Analysis of advantages and disadvantages of gear machining and powder metallurgy

Analysis of advantages and disadvantages of gear machining and powder metallurgy

1、 Advantages of powder metallurgy gear:

1. Low cost, high production efficiency, one-time molding, no need to re process gear teeth after molding.

2. Due to the processing characteristics of powder metallurgy, oil-bearing parts can be made into non lubricating parts, but the effect is still worse than that of oil bath lubrication, which belongs to boundary lubrication.

3. There is no waste in the gear forming process, which is conducive to the utilization of steel resources.

2、 Powder metallurgy gear defects:

1. Powder metallurgy is a recrystallization process that allows metal powders to form at high temperatures. It has no rolling process and no metal fiber flow. It is a non oriented mechanical property. Therefore, the bending strength and shear strength of gear teeth are not as good as those of traditional gear processing.

2. It is also due to 1 that the contact strength of P/M gear teeth is also very low, so they cannot transmit large torque.

3. Although gear teeth containing oil can be made, the effective time limit of oil lubrication is relatively short. To ensure normal use, additional lubrication should be considered. The oil bath is well lubricated.

4. The precision of powder metallurgy gear is relatively low, because it can not be controlled in the process of high-temperature sintering molding. Just like burning bricks, the size of green bricks cannot be controlled. Therefore, the transmission stability is poor.

5. For four reasons, the surface roughness of gear teeth is relatively large, which will produce noise in transmission.

In short, powder metallurgy gears, such as toys, precision transmission, high torque transmission, etc. Or gears to be machined can be considered in some unimportant mechanisms

The gear degree made by powder metallurgy is not very high, usually about 10, which is not suitable for precision transmission.