A connecting rod assembly connects to a cross head by means of what component?

The wrist pin is the component that connects the connecting rod assembly to the cross head in an engine's mechanism. It allows for the pivoting movement of the connecting rod, enabling the conversion of linear motion from the piston into rotary motion through the crankshaft. The wrist pin is crucial for the articulation between the connecting rod and the piston, facilitating the movement needed for proper engine operation. This connection is essential for the functionality of the engine, ensuring that the forces generated during combustion can be efficiently transmitted through the connecting rod to the crankshaft.

The other components listed have specific functions but do not serve the same purpose as the wrist pin in connecting the connecting rod to the cross head. Piston pins are typically associated with the connection between the piston and the connecting rod but do not directly relate to the cross head. The crankshaft is responsible for converting the linear motion from the connecting rods into rotational motion but does not directly connect to the cross head. A linkage rod typically refers to a different type of mechanical connection often found in different mechanisms. Thus, the wrist pin is the correct component for this specific connection in the assembly.