Why is it not allowed to grind the tooth root groove part in gear grinding?

Why is it not allowed to grind the tooth root groove part in gear grinding?The specific reasons are as follows, for reference and understanding.

1. According to relevant domestic and foreign data, for hard-toothed heavy-duty gears, the service life of the non-ground tooth groove part of the ground tooth is 1.7 to 170 times that of the ground tooth root tooth groove part. It is good to grind the tooth root and round tooth groove.

2. It is a pity to grind off the hardened hardened layer of the hardened tooth root tooth groove after carburizing and quenching. The hardness of the tooth root tooth groove is greatly reduced.gearThe bending fatigue strength.

3. After the gear is strengthened by shot peening, the maximum residual pressure stress value is located at about 0.05mm on the next surface layer of the tooth surface, and the residual pressure stress can be as high as -800～-1200MPa.Once the tooth root circular tooth groove is ground, the residual compressive stress formed at the tooth root disappears, which will cause the residual compressive stress to become tensile stress, which will have a serious impact on the fatigue resistance and long life of the gear.

4. From the perspective of anti-breaking ability, there must be a certain amount of undercutting at the root of the tooth. There is no certain amount of undercutting at the root of the tooth. It is inevitable to produce a boss at the root of the tooth during tooth grinding, which will cause serious stress concentration and resist The ability to break teeth has a great influence, and it is found that the boss is absolutely not allowed.

5. The tooth root circular tooth groove is narrow, the heat dissipation capacity is poor, and the margin at the transition curve changes greatly, the grinding wheel tooling condition is poor, and grinding burns and grinding cracks are prone to occur in grinding teeth.

6. The grinding conditions of the tooth root and the tooth groove are poor, and the external abrasive grains of the grinding wheel are easy to fall off and wear, which affects the quality of the grinding teeth.

In short, the non-grinding tooth root circular tooth groove can significantly improve the fatigue strength, bearing capacity and service life of the gear, avoid grinding tooth damage, improve grinding tooth quality, reduce grinding tooth load, and increase productivity.