The Dynamic Roller Chains of The World
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The chain used for lifting the carriage on a forklift and the cutting chain on chainsaws are the same sort of chain: they're roller chains. These are used on slower drives, which attain speeds of 600 to 800 feet per minute. Bicycles are pretty common examples, and some motorcycles use them.
This type of chain drive consists of cylindrical rollers held together by side links. The bush roller chains have 2 types of links that alternate: inner links made of 2 inner plates that are held together by 2 bushings, and outer links that are made of plates that are held together by pins that pass through the bushings. Machines use roller chains to get mechanical power from one part to another (for instance, bike chains transfer power from pedals to wheels.) They use sprockets rolling over the bushings to move power. People generally make them with carbon or alloy steel, although people can make them with stainless steel.
You generally hook up roller chains with a master link (also called a connecting link) using a horseshoe clip. You can adjust this type of roller chain part with cottered links. Some master links have riveted ends, however, and you can't adjust the length of those type of chains.
Roller Chain History
The roller chain has been with us for quite a long time. Leonardo Da Vinci drew sketches of chains with roller bearings in the 16th century, but the person officially recognized for inventing roller chains is Hans Renold. He moved to Manchester from his native Switzerland in 1873 and bought a textile-chain factory in 1879. In 1880, he bought chain from the former business owner, James Slater, and modified it to include solid bushings that made the chain better, and this is what modern roller chains are based on. Bushings are the cylinders that are connected by face plates which provide spaces the teeth of sprockets could land in between.
Size and Strength of Roller Chains
When you are making something with a roller chain, an important thing to know is the tensile strength. This is because an overloaded chain wears out quickly. A good rule of thumb is to keep the load 1/6 to 1/9 of the tensile strength (which is how much a chain can hold at one time before the chain breaks) in order to keep a continuous drive. Different sizes of roller chain have different strengths, and these sizes generally come in standard sizes set by bodies such as the American National Standards Institute, and the American Society of Mechanical Engineers. Their size labels indicate the pitch and type of chain by numbers. The pitch of the chains is the distance between roller centers, which get wider as the chain gets stronger. This you measure in eighths of an inch, and the size labels express it in the first digit of the size. The type of chain is indicated in the second digit, with 0 indicating a standard chain, 1 indicating a lightweight chain, and 5 indicating a bushed chain without rollers. So, for instance, a size 40 is a roller chain with a 1/2 inch pitch on a standard chain.
The most common sizes are 40, 50, 60 and 80. The minimum tensile strength of a #40 is 3,125 pounds, and the tensile strength of a #80 is 12,500 pounds. It should be mentioned here that 'bushingless' roller chains exist, which consist of plates where tubes are stamped on them for threading.
Roller chains have been a big part of our industrial processes. In fact, old cars used them to drive the camshaft off the crankshaft. They are a hardy and efficient way to move mechanical power from one place to another. If you need roller chain parts, contact us. We have what you need for your projects.