Plastic gears are gears made from plastic materials. Common materials include polyamides (PA), polyetheretherketones (PEEK), nylons (PA), polypropylene (PP), and polycarbonate (PC); they are commonly used in various mechanical equipment.
(1) Polyamides (PA): Possess high strength, rigidity, and wear resistance, suitable for applications involving high loads and high-speed motion. They have good temperature resistance and can operate at relatively high temperatures. They also exhibit good chemical stability and corrosion resistance.
(2) Polyetheretherketones (PEEK): Possess excellent high-temperature resistance and mechanical strength, enabling operation under extreme conditions. They are wear-resistant, have a low coefficient of friction, and good corrosion resistance. Suitable for special working conditions requiring high temperature, high speed, and high load.
(3) Nylons (PA): Common nylon materials such as nylon 6 (PA6) and nylon 66 (PA66) possess good strength, rigidity, and wear resistance. They have good cold resistance and maintain good mechanical properties even at low temperatures.
(4) Polypropylene (PP): Has low density, good chemical stability, and corrosion resistance. Lower mechanical properties, but good cold resistance and impact resistance. Suitable for low-load, low-speed applications.
(5) Polycarbonate (PC): Has high strength, rigidity, and excellent impact resistance. High temperature resistance, can operate over a wide temperature range. Good resistance to chemical corrosion. Suitable for applications requiring high strength and high impact resistance.
The characteristics of these materials need to be considered comprehensively based on actual application requirements, and the most suitable plastic gear material for specific working conditions should be selected.
Compared to metal gears, plastic gears have advantages such as light weight, low inertia, low noise, self-lubrication, corrosion resistance, and high production efficiency and low cost due to mold processing. Due to different material properties, the failure modes of plastic (composite material) gears are significantly different from those of metal gears. In addition to tooth root fracture and tooth surface contact fatigue, they are more prone to wear failure and thermal failure caused by higher contact temperatures. VDI-2736 is the current guideline standard specifically for design calculations of plastic gears.
