Meaning of Connecting Rod

Connecting Rod

Before entering fully into the the term biela, it is essential that we know its etymological origin. In that case, we can establish that it derives from a word of French origin such as “bielle”. With the same one came to refer to a mechanical organ that exists in what are internal combustion engines.

The term of connecting rod is used to name the object that allows the transformation of a movement of rotation into a reciprocating motion or vice versa.

The connecting rod is a piece that, when subjected to a compression or traction stress, is responsible for transmitting the movement to other parts of a machine. In internal combustion engines, this object is specifically designed to link the piston to the crankshaft.

The piston, which constitutes the moving wall of the chamber where the combustion takes place, transmits the energy generated by the gases of said combustion to the connecting rod through an alternative movement. This movement is copied at the foot of the connecting rod, but this piece is responsible for transforming it until it reaches its head, which is attached to the crankshaft. The energy finally mobilizes the crankshaft, which converts the rectilinear reciprocating motion into uniform motion (and vice versa). This is how torque is produced: the moment of force exerted by the motor on the shaft that transmits power.

In addition to the above, we can underline that a connecting rod is made up of three clearly differentiated ones: the foot, which is where the piston is attached; the connecting rod body and the connecting rod head, which is the part where the crankshaft is placed. The latter is also identified as the hole in the piece with the largest diameter and is usually made up of two clearly differentiated halves.

Made from aluminum, titanium or steel alloys, the connecting rods used by automobiles can be produced through a process known as machining or by forging.

Other information of interest about the connecting rod are the following:
-It is manufactured by forging it. This means that it is created at a very high temperature in order to be able to give it shape and then proceed to mechanize that allow movement.
-In order for it to function properly, it is essential that there is equal weight for each group of connecting rods of an engine.
-It is necessary, in the same way, that in order to perform its functions correctly, the connecting rod has the correct precision in terms of length.
-It is also essential that the parallelism between the axes of symmetry is controlled in its manufacture.

The bikes also have cranks. It is the bar that connects the pedal (the element that the cyclist mobilizes with his legs to rotate on an axis) with the chainring (the device with teeth that meshes the chain links to transmit power to the rear wheel). Thanks to the crank or crank assembly, the reciprocal movement that the cyclist makes with their legs becomes a rotational movement that allows the chain to move and, therefore, also the rear wheel of the vehicle, making it possible to move.

Connecting Rod