英语1.doc.gzip

It is essential that you known the desires and expectations of all customers before product design. Marketing professionals are often employed to manage the definition of customer expectations , designers will likely work with them as a part of a product development team.在产品设计之前了解顾客的愿望和期望是十分必要的。

经常请市场专业人员来对顾客期望进行评定，但设计人员却很可能作为产品开发小组的一部分与市场专业人员一起合作。

Specialized knowledge of the behavior of machine elements , such as gears ,belt drives ,chain drives，shafts, bearings, keys, splings, couplings, seals, springs, connections (bolted, riveted, welded，adhesive)，electric motors，linear motion devices，clutches，and brakes.机械元件的专业知识，如齿轮，皮带传动，链传动，轴，轴承，键，花键，联轴器，密封件，弹簧，连接（螺栓，铆接，焊接，粘接），电动马达，直线运动装置，离合器和刹车One popular method ,called quality function deployment or QFD, seeks to identify all of the features and performance factors that customers desire and to assess the relative importance of these factors .一种通用的方法，称为质量功能展开（简称QFD），寻求识别顾客期望的所有特征和性能因素，并用于评定这些因素之间的相对重要性。

It is also important to consider how design process fits with all functions that must happen to deliver a satisfactory product to the customer and to service the product throughout its life cycle . 考虑设计过程如何满足所有功能也是很重要的，这些功能必须恰好把满意的产品交给顾客并在整个产品的生命周期内服务该产品。

Section 1 emphasized the importance of carefully identifying the needs and expectations of the customer prior to beginning the design of a mechanical device.在第一部分强调了在开始设计机械装置之前仔细的了解顾客要求与期望的重要性。

The driving teeth push on the driven teeth，exerting a force perpendicular to the radius of the gear. 主动齿轮推动从动齿轮运动，产生一个垂直与齿轮半径方向的力。

Gear are toothed, cylindrical wheels used for transmitting motion and power form one rotating shaft to another .齿轮是带有齿的，圆柱形的轮子，用来将运动和动力从一个旋转轴传递给另一旋转轴。

Otherwise there would be speeding up or slowing down during the engagement,with the resulting accelerations causing vibration ,noise, and dangerous torsional oscillations in the system.若情况并非如此，啮合时，时而加速、时而加速，产生的减速度会引起系统振动、噪声以及危险的扭转摆动。

It is a fundamental principle of kinematics ,the study of motion ,that if the line drawn perpendicular to the centerline between the two bodies at the same place ,the angular velocity ratioof the two bodies will be constant .研究运动的运动学的一条基本原理是，如果在接触点垂直于两个定轴转动物体的直线是过两物体的中心线，则两物体的角速度保持常数。

The parallel shaft arrangement for helical gears is preferred because it results in a much higher power-transmitting capacity for a given size of gear than the crossed helical arrangement .对斜齿轮优先安排平行轴安装，因为对于一定尺寸的齿轮，平行轴安装可比交错轴安装传递更大的功率。

A key is the machinery component placed at the interface between a shaft and the hub of a power-transmitting element for the purpose of transmitting torque.键是一种置于轴与传递动力的轮毂之间的机械零件，用于传递扭矩。

The keyseats in shaft and the hub are designed so that exactly one-half of the height of the key is bearing on the side of the shaft keyseat and the other half on the side of the hub keyseat .轴上的键槽和轮毂上的键槽深度刚好是建高度的一半，键的一半在轮毂键槽中另一半在轴上键槽中。

Flexible coupling are designed to transmit torque smoothly while permitting some axial ,radial ,and angular misalignment.柔性联轴器被设计用于当轴向、径向以及角度偏斜时仍能传递平稳运动。

The rectangular key is recommended for certain kinds of equipment in which precise alignment of two shaft is required and can be provided.对于较大的轴，推荐采用矩形键，档高度较低的一边允许是，可用于较小的轴。

This design is desirable for certain kinds of equipment in which precise alignment of two shafts is required and can be provided.对于某些设备而言，当两轴要求具有精确的队中性时，这种设计才是令人满意的。

A typical rigid coupling in which flange ser mounted on the ends of each shaft and are drawn together by a series of bolts.典型的刚性联轴器每根轴的末端装上末端上凸缘并用螺栓连在一起。

The term rolling contact bearing refers to the wide variety of bearing that use spherical balls or some other type of roller between the stationary and the moving elements.滚动接触球轴承是指在静止元件和运动元件之间使用球或其他类型滚动体的、种类繁多的轴承。

Misalignment refers to the angular deviation of the axis of the shaft at the bearing from the true axis of the bearing itself .偏斜是指轴在轴承上的中心线与轴承自身中心线的角度偏差。

A bearing with affair rating can withstand up to 0.15,while a poor rating indicates that rigid shafts with less than 0.05 of misalignment are required.较高等级的轴承最高可以承受0.15°得偏斜，而较低等级的则要求刚性周的偏斜小于0.05°The component of a typical rolling contact bearing are inner race, the outer race,and the rolling elements.Rotary power is developed by the electric motor ,but motors typically operate at too high a speed and deliver too low a torque to be appropriate for the final drive application .回转动力尽管有电动机供给，然而，一般的电动机由于转速过高、传递转矩过低，无法成为最终的驱动装置。