Generally speaking, carburizing steel, powder metallurgy and plastics are usually used in the design of gear materials for gear motors
1. Powder metallurgy gear (metal gear, powder gear) is a kind of commonly used powder metallurgy parts. It can better meet the dimensional accuracy requirements, especially the tooth profile accuracy, through one-step forming and finishing without any other post-processing technology. Powder metallurgy gears are usually used in small low power gear motors
1.1 powder metallurgy is a recrystallization process of metal powder formed at high temperature. No rolling process, no metal fiber flow, is a kind of non directional mechanical properties. Therefore, the bending strength and shear strength of the teeth are not as good as those of traditional machines.
1.2 the precision of P / M gear is relatively low because it is unable to control all aspects in the process of high temperature sintering. Uncontrollable factors include brick firing, brick firing shape, accurate size, etc. Therefore, the stability of the transmission is poor.
1.3 the contact strength of PM gear teeth is also relatively low, so it is unable to transfer high torque.
1.4 the surface roughness of P / M gears is relatively large, which will produce noise during transmission.
1.5 although oil-bearing gear teeth can be made, the effective time of oil lubrication is relatively short. In order to expand normal use, external application lubrication (bath lubrication is better) must be considered.
2. The gear material of gear motor is carburized steel, and its performance requirements are as follows:
2.1 the ability to absorb carbon is strong. The surface can absorb enough carbon; The permeability is fast and the carbon gradient is flat; The content of retained austenite is suitable; The volume, complete number, size and uniform distribution of carbides together improve the hardness, strength and toughness of the layer.
2.2 low overheating sensitivity. Austenite can still keep fine grain state when heated for a long time at carburizing temperature, so as to realize direct quenching and prevent martensite from large grain size and deterioration of mechanical properties after quenching.
2.3 after quenching, the center has high yield strength and toughness, which requires sufficient hardenability; In addition, mild cooling medium can be used to greatly reduce the possibility of deformation and cracking of carburized parts.
2.4 alloy carbon steel with serious banded structure, coarse inclusions and no cracks. Especially the surface of carburized layer should pay more attention to these factors.
3. plastic gears are mainly used in micro precision gear motors. The common characteristics are as follows:
3.1 the precision of injection gear depends on the precision of mold and plastic properties to a great extent.
3.2 good chemical stability helps to resist the erosion of acids, bases and organic solvents.
3.3 good wear resistance, self lubrication, smooth transmission and no noise.
3.4 good electrical insulation and poor thermal diffusivity.
3.5 the density of plastic is small, and the weight of product can be reduced by plastic gear.
Contact: Jack He
Add: BuildingA 125 WeiMin Road,DongSheng Town,ZhongShan city,GuangDong Province,China