The apparatus 1, wherein the gear and the balance shaft comprise cast iron, which has {HEAD ~ a phosphorous component} of {TAIL ~ at most 0.03 mass percent} 
of
The apparatus 1 , wherein the gear and the balance shaft comprise cast iron , which has { HEAD ~ a phosphorous component } of { TAIL ~ at most 0.03 mass percent }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL