机械制造及其自动化专业英语汇总.doc

Basic Concept in Mechanics The branch of scientific analysis which deals with motions time and forces is called mechanics and is made up of two parts statics and dynamics. Statics deals with the analysis of Stationary ,i .e.,those in which time is not a factor,and dynamics deals with systems which change with time . 对运动、时间和作用力进行科学分析的分支称为力学它由静力学和动力学俩部分组成。静力学对静止系统进行分析即在其中不考虑时间这个因素动力学对随时间而变化的系统进行分析。 Forces are transmitted into machine members through mating surfaces ,e.g.,form a gear to a shaft or form one gear through meshing teeth to another gear,from a V belt to a pulley,or from a cam to a follower. It is necessary to know the magnitudes of these forces for a variety of Reasons. The distribution of the forces at the boundaries or mating surfaces must be reasonable and their intensities must be within the working limits of the materials composing thesurfaces. For example if the force operating on a journal bearing becomes too high it will squeeze out the oil film and cause metal-to-metal contact overheating and rapid failure of the bearing. If the forces betweens gear teeth are too large the oil film may be squeezed out from between them. This could result in flaking and spalling of the metal noise rough motion and eventual failure. In the study of mechanics we are principally interested in determining the magnitude direction and location of the Forces. 力通过接触表面传到机器中的各构件上。例如从齿轮传到轴或者从齿轮通过与其啮合的轮齿传到另一个齿轮从V带传到带轮,或者从凸轮传到从动件。由于很多原因人们必须知道这些力的大小。这些力在边界或在接触表面的分布必须合理,它们的大小必须在构成配合表面的材料的工作极限以内。例如如 果作用在一个滑动轴承上的力太大,它就会将油膜挤出,造成金属与金属的直接接触,产生过热和使轴承快速失效。如果齿轮相啮合的齿与齿之间的力过大就会将油膜从齿间挤压出来。这会造成金属表层的碎裂和剥落,噪音增大,运动不精确直至报废。在力学研究中,我们主要关心力的大小、方向和作用点。 Some of the terms used in mechanics are defined below. 在力学中要用到的一些术语定义如下。 Force Our earliest ideas concerning forces arose because of our desire to push , lift , or pull various objects . So force is the action of one body on another . Our intuitive concept of force includes such ideas as place of application , direction ,and magnitude , and t