The steels commonly used in manufacturing gears are quenched and tempered steel, hardened steel, carburized hardened steel, and nitrided steel. The strength of cast steel is slightly lower than that of forged steel, and it is often used in gears with larger sizes. Gray cast iron has poor mechanical properties and can be used in light-loaded open gear transmissions. Ductile iron can partially replace steel to make gears. Plastic gears are often used. For light loads and where low noise is required, the gear paired with it is generally a steel gear with good thermal conductivity.
In the future, gears are developing in the direction of heavy load, high speed, high precision and high efficiency, and strive to be small in size, light in weight, long in life and economical and reliable.
Gear Introduction
A gear is a mechanical element with teeth on the rim that can continuously mesh and transmit motion and power. It is a toothed mechanical part that can mesh with each other. The diameter of the large gear is twice the diameter of the small gear. The use of gears in transmission has been around for a long time. In more than 300 BC, the ancient Greek philosopher Aristotle explained the problem of transmitting rotary motion with bronze gear or cast iron gears in “Mechanical Problems”. At the end of the 19th century, the principle of the gear cutting method and the use of special machine tools and tools for gear cutting have appeared in succession, so that gear processing has a more complete means. With the development of production, the smoothness of gear operation has been valued.
Gear processing method
There are two main types of involute gear machining methods. One is the profiling method, which uses a forming milling cutter to mill the cogging of the gear, which is “imitating the shape”. The other is Fan Chengfa (spreading method).
(1) Hobbing machine hobbing: It can process helical gears with less than 8 modules
(2) Milling and milling: it can process straight rack
(3) Slotting gear: can process internal teeth
(4) Tooth cutting by cold beater: can be processed without chips
(5) Gear planing machine: can process 16 modules
(6) Precision cast teeth: cheap pinions can be processed in large quantities
(7) Gear grinding machine: can process gears on precision mother machine
(8) Die-casting machine teeth: most machining non-ferrous metal gears
(9) Shaving machine: a metal cutting machine for gear finishing