- Local time
- 7:50 PM
- Apr 24, 2020
- Reaction score
Interesting. Sorta makes sense. I’ve built plenty of machinery using same-same materials with less lubrication that has run for decades. The galling thing / common metals I’ve only seen with soft metals, SS being the worst.Hydraulic and solid cams are cast cores so they use a "dissimilar metal" steel intermediate gear. Roller cores are billet steel so they need a "dissimilar metal" gear to prevent galling and possible fusing. Therefore they have been using bronze. But the bronze has wear issues - seems to be great as a bushing but not so good as a gear. And not just in engines, I've seen bronze gears in all sorts of machines that have failed. All for the lack of anything better. Nowadays there are some better choices. In some cases nylon gears are an excellent replacement but in cases such as we're talking about, treatments of steel gears is the hot ticket.
One thing that has me puzzled though is transmission and differential gears. But these run in an oil bath so maybe that's why the hold up.