Gears are one of several fixed transmission settings in a vehicle used in order to determine power or direction. In industrial product categories, however, the gear is that toothed mechanical part - commonly a wheel or a cylinder - that engages with another toothed part in the transmission of motion from one rotating body to another. In this second definition, there are several materials used in the process. A popular subcategory is known as plastic gears.

Plastic gears are available in a wide array of materials and are constructed in different ways. It may also be designed depending on the industry that makes use of these items. They may be hubless or they may also have pins with or without set screws. They may also be set on a brass insert, a stainless steel hub, aluminum core, Bakelite or nylon. Below are further details about construction, design and materials in the manufacture of these items.

Construction

Plactic gears are produced through two significant processes known as hobbing and shaping. Additionally, though, some molding techniques are also employed in its construction. But then again, these techniques are not relied upon that much because of some disadvantages. Most of the times, molding strategies are not accurate due to mold variations and other inconsistencies. In all these techniques, though, plastic gear fabrication is not as favorable as metal gear processing.

Design - advantages and disadvantages

Despite the disadvantages seen in the manufacture and construction of plastic gears, more industries rely upon these industrial products. Their features have been enhanced through time and they are now designed to meet the requirements of their various applications. Backing up the different plastic gear designs are some attributes or characteristics in the process. Designing these types of gears is considered a cost effective measure. It is also lightweight, has uniform parts, capable of shock absorption and has low coefficient of friction. Furthermore, it eliminates machining operations.

However, to some extent, the designs have some limitations too. They are relatively less capable of carrying heavy loads and they possess greater instabilities in terms of dimension. They are also affected by chemical products and lubricants.

Properties of different materials used in construction

Plastic gears are produced with different materials including acetal resins and copolymers as well as nylon resins. All of these materials have varied physical and mechanical properties whose strength, dimensional resistance, moisture absorption and fabrication requirements vary from one another. Generally, these materials have the capacity to withstand varied formulations.