The sprocket  is a crucial element of any chain-driven machine, like a conveyor belt, but they are often overlooked until they fail. The teeth that rotate and engage with the chain links, must be the correct dimension and shape for guiding movement. Despite their importance, they are often subjected to some of the harshest conditions like speed, corrosion and wear.  They should be replaced each time  the chain is replaced. To ensure the correct replacement, understanding the basic terminology and types of these parts is critically important.

What Is the Basic Design of a Sprocket?

All sprockets are designed to a specific standard, with ANSI being the most common in the U.S. Under ANSI standards, pitch refers to the distance between the center of one tooth to the next. The pitch is given a corresponding number that matches a specific roller chain size. For example, a #80 chain runs on #80 sprockets. The chain and sprockets are measured in 1/8 inch increments. In addition to selecting the correct pitch, the sprocket needs to match the chain in terms of type; for example, a double-strand sprocket is required for a double-strand chain. 

Once you have determined the pitch, the sprocket needs to have the correct hub style and number of teeth. Some sprockets do not have hubs, while others have a hub on one or both sides. Some double-sided hubs are offset for specialty applications. The parts can also have varying numbers of teeth; you can determine how many teeth it has by simply counting. Additionally, some teeth are designed to be harder, giving them a longer life span.

The bore is the center hole of the sprocket and must be designed to a thickness adequate to withstand the forces that will be placed on it. The length through bore (LTB) is the diameter of the inside bore and the length that the piece is machined to. The LTB must be long enough to be attached via the keyway and set screws and withstand the typical levels of torque and force on the chain. 

What Are the Types of Sprockets?

Once you identify the technical specifications of the sprocket you need, there are many to choose from. Some of the most common sprockets include:

• Double Duty: has an extra set of teeth to keep the chain moving when the first set wears down.
• Hunting Teeth: have an uneven number of teeth so the links engage with different teeth at every rotation, allowing the teeth to last longer.
• Idler: help distribute loads evenly, tension or maneuver chain around obstructions.
• Multiple Strand: can support multiple chains and offer more torque and power.

If you need help selecting the right sprocket for your machinery, contact Industrial Component Sales Inc. With offices in Madison and Hudson, WI, and Bemidji, MN, they offer a range of components for machines to keep your enterprise functioning efficiently. In addition to providing the parts you need, they have the knowledge and skills to help solve machinery problems. Speak with a representative by calling (651) 270-0151 and visit the website to learn more about the product lines they offer.