The term mechanical power transmission is a reference to any product which is used within a system powered by moving parts, as opposed to systems that are powered electronically.
Such systems include a variety of different power transmission components, including chains, sprockets, belts, shaft couplings and drive components.
The belt pulleys within power transmission systems transfer mechanical power between components. Their external teeth interlock with the timing belt’s teeth in order to transmit the high torque between the components.
Types of belt pulleys, such as variable pitch and timing belt, are commonly seen in a range of different applications, with timing belt pulleys being common in the automotive industry to connect the camshaft and crankshaft in order to control the engine valves.
Inline timing pulleys, variable pitch pulleys have pulley which is used to connect a companion or driven pulley to the attached driving motor shaft.
The belt within a power transmission is used in a wide range of applications to transfer power and is great at reducing slippage. Commonly used in manufacturing systems, both synchronous drive belts and v-belts work alongside the sheaves and pulleys within a power transmission system.
Also used in HVAC, and agricultural industries, the power transmission belts come in a range of different types which make them more efficient for certain applications.
V-belts have cross-sections which are tapered, allowing them to lodge into the pulley’s grooves; this is how the torque is transmitted and how slippage is reduced. Round belts are typically only used in pulley systems which have a 60-degree V-groove.
Flat belts, an older-style belt which has been largely replaced with v-belts and timing belts, are typically used in conjunction with pulleys with a crowned surface to prevent them from slipping under heavy loads.
The chain sprockets and chains within power transmission systems are used to transmit the mechanical power between rotating shafts. It takes at least a roller chain and two sprockets to make up a chain drive, within which the roller chain will interlock with the teeth of the sprockets. The number of teeth on a chain sprocket can help to dictate how heavy a load it can carry – more teeth mean a heavier load.
However, the drawback of having more teeth is that it can cause increased friction. Even with the roller chain lubricated to help to reduce wear from friction, systems with sprockets which have a large number of teeth won’t be able to be operated for as long as those with fewer teeth due to the friction.
Chain and sprocket drives are often used instead of belt and pulley drives within certain systems and do not allow for slip, which is why friction can be an issue in systems with sprockets with a high number of teeth. The most common chain and sprocket system is the bicycle.
As well as the components within a power transition system, there are several tools and parts that are used to maintain the chains within the systems. Two of the most common chain tools are the chain wear gauge and the tensioner.
Chain wear gauges are used to measure the distance between the links in the chain in order to ascertain if stretching has occurred and how bad the stretching may be. Tensioners are used to reduce the slack of both belts and chains to improve the torque levels that are being transmitted.
There are a few different types of tensioners; spring-loaded, floating and manual.
Spring-loaded tensioners automatically correct the tension within belts and chains using springs, while floating tensioners use two pulleys or sprockets and manual tensioners use screws.