| 摘要 |
A piston 10 comprising a compression ring 28 disposed in a compression ring groove 18 and a heat barrier groove extending inwardly into the piston farther than the compression ring groove, wherein a split ring 34 is disposed in an outer portion of the heat barrier groove. A material of low thermal conductivity 32, for example a ceramic, may be disposed in an inner portion of the heat barrier groove. Preferably, the thickness of an inner portion of the heat barrier groove is less than a thickness at which convective currents are substantially absent at the operating conditions of the piston. Also claimed is a method of fabricating a piston comprising a heat barrier groove closer to the piston top than a compression ring groove. The heat barrier groove protects the compression ring from high temperatures, so as to prevent ring sticking due to lubricant breakdown, and the split ring overcomes the structural impact of the heat barrier groove on the piston. |
