| 摘要 |
PURPOSE:To improve the oil feeding capacity, to increase the feed oil quantity to each sliding portion, and to prevent the seizure of a bearing, etc. by increasing the contact area between the lubricating oil and the inner wall surface of an oil lifting pipe so as to increase the friction force based on the viscosity of the oil on the inner wall surface of the oil lifting pipe. CONSTITUTION:The roughened surface of the inner wall 9 of an oil lifting pipe 7 is constituted in a spiral with a pitch of (l) and a roughened surface width of W, and the direction of the spiral is determined by the rotating direction of a main shaft. Accordingly, the contact area between the lubricating oil and the inner wall surface 9 of the oil lifting pipe 7 is increased, thus improving the oil lifting capacity. That is, the friction force based on the viscosity of the oil on the inner wall surface of the lubricating oil is increased, and the feed oil quantity is increased furthermore. As a result, the feed oil quantity to each sliding portion during the initial start and normal operation is increased, thereby the seizure of a bearing can be prevented. |
