Overview of gear heat treatment

As we all know, gear is the key part of mechanical equipment, which is widely used in automobile, aircraft, tank, ship and other industrial fields. It has the advantages of accurate transmission, compact structure and long service life. Gear transmission is the most common mechanical vibration in modern machines, which is an important form of transmitting mechanical power and motion and an important basic part of mechanical products. Compared with belt, chain, friction, hydraulic and other machines, it has a series of advantages, such as large power range, high transmission efficiency, high peripheral speed, accurate transmission ratio, long service life, small size and structure. Therefore, it has become an indispensable transmission part of many mechanical products, and it is also the transmission form with the largest proportion in the machine. Due to the prominent position of gear in the industrial development, gear is recognized as a symbol of industrialization. Thanks to the pull of automobile, wind power and nuclear power industry in recent years, the demand growth of automobile gear processing machine tools and large-scale gear processing machine tools is very dazzling. It is understood that with the increasing demand for gear processing machine tools, the number of enterprises involved in the manufacturing of gear processing machine tools is also increasing in recent years. Whether it is the traditional automobile, ship, aerospace, military and other industries, or the emerging high-speed rail, railway, electronics and other industries in recent years, all of them have put forward urgent needs for the rapid development of the machine tool industry, and new requirements for the gear processing machine tool manufacturers. According to the authoritative department, it will reach 2 million tons in 2012. However, the quality of gears in our country still has a certain gap compared with similar products in other developed countries, mainly in the average service life of gears, energy consumption per unit product and productivity. This design is an exploration and attempt after learning the knowledge of heat treatment in class. Its content discusses how to design the heat treatment process of gear. The key is to make a reasonable heat treatment procedure and design the heat treatment method of gear according to this.

Gear is one of the most widely used important parts in mechanical industry. Its main function is to transfer power, change the speed and direction of motion. Is the main part. The service conditions are as follows:

(1) When the gear works, it transmits the power through the contact of the tooth surface. In the process of relative motion, the two gears have both rolling and sliding. Therefore, the gear surface is affected by a lot of contact fatigue stress and friction. It is affected by bending stress at the root of tooth;

(2) the overload of high-speed gear in the operation process produces vibration and bears certain impact force or overload;

(3) in some special environments, it is affected by the medium environment and bears other special forces.

Therefore, the surface of the gear has high hardness and wear resistance, high contact fatigue strength, high bending strength of the tooth root and high impact resistance of the center.