Group members:Syed Raheel Adeel IM-098Jasim Arif IM-091Rashid Ansari IM-087Mohammad Hasany IM-88

INTRODUCTION Chain driveis a way of transmitting mechanical power from one place to another. It is a system where the input is provided by a gear or sprocket which turns and moves a chain.

A chain drive consists of an endless chain wrapped around sprocket wheels (shown in Figure). The chain has a number of links connected by pins. The sprockets have teeth of special profile. Chains are used for power transmission and as conveyors. The chain drives have some features of both belt (flexibility of location of driver and driven) and gear drives (ruggedness). Chain drives are recommended for velocity ratio below 10:1, chain velocity 1550 m/min and power transmission up to 100 kW.

A chainsaw (or chain saw) is a portable, mechanical saw which uses a set of teeth attached to a roller chain that runs along the blade. It is used in activities such as tree felling, limbing, bucking, pruning, to fell snags and assist in cutting firebreaks in wild land fire suppression, and to harvest firewood. Chainsaws with specially designed bar and chain combinations have been developed as tools for use in chainsaw art and chainsaw mills. Specialist chainsaws are used for cutting concrete.

A bicycle chain is a roller chain that transfers power from the pedals to the drive-wheel of a bicycle, thus propelling it. A bicycle chain is a 'roller chain' that has the task of transferring power from the cranks to the rear wheel of the bike thus propelling it. Most bicycle chains are made from alloy steel, but some are chrome plated or stainless steel to prevent rust, or simply for good looks. Chains will vary in width depending on the amount of gears you have, most are 3/32 inch for use with geared systems and then come in 'speeds' which needs to matched to the cassette, ie a 10 speed cassette will need a 10 speed chain and so on. Track bikes or single speeds often run 1/8 inch rings so will need a 1/8 inch chain as well, these will have larger plates to aid stopping on a fixed wheel, which can add extra stress to a chain.

Comparison Between Different Transmission Devices

ADVANTAGES 1. As no slip takes place during chain drive, hence perfect velocity ratio is obtained. 2. Since the chains are made of metal, therefore they occupy less space in width than a belt or rope drive. 3. It may be used for both long as well as short distances. 4. It gives a high transmission efficiency (upto 98 percent). 5. It gives less load on the shafts. 6. It has the ability to transmit motion to several shafts by one chain only. 7. It transmits more power than belts. 8. It permits high speed ratio of 8 to 10 in one step. 9. It can be operated under adverse temperature and atmospheric conditions.

DISADVANTAGES 1. The production cost of chains is relatively high. 2. The chain drive needs accurate mounting and careful maintenance, particularly lubricationand slack adjustment. 3. The chain drive has velocity fluctuations especially when unduly stretched.