机械工程专业英语14课.ppt

Concepts n. 概念，观念；思想（concept[k?nsept]复数形式） mechanism [mek?niz?m]n. 机械装置；机制；技巧；原理，途径；进程 马驰 马盛杰 潘锦阳 A combination of interrelated parts having definite motions and capable of performing useful work may be called machine. A mechanism is a component of a machine consisting of two or more bodies arranged so that the motion of one compels the motion of the others. combination?[,k?mbinei??n]n.?结合；化合；联合；组合? interrelated?[,int?rileitid]adj.?相关的；互相联系的v.?使相互联系? definite?[definit]adj.?确切的；一定的? motion?[m?u??n]n.?动作；请求；手势；移动；意向i.?运动；打手势vt.?运动；向…打手势? capable?[keip?bl]adj.?能干的，能胜任的；有才华的? mechanism [mek?niz?m]n. 机械装置；机制；技巧；原理，途径；进程 一些有关联的部分综合起来能够实现一定运动并能完成有用的工作叫做机器。一个机构是一个由两个以上的部分装配成的机器的一个组件以实现一个部件的运动带动其他部分运动。 Kinematics is the study of motion in mechanisms without reference to the forces that act on the mechanism. Dynamics is the study of motion of individual bodies and mechanisms under the influence of forces and torques. The study of forces and torques in stationary systems ( and systems with negligible inertial effects ) is called statics. reference [ref?r?ns]n. 参考，参照；涉及，提及；参考书目；介绍信；证明书vi. 引用vt. 引用 dynamics [dain?miks]n. 动力学，力学 torque [t?:k]n. 转矩，扭矩；项圈，金属领圈 negligible [neɡlid??bl] adj. 微不足道的，可以忽略的 运动学是研究机构的运动而不涉及施加在机构上的力。动力学是研究运动的部分和受力和力矩影响的机构。研究静止系统的力和力矩叫做静力学（或者说是惯性影响对系统是微不足道的）。 The definitions of some terms and concepts fundamental to the study of kinematics dynamics of mechanisms are defined below. 一些术语的定义和运动学动力学的研究的基础的概念上定义如下。 Degrees of Freedom Any?mechanical?system?can?be?classified?according?to?the?number?of?degree?of?freedom?(DOF)?which?it?processes.?The?system’s?DOF?is?equal?to?the?number?of?independent?parameters?which?are?needed?to?uniquely?define its position in space at any instant of time. 根据机构所具有的自由度，任何机械系统都可以被分类。系统的自由度是在任何时候限制它的位置独立的参数数目。 An unconstrained rigid body has six degrees of freedom; translation in three coordinate directions and rotation about three coordinate axes. If the body is restricted to motion in a plane, there are three degrees o