摘要 |
An internal combustion engine comprises a cylinder block formed of aluminum alloy and having main bearing bulkheads each of which is formed with a bearing surface. Main bearing caps are securely connected respectively with the bearing bulkheads and formed of aluminum alloy. Each bearing cap is formed with a bearing surface which is located in opposition to the bearing surface of the bearing bulkhead. Additionally, the main journal of a crankshaft formed of iron alloy is rotatably disposed between the bearing surfaces of the bearing bulkhead and bearing cap. The surfaces of the crankshaft main journal is in direct contact with the bearing surfaces of the bearing bulkhead and bearing cap without using conventional bearing metals, thereby cutting off engine noise due to the existence of the bearing metals. |