机械工程专业英语教程 (第5版)课件 (18)[18页]

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《机械工程专业英语教程》
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Lawn-mower 割草机，草坪修剪机
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《机械工程专业英语教程》
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Crankcase The metal case enclosing the crankshaft and associated parts in a reciprocating engine 曲轴箱：在往复式发动机内装有曲轴和相关部件的金属箱 体。
2. A force that resists the relative motion or tendency to such motion of two bodies in contact. 摩擦力：一种阻碍两个相接触物体之间产生相对位置 移动的力。
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《机械工程专业英语教程》
mechanical advantage 机械效益
because no work takes place. [2]
2. mechanical advantage意为“机械效益”，lost energy意为“损失的能量”。这两句可译为：在 一台机器中，运动零件之间的摩擦是有害的，因 为它会降低这个装置的机械效益。因为摩擦所产 生的热量不做功，它是被损失的能量。
Piston 活塞
2020/11/13
《机械工程专业英语教程》
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Filing 锉削
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《机械工程专业英语教程》
பைடு நூலகம்
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Cyclic loading parameters 循环载荷的参数
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《机械工程专业英语教程》
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• connecting rods 连杆
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《机械工程专业英语教程》
Text tour
Our common experience is that objects in motion do not usually stay in motion. In practice we move, or try to move one object against another, and there are interactions that resist the motion. When surfaces in contact move relative to each other, the friction between the two surfaces converts kinetic energy into
Lesson 20 Friction, wear, and Lubrication
• Terminology
• Text tour
2020/11/13
《机械工程专业英语教程》
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Terminology
Friction
1. Friction is the resistance to motion of two moving objects or surfaces over each other. 摩擦：两个相互接触的物体当有相互运动或相互运动 趋势时，在接触面产生的阻碍运动的作用。
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《机械工程专业英语教程》
• The friction of moving parts in a machine is harmful because it reduces the mechanical advantage of the device. The heat produced by friction is lost energy
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《机械工程专业英语教程》
Wear can be defined as the progressive loss of material from the operating surface of a body occurring as a result of relative motion at the surface.[3] The problem of wear arises wherever there are load and motion between surfaces, and is therefore important in engineering practice, often being the major factor governing the life
the ratio of the force produced by a machine to the force applied to it, used in assessing the performance of a machine 一台机器的输出力对其输入力的比值，用来评估机器的性能
Crankshaft 曲轴
and performance of machine components.
3. operating surface 意为“工作表面”。全句可译为： 磨损可以被定义为物体的工作表面在相对运动中逐渐 损耗的现象。
thermal energy (that is, it converts work into heat).[1]
1. move one object against another意为“使两个接触的物体作
相对运动”，kinetic energy意为“动能”。全段可译为：我 们的日常经验是运动中的物体通常不会持续保持运动状态。 在实践中，我们使两个相互接触的物体作相对运动或试图使 其作相对运动时，它们之间的相互作用会对运动产生阻抗。 当接触表面作相对运动时，两个表面之间的摩擦会把动能转 化为热能（也就是说，它把功转化为热）。
Additive A substance added in small amounts to something else to improve, strengthen, or otherwise alter it. 添加剂：一种少量添加后可以使其它物质的性能得到改进、 提高或改变的物质。
Abrasive Wear 磨粒磨损，磨料磨损