Curved face width (CFW) spur gears are not popular in the gear industry. But these non-metallic gears have advantages over standard spur gears: higher contact ratio, higher tooth stiffness, and lower contact and bending stresses.
There is an increasing significance of screw helical and worm gears that combine use of steel and plastics. This is shown by diverse and continuously rising use in the automotive and household appliance
industries. The increasing requirements for such gears can be
explained by the advantageous qualities of such a material combination in comparison with that of the traditional steel/bronze pairing.
Surface coatings or finishing processes are the future technologies
for improving the load carrying capacity of case hardened gears. With
the help of basic tests, the influence of different coatings and finishing
processes on efficiency and resistance to wear, scuffing, micropitting,
and macropitting is examined.
The aim of our research is to clearly show the influence of defects on the bending fatigue strength of gear teeth. Carburized gears have many types of defects, such as non-martensitic layers, inclusions, tool marks, etc. It is well known that high strength gear teeth break from defects in their materials, so it’s important to know which defect limits the strength of a gear.
Where were you? We were hoping to see you here at Gear Expo. We were surprised that you didn't make it.
Anyway, we had a really good show, along with more than a hundred other leading companies in the gear industry
who exhibited this year.
Carburized helical gears with high retained austenite were tested for surface contact fatigue. The retained austenite before test was 60% and was associated with low hardness near the case's surface. However, the tested gears showed good pitting resistance, with fatigue strength greater than 1,380 MPa.