发动机图一部分，包括曲轴，主连杆总成、凸轮、凸轮转动齿轮、挺杆导套、滚柱、托架等。

A The section of the engine which contains the sleeve, master and link rod assemblies, cams, cam drive gears, tappet guides, carriers, etc.

B The section of the engine which Contains the crankshaft, master and link rod assemblies, cams, cam drive gears, tappet, guides, rollers, carriers, etc.

C The section of the engine which contains the crankshaft, master and manifold assemblies, cams, cam drive gears, tappet, guides, rollers, carriers, etc.