What is piston rod?

Answer 1

The piston rod is more usually called the con rod or connecting rod. It is connected at the top end to the piston with what is called a wrist pin. (The wrist pin is a cylinder of steel that slides through the side of the piston and through the top hole in the connecting rod.) At the bottom end the connecting rod mates up to the crankshaft. There is what is called a rod cap that goes on the bottom of the connecting rod to hold that rod onto the journal of the crankshaft.

The connecting rod's purpose is to transfer downward and upward thrust between the piston and crank. The combustion of fuel drives the piston down to the crankshaft were it is converted to rotary force which drives your wheels.

The wrist pin, is called a piston pin or gudgeon pin in the UK. The hole in the con-rod is commonly called the small or little end, and the other end where the cap holds it to the crankshaft is the big end.