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In automotive engineering, “throw” has two primary meanings related to the crankshaft and connecting rods:
- Crankshaft Throw:
- Definition: The throw of a crankshaft refers to the offset portion of the crankshaft where the crankpins or crankshaft journals are located.
- Function: The crankshaft throw determines the distance between the center of the main bearing and the center of the crankpin journal, which is where the connecting rod attaches. This distance determines the stroke of the engine.
- Importance: The throw plays a crucial role in converting the reciprocating motion of the pistons into rotational motion in the crankshaft. It influences the engine’s displacement, torque characteristics, and overall performance.
- Connecting Rod Throw:
- Definition: The connecting rod throw refers to the distance between the center of the crankpin journal and the center of the wrist pin or piston pin where the connecting rod attaches.
- Function: The connecting rod throw determines the length of the connecting rod and, along with the crankshaft throw, influences the stroke of the engine.
- Importance: The connecting rod throw affects the motion of the piston and the forces transmitted to the crankshaft during the engine’s operation. It plays a role in determining engine balance, piston acceleration, and overall durability.
Together, the crankshaft throw and connecting rod throw are critical design parameters that affect engine performance, durability, and efficiency. They contribute to the engine’s displacement, bore, stroke, and other geometric characteristics, ultimately influencing its power output and operational characteristics.
See
- Crankpin
- Crank throw