Thanks! Just started reading about rocket engines, I don't think most people realize how many moving parts the SpaceX engines have!
Assuming the fuel and oxidizer impellers are on a common shaft, that's one. There must be a throttle valve somewhere, so that's two. What am I missing? Are there reduction gears?
I have studied a lot of pintle injector designs and it can go either way. Reguardless, a moving pintle injector typically only has two moving parts.