The crank mechanism supported in the crankcase consists of a double crank and six connecting rods.
The sturdy crankcase is made of cast iron and its bottom serves as an oil pan. Another special oil storage tank, as a continuation of the oil pan, draws in the lubricating oil required by the crank mechanism from here. An oil distributor is installed on the side of the crankcase, and the oil from the oil distributor flows through the oil filter. The oil filler pipe is installed on the upper part of the crankcase.