一、将下列句子翻译成中文
pulleys1. If the forces between gear teeth are too large, the oil film may be squeezed out from between them. This could result in flaking and spilling of the metal, noise, rough motion, and eventual failure.
如果齿轮间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。这会造成金属的脆裂和剥落，噪音增大，运动不精确，直至报废。
2. The branch of scientific analysis which deals with motions,time,and forces is called mechanics and is made up of two parts,static and dynamics.
对运动，时间和作用力做出科学分析的分支称为力学。它由静力学和运动学两部分组成。
3. Forces are transmitted into machine memebers through mating ,from a gear to a shaft or from one gear through meshing teeth to another gear,from a V belt to a pulley,or from a cam to a follower.
力通过配合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啮合的齿轮传到另一个齿轮，从V带传到带轮，或者从凸轮传到从动件。
4. Gears are manufactured from a wide variety of materials,both metallic as well as nonmetallic.
齿轮由多种种类的材料制造，包括金属材料和非金属材料。
5. Still another kind of force,which seems to make the layers or molecules of a material slide or slip on one another, is a shearing force.
还有另一种力，它似乎会使材料的各层或分子间产生相对滑移，称为剪切力。
6. Rectangular shafts are sometimes used,as in screw driver blades, scoket wrenches and control knob stems.
有时也采用矩形轴，例如，螺丝起子的头部、套筒扳手和控制旋钮的杆。
7. Generally speaking, the angle of twist should noe exceed one degree in a shaft length e
qual to 20 diameters.
一般来说，在长度等于轴的直径的20倍时，轴的扭转角不应该超过1°。
8. A third force is known as a tensional force or a torque since it tends to twist an object.
（我们知道的）第三种力是扭转力，或者叫扭矩，因为它会扭曲物体。
9. It must also be torsionally stiff enough so that one mounted component does not deviate excessively from its original angular position relative to a second component mounted on the same shaft.
轴还应该具有足够的抗扭强度，以使在同一个轴上的两个传动零件之间的相对转角不会过大。
四．用英文解释下列词汇，并将解释的英文句子翻译成中文。
1.Bearing: A device that supports, guides, and reduces the friction of motion between fixed and moving machine parts.
轴承：在机器的固定和运动部件之间起支撑、引导和减少运动摩擦的装置。
2.Gear:A toothed machine part, that meshes with another toothed part to transmit motion or to change speed or direction.
齿轮：有齿的机器零件，与另一个有齿零件相啮合，从而传递运动或者改变运动的方向或速度。
3.Sprocket: Any of various tooth like projections arranged on a wheel rim to engage the links of a chain.
链轮：在轮缘上有牙状凸出物，与链条相啮合的轮子。
4.Coupling: A coupling is a device for connecting the ends of adjacent shafts.
联轴器：联轴器是用来把相邻的两个轴的轴端联接起来的装置。
5.Couple: A pair of forces of equal magnitude acting in parallel but opposite directions, capable of causing rotation but not translation.
力偶：数值相等但方向相反的两平行力，它能使物体转动但不能产生平移。
6.Scalar: A quantity, such as mass, length, or speed, that is completely specified by its magnitue and has no direction.
标量：一个只有大小没有方向的量，如质量、长度或速度等
五．将下列句子翻译成英文
1.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。
Statics deals with the analysis of stationary systems, i.e., those in which time is not a factor,and dynamics deals with systems which change with time.
2.为了在传递扭矩时不发生过载，轴应该具有适当的抗扭强度。
A shaft much have adequate torsional strength to transmit torque and not be over stressed
3.因为扭矩和弯矩会产生交变应力，在许用应力中也应该有一个考虑疲劳现象的安全系数。
Also, the allowable stress must contain a factor of safety which includes fatigue, since torsional and bending stress reversals occur.
4.许多轴需要三个或更多的轴承来支撑，这就意味着它是一个超静定问题。
Many shafts are supported by three or more bearings, which means that the problem is statically indeterminate.
5.由于塑料是电的不良导体，在电气中采用塑料比较安全。
One advantage of using plastic is safety in electrical applications, since plastic is a poor conductor of electricity.
6.轴的最常见的形状是圆形，其截面可以是实心的，也可以是空心的（空心轴可以减轻重量）.
The most common shape for shafts is circular and the cross section can be either solid or hollow(hollow shafts can result in weight savings)
六：将下段文字翻译成中文
1.Shafts are mounted in bearings and transmit power through such devices as gears,pulleys,cams and clutches.These devices introduceforces which attempt to bend the shaft ;hence, the shaft must be rigid enough to prevent ouerloading of the supporting bearings. In general,the bending deflection of a shaft should not exceed 0.01in.per ft of length between bearing supports.
轴安装在轴承中，通过齿轮，皮带轮，凸轮和离合器等零件传递动力，通过这些零件传来的力可能会使轴产生弯曲变形，因此，轴应该有足够的刚度以防止支撑轴承受力过大，总而言之，在两个轴承支撑之间，轴在每英尺长度上的弯曲变形不应该超过0.01英寸。
2.Components such as gears and pulleys are mounted on shafts by means of key. The design of the key and the corresponding keyway in the shaft must be properly evaluated. For example, stress concentrations occur in shafts due to keyways, and the material removed to form the keyway further weakens the shaft.