机械工程英语(刘镇昌)翻译11.doc

Lesson11 Designs of ponents-Bearings
A bearing is a support system for rotating, oscillating, or translating machine elements, in which friction has been greatly reduced. Since it has been estimated in various studies that on the average about 30% of all mechanically transmitted energy are lost to friction, an understanding of friction phenomena in bearings is essential to the machine designer.
轴承是一个用于旋转,摆动,或移动机构中大大降低摩擦的支持系统。据各项研究中估计,摩擦所造成的能量损失平均大约占全部机械传递能量的30%,机械设计者对轴承中摩擦现象的了解是必不可少的。
Plain bearings provide sliding support, and friction is usually reduced by a liquid, solid, or gaseous lubricant. The following types of plain bearings are in use:
滑动轴承提供滑动支承,摩擦通常由液体、固体或气体的润滑剂减少。滑动轴承有以下类型的使用:
1 Journal bearings or sleeve bearings support a rotating or oscillating shaft. The bearing usually has a cylindrical shape, while the journal is most often physically a portion of the shaft. When the pletely surrounds the journal, we speak of a full bearing; when the bearing only partly surrounds the journal, it is called a partial bearing.
轴颈轴承或套筒轴承支撑旋转或摆动轴。轴承通常具有圆柱形状,而轴颈是物理轴最多的一部分。当轴承完全包围轴颈时,我们称之为一个完整的轴承;当轴承仅部分地围绕轴颈时,它被称为一个局部轴承。
2 Thrust bearings support an axial load on a rotating or oscillating shaft.
旋转或摆动轴上的推力轴承支撑轴向负荷。
3 Line or guide bearings guide and support translating motion.
线或导轨轴承引导和支持平移运动。
The lubricant in journal bearings is most often oil, in special cases water, an