According to the material that geared motor adopts, geared motor is divided into plastic and metal types. It means that the material of the housing part is plastic or metal. In fact, our metal gears include power metallurgy and hardware processing. But in fact, no matter metal or plastic version, they have their own advantages and limitations. Here are the reasons for choosing plastic geared motor.
1. Lower cost: Generally, the production cost of plastic gear is cheaper than that of metal gear. Since there is usually no need for secondary finishing, plastic gears typically represent a 50% to 90% saving relative to stamped or machined metal gears, according to Plastics Technology.
2. Low noise: Strong shock absorption performance of plastic gear motor contributes to low noise during operation.
3. High Degree of design freedom: Molding plastic offers more efficient gear geometries than metal. Molding is ideal for creating shapes, such as internal gears, cluster gears, and worm gears, where the cost for forming them in metal can be prohibitive.
4. High precision: The plastic gear can achieve high precision with consistent material quality and precise molding process control.
5. Strong bearing capacity: Since plastic gears can be wider than metal gears, they can achieve greater load-bearing capacity and more power transfer in a single stage.
6. Corrosion resistance: Unlike metal gears, plastic gears do not corrode because they are nonconductors. Their relative inertia means they can be used in water meters, chemical plant controls, and other situations that may cause corrosion or degradation of metal gears.
7. Lubrication: The inherent lubricity of many plastics makes them very suitable for computer printers, toys, and other low-load situations requiring dry gears. Plastics can also be lubricated with grease or oil.
8. Lightweight: The weight of plastic gear is often lighter than that of metal gear.
9. Good shock absorption performance: Plastic gear has more bearing force than metal gear because plastic can deflect to absorb impact load. It also does a better job of distributing localized loads caused by misalignment and tool errors.
Limitations of Plastic Gears
Compared with metal gear, plastic gear has the limitations of low modulus of elasticity, low mechanical strength, poor heat conduction performance, and a large coefficient of thermal expansion. Temperature is the main factor affecting wear, and rotation speed and transmission torque are more important factors affecting tooth surface temperature and wear, which limit the use of plastic gear in high load and high-speed occasions.