Gudgeon pin

The piston pin is a design element in the crank mechanisms for the transmission of forces between the piston and connecting rod. In internal combustion engines and compressors, gas and inertial forces acting on the bolt. In general, a distinction is made between chamfer and radius bolts, also come increasingly masseerleichterte piston pins used. These are distinguished from by a relatively large inner bevel of standard bolts, but without weakening the highly stressed midsection materially.

The piston pin is mounted in floating manner to the power transmission pin boss of the piston and the connecting rod. Depending on the type of machine to take on the connecting rod needle bearing or plain bearing, the power transmission from the pin to the connecting rod. Next to the oil lubrication Since around 2010 come from DLC coatings used in order to minimize friction between the piston pin and connecting rod or its stock. This can be completely dispensed with oil lubrication on the piston pin almost, and there are by these carbonaceous coating very good emergency running properties. Double-sided bolt locks prevent any axial migration, which is particularly at slot -controlled two-stroke engines of particular importance. The backup can be taken unilaterally by the piston. In many smaller units, the bolts are also held by a shrinkage stress in the connecting rod can be so that dispensed more Kolbenbolzensicherung.

The materials used for these highly loaded components primarily use steel as 16MnCr5 and 17Cr3 and possibly nitrided used. In racing, or in other areas, represent the extreme requirements, other materials have been proven. Initial shape is a tube, wherein the dimensions are chosen as small as possible, due to the inertia forces. The manufacturing and production of these parts makes very high demands on the manufacturing accuracy in roundness, cylindricity and the dimensional stability of the outer diameter. The length is mostly in the minus tolerance, that is, the bolt is a few 1/10 mm less than the nominal dimension. Thus jamming is prevented by the high thermal stresses during combustion or compression process. The outer surfaces are in the hardening process only use or surface hardened ( hardness depth is only a few 1/10 mm to a maximum of 2 mm). Thus, a certain degree of elasticity is ensured because the force direction change would result in through-hardened parts for immediate breakage. The outer diameter is placed after the hardening process by suitable methods such as grinding followed by lapping or Superfinischen to the nominal dimension. This diameter tolerances must be observed depending on the size and purpose of a few 1 /100 mm up to 1/ 1000 mm, which also affects the roundness and cylindricity. Perform even the smallest damage in the region of the plan or side surfaces when they are not noticed, in spite of assembly damage to the piston itself and bring a premature failure or wear with it.