The Advantages of Sintered Gears
1, Low cost; High efficiency; A near net-shaping technology without machining.
2, PM could achieve oil-contained parts, then make the parts free of lubrication.
3, There is no waste in the forming process. PM has the best usage of material.
The disadvantages of Sintered Gears
1, PM is inferior to conventional machined gears in flexture strength, shear strength.
2, Gears made by powder metallurgy has relatively low contact strength, there are not able to transmit large torque.
3, PM could make oil-contained gears, but the valid time is kind of short. If keep the oil-contained gears be used normally, they need to be coated with lubrication oil. Oil bath lubrication works best.
4, PM could only achieve low accuracy. Because it’s difficult to control it in the sintering process, just like making bricks. Therefore the transmission stability of sintered gears is poor.
5, Sintered gears is inferior to conventional machined gears in surface roughness, which will make noises in the transmission.
Above all, normally sintered gears are used in important structure, such as toys. The gears used in precision transmission, large torque transmission should be made by machining.
The development of sintered gears in China
However, powder metallurgy has been boomed with its incomparable advantages, and the accuracy, surface roughness, mechanical properties are more and more close to the parts made by machining.
As one of the first batch of manufacturers use powder metallurgy, with development of 19 years, Sints could achieve a tolerance of 0.02-0.05mm, a roughness of R1.6. Sints has a special workshop manufacturing auto gears by powder metallurgy.