篇一：毕业设计：机械专业毕业论文英文翻译
英文原文：
CNC technology and equipment trends
Level of technology and equipment industry determines the degree of modernization of the entire national economy level and the degree of modernization, numerical control technology and equipment is the development of new high-tech industries and cutting-edge industries (such as information technology and industry, biotechnology and its industrial, aviation, aerospace and other defense industrial property) enabling technologies and the most basic equipment.Manufacturing technology and equipment is the most basic human activities of production, and numerical control technology is today the most advanced manufacturing technology and equipment, the core technology. Widely used in today's world of CNC manufacturing technology to improve manufacturing capability and level, to improve the dynamic changing market adaptability and competitiveness.In addition, all the world's industrialized countries and CNC numerical control technology equipment will be listed as a national strategic materials, not only to take significant steps to develop their own CNC technology and industry, but also in the "sophisticated" numerical aspects of key technologies and equipment China adopted a policy of blockade and restrictions.In short, efforts to develop advanced numerical control technology as the core manufacturing technology has become the world's developed countries to accelerate economic development, improve the comprehensive national strength and an important way to statehood.
CNC technology with digital information on the mechanical movement and the work process control technology, numerical control equipment is CNC technology as the representative of new technologies on traditional manufacturing industries and emerging manufacturing penetration mechatronic products formed, the so-called digital equipment , its technical scope covers many areas: (1) manufacturing Technology; (2) information processing, processing, transmission technology; (3) automatic control technology; (4) servo drive technology; (5) sensor technology; (6) software technology.
1 CNC technology trends
CNC technology trends not only to the traditional manufacturing industry has brought a revolutionary change, so that manufacturing industry to become a symbol of industrialization, and with the continuous development of numerical control technology and expansion of application fields, some of his people's livelihood important sectors (IT, automobile, light industry, medical and other) development plays an increasingly important role, because these industries digitization equipment required is the development trend of modern. From the world of CNC technology and equipment development trend, its main research focus in the following areas [1 ~ 4].
1.1 high-speed, high precision technology and new trends in equipment
1.2 axis machining and rapid development of machine tool
1.3 intelligent, open, networked CNC system developed to become a major contemporary trends
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1.4 emphasis on new technical standards and specifications established
Two pairs of numerical control technology and industrial development of the basic estimates of CNC technology started in 1958, nearly 50 years of development history can be divided into three stages: the first stage, from 1958 to 1979, that enclosed stage of development.At this stage, the blockade of foreign technology and our basic conditions, numerical control technology development is relatively slow. The second stage is in the country's "Plan", "Plan" period and the "85" preliminary, that the introduction of technology digestion and absorption, initially established localization system phase.At this stage, since the reform and opening up national attention, and research and development to improve the environment and the international environment, China's CNC technology research, development and localization of the product have made considerable progress.The third stage is the country's "85" late "Ninth Five-Year" period, namely the implementation of the industrialization of research into the market competition stage. At this stage, China's domestic CNC equipment industry has made substantial progress.Throughout our CNC technology nearly 50 years of development, especially through four five-year plan of research, on the whole achieved the following results.
a. laid the foundation for the development of numerical control technology, basic grasp of modern CNC technology. Our country is now basically mastered from the CNC system, servo drives, CNC hosts special plane and fittings of the underlying technology, most of which technology is ready for commercial development foundation, part of the technology has been the commercialization and industrialization.
b. initial formation of the numerical control industrialization bases. In the commercialization of research results and some technology, based on the establishment of such central NC, aerospace CNC numerical control system having a production capacity production plant. Lanzhou Electric Plant, and a number of CNC servo system and servo motor production plant and the Beijing First Machine Tool Plant, Jinan First Machine Tool Plant, etc. Several CNC host plant. The basic form of the production plant of CNC industrial base.
c. established a numerical research, development, management personnel of the basic team.
Although the numerical control technology research and development and industrialization has made considerable progress, but we must clearly recognize that our high-end CNC technology research and development, especially in the industrialization of technological level of China's actual situation and needs further there is a big gap. Although the development of our country from the longitudinal look fast, but the lateral ratio (compared with foreign countries) is not only a technical level there are gaps, the pace of development in some areas there are gaps that some sophisticated level of technology CNC equipment gap widening.
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中文翻译：
数控技术和装备发展趋势
装备工业的技术水平和现代化程度决定着整个国民经济的水平和现代化程度，数控技术及装备是发展新兴高新技术产业和尖端工业（如信息技术及其产业、生物技术及其产业、航空、航天等国防工业产业）的使能技术和最基本的装备。制造技术和装备就是人类生产活动的最基本的生产资料，而数控技术又是当今先进制造技术和装备最为核心的技术。当今世界各国制造业广泛采用数控技术，以提高制造能力和水平，提高对动态多变市场的适应能力和竞争能力。世界上各工业发达国家还将数控技术及数控装备列为国家的战略物资，不仅采取重大措施来发展自己的数控技术及其产业，而且在“高精尖”数控关键技术和装备方面对我国实行封锁和限制政策。总之，大力发展以数控技术为核心的先进制造技术已成为世界各发达国家加速经济发展、提高综合国力和国家地位的重要途径。数控技术是用数字信息对机械运动和工作过程进行控制的技术，数控装备是以数控技术为代表的新技术对传统制造产业和新兴制造业的渗透形成的机电一体化产品，即所谓的数字化装备，其技术范围覆盖很多领域：(1)机械制造技术；(2)信息处理、加工、传输技术；(3)自动控制技术；(4)伺服驱动技术；(5)传感器技术；(6)软件技术等。
1 数控技术的发展趋势
数控技术的应用不但给传统制造业带来了革命性的变化，使制造业成为工业化的象征，而且随着数控技术的不断发展和应用领域的扩大，他对国计民生的一些重要行业（IT、汽车、轻工、医疗等）的发展起着越来越重要的作用，因为这些行业所需装备的数字化已是现代发展的大趋势。从目前世界上数控技术及其装备发展的趋势来看，其主要研究热点有以下几个方面〔1～4〕。
1.1 高速、高精加工技术及装备的新趋势
1.2 五轴联动加工和复合加工机床快速发展
1.3 智能化、开放式、网络化成为当代数控系统发展的主要趋势
1.4 重视新技术标准、规范的建立
2 对我国数控技术及其产业发展的基本估计
我国数控技术起步于1958年，近50年的发展历程大致可分为3个阶段：第 3
一阶段从1958年到1979年，即封闭式发展阶段。在此阶段，由于国外的技术封锁和我国的基础条件的限制，数控技术的发展较为缓慢。第二阶段是在国家的“六五”、“七五”期间以及“八五”的前期，即引进技术，消化吸收，初步建立起国产化体系阶段。在此阶段，由于改革开放和国家的重视，以及研究开发环境和国际环境的改善，我国数控技术的研究、开发以及在产品的国产化方面都取得了长足的进步。第三阶段是在国家的“八五”的后期和“九五”期间，即实施产业化的研究，进入市场竞争阶段。在此阶段，我国国产数控装备的产业化取得了实质性进步。纵观我国数控技术近50年的发展历程，特别是经过4个5年计划的攻关，总体来看取得了以下成绩。
a. 奠定了数控技术发展的基础，基本掌握了现代数控技术。我国现在已基本掌握了从数控系统、伺服驱动、数控主机、专机及其配套件的基础技术，其中大部分技术已具备进行商品化开发的基础，部分技术已商品化、产业化。
b. 初步形成了数控产业基地。在攻关成果和部分技术商品化的基础上，建立了诸如华中数控、航天数控等具有批量生产能力的数控系统生产厂。兰州电机厂、华中数控等一批伺服系统和伺服电机生产厂以及北京第一机床厂、济南第一机床厂等若干数控主机生产厂。这些生产厂基本形成了我国的数控产业基地。
c. 建立了一支数控研究、开发、管理人才的基本队伍。
虽然在数控技术的研究开发以及产业化方面取得了长足的进步，但我们也要清醒地认识到，我国高端数控技术的研究开发，尤其是在产业化方面的技术水平现状与我国的现实需求还有较大的差距。虽然从纵向看我国的发展速度很快，但横向比（与国外对比）不仅技术水平有差距，在某些方面发展速度也有差距，即一些高精尖的数控装备的技术水平差距有扩大趋势。
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英文翻译
学院：年级、专业：学生：学号：指导教师：
机械工程与自动化学院09级机械电子工程 ???李 明
篇二：机械专业英语文章中英文对照
英语原文
NUMERICAL CONTROL
Numerical control(N/C)is a form of programmable automation in which the processing equipment is controlled by means of numbers, letters, and other symbols, The numbers, letters, and symbols are coded in an appropriate format to define a program of instructions for a particular work part or job. When the job changes, the program of instructions is changed. The capability to change the program is what makes N/C suitable for low-and medium-volume production. It is much easier to write programs than to make major alterations of the processing equipment.
There are two basic types of numerically controlled machine tools：point—to—point and continuous—path(also called contouring).Point—to—point machines use unsynchronized motors, with the result that the position of the machining head Can be assured only upon completion of a movement, or while only one motor is running. Machines of this type are principally used for straight—line cuts or for drilling or boring.
The N/C system consists of the following components：data input, the tape reader with the control unit, feedback devices, and the metal—cutting machine tool or other type of N/C equipment.
Data input, also called “man—to—control link”, may be provided to the machine tool manually, or entirely by automatic means. Manual methods when used as the sole source of input data are restricted to a relatively small number of inputs. Examples of manually operated devices are keyboard dials, pushbuttons, switches, or thumbwheel selectors. These are located on a console near the machine. Dials ale analog devices usually connected to a syn-chro-type resolver or potentiometer. In most cases, pushbuttons, switches, and other similar types of selectors are digital input devices. Manual input requires that the operator set the controls for each operation. It is a slow and tedious process and is seldom justified except in elementary machining applications or in special cases.
In practically all cases, information is automatically supplied to the control unit and the machine tool by cards, punched tapes, or by magnetic tape. Eight—channel punched paper tape is the most commonly used form of data input for conventional N/C systems. The coded instructions on the tape consist of sections of punched holes called blocks. Each block represents a machine function, a machining operation, or a combination of the two. The entire N/C program on a tape is made up of an accumulation of these successive data blocks. Programs resulting in long tapes all wound on reels like motion-picture film. Programs on relatively short tapes may be continuously repeated by joining the two ends of the tape to form a loop. Once installed, the tape is used again and again without further handling. In this case, the operator simply loads and
unloads the parts. Punched tapes ale prepared on type writers with special tape—punching attachments or in tape punching units connected directly to a computer system. Tape production is rarely error-free. Errors may be initially caused by the part programmer, in card punching or compilation, or as a result of physical damage to the tape during handling, etc. Several trial runs are often necessary to remove all errors and produce an acceptable working tape.
While the data on the tape is fed automatically, the actual programming steps ale done manually. Before the coded tape may be prepared, the programmer, often working with a planner or a process engineer, must select the appropriate N/C machine tool, determine the kind of material to be machined, calculate the speeds and feeds, and decide upon the type of tooling needed. The dimensions on the part print are closely examined to determine a suitable zero reference point from which to start the program. A program manuscript is then written which gives coded numerical instructions describing the sequence of operations that the machine tool is required to follow to cut the part to the drawing specifications.
The control unit receives and stores all coded data until a complete block of information has been accumulated. It then interprets the coded instruction and directs the machine tool through the required motions.
The function of the control unit may be better understood by comparing it to the action of a dial telephone, where, as each digit is dialed, it is stored. When the entire number has been dialed, the equipment becomes activated and the call is completed.
Silicon photo diodes, located in the tape reader head on the control unit, detect light as it passes through the holes in the moving tape. The light beams are converted to electrical energy, which is amplified to further strengthen the signal. The signals are then sent to registers in the control unit, where actuation signals are relayed to the machine tool drives.
Some photoelectric devices are capable of reading at rates up to 1000 characters per second. High reading rates are necessary to maintain continuous machine—tool motion；otherwise dwell marks may be generated by the cutter on the part during contouring operations. The reading device must be capable of reading data blocks at a rate faster than the control system can process the data.
A feedback device is a safeguard used on some N/C installations to constantly compensate for errors between the commanded position and the actual location of the moving slides of the machine tool. An N/C machine equipped with this kind of a direct feedback checking device has what is known as a closed-loop system. Positioning control is accomplished by a sensor which, during the actual operation, records the position of the slides and relays this information back to the control unit. Signals thus received ale compared to input signals on the tape, and any discrepancy between them is automatically rectified.
In an alternative system, called an open—loop system, the machine is positioned solely by stepping motor drives in response to commands by a controllers. There is one basic type of NC motions. Point-to-point or Positional Control In point-to-point control the machine tool elements (tools, table, etc.) are moved to programmed locations and the machining operations performed
after the motions are completed. The path or speed of movement between locations is unimportant; only the coordinates of the end points of the motions are accurately controlled. This type of control is suitable for drill presses and some boring machines, where drilling, tapping, or boring operations must be performed at various locations on the work piece. Straight-Line or Linear Control Straight-Line control systems are able to move the cutting tool parallel to one of the major axes of the machine tool at a controlled rate suitable for machining. It is normally only possible to move in one direction at a time, so angular cuts on the work piece are not possible, consequently, for milling machines, only rectangular configurations can be machined or for lathes only surfaces parallel or perpendicular to the spindle axis can be machined. This type of controlled motion is often referred to as linear control or a half-axis of control. Machines with this form of control are also capable of point-to-point control.
The original N/C used the closed—loop system. Of the two systems, closed and open loop, closed loop is more accurate and, as a consequence, is generally more expensive. Initially, open—loop systems were used almost entirely for light-duty applications because of inherent power limitations previously associated with conventional electric stepping motors. Recent advances in the development of electro hydraulic stepping motors have led to increasingly heavier machine load applications.
中文译文
数控技术
数控是可编程自动化技术的一种形式,通过数字、字母和其他符号来控制加工设备。数字、字母和符号用适当的格式编码为一个特定工件定义指令程序。当工件改变时,指令程序就改变。这种改变程序的能力使数控适合于中、小批量生产,写一段新程序远比对加工设备做大的改动容易得多。
数控机床有两种基本形式：点位控制和连续控制(也称为轮廓控制)。点位控制机床采用异步电动机,因此,主轴的定位只能通过完成一个运动或一个电动机的转动来实现。这种机床主要用于直线切削或钻孔、镗孔等场合。
数控系统由下列组件组成：数据输入装置,带控制单元的磁带阅读机,反馈装置和切削机床或其他形式的数控设备。
数据输人装置,也称“人机联系装置”,可用人工或全自动方法向机床提供数据。人工方法作为输人数据唯一方法时,只限于少量输入。人工输入装置有键盘,拨号盘,按钮,开关或拨轮选择开关,这些都位于机床附近的一个控制台上。拨号盘通常连到一个同步解析器或电位计的模拟装置上。在大多数情况下,按钮、开关和其他类似的旋钮是数据输入元件。人工输入需要操作者控制每个操作,这是一个既慢又单调的过程,除了简单加工场合或特殊情况,已很少使用。
几乎所有情况下,信息都是通过卡片、穿孔纸带或磁带自动提供给控制单元。在传统的数控系统中,八信道穿孔纸带是最常用的数据输入形式,纸带上的编码指令由一系列称为程序块的穿孔组成。每一个程序块代表一种加工功能、一种操作或两者的组合。纸带上的整个数控程序由这些连续数据单元连接而成。带有程序的长带子像电影胶片一样绕在盘子上,相对较短的带子上的程序可通过将纸带两端连接形成一个循环而连续不断地重复使用。带子一旦安装好,就可反复使用而无需进一步处理。此时,操作者只是简单地上、下工件。穿孔纸带是在带有特制穿孔附件的打字机或直接连到计算机上的纸带穿孔装置上做成的。纸带制造很少不出错,错误可能由编程、卡片穿孔或编码、纸带穿孔时的物理损害等形成。通常,必须要试走几次来排除错误,才能得到一个可用的工作纸带。
虽然纸带上的数据是自动进给的,但实际编程却是手工完成的,在编码纸带做好前,编程者经常要和一个计划人员或工艺工程师一起工作,选择合适的数控机床,决定加工材料,计算切削速度和进给速度,决定所需刀具类型,仔细阅读零件图上尺寸,定下合适的程序开始的零参考点,然后写出程序清单,其上记载有描述加工顺序的编码数控指令,机床按顺序加工工件到图样要求。
控制单元接受和储存编码数据,直至形成一个完整的信息程序块,然后解释数控指令,并引导机床得到所需运动。
为更好理解控制单元的作用,可将它与拨号电话进行比较,即每拨一个数字,就储存一个,当整个数字拨好后,电话就被激活,也就完成了呼叫。
装在控制单元里的纸带阅读机,通过其内的硅光二极管,检测到穿过移动纸带上的孔漏
过的光线,将光束转变成电能,并通过放大来进一步加强信号,然后将信号送到控制单元里的寄存器,由它将动作信号传到机床驱动装置。
有些光电装置能以高达每秒1000个字节的速度阅读,这对保持机床连续动作是必须的,否则,在轮廓加工时,刀具可能在工件上产生划痕。阅读装置必须要能以比控制系统处理数据更快的速度来阅读数据程序块。
反馈装置是用在一些数控设备上的安全装置,它可连续补偿控制位置与机床运动滑台的实际位置之间的误差。装有这种直接反馈检查装置的数控机床有一个闭环系统装置。位置控制通过传感器实现,在实际工作时,记录下滑台的位置,并将这些信息送回控制单元。接受到的信号与纸带输入的信号相比较,它们之间的任何偏差都可得到纠正。
在另一个称为开环的系统中,机床仅由响应控制器命令的步进电动机驱动定位,工件的精度几乎完全取决于丝杠的精度和机床结构的刚度。有几个理由可以说明步进电机是一个自动化申请的非常有用的驱动装置。对于一件事物,它被不连续直流电压脉冲驱使,是来自数传计算机和其他的自动化的非常方便的输出控制系统。当多数是索引或其他的自动化申请所必备者的时候,步进电机对运行一个精确的有角进步也是理想的。因为控制系统不需要监听就提供特定的输出指令而且期待系统适当地反应的公开- 环操作造成一个回应环,步进电机是理想的。 一些工业的机械手使用高抬腿运步的马乘汽车驾驶员,而且步进电机是有用的在数字受约束的工作母机中。 这些申请的大部分是公开- 环 ,但是雇用回应环检测受到驱策的成份位置是可能的。 环的一个分析者把真实的位置与需要的位置作比较,而且不同是考虑过的错误。 那然后驾驶员能发行对步进电机的电脉冲,直到错误被减少对准零位。在这个系统中,没有信息反馈到控制单元的自矫正过程。出现误动作时,控制单元继续发出电脉冲。比如,一台数控铣床的工作台突然过载,阻力矩超过电机转矩时,将没有响应信号送回到控制器。因为,步进电机对载荷变化不敏感,所以许多数控系统设计允许电机停转。然而,尽管有可能损坏机床结构或机械传动系统,也有使用带有特高转矩步进电机的其他系统,此时,电动机有足够能力来应付系统中任何偶然事故。
最初的数控系统采用开环系统。在开、闭环两种系统中,闭环更精确,一般说来更昂贵。起初,因为原先传统的步进电动机的功率限制,开环系统几乎全部用于轻加工场合,最近出现的电液步进电动机已越来越多地用于较重的加工领域。
篇三：机械专业论文中英文
Gearbox Noise?——?Correlation with Transmission Error and
Influence of Bearing Preload?
变速箱噪声——相关的传输错误和轴承预压的影响
摘要
ABSTRACT
The five appended papers all deal with gearbox noise and vibration. The first
paper presents a review of previously published literature on gearbox noise and vibration.
The second paper describes a test rig that was specially designed and built for
noise testing of gears. Finite element analysis was used to predict the dynamic
properties of the test rig, and experimental modal analysis of the gearbox housing was used to verify the theoretical predictions of natural frequencies.In the third paper, the influence of gear finishing method and gear deviations on gearbox noise is
investigated in what is primarily an experimental study. Eleven test gear pairs were manufactured using three different finishing methods. Transmission error, which is considered to be an important excitation mechanism for gear noise, was measured as well as predicted. The test rig was used to measure gearbox noise and vibration for the different test gear pairs. The measured noise and vibration levels were compared with the predicted and measured transmission error. Most of the experimental results can be interpreted in terms of measured and predicted transmission error. However, it does not seem possible to identify one single parameter,such as measured
peak-to-peak transmission error, that can be directly related to measured noise and vibration. The measurements also show that disassembly and reassembly of the gearbox with the same gear pair can ch
vibration considerably.This finding indicates that other factors besides the gears affect
gear noise.In the fourth paper, the influence of bearing endplay or preload on gearbox noise and vibration is investigated. Vibration measurements were carried out at torque levels of 140 Nm and 400Nm, with 0.15 mm and 0 mm bearing endplay, and with 0.15 mm bearing preload. The results show that the bearing endplay and preload
influence the gearbox vibrations. With preloaded bearings, the vibrations increase at speeds over 2000 rpm and decrease at speeds below 2000 rpm, compared with
bearings with endplay. Finite element simulations show the same tendencies as the measurements.The fifth paper describes how gearbox noise is reduced by optimizing the gear geometry for decreased transmission error. Robustness with respect to gear deviations and varying torque is considered in order to find a gear geometry giving low noise in an appropriate torque range despite deviations from the nominal
geometry due to manufacturing tolerances. Static and dynamic transmission error, noise, and housing vibrations were measured. The correlation between dynamic transmission error, housing vibrations and noise was investigated in speed sweeps from 500 to 2500 rpm at constant torque. No correlation was found between dynamic transmission error and noise. Static loaded transmission error seems to be correlated with the ability of the gear pair to excite vibration in the gearbox dynamic system.
论文描述了该试验台是专门设计和建造噪音齿轮测试。有限元分析，用于预测试验台的动态特性和实验的变速箱壳体模态分析用于验证自然试验台。这第三个文件，齿轮精加工方法和变速箱齿轮的偏差影响的理论预测噪声主要是研究在什么的实验研究。十对被测试设备制造使用三种不同的整理方法。传输错误，这被认为是一个重要的激励机制齿轮噪音，测量以及预测。该试验台是用于测量变速箱噪音及不同的测试装置对振动。测得的噪音和振动水平进行比较，预测和实测的传输错误。实验结果大多可以解释和预测传输测量误差项。但是，它似乎并不能够确定一个单一的参数，如测得的峰 - 峰值传输错误，可直接与测得的噪声和振动。测量结果还显示，拆卸和使用相同的变速箱齿轮副重组可以改变测得噪声和振动.这个水平发现表明，除了其他因素的影响齿轮齿轮噪音。第四，轴承影响或变速箱噪音和振动预紧力进行了调查。振动测量均在140牛米和400nm的扭矩水平，用0.15毫米和0毫米轴承间隙，并用0.15 mm轴承预紧力。结果表明，轴承间隙和预紧力影响变速箱的振动。预装轴承，振动增加超过2000转和2000转的速度低于下降速度，相比与轴端间隙轴承。有限元模拟表现出同样
的倾向作为测量值。第五本文介绍如何通过优化变速箱噪声为减少传输错误齿轮几何减少。关于齿轮偏差和不同扭矩的鲁棒性考虑，以便找到一个齿轮几何给予尽管从名义几何由于制造公差偏差范围内以适当的扭矩，噪音低。静态和动态的传输错误，噪声，振动测量和该。之间的动态传输错误，房屋振动和噪声的相关性研究了扫描速度从500到2500在恒转矩转速。没有相关关系的动态传递误差和噪声。静态加载的传输错误似乎与齿轮副的能力，激发动力系统中的齿轮箱振动相关。
Keywords: gear, gearbox, noise, vibration, transmission error, bearing preload. 关键词：齿轮，变速箱，噪声，振动，传输错误，轴承预紧力。
1 INTRODUCTION
1 引言
1.1 Background
Noise is increasingly considered an environmental issue. This belief is reflected in demands for lower noise levels in many areas of society, including the working environment. Employees spend a lot of time in this environment and noise can lead not only to hearing impairment but also to decreased ability to concentrate, resulting in decreased productivity and an increased risk of accidents. Quality, too, has become increasingly important. The quality of a product can be defined as its ability to fulfill customers’ demands. These demands often change over time, and the best competitors in the market will set the standard.Noise concerns are also expressed in relation to construction machinery such as wheel loaders and articulated haulers. The gearbox is sometimes the dominant source of noise in these machines.Even if the gear noise is not the loudest source, its pure high frequency tone is easily distinguished from other noise sources and is often perceived as unpleasant. The noise creates an impression of poor quality. In order not to be heard, gear noise must be at least 15 dB lower than other noise sources, such as engine noise.
1.1背景
噪音是越来越认为是环境问题。这种信念体现在许多领域中的社会，包括工
作环境，降低噪音水平的要求。在这种环境下员工花了很多时间和噪声不仅会导致听力损伤，而且要集中能力下降，生产力下降和事故造成的风险增加。质量也变得越来越重要。一个产品的质量可以被定义为有能力满足客户的需求。这些要求往往随时间而改变，而在市场上最好的竞争对手将设置标准。噪音问题也涉及到工程机械的轮式装载机和铰接式这样表示。变速箱是有时在这些机械中。甚至噪音的主要来源，如果齿轮噪音并不是最响亮的来源，它的纯高频音很容易区别于其他噪声源，通常为不愉快的感觉。噪音创建了一个质量差的印象。为了不被听到，齿轮噪声必须至少15分贝外，其他噪声源，例如发动机噪音低
1.2 Gear noise
This dissertation deals with the kind of gearbox noise that is generated by gears under load.This noise is often referred to as “gear whine” and consists mainly of pure tones at high frequencies corresponding to the gear mesh frequency and multiples thereof, which are known as harmonics. A tone with the same frequency as the gear mesh frequency is designated the gear mesh harmonic, a tone with a frequency twice the gear mesh frequency is designated the second harmonic, and so on. The term “gear mesh harmonics” refers to all multiples of the gear mesh
frequency.Transmission error (TE) is considered an important excitation mechanism for gear whine. Welbourn [1] defines transmission error as “the difference between the actual position of the output gear and the position it would occupy if the gear drive were perfectly conjugate.” Transmission error may be expressed as angular
displacement or as linear displacement at the pitch point. Transmission error is caused by deflections, geometric errors, and geometric modifications.In addition to gear whine, other possible noise-generating mechanisms in gearboxes include gear rattle from gears running against each other without load, and noise generated by
bearings.In the case of automatic gearboxes, noise can also be generated by internal oil pumps and by clutches. None of these mechanisms are dealt with in this work, and from now on “gear noise” or “gearbox noise” refers to “gear whine”. MackAldener [2] describes the noise generation process from a gearbox as consisting of three parts: excitation, transmission, and radiation. The origin of the noise is the gear mesh, in which vibrations are created (excitation), mainly due to transmission error. The vibrations are transmitted via the gears, shafts, and bearings to the housing
(transmission). The housing vibrates, creating pressure variations in the surrounding air that are perceived as noise (radiation).Gear noise can be affected by changing any one of these three mechanisms. This dissertation deals mainly with excitation, but transmission is also discussed in the section of the literature survey concerning dynamic models, and in the modal analysis of the test gearbox in Paper B.
Transmission of vibrations is also investigated in Paper D, which deals with the influence of bearing endplay or preload on gearbox noise. Differences in bearing preload influence a bearing’s dynamic properties like stiffness and damping. These properties also affect the vibration of the gearbox housing.
1.2齿轮噪音
随着变速箱噪声是一种由下负载。这种噪音齿轮生成此论文交易是通常被称为“齿轮哀鸣”，并包括在高频率所对应的齿轮啮合频率和倍数，这是已知的纯色调为主为谐波。一个与齿轮啮合频率相同的频率音调被指定为谐波齿轮啮合，一个频率音调的两倍齿轮啮合频率被指定为二次谐波，依此类推。术语“谐波齿轮啮合”指的是齿轮啮合频率。变速箱错误（TE）的倍数被认为是重要的激励机制齿轮哀鸣。Welbourn [1]定义为“之间的输出齿轮的实际位置和地位，将占据如果齿轮传动是完美结合的差异。”传输错误传输错误可能表现为角位移或在球场上点线位移。传输错误是由变形，几何误差和几何变动。除了齿轮嗲引起的，其他可能产生噪声的机制，包括在变速箱齿轮嘎嘎从对对方的情况下运行负荷齿轮，噪音轴承的情况下产生的自动变速箱，噪音也可以由内部生成的油泵和离合器。这些机制没有得到处理，在此工作，并从“齿轮噪音”或“齿轮箱噪音”现在是指“齿轮哀鸣”。奥尔登 描述了从以三部分组成的变速箱噪音的产生过程：激发，传播和辐射。噪声的来源是齿轮啮合，其中振动产生（激励），主要是由于传输错误。的振动传输通过齿轮，轴和轴承的该（传输）。该震动，创造了周围的空气都作为噪声（辐射）感知压力的变化。齿轮噪音可以通过改变任何这三种机制之一的影响。本论文主要涉及激励，但传输也是在文献关于动态模型统计调查组讨论，并在文件中B.振动模态分析传输测试变速箱也是，这与交易调查影响轴承的轴端间隙或变速箱噪音预紧力。轴承预紧力影响的差异像轴承刚度和阻尼的动态特性。这些属性也影响了变速箱外壳的振动。
1.3 Objective
The objective of this dissertation is to contribute to knowledge about gearbox