higher speed than quietly and at higher speed than roller chain of comparable size.roller chain of comparable size.

LubricationLubrication

Chains are usually Chains are usually prelubricated with rust-prelubricated with rust-prevention oil before prevention oil before shipping. Nevertheless, it shipping. Nevertheless, it is essential to lubricate is essential to lubricate roller chain. Properly roller chain. Properly lubricated chain has a lubricated chain has a longer wear life and is less longer wear life and is less likely to develop rust.likely to develop rust.

Lubricate the chain where Lubricate the chain where the tension is minimal, the tension is minimal, applying the lubricant in applying the lubricant in the clearance between the the clearance between the link plates link plates

 Lubrication Method

Manual Application.Oil is applied with an oil filler or brush 

on the slack side of the chain.

Drip Lubrication.A simple case can be used. Oil from the 

oil cup is supplied by drip feeding

Oil Bath Lubrication.The chain is installed in a leak free

casing.

ApplicationApplication

Chain drives are a very widely used transmission system and can Chain drives are a very widely used transmission system and can be found extensively in all mechanical industries and even on be found extensively in all mechanical industries and even on some civil engineering projects. some civil engineering projects.

Applications range from machine tool, marine and aerospace Applications range from machine tool, marine and aerospace drives, motor cycle and bicycle transmissions. drives, motor cycle and bicycle transmissions.

They are also widely used in the nuclear, mining and food They are also widely used in the nuclear, mining and food industries and on conveying and packaging machinery. industries and on conveying and packaging machinery.

For example, in many motor vehicle and ships engines, the cam For example, in many motor vehicle and ships engines, the cam shaft is driven by a chain. shaft is driven by a chain.

Chain drives are used on civil aircraft such as Concorde and Chain drives are used on civil aircraft such as Concorde and military aircraft.military aircraft.

Sprockets Sprockets

A A sprocketsprocket is a profiled is a profiled wheelwheel with teeth that meshes with teeth that meshes with a with a chainchain, , tracktrack or other perforated or indented or other perforated or indented material. It is distinguished from a material. It is distinguished from a geargear in that sprockets in that sprockets are never meshed together directly, and from a are never meshed together directly, and from a pulleypulley by by not usually having a flange at each side.not usually having a flange at each side.

The sprocket looks like a gear but differs in three important ways:The sprocket looks like a gear but differs in three important ways:1.1. Sprockets have many engaging teeth; gears usually have only one Sprockets have many engaging teeth; gears usually have only one

or two. or two. 2.2. The teeth of a gear touch and slip against each other; there is The teeth of a gear touch and slip against each other; there is

basically no slippage in a sprocket. basically no slippage in a sprocket. 3.3. The shape of the teeth are different in gears and sprockets. The shape of the teeth are different in gears and sprockets.

Types of SprocketsTypes of Sprockets

There are four types of sprocket; There are four types of sprocket;

1.1. Type A: Plain Plate sprockets Type A: Plain Plate sprockets

2.2. Type B: Hub on one side Type B: Hub on one side

3.3. Type C: Hub on both sides Type C: Hub on both sides

4.4. Type D: Detachable hub Type D: Detachable hub

ApplicationApplication

Sprockets are used in bicycles, Sprockets are used in bicycles, motorcycles, cars, tanks, and other motorcycles, cars, tanks, and other machinery either to transmit rotary machinery either to transmit rotary motion between two shafts where gears motion between two shafts where gears are unsuitable or to impart linear motion are unsuitable or to impart linear motion to a track, tape etc.to a track, tape etc.

In the case of vehicles with In the case of vehicles with caterpillar trackscaterpillar tracks the engine-driven the engine-driven toothed-wheel transmitting motion to toothed-wheel transmitting motion to the tracks is known as the the tracks is known as the drive drive sprocketsprocket and may be positioned at the and may be positioned at the front or back of the vehicle, or in some front or back of the vehicle, or in some cases, both.cases, both.

Sprockets are used in the film transport Sprockets are used in the film transport mechanisms of mechanisms of movie projectorsmovie projectors and and movie camerasmovie cameras. In this case, the . In this case, the sprocket wheels engage sprocket wheels engage film perforationsfilm perforations in the in the filmfilm stock. stock.

Sprocket feed was also used for Sprocket feed was also used for punched tapepunched tape and is used for and is used for paperpaper feed feed to some to some computer printerscomputer printers..

BibliographyBibliography

www.chain-guide.comwww.chain-guide.comwww.google.comwww.google.comwww.wikipedia.comwww.wikipedia.com

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