Hardened gear

Hardened gear材料一般选择40Cr、 45#、45Mn2钢、20Cr、20CrMnTi、20CrMnVB、20CrNiH、38CrMnAl等，因其承载能力高多用来进行大扭矩大功率动力传动场合。硬齿面齿轮为根据产品齿面硬度大小来划分出来的，另外一类就是软齿面齿轮。下面EP 加工 为你一一解答，希望能对大家有所帮助。

Hardened gear: YesgearAfter fine cutting, quenching, surface quenching or carburizing quenching is performed to increase the hardness.Generally, the tooth surface hardness of a pair of meshing gears is greater than 350HBW, and the gear with a soft surface is less than 350HBW.The higher the tooth surface hardness, the greater the load-bearing capacity of the product, which is easy to understand.

1. Deep carburizing, quenching and grinding of high-precision hardened gears, especially suitable for low-speed and heavy-duty gear transmissions, with high precision and high surface hardness (HRC58+4), and the contact strength is doubled compared with quenched and tempered gears. Compared with quenched and tempered gears, the strength is increased by more than 50%, and the hardened layer of the tooth surface is uniform.

2. In the hard tooth surface, the nitriding hard tooth surface is not suitable for the vulgar and heavy-duty gear transmission. On the one hand, the depth of the nitriding layer is very shallow.

3. The transition interface between the hardened layer and the non-hardened layer of surface quenching (such as high, intermediate frequency or flame quenching) is obvious, the distribution of hardness is too large, and the quality of hardening is uneven, hardening of the tooth root is difficult, and surface cracks are easy to form , The tooth surface hardness is low (about HRC55), and the application is gradually reduced.

4. The adoption of hard-tooth surface gears greatly promotes the light weight, miniaturization and quality performance of the machine, and increases the working speed of the machine by a level.

5. For hardened gears, the gear accuracy after grinding is generally selected as level 6 accuracy.When the line speed is particularly high, choose level 4-5. When there are special requirements for vibration and noise, the current accuracy can be as high as level 3.

6. Use the common normal line micrometer type hardness tester to test the hardness from the tooth tip to the tooth root, and the hardness difference is very small.

7. In order to improve the bearing capacity of the gear, the computer is used to optimize the design of the geometric parameters and the modification coefficient of the gear.

8. The main failure form of hard tooth surface is bending failure. To calculate the tooth root stress, the bending strength, compression stress, shear stress, gear heat treatment effect and internal stress generated during assembly are mainly considered.

9. Use a computer to calculate the composite stress of the tooth surface and tooth root, comprehensively consider the contact strength and bending fatigue strength, determine the geometric parameters, materials, allowable fatigue strength of the gear, and the hardness curve of the gear and the depth of the hardened layer of the tooth surface.

10. After the modulus of the hardened gear is increased, or the diameter of the quenched and tempered gear is increased, if the gear accuracy is not improved, the increase in strength caused by the increase in modulus and diameter will offset the increase in passive load

11. For carburized and hardened gears with high load-bearing capacity and high hardness, tooth tip and tooth direction trimming technology is an indispensable condition for ensuring product performance.

The above is what I shared with you todayHardened gearRelevant instructions, including but not limited to, are for reference and understanding. For more questions, please consult EP Processing for free.