求人类翻译呀 机械工程专业英语Although wear generally alters a part's surface topography and may result in severe surface damage, it also can have a beneficial effect. The running-in period for various machines and engines produces this

求人类翻译呀 机械工程专业英语Although wear generally alters a part's surface topography and may result in severe surface damage, it also can have a beneficial effect. The running-in period for various machines and engines produces this
求人类翻译呀 机械工程专业英语
Although wear generally alters a part's surface topography and may result in severe surface damage, it also can have a beneficial effect. The running-in period for various machines and engines produces this type of wear by removing the peaks from asperities(fig. 16.3). Thus, under controlled conditions , wear may be regarded as a type of smoothing or polishing process.
Lubrication is a process by which the friction and wear between two solid surfaces in relative motion is reduced significantly by the interposing a lubricant between them. There are four types of fluid lubrication that are generally of interest in engineering practice(Fig. 16.4):
1. In thick-film lubrication,the two surfaces are completely separated from each other by a continuous fluid film. The fluid film can be developed either hydrostatically or, more often by the wedge effect of the sliding surfaces in the presence of a viscous fluid at the interface.
2. As the load between the two surfaces increases or as the sliding speed and viscosity of the fluid decrease, the lubricant film becomes thinner(thin-film lubrication). This condition raises the friction at the sliding interfaces and results in slight wear.
3. in mixed lubrication.although the contacting surfaces are separated by a thin lubricant film,asperity contact also may take place.the total applied load is thought to be carried by asperity contacts and partly by hydrodynamic action.
4. in boundary lubrication ,the load is supported by contacting surfaces covered with a boundary film of lubricant(fig.16.4d).this is a thin(molecular)lubricant layer that is attacted physically to the metal surfaces,thus preventing direct metal-to-metal contact of the two bodies and reducing wear.

求人类翻译呀 机械工程专业英语Although wear generally alters a part's surface topography and may result in severe surface damage, it also can have a beneficial effect. The running-in period for various machines and engines produces this
注：楼上的翻译的很好,但有些专业性的词汇和原理没有翻译出来,本人在其基础上加以修改.
Although wear generally alters a part's surface topography and may result in severe surface damage, it also can have a beneficial effect. The running-in period for various machines and engines produces this type of wear by removing the peaks from asperities(fig. 16.3). Thus, under controlled conditions , wear may be regarded as a type of smoothing or polishing process.
尽管磨损总体上改变了部件的表面微观几何形状并且可能造成严重的表面损坏,但也有好的作用.在磨合期,各种机器及发动机通磨损作用把工件表面微观轮廓曲线的峰顶去除.（图16.3）.所以,在可控状态下,磨损可认为是一种光滑作用或抛光作用.
Lubrication is a process by which the friction and wear between two solid surfaces in relative motion is reduced significantly by interposing a lubricant between them. There are four types of fluid lubrication that are generally of interest in engineering practice(Fig. 16.4):
润滑的作用原理是：通过在两个相对运动的固体表面之间注入润滑剂使它们的摩擦及磨损大大降低.在工程应用中常用到4种液体润滑油（图16.4）：
1. In thick-film lubrication,the two surfaces are completely separated from each other by a continuous fluid film. The fluid film can be developed either hydrostatically or, more often by the wedge effect of the sliding surfaces in the presence of a viscous fluid at the interface.
1.在厚膜润滑中,通过一层连续的液膜使两个表面完全分离.液膜可通过两种方法形成：一种是流体静力法,另一种是楔效应法,即：通过两滑动面之间的粘性流体产生楔效应,这种方法运用更广泛.
2. As the load between the two surfaces increases or as the sliding speed and viscosity of the fluid decrease, the lubricant film becomes thinner(thin-film lubrication). This condition raises the friction at the sliding interfaces and results in slight wear.
2.当两表面间负载增大或滑动速度及流体粘性降低时,润滑油膜变得很薄（薄膜润滑油）.这种状态下滑动表面间的摩擦增大并造成轻微磨损.
3. in mixed lubrication.although the contacting surfaces are separated by a thin lubricant film,asperity contact also may take place.the total applied load is thought to be carried by asperity contacts and partly by hydrodynamic action.
3.在混合润滑油中,尽管接触面被一层薄的润滑油膜隔离,粗暴接触也可能发生.粗暴接触被认为是总实际载荷,并且部分为流体运动.
4. in boundary lubrication ,the load is supported by contacting surfaces covered with a boundary film of lubricant(fig.16.4d).this is a thin(molecular)lubricant layer that is attacted physically to the metal surfaces,thus preventing direct metal-to-metal contact of the two bodies and reducing wear.
4.在边界润滑油中,载荷由表面布满边界油膜的接触面支撑（图16.4d）.这是一层很稀薄（由分子构成）的润滑油层,此油膜与金属表面物理性接合,从而避免两个零件间的金属与金属的直接接触并减少磨损.