机械设备管理规定中英文对照版

第一篇：机械设备管理规定中英文对照版

机械设备管理规定

Mechanical equipment regulations

1．总则

1.General rules

1.1为了加强项目部施工机械设备的管理，提高设备使用寿命和经济效益，保证设备安全生产和正常运行,特制订本规定。

1.1 In order to strengthen the management of construction machinery and equipment of the project department , improve equipment life and economic efficiency, ensure safe production and normal operation of the equipment.1.2设备是项目部施工的物质技术基础，要贯彻执行“预防为主”的方针，要坚持使用与保养相结合，修理与改造相结合，技术管理与经济效益相结合的原则。

1.2 Equipment is the material and technical basis of construction for the project department.Implement the “prevention first” principle and adhere to the principle of combining the use and maintenance, the repair and renovation, technology management and economic efficiency.1.3设备管理的主要任务是：贯彻落实上级有关方针、政策、法令、法规，通过技术和组织措施，做到全面规划，合理配置，择优选购、正确使用，精心维护、科学检修、适时改造和更新，既对设备进行综合管理。保证设备完好，不断改善和提高技术装备素质，充分发挥设备的综合效能，为项目部提供性能优良、安全可靠的设备，并使设备增值保值。

1.3 the main task of equipment management : to implement the relevant guidelines, policies, laws, regulations of the superior, through technical and organizational measures to achieve comprehensive planning, rational distribution, perfect purchase, the proper use, meticulously care, scientific maintenance, timely rehabilitation and renewal.That means the integrated management shall be applied for the equipment.Ensure that the equipment is intact, continually improve and enhance the quality of technical equipment and make full use of the integrated performance of the equipment, providing excellent, safe and reliable equipment for the project department while preserving and increasing the value of the equipment.1.4积极采用先进的设备管理方法和维修新技术，不断提高设备管理和维修技术水平。

1.4 Actively apply advanced equipment management methods and new maintenance technology, and continually improve the management and maintenance technology standards for the equipment.1.5管好、用好、维修好、改造好设备，保证财产不受损失，使设备经常保持良好的技术状态，保证经营发展和施工生产的需要，是项目部领导和各部门的重要职责。

1.5 The equipment shall be well managed, used, repaired, altered to ensure the property against loss.Keeping the equipment in good technical condition and ensuring to meet the needs of business development and construction are an important responsibility of the project leaders and various departments.2.设备的使用和保养规定

2.The use and maintenance regulations for the equipment

2.1设备的使用，大型设备必须人机固定，并实行机长负责制。鼓励操作人员 1

（及其它工种）多学技术，成为一专多能的复合型人才，各设备之间操作人员以及当地雇用操作人员调换频繁，所以特规定对多班制、替班作业的设备，必须实行设备交接班制度，并认真填写交接班记录。

2.1 The person using the equipment, especially for large equipment, must be fixed and the captain responsibility system shall be implemented.Encourage operators(and other types of workers)to learn techniques and become complex talents who become expert in one field while possessing all-round.The operation staff between different types of equipment and locally employed operating staff exchange frequently, so the equipment shift system shall be implemented and the shift records shall be seriously recorded for the equipment which needs many shifts.2.2操作人员在独立使用前，要对设备的性能、技术规范、维护知识和安全操作规程等技术理论教育以及实际操作技术培训，设备部会同安保部、办公室对操作人员进行考试，经过考试合格的，方可独立操作（已在取得中国相应工种技能等级证书的可免于技能考试）。雇佣当地的牙工操作人员必须持证上岗。

2.2 Before the operator use the equipment independently, he shall be educated and trained on the performance of equipment, technical specifications, maintenance knowledge, safety procedures and other technical theories and practical skills.Equipment department in conjunction with HSE department and office shall arrange exams for the operating persons.After passing the examination, they shall operate the equipment independently(persons who have already achieved the relevant work skill level certificates are exempt from skill exams).The local operating workers hired from Jamaica must be employed with certificates.2.3大型设备使用前，设备使用部门/人员必须提前告知设备部设备使用计划，以便合理安排预使用的设备。设备部应做好钥匙发放登记。设备操作人员须是经过考试合格的人员。设备钥匙交付后，设备由使用部门负责日常使用管理，原则上禁止牙籍操作人员将设备钥匙带回家，即每日上班时发放钥匙，下班时收回钥匙，设备使用专人专机。

2.3 Before using the large equipments, the equipment using department/ personnel shall inform the equipment department in advance about the equipment using plan so that they can pre-arrange for the equipments needed.The equipment department should make registration of the using situation of keys.The equipments operators should be qualified staff passing the examination.After the delivery of keys, the equipments should be maintained and managed daily by the using department.Regarding the principles, the local operators from Jamaica can not take the keys home.The reasonable principle is to distribute the keys at the time starting to work and take the keys back after they are off duty.The equipments should be operated by designated personnel.2.4设备操作人员对设备要实行日检制度（每日进行例行保养检查），并认真填写记录（施工机械工作日志），严格遵守《施工机械操作规程》和随车《操作保养手册》，做到精心操作，严禁超负荷、拼设备和带病运转。

2.4 The operators should check the equipments daily and fill in the records(construction machinery work diary)in real earnest.Strictly abide by the Construction machinery operating procedures and Operation & maintenance manuals.Operate carefully, do not overload and wrongly operate the

equipments.2.5操作人员必须熟练掌握“四懂”(懂性能、懂原理、懂结构，懂用途)、“三会”（会操作、会保养、会排除故障）、“十字作业法”（调整、紧固、防腐、润滑、清洁）。

2.5 The operator must be familiar with the “four understanding”(understand performance, understand the principles, understand the structure, understand function), “Three skills”(operation, maintenance, troubleshooting), and “Ten words operation method”(adjustment, tightening , corrosion prevention, lubrication, cleaning).2.6操作人员应做到：“五不接”（机械状况不良好不接、保养不良好不接、工具附件不齐全不接、原始记录填写不全不接，生产任务不清不接）;班前“两件事”（检查机械完好情况，进行例行保养、检查电源或油料进行试车运转）；班中“五注意”(注意讯号、听从指挥，遵守规程、确保安全，重视质量、配合生产，注意紧固、及时加油，倾听声音，观察仪表)；班后“五不走”（电源不切断不走、机械设备清洗保养不彻底不走、工具附件丢失找不到不走、不办清接班手续不走、不做好原始记录不走）；对设备润滑做到“五定”（定人、定质、定量、定点、定时），切实做好润滑工作。

2.6 The operator should follow: “Five unacceptable circumstances ”(no accept when the mechanical condition is poor, no accept when the maintenance is bad , no accept when tools and accessories are not complete, no accept when the original record is not complete, no accept when the production tasks are not clear);the “two thing ” before work(check conditions of machinery, conduct routine maintenance, power or fuel check and perform trial operation);“ five note ” during work(note the signal, obey the command, comply with regulations, ensure the safety, pay attention to quality, assist with production, pay attention to fastening, refuel timely , listen to the sound, observe instruments);“no departure under five circumstances”(do not leave without cutting off the power does , do not leave without conduct thoroughly cleaning and maintenance for machinery and equipment, do not leave without finding the lost tools and accessories, do not leave without finishing succession procedures, do not leave without making original records);“five points to be fixed” for equipment lubrication(fixed people, fixed quality, fixed quantity, fixed place, fixed time), achieving really good lubrication.3.设备的修理

3.Repair of the equipment

3.1设备日常维修保养工作由维修班组织实施，并做好维修保养记录。

3.1 The maintenance team shall organize and implement routine repair and maintenance work for the equipment and make maintenance records.3.2设备修理按照“养修并重、预防为主”的原则，实行计划养护、状态检测与故障诊断修理。

3.2 For the equipment repair, be in accordance with the principle of “both maintenance and repair, prevention-oriented” and implement the repair through planned maintenance, state detection and fault diagnosis.3.3设备部根据设备运转小时数、使用人员填写的机械设备工作日志、设备月检记录结合实际情况，根据设备的动力性、经济性、安全性，制订修理计划。并加强修理工艺的管理，确保修理质量，缩短停修时间；修理时应根据具体条件制

订合理的修理工艺、技术标准，从目前的综合性修理逐步过渡到按部件分工修理，并积极创造条件逐步实行总称互换修理。

The equipment department shall develop the repair plan according to the equipment operating hours, machinery and equipment work log written by using staff, equipment monthly inspection record and the actual situation.The power, economy efficiency and safety shall be taken into consideration.The equipment department shall strengthen the management of repair technology to ensure the repair quality and to short repair time.A reasonable repairing technology and technical standards shall be formulated for the repair according to the actual conditions.The current comprehensive repair shall be gradually transited to the repair based on different parts, actively creating conditions for achieve interchangeable repair.3.4设备大修过程中，设备部要严格把关，首先确定机务主办，并填写技术交底和安全/环保技术交底，修理人员必须认真做好修理过程中的多项基础工作。

3.4 during the thorough repair for the equipment , equipment department shall strictly control procedures.First, determine the machinery supervisor and complete technical disclosure and safety / environmental technical disclosure.The repairman must earnestly do various basic works during repair process.3.4.1严把修理关，严格执行修理前、修理中和修理后的三检制度。修理前，要做好拆检记录，拆检项目，零部件损坏情况，运动件的磨损情况及测量的数据等。

3.4.1 strictly control procedures of repair and implement the inspection system pre-repair, under repair and after repair.Before repair, make records on dismantling , such as dismantling items, damaged conditions of spare parts, wear of moving parts, measuring data and so on.3.4.2严把配件关，对于质量不合格的材料配件不准使用，质量不合格的总成不准装配，所用的材料配件和修理质量均按规定标准进行检验。

3.4.2 strictly manage the accessories.Materials and accessories which are of substandard quality materials are not allowed to use.The assemblies which are of substandard quality are not allowed to be assembled.Conduct inspection for materials, accessories and repair quality according to the provisions of the standards.3.4.3修理过程中，尽量做到修旧利废，要认真推广：“焊、补、喷、镀、铆、镶、配、改、校、涨、缩、粘”十二字修旧经验，不断扩大修旧范围，保证修旧质量，节约修理资金，降低修理成本。

3.4.3 during repair process, the old equipment shall be repaired and the waste shall be fully used, earnestly implement the “ twelve words guideline”, that is welding, mend, spray, plating, riveting, mount, match, change, check , expand, shrink, stick.The repair range shall be expand, the repair quality shall be ensured, the repair money shall be saved, and the repair cost shall be reduced.3.4.4设备修理完毕，机务科要组织竣工验收，进行试运转，并做好记录，填写竣工验收资料。废零件、废油、废料（油手套、油棉纱）要回收，并交有关部门处置，做到工完、料净、场地清。

3.4.4 when the repair for the equipment is completed, mechanical department shall organize the completion acceptance, conduct test run, make a record and fill in the completion acceptance data.Scrap parts, waste oil and

waste material(oil gloves and oil cotton yarn)shall be recycled and transferred to relevant departments for disposal, so when the work is finished, the material is fully used and the site is clean.3.4.5设备大修出厂应严格按技术要求进行大修走合期。

3.4.5The breaking-in period shall be strictly arranged according to the technical requirements for the equipment which has gone through a thorough repair in the factory.3.5设备的技术革新与技术改造可根据生产需要和设备技术状况，结合大修进行，积极推广和应用新技术、新工艺、新材料。

3.5 Technological innovation and transformation for the equipment shall be conducted according to the production needs and equipment technical conditions, combining with the thorough repair.The new technologies, new processes and new materials shall be actively promoted and applied.4.设备安全管理

4.Safety management of equipment

4.1设备安全工作必须落实“安全第一，预防为主”的方针，严格执行公司及当地政府有关安全生产的规定。

4.1 Equipment safety work shall be done in accordance with the “safety first, prevention first” principle.strictly implement the provisions of the company and the local government on production safety.4.2 项目部根据施工特点，建立健全设备安全制度和安全组织，认真贯彻执行各类设备的安全操作规程和保养检修规程，使设备安全管理工作落到实处。

4.2 The project department shall establish and improve the safety systems and safety organizations for the equipment according to the construction characteristics, and earnestly implement safe operation procedures and maintenance and service procedures of various types of equipment, making the equipment safety management fall into place.4.3各类机械设备都应有可靠的安全装置和防护措施，保证设备的安全运行。

4.3 All types of machinery and equipment should have reliable safety devices and protective measures to ensure the safe operation of the equipment.4.4设备操作人员必须熟知机械基本原理与构造，熟悉安全操作规程，掌握有关安全生产的知识和值班运转制度，设备运转时发现异常，要立即采取措施。

4.4 Equipment operators must be familiar with the basic mechanical principles and structure, the safety procedures, knowledge on production safety and duty operating system.If the equipment operation is abnormal, take measures immediately.4.5项目部根据实际情况与设备操作人员签订“设备操作责任书”，界定责任范围。

4.5 Project Department shall sign a “equipment operating responsibility agreement” with equipment operators according to the actual situation to define the responsibility scope.4.6项目部制订设备安全事故的防范措施及事故应急预案，经常组织学习，加强设备安全教育。

4.6 Project Department shall develop equipment security accident

prevention measures and emergency plans, frequently organize learning, and enhance equipment safety education.

第二篇：机械名称中英文对照

一、除大块机Eliminates the bulk machine

二、齿型筛分除杂物机The screening and eliminates the sundry goods machine

三、振动煤箅Vibration Coal Grate

四、滚轴筛Roller Screen

五、滚筒筛Trommel Screen

六、振动概率筛Vibration Probability Screen

七、减振平台Antivibration Platform

八、布料器Distributing Device

九、皮带机头部伸缩装置Conveyer Belt Telescopiform Device

十、胶带给料机Belt Feeder

十一、往复式给料机Reciprocating Feeder

十二、振动给煤机Vibrator Feeder

十三、叶轮给煤机Coal Impeller Feeder

十四、埋刮板输送机Buried Scraper Conveyer

十五、螺旋输送机Screw Conveyer

十六、板式喂料机Apron Feeder

十七、缓冲弹簧板式大块输送机Buffer Spring Apron Bulk Converyor

十八、斗式提升机Chain-Bucket Elevator

十九、TD75、DTⅡ型带式输送机Type TD75/DTII Belt Conveyer

二十、电动三通3-Through-Chute With Electric Drive Gate 二

十一、重力式煤沟挡板Gravity Type Coal Ditch Baffle

二十二、物料稳流器Material Constant Staticizer

二十三、犁式卸料器、刮水器Plough Type Tripper/Wiper 二

十四、栈桥冲洗器Flusher

二十五、喷雾除尘系统Exhaust System 二

十六、缓冲锁气器Buffer Air Lock 二

十七、缓冲滚筒Snub Pulley二十八、二十九、三

十、缓冲平台Buffer Platform 胶带防撕裂保护装置Belt Protective Device 链斗卸车机Bucket-Chain Unloader

第三篇：机械专业论文中英文对照

Gearbox NoiseCorrelation with Transmission Error and Influence of Bearing Preload

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 change the levels of measured noise and 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.Keywords: gear, gearbox, noise, vibration, transmission error, bearing preload.ACKNOWLEDGEMENTS This work was carried out at Volvo Construction Equipment in Eskilstuna and at the Department of Machine Design at the Royal Institute of Technology(KTH)in Stockholm.The work was initiated by Professor Jack Samuelsson(Volvo and KTH), Professor Sören Andersson(KTH), and Dr.Lars Bråthe(Volvo).The financial support of the Swedish Foundation for Strategic Research and the Swedish Agency for Innovation Systems – VINNOVA – is gratefully acknowledged.Volvo Construction Equipment is acknowledged for giving me the opportunity to devote time to this work.Professor Sören Andersson is gratefully acknowledged for excellent guidance and encouragement.I also wish to express my appreciation to my colleagues at the Department of Machine Design, and especially to Dr.Ulf Sellgren for performing simulations and contributing to the writing of Paper D, and Dr.Stefan Björklund for performing surface finish measurements.The contributions to Paper C by Dr.Mikael

Pärssinen are highly appreciated.All contributionsto this work by colleagues at Volvo are gratefully appreciated.1 INTRODUCTION 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.1.2 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.1.3 Objective The objective of this dissertation is to contribute to knowledge about gearbox noise.The following specific areas will be the focus of this study: 1.The influence of gear finishing method and gear modifications and errors on noise and vibration from a gearbox.2.The correlation between gear deviations, predicted transmission error, measured transmission error, and gearbox noise.3.The influence of bearing preload on gearbox noise.4.Optimization of gear geometry for low transmission error, taking into consideration robustness with respect to torque and manufacturing tolerances.2 AN INDUSTRIAL APPLICATION − TRANSMISSION NOISE REDUCTION 2.1 Introduction This section briefly describes the activities involved in reducing gear noise from a wheel loader transmission.The aim is to show how the optimization of the gear geometry described in Paper E is used in an industrial application.The author was project manager for the “noise work team” and performed the gear optimization.One of the requirements when developing a new automatic power transmission for a wheel loader was improving the transmission gear noise.The existing power transmission was known to be noisy.When driving at high speed in fourth gear, a high frequency gear-whine could be heard.Thus there were now demands for improved sound quality.The transmission is a typical wheel loader power transmission, consisting of a torque converter, a gearbox with four forward speeds and four reverse speeds, and a dropbox partly integrated with the gearbox.The dropbox is a chain of four gears transferring the powerto the output shaft.The gears are engaged by wet multi-disc clutches actuated by the transmission hydraulic and control system.2.2 Gear noise target for the new transmission Experience has shown that the high frequency gear noise should be at least 15 dB below other noise sources such as the engine in order not to be perceived as disturbing or unpleasant.Measurements showed that if the gear noise could be decreased by 10 dB, this criterion should be satisfied with some margin.Frequency analysis of the noise measured in the driver's cab showed that the dominant noise from the transmission originated from the dropbox gears.The goal for transmission noise was thus formulated as follows: “The gear noise(sound pressure level)from the dropbox

gears in the transmission should be decreased by 10 dB compared to the existing transmission in order not to be perceived as unpleasant.It was assumed that it would be necessary to make changes to both the gears and the transmission housing in order to decrease the gear noise sound pressure level by 10 dB.2.3 Noise and vibration measurements In order to establish a reference for the new transmission, noise and vibration were measured for the existing transmission.The transmission is driven by the same type of diesel engine used in a wheel loader.The engine and transmission are attached to the stand using the same rubber mounts that are used in a wheel loader in order to make the installation as similar as possible to the installation in a wheel loader.The output shaft is braked using an electrical brake.2.4 Optimization of gears Noise-optimized dropbox gears were designed by choosing macro-and microgeometries giving lower transmission error than the original(reference)gears.The gear geometry was chosen to yield a low transmission error for the relevant torque range, while also taking into consideration variations in the microgeometry due to manufacturing tolerances.The optimization of one gear pair is described in more detail in Paper E.Transmission error is considered an important excitation mechanism for gear whine.Welbourn [1] defines it as “the difference between the actual position of the output gear and the position it would occupy if the gear drive were perfectly conjugate.” In this project the aim was to reduce the maximum predicted transmission error amplitude at gear mesh frequency(first harmonic of gear mesh frequency)to less than 50% of the value for the reference gear pair.The first harmonic of transmission error is the amplitude of the part of the total transmission error that varies with a frequency equal to the gear mesh frequency.A torque range of 100 to 500 Nm was chosen because this is the torque interval in which the gear pair generates noise in its design application.According to Welbourn [1], a 50% reduction in transmission error can be expected to reduce gearbox noise by 6 dB

(sound pressure level, SPL).Transmission error was calculated using the LDP software(Load Distribution Program)developed at the Gear Laboratory at Ohio State University [3].The “optimization” was not strictly mathematical.The design was optimized by calculating the transmission error for different geometries, and then choosing a geometry that seemed to be a good compromise, considering not only the transmission error, but also factors such asstrength, losses, weight, cost, axial forces on bearings, and manufacturing.When choosing microgeometric modifications and tolerances, it is important to take manufacturing options and cost into consideration.The goal was to use the same finishing method for the optimized gears as for the reference gears, namely grinding using a KAPP VAS 531 and CBN-coated grinding wheels.For a specific torque and gear macrogeometry, it is possible to define a gear microgeometry that minimizes transmission error.For example, at no load, if there are no pitch errors and no other geometrical deviations, the shape of the gear teeth should be true involute, without modifications like tip relief or involute crowning.For a specific torque, the geometry of the gear should be designed in such a way that it compensates for the differences in deflection related to stiffness variations in the gear mesh.However, even if it is possible to define the optimal gear microgeometry, it may not be possible to manufacture it, given the limitations of gear machining.Consideration must also be given to how to specify the gear geometry in drawings and how to measure the gear in an inspection machine.In many applications there is also a torque range over which the transmission error should be minimized.Given that manufacturing tolerances are inevitable, and that a demand for smaller tolerances leads to higher manufacturing costs, it is important that gears be robust.In other words, the important characteristics, in this case transmission error, must not vary much when the torque is varied or when the microgeometry of the gear teeth varies due to manufacturing tolerances.LDP [3] was used to calculate the transmission error for the reference and optimized gear pair at different torque levels.The robustness function in LDP was used to analyze the sensitivity to deviations due to manufacturing tolerances.The “min, max, level” method involves assigning three levels to each parameter.2.5 Optimization of transmission housing Finite element analysis was used to optimize the transmission housing.The optimization was not performed in a strictly mathematical way, but was done by calculating the vibration of the housing for different geometries and then choosing a geometry that seemed to be a good compromise.Vibration was not the sole consideration, also weight, cost, available space, and casting were considered.A simplified shell element model was used for the optimization to decrease computational time.This model was checked against a more detailed solid element model of the housing to ensure that the simplification had not changed the dynamic properties too much.Experimental modal analysis was also used to find the natural frequencies of the real transmission housing and to ensure that the model did not deviate too much from the real housing.Gears shafts and bearings were modeled as point masses and beams.The model was excited at the bearing positions by applying forces in the frequency range from 1000 to 3000 Hz.The force amplitude was chosen as 10% of the static load from the gears.This choice could be justified because only relative differences are of interest, not absolute values.The finite element analysis was performed by Torbjörn Johansen at Volvo Technology.The author’s contribution was the evaluation of the results of different housing geometries.A number of measuring points were chosen in areas with high vibration velocities.At each measuring point the vibration response due to the excitation was evaluated as a power spectral density(PSD)graph.The goal of the housing redesign was to decrease the vibrations at all measuring points in the frequency range 1000 to 3000 Hz.2.6 Results of the noise measurements The noise and vibration measurements described in section 2.3 were performed after optimizing the gears and transmission housing.The total sound power level decreased by 4 dB.2.7 Discussion and conclusions It seems to be possible to decrease the gear noise from a transmission by

decreasing the static loaded transmission error and/or optimizing the housing.In the present study, it is impossible to say how much of the decrease is due to the gear optimization and how much to the housing optimization.Answering this question would have required at least one more noise measurement, but time and cost issues precluded this.It would also have been interesting to perform the noise measurements on a number of transmissions, both before and after optimizing the gears and housing, in order to determine the scatter of the noise of the transmissions.Even though the goal of decreasing the gear noise by 10 dB was not reached, the goal of reducing the gear noise in the wheel loader cab to 15 dB below the overall noise was achieved.Thus the noise optimization was successful.3 SUMMARY OF APPENDED PAPERS 3.1 Paper A: Gear Noise and Vibration – A Literature Survey This paper presents an overview of the literature on gear noise and vibration.It is divided into three sections dealing with transmission error, dynamic models, and noise and vibration measurement.Transmission error is an important excitation mechanism for gear noise and vibration.It is defined as “the difference between the actual position of the output gear and the position it would occupy if the gear drive were perfectly conjugate” [1].The literature survey revealed that while most authors agree that transmission error is an important excitation mechanism for gear noise and vibration, it is not the only one.Other possible time-varying noise excitation mechanisms include friction and bending moment.Noise produced by these mechanisms may be of the same order of magnitude as that produced by transmission error, at least in the case of gears with low transmission error [4].The second section of the paper deals with dynamic modeling of gearboxes.Dynamic models are often used to predict gear-induced vibrations and investigate the effect of changes to the gears, shafts, bearings, and housing.The literature survey revealed that dynamic models of a system consisting of gears, shafts, bearings, and gearbox casing can be useful in understanding and predicting the dynamic behavior of a gearbox.For

relatively simple gear systems, lumped parameter dynamic models with springs, masses, and viscous damping can be used.For more complex models that include such elements as the gearbox housing, finite element modeling is often used.The third section of the paper deals with noise and vibration measurement and signal analysis, which are used when experimentally investigating gear noise.The survey shows that these are useful tools in experimental investigation of gear noise because gears create noise at specific frequencies related to the number of teeth and the rotational speed of the gear.3.2 Paper B: Gear Test Rig for Noise and Vibration Testing of Cylindrical Gears Paper B describes a test rig for noise testing of gears.The rig is of the recirculating power type and consists of two identical gearboxes, connected to each other with two universal joint shafts.Torque is applied by tilting one of the gearboxes around one of its axles.This tilting is made possible by bearings between the gearbox and the supporting brackets.A hydraulic cylinder creates the tilting force.Finite element analysis was used to predict the natural frequencies and mode shapes for individual components and for the complete gearbox.Experimental modal analysis was carried out on the gearbox housing, and the results showed that the FE predictions agree with the measured frequencies(error less than 10%).The FE model of the complete gearbox was also used in a harmonic response analysis.A sinusoidal force was applied in the gear mesh and the corresponding vibration amplitude at a point on the gearbox housing was predicted.3.3 Paper C: A Study of Gear Noise and Vibration Paper C reports on an experimental investigation of the influence of gear finishing methods and gear deviations on gearbox noise and vibration.Test gears were manufactured using three different finishing methods and with different gear tooth modifications and deviations.Table3.3.1 gives an overview of the test gear pairs.The surface finishes and geometries of the gear tooth flanks were measured.Transmission error was measured using a single flank gear tester.LDP software from Ohio State University was used for transmission error computations.The test rig described in Paper B was used to measure gearbox noise and vibration for the different test gear pairs.The measurements showed that disassembly and reassembly of the gearbox with the same gear pair might change the levels of measured noise and vibration.The rebuild variation was sometimes of the same order of magnitude as the differences between different tested gear pairs, indicating that other factors besides the gears affect gear noise.In a study of the influence of gear design on noise, Oswald et al.[5] reported rebuild variations of the same order of magnitude.Different gear finishing methods produce different surface finishes and structures, as well as different geometries and deviations of the gear tooth flanks, all of which influence the transmission error and thus the noise level from a gearbox.Most of the experimental results can be explained in terms of measured and computed transmission error.The relationship between predicted peak-to-peak transmission error and measured noise at a torque level of 500 Nm is shown in Figure 3.3.1.There appears to be a strong correlation between computed transmission error and noise for all cases except gear pair K.However, this correlation breaks down in Figure 3.3.2, which shows the relationship between predicted peak to peak transmission error and measured noise at a torque level of 140 Nm.The final conclusion is that it may not be possible to identify a single parameter, such as peak-to-peak transmission error, that can be directly related to measured noise and vibration.3.4 Paper D: Gearbox Noise and Vibration −Influence of Bearing Preload The influence of bearing endplay or preload on gearbox noise and vibrations is investigated in Paper D.Measurements were carried out on a test gearbox consisting of a helical gear pair, shafts, tapered roller bearings, and a housing.Vibration measurements were carried out at torque levels of 140 Nm and 400 Nm with 0.15 mm and 0 mm bearing endplay and with 0.15 mm bearing preload.The results shows that the bearing endplay or preload influence gearbox vibrations.Compared with bearings

with endplay, preloaded bearings show an increase in vibrations at speeds over 2000 rpm and a decrease at speeds below 2000 rpm.Figure 3.4.1 is a typical result showing the influence of bearing preload on gearbox housing vibration.After the first measurement, the gearbox was not disassembled or removed from the test rig.Only the bearing preload/endplay was changed from 0 mm endplay/preload to 0.15 mm preload.Therefore the differences between the two measurements are solely due to different bearing preload.FE simulations performed by Sellgren and Åkerblom [6] show the same trend as the measurements here.For the test gearbox, it seems that bearing preload, compared with endplay, decreased the vibrations at speeds below 2000 rpm and increased vibrations at speeds over 2000 rpm, at least at a torque level of 140 Nm.3.5 Paper E: Gear Geometry for Reduced and Robust Transmission Error and Gearbox Noise In Paper E, gearbox noise is reduced by optimization of gear geometry for decreased transmission error.The optimization was not performed strictly mathematically.It was done by calculating the transmission error for different geometries and then choosing a geometry that seemed to be a good compromise considering not only the transmission error, but also other important characteristics.Robustness with respect to gear deviations and varying torque was considered in order to find gear geometry with low transmission error in the appropriate torque range despite deviations from the nominal geometry due to manufacturing tolerances.Static and dynamic transmission error as well as noise and housing vibrations were measured.The correlation between dynamic transmission error, housing vibrations, and noise was investigated in a speed sweep from 500 to 2500 rpm at constant torque.No correlation was found between dynamic transmission error and noise.4 DISCUSSION AND CONCLUSIONS Static loaded transmission error seems to be strongly correlated to gearbox noise.Dynamic transmission error does not seem to be correlated to gearbox noise in speed

sweeps in these investigations.Henriksson [7] found a correlation between dynamic transmission error and gearbox noise when testing a truck gearbox at constant speed and different torque levels.The different test conditions, speed sweep versus constant speed, and the different complexity(a simple test gearbox versus a complete truck gearbox)may explain the different results regarding correlation between dynamic transmission error and gearbox noise.Bearing preload influences gearbox noise, but it is not possible to make any general statement as to whether preload is better than endplay.The answer depends on the frequency and other components in the complex dynamic system of gears, shafts, bearings, and housing.To minimize noise, the gearbox housing should be as rigid as possible.This was proposed by Rook [8], and his views are supported by the results relating to the optimization of a transmission housing described in section 2.5.Finite element analysis is a useful tool for optimizing gearbox housings.5 FUTURE RESEARCH It would be interesting to investigate the correlation between dynamic transmission error and gearbox noise for a complete wheel loader transmission.One challenge would be to measure transmission error as close as possible to the gears and to avoid resonances in the connection between gear and encoder.The dropbox gears in a typical wheel loader transmission are probably the gears that are most easily accessible for measurement using optical encoders.See Figure 5.1.1 for possible encoder positions.Modeling the transmission in more detail could be another challenge for future work.One approach could be to use a model of gears, shafts, and bearings using the transmission error as the excitation.This could be a finite element model or a multibody system model.The output from this model would be the forces at the bearing positions.The forces could be used to excite a finite element model of the housing.The housing model could be used to predict noise radiation, and/or vibration at the attachment points for the gearbox.This approach would give absolute values, not just relative levels.REFERENCES [1] Welbourn D.B., “Fundamental Knowledge of Gear Noise −A Survey”, Proc.Noise & Vib.of Eng.and Trans., I Mech E., Cranfield, UK, July 1979, pp 9–14.[2] MackAldener M., “Tooth Interior Fatigue Fracture & Robustness of Gears”, Royal Institute of Technology, Doctoral Thesis, ISSN 1400-1179, Stockholm, 2001.[3] Ohio State University, LDP Load Distribution Program, Version 2.2.0, http://www.xiexiebang.com/ , 2007.[4] Borner J., and Houser D.R., “Friction and Bending Moments as Gear Noise Excitations”,SAE Technical Paper 961816.[5] Oswald F.B.et al., “Influence of Gear Design on Gearbox Radiated Noise”, Gear Technology, pp 10–15, 1998.[6] Sellgren U., and Åkerblom M., “A Model-Based Design Study of Gearbox Induced Noise”, International Design Conference – Design 2004, May 18-21, Dubrovnik, 2004.[7] Henriksson M., “Analysis of Dynamic Transmission Error and Noise from a Two-stage Gearbox”, Licentiate Thesis, TRITA-AVE-2005:34 / ISSN-1651-7660, Stockholm, 2005.[8] Rook T., “Vibratory Power Flow Through Joints and Bearings with Application to Structural Elements and Gearboxes”, Doctoral Thesis, Ohio State University, 1995.

第四篇：机械类专业课程名称中英文对照

机械制图 Mechanical Drawing

可编程序控制技术 Controlling Technique for Programming

金工实习Metal Working Practice

毕业实习Graduation Practice理论力学 Theoretical Mechanics

材料力学 Material Mechanics

数字电子电路 Fundamental Digital Circuit

机械控制工程 Mechanical Control Engineering

可靠性工程 Reliability Engineering

机械工程测试技术 Measurement Techniques of Mechanic Engineering

计算机控制系统 Computer Control System

机器人技术基础 Fundamentals of Robot Techniques

最优化技术 Techniques of Optimum

工程测试与信号处理 Engineering Testing & Signal Processing

金属工艺及设计 Metal Technics & Design

机械工业企业管理 Mechanic Industrial Enterprise Management

机械零件课程设计 Course Design of Machinery Elements

投资经济学 Investment Economics

现代企业管理 Modern Enterprise Administration

市场营销学 Market Selling生产实习Production Practice

课程设计 Course Exercise

有限元法 FInite Element

金工实习Metalworking Practice

液压传动 Hydraulic Transmission微机原理及接口技术 Principle & Interface Technique of Micro-computer微机原理及接口技术 Principle & Interface Technique of Micro-computer

数控技术 Digit Control Technique活塞膨胀机 Piston Expander

活塞式制冷压缩机 Piston Refrigerant Compreessor

活塞式压缩机 Piston Compressor

活塞式压缩机基础设计 Basic Design of Piston Compressor

活塞压缩机结构强度 Structural Intensity of Piston Compressor

活赛压机气流脉动 Gas Pulsation of Piston Pressor

货币银行学 Currency Banking

基本电路理论 Basis Theory of Circuit

基础写作 Fundamental Course of Composition

机床电路 Machine Tool Circuit

机床电器 Machine Tool Electric Appliance

机床电气控制 Electrical Control of Machinery Tools

机床动力学 Machine Tool Dynamics

机床设计 Machine Tool design

机床数字控制 Digital Control of Machine Tool

机床液压传动 Machinery Tool Hydraulic Transmission

机电传动 Mechanical & Electrical Transmission

机电传动控制 Mechanical & electrical Transmission Control

机电耦合系统 Mechanical & Electrical Combination System

机电系统计算机仿真 Computer Simulation of Mechanic/Electrical Systems

机电一体化 Mechanical & Electrical Integration

机构学 Structuring

机器人 Robot

机器人控制技术 Robot Control Technology

机械产品学 Mechanic Products

机械产品造型设计 Shape Design of Mechanical Products

机械工程控制基础 Basic Mechanic Engineering Control

机械加工自动化 Automation in Mechanical Working

机械可靠性 Mechanical Reliability

机械零件 Mechanical Elements

机械零件设计 Course Exercise in Machinery Elements Design

机械零件设计基础 Basis of Machinery Elements Design

机械设计 Mechanical Designing

机械设计基础 Basis of Mechanical Designing

机械设计课程设计 Course Exercise in Mechanical Design

机械设计原理 Principle of Mechanical Designing

机械式信息传输机构 Mechanical Information Transmission Device

机械原理 Principle of Mechanics

机械原理和机械零件 Mechanism & Machinery

机械原理及机械设计 Mechanical Designing

机械原理及应用 Mechanical Principle & Mechanical Applications

机械原理课程设计 Course Exercise of Mechanical Principle

机械原理与机械零件 Mechanical Principle and Mechanical Elements

机械原理与机械设计 Mechanical Principle and Mechanical Design

机械噪声控制 Control of Mechanical Noise

机械制造概论 Introduction to Mechanical Manufacture

机械制造工艺学 Technology of Mechanical Manufacture

机械制造基础 Fundamental of Mechanical Manufacture

机械制造基础(金属工艺学)Fundamental Course of Mechanic Manufacturing(Meta

机械制造系统自动化 Automation of Mechanical Manufacture System

机械制造中计算机控制 Computer Control in Mechanical Manufacture

互换性与技术测量 Elementary Technology of Exchangeability Measurement焊接方法 Welding Method

焊接方法及设备 Welding Method & Equipment

焊接检验 Welding Testing

焊接结构 Welding Structure

焊接金相 Welding Fractography

焊接金相分析 Welding Fractography Analysis

焊接冶金 Welding Metallurgy

焊接原理 Fundamentals of Welding

焊接原理及工艺 Fundamentals of Welding & Technology

焊接自动化 Automation of Welding工程材料的力学性能测试 Mechanic Testing of Engineering Materials

工程材料及热处理 Engineering Material and Heat Treatment

工程材料学 Engineering Materials

工程测量 Engineering Surveying

工程测试技术 Engineering Testing Technique

工程测试实验 Experiment on Engineering Testing工程测试信息 Information of Engineering Testing工程动力学 Engineering Dynamics

工程概论 Introduction to Engineering

工程概预算 Project Budget

工程经济学 Engineering Economics

工程静力学 Engineering Statics

工程力学 Engineering Mechanics

工程热力学 Engineering Thermodynamics

工程项目评估 Engineering Project Evaluation

工程优化方法 Engineering Optimizational Method工程运动学 Engineering Kinematics

工程造价管理 Engineering Cost Management

工程制图 Graphing of Engineering电机学 Electrical Motor电机学及控制电机 Electrical Machinery Control & Technology

第五篇：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 and1

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。