外文翻译--长臂式采煤用的采煤机

附录一（英文） I.SHEARER LOADERS FOR LONGWALL MINING In Europe， longwall mining is comprehensively mechanized by the almost exclusive use of shearer loaders and ploughs. In the Federal Republic of Germany ploughing has been applied to a greater extent than in other coutries .In spite of this ，the proportion of coal extracted by shearer loaders is steadily increasing .It accounted for 36 percent of the total national output in October 1977. There are a number of convincing reasons why shearer loaders are gaining ground. Their operation is essentionly more independent of the floor and roof conditions ， dirt bands and changing seam conditions than that of ploughs. Optimum adaptation of the cutting height， the fixed cutting depth， and better roof control are further arguments in favour of shearer loaders. In October 1976 the effective working time on a plough face was in the range of 35 percent ， compared with 48 percent on a shearer face. The average outputs reflect the aboxe figures (FRG October 1977 1130 t from a plough face ， 1678 t from a shearer face).It should be noticed ， however， that shearer loaders are generally operating in seams of greater thickness. Shearer loaders are now available for seams ranging from 0.75 m to 4.50 m in thickness. The various machine versions for the respective operating conditions encountered are assembled from a great number of major components in accordance with the unit principle of construction. Eickhoff shearer loaders， for instance， can be equipped with longitudinal motors having ratings of 170， 200， and 300 kw ， and 450 kw at present and 230 kw units will be available soon. The shearers travel on or alongside the conveyor . Ranging arms of different length from 740 mm to 2230 mm are available .The shearers can be manufactured to operate on various voltages and frequencies generally used ， with various haulage methods and speeds， and different drum speeds and drum design for various machine heights. Contrary to former years the manufacturers of such machines are therefore no longer in a position to produce identical machines in large series ， but are compelled to assemble the mining machines from a large number of existing components according to principles which require continuous revision and improvement ， and to integrate them into complete systems together with the face conveyor and roof supports as required by the mining conditions encountered. Although a high degree of development and great operational safety for the severe operating conditions underground have already been reached， efforts have to be made to develop the mining machines further with a view to meet the following future requirements： (1) increased outputs (and at the same time a further improvement in operational safety )， (2) Extension of the working range (e.g. into steeply inclined seams )， (3) Improvement of the ergonomical conditions (e.g. reduction of dust make and noise ). Increased Outputs The current trend is for more coal to be extracted from fewer faces. The output from some faces is already so high that even short stoppages on a face result in an enormous loss of output .The required increase of outputs from shearer loaders is therefore closely connected with the requirement for higher operational safety ， a better degree of utilisation and easier monitoring of all functions of the machine . The improvement in performance is therefore not limited to the development of more powerful motors ， haulgeaboxes ， gearheads， and ranging arms ， but also includes the electrical monitoring of the machines and eventually full automation. This also applies to the development of cutting tools， as the tool life and the tool costs are decisive for the performance of a machine . Outputs can also be increased by multi-machine operation on a face .The efficiency can be improved by the elimination of stable holes and by avoiding stoppages caused ， for instance ， by large lumps breaking out of the face and which must be crushed manually. It is also obvious that the limitation of the operating voltage to 1000 v sets a limit to performance and that the further increase of the nominal motor ratings will require the introduction of higher voltages. Extension of the Working Range Comprehensive experience has been gained with shearer loaders in level and slightly inclined seams or workings to the rise. The mining of thin seams is affected by inherent limitations set by the height of the conveyor ， the necessary clearance underneath the machine ， and the height of the machine itself .Thin seams can therefore only be extracted by shearer loaders if the machine travels alongside the conveyor. This results in guiding problems which can not be solved by the use of a guiding arrangement provided in the traveling track only. A solution eventually found was to trap the machine against the conveyor. This opened possibilities for the shearer loader in a seam thickness which so far was reserved for the plough .A great number of EDW 170 LN shearers are now operating ， particularly in Great Britain where they extract thin seams of high-grade coking coal . In steeply inclined seams the use of shearer loaders has been limited due to haulage difficulties， and finding adequate safety devices to retain the shearer on the gradient .New developments which dispense with additional safety devices outside of the machine and which provide for the necessary haulage arrangements have extended the working range of shearer loaders into steeply inclined seams . The cost of roadway drivage and maintenance increase considerably with the depth of the workings. The development of advanced heading has so far impeded face advance .The chainless haulage system for shearer loaders now allows for multimachine operation .Within such a system face and machines can be used which are designed for the purpose and which thus not only eliminate stable holes ， but also cut the roadway section， so that high outputs are achieved with the resulting increased productivity . Improvement of Ergonomical Conditions Underground Compared with other industrial activities， working underground is particularly laborious and dangerous. Efforts are therefore being made to ease the tasks and to increase the safety of the workings underground not only because of the necessity to obtain people who are willing to operate the equipment .This also urges the need for further development . For many years the problem of dust suppression on shearer loader faces has been a concern ， and much remains to be done in this field .In this connection， reference is lately often made to the hydraulic extraction of coal by water jets or to the use of water jets for assisting conventional mining machine . Underground operations are continuously jeopardized by the occurrence of fire damp .To eliminate such hazards hollow shaft ventilation is frequently used in the U.K. for feeding water and air into the depth of cut by means of Venturi spray jets. The operation of shearer loaders is also improved by the provision of controls at each end of the machine by radio control ， and by automatic control enabling independent operation of the shearer on the face . COMPONENTS OF SHEARER LOADERS The targets of development outlined in the foregoing call for continuous improvement and further development of all machine components. Motors： High outputs require high motor ratings .An optimum machine adaptation must be employed for each particular type of coal to keep the specific energy at a minimum . The accommodation of high ratings within the limited space necessitates the use of water-cooled motors .Whilst cooling the stators of motors is now an accepted standard and end-shield cooling is applied for the latest motor designs ， trials are now also being made to increase the motor rating further within a given space by cooling the shafts. The motors used so far for longwall power loading machinery are three-phase induction motors which due to their design are sufficiently robust to meet the operating conditions underground .In an effort to reduce the specific energy to a minimum it is necessary to coordinate the drum speed with the traveling speed of the power loader ， and this could be achieved by a machine equipped with d.c. motors for powering the drums which is said to have been developed in the USSR， although there is no information of the operating results. The motors of conventional shearer loaders are positioned in the longitudinal axis of the machine and require a shaft at either side for power transmission to the gearheads. Such machines therefore require a complex gearing system which ，however ， offers the advantage that the motor power can be divided among the two drums and the haulage box as required . New machines such as ， for instance ， the EDW-150-2L are equipped with transverse motors fitted direct to the ranging arm .The advantage ， however ， is achieved at the expense of the power distribution the two drums which is no longer possible ， and the drum which is subjected to the higher load determines the traveling speed of the shearer by marking full use of its motor power . Haulage Units Hydraulic haulage units for power loaders have been used for nearly 30 years now .In the course of the decades they have been improved to a high degree of the shearer as a function of the lood on the motor and the haulage box (Eicomatik).They prevent overloads and operate safely using flame-resistant fluids . However ， the development of the semi-conductor technique has progressed to a stage during the last decade that it is now possible to design electrical haulage units powered by d.c. motors the speed of which is controlled by thyristors .Compared with hydraulic haulage units electric haulages are simpler and maintained via the use of plug in control units .In addition ， their various functions are monitored and they respond more rapidly to speed alterations than hydraulic haulage units . Amongst the first power loaders equipped with such electric haulage units are the Eickhoff double-ended ranging drum shearers EDW-150-2L， and the electric haulages have fully met the expectations from the very first installation. Chainless Haulage Systems After the use of haulage ropes and chains ， chainless haulage systems are now gaining ground .They offer the advantages of greater safety ， of a steadier machine operation ， and of multi-machine operation on a face . In Great Britain， a number of various designs are used .A problem connected with some chainless haulage systems is the fact that they impede the flexibility of the face conveyor and can cause operational restrictions. The Eicotrack system of Gebr. Eickhoff has overcome this problem， because contrary to other systems the rack sections have half the pan length ， so that displacements and deflections between the line pans have only half the effect between the rack sections .This unique advantage naturally entails higher costs . In special cases， however ， the flexibility of the face conveyor is still not considered sufficient .In such cases， the rack sections are not fixed to the face accessories ， but are slidingly arranged in a channel or at the trapping tube .This fully eliminates any effect on the flexibility of the conveyor .Depending on the conditions ， the line of rack sections is fixed at one or several points along the face. Existing haulage units can be converted for operation via Eicotrack .Haulage forces of up to 300 KN are currently ased for present-day power loaders . But even these forces are sometimes insufficient for heavy machines in steeply inclined seams. Higher haulage forces are obtained if booster haulage units are installed in addition to an existing haulage unit to house an additional hydraulic motor and with the follow up train of gear wheels .The oil flow from the pump in the main haulage unit is then distributed to the two hydraulic motors which transmit the power to the two rack wheels .This hydraulic arrangement ensures that both rack wheels exert the same force on to the rack .Higher haulage forces are therefore reached at the expenses of correspondingly reduced traveling speed. Gear Boxes Shearers powered by longitudinal motors need gearboxes to which the ranging arms with the planetary gearings can be mounted .The gearheads are built in different sizes in accordance with the existing motors and house the bevel wheels ， lubrication pumps and hydraulic pumps . Oil cooling is required for high ratings .Intermediate ，two-speed gearboxes are available when a lower drum speed is required . It is unavoidable ， however， that low drum speeds result im a higher torque load on the gearings at a given rating . All two-speed gearboxes known so far can therefore not operate at full load and should therefore be protected against overloads. However ， the trend for low drum speeds is quite obvious ， and new developments must be planned from the beginning to transmit the full motor power at low speeds. Ranging Arms Ranging Arms in many different lengths are available for shearer loaders .For face end machines ， for instance ， extra long ranging arms ， sometimes obtained by bolting two together ， can be installed .Here again ， oil circulation and oil cooling are required for the transmission of high powers .The low drum speed is now finally reached at the end of the ranging arm in the planetary gearing .If the requirement for low drum speeds continues in the future ， even higher reduction ratios and loads must be coped with by the planetary gearing .If ， in addition ， the use of hollow shafts increases with dimensions foe a sufficient air flow to ensure adequate ventilation ， the only practical solution seem to be double planetary gearings . Meeting such requirements will lead to very complex and expensive designs . Electrical Equipment With the almost universal use of shearer loaders for longwall mining and the demand for increased productivity the demand for monitoring and control functions has become extremely urgent . The realization of this however ， has only become feasible after the introduction of instrinsically safe electronics . The latest machines are therefore equipped with s great number of sensors at various points to detect and indicate conditions of temperatures ， pressures， flow rates ， circulation， voltages etc. On Eickhoff shearer loaders the monitored functions are relayed to function indicators which provide the facility for obtaining the desired information by means of selective push-buttions and digital read-outs. Considerable progress still has to be achieved in the field of horizon control .So far ， there is no reliable and operationally safe method for horizon control which would enable the shearer to cut automatically along the roof or floor line . All concepts and designs conceived and tried so far have not had the expected success ，although the height control of the drums of s shearer is now possible . A programmed shearer loader was already shown by Eickhoff during the 1976 mining exhibition in Dusseldort .Still lacking full automatic horizon control ， the system is based on manually measureing the actual roof and floor cutting horizons along the face at predetermined intervals .and if satisfactory ， programming the shearer so that the cutting profile is respeated during successive shears . Electrical supply to shearer loaders has ben improved in the course of the last years .The shearer cables originally used had no armouring and were therefore vulnerable to mechanical damage when guided in the open spill plate channel .Shearer cables have therefore been provided with a steel mesh armouring or they are protected by a cable handling chain .It must be noted ， however ， that the failure rate of shearer cables is often complained about and that in steeply inclined seams neither the armoured shearer cable in the handling chain offer acceptable solutions . The cable carrier operating in a closed channel of the spill plate developed within a research program sponsored by the Federal Minister for Economy is therefore recognized as the better solution .The production of this idea by Eickhoff and the first installation in a steeply inclined seam at Erin Colliery of Eschweiler showed good results. The shearer cable and the water house are held tight in the channel from the maingate by a pulley in the cable carrier by maintaining an even pull. Hence ， the cable is no longer subjected to torsion at the cable entry into the shearer loader .The operating lift of the shearer cable has thereby been considerably extended. 附录二（译文） 长臂 式采煤用的采煤机 长臂式采煤在欧洲已普遍机械化，几乎全部使用采煤机和刨煤机。在德意志联邦共和国，刨削式采煤比其他国家用得更为广泛，尽管如此，用采煤机采出煤炭时的比率稳步增加。在 1977 年 10 月，他的产量占全国总产量的 36%。 采煤机之所以得到发展有许多令人信服的理由。采煤机的运转比刨煤机受顶底板条件，夹石和煤层厚度的变化影响更小。截高适应性强，截深稳定、顶板易于控制，是倾向于使用采煤机的另一些理由。 1976 年 10 月，刨煤机工作面的有效工作时间在 35%左右，相比之下，采煤机工作面为 48%。平均日产量 也反映了上列数字（在德意志联邦共和国 1977 年10 月刨煤机工作面平均日产煤 1180 吨，采煤机工作面采煤 1678 吨）。但是，这里必须指出，采煤机通常是在厚度较大的煤层中使用。 目前采煤机的适用范围是厚度从 0.75 米到 4.5 米的煤层。适用于可能遇到的不同工作条件的各种形式的采煤机是根据积木式结构原理由许多主要部件组装而成的。例如， Eickhoff 采煤机分别备有纵置式电动机，功率为 170， 200， 300千瓦，而 450 千瓦的不久即将问世。横置式电动机目前为 150 千瓦， 230 千瓦的也即将供货。 采煤及骑在输送机上面或 者贴着输送机移动。摇臂有不同长度，从 740 毫米至 2230 毫米，各种采煤机可以制造成在常用的各种电压和频率下运转，可以用各种的牵引方法和速度，可以有不同的滚筒速度以及为各种高度的机型作出不同的滚筒设计。与前些年不同，这类机械的制造厂商不再大批生产同型号的机械设备，而不得不根据不断修正与改进的原则利用现有的大量组件组装采矿机械，并根据所遇到的采掘条件使这些机械与工作面输送机和顶板支护设备配套，形成完整的系统。尽管对于恶劣的井下工作条件来说已经取得了很大的技术发展并达到了很高的工作安全性，为了满足下列的要求，尚需 进一步做出努力来发展采掘机械：增加产量（同时进一步改进操作安全性）；扩大工作范围（例如，开采急倾斜煤层）；改善工人工作条件（例如，减少粉尘产生和噪音）。 增加产量 当前的趋势是从更少的工作面中采出更多的煤炭。 某些工作面的产量已经很高，以致工作面工作稍有停顿，即会造成大量损失产量的后果。因此，采煤机产量的提高就与提高运转安全性、提高利用率，以及更方便的监控机械所有的功能密切相关。 因此性能的改进就不仅限于研制更大功率的电动机、牵引部、机头和摇臂，而且还包括研制机器的电器监控系统，最终实现全面自动化。这也适用 于截齿的改进，因为截齿的寿命和价格决定采煤机的性能。提高产量，还可以通过在一个工作面使用多台采煤机的办法实现。这样，由于免开切口，避免因大块煤从工作面脱落不得不用人力破碎等原因而造成的停顿，就可以提高效率。还有一个很明显的问题，那就是把工作电压限制在 1000 伏以内限制了采煤机的性能发挥，要进一步增大电动机的额定功率，就必须采用更高的电压。 扩大应用范围 在水平煤层，缓倾斜煤层或仰斜开采中，采煤机的应用已经取得全面经验。薄煤层的开采受到难以克服的限制，这是由于输送机的高度，采煤机下应留有必要的间隙，以及采煤机 本身高度的限制。因此只有当采煤机贴着输送机移动式薄煤层的煤才能被采出。这就造成一个导向问题，仅仅利用行走道轨上的导向设备是解决不了问题的。一个新近发现的解决办法是使采煤机卡住输送机滑行。这就使得把采煤机运用于到目前为止只适用于使用刨煤机的煤层厚度成为可能。大量的 EDW-170-LN 型采煤机正在工作，特别是在英国，用于开采高品位炼焦煤的薄煤层。在急倾角的煤层，采煤机的使用受到牵引困难的限制，而且不易找到一种能把采煤机保持在坡道上的使用装置。一些新的设计，无需在采煤机以外另设安全装置，它备有必要的牵引装置，已把 采煤机的工作范围扩大到急倾斜煤层。 随着作业深度增加，巷道的掘进与维护费大量增加。掘进超前平巷一向妨碍采煤工作面的推进。目前用于采煤机的无链牵引系统允许使用多机操作。专门设计的工作面端头采煤机可以在此种系统中使用，它不仅可以免开切口，还可以切割巷道部分，因此产量提高，结果导致生产效率的提高。 改善井下工人工作条件 与其他工业活动相比，在井下工作特别劳累而且危险。因此目前正在致力于减轻劳作负担和提高井下作业的安全性，这不仅是由于有严格的规程，而且还处于能招募到愿意开采煤机的工人的需要。这一点也促进了不断改进技 术的必要性。 多年以来，采煤机工作面的防尘问题一直是个至关重要的问题，至今在这方面还有许多工作要做。为此最近常常有人议论用水枪进行水力开采，或是用水枪协助传统的采煤机。 井下作业不断地受到爆炸性气体的威胁。为了消灭这类事故，在英国常常采用空心轴通风法，用文丘里喷嘴把水和空气注入截槽深部。 采煤机的操作改进，还包括在采煤机的两端配备了控制设备，用无线电控制，还可用自动控制使采煤机在工作面独立运转。 采煤机的部件 上文简要谈到的发展目标不断改善和进一步发展采煤机的所有部件。 电 动 机 提高产量要求强大的电动机 功率。每一特定的煤种应该使用一种最适用的机械设备以便使单位能耗（千瓦小时 /立方米）最低。在有限的空间内容纳很高的功率需要采用水冷式电机。目前，冷却电机定子已作为既定标准，最新设计的电动机已有了端罩冷却，此外，为了进一步提高一定空间内的电动机功率还正在试验冷却主轴。 到目前为止，长臂采煤机所用的电动机都是三相感应电动机，由于它的结构足够坚固，可以应付井下运转条件。为尽量把单位能耗（千瓦小时 /立方米）降至最小，就必须使滚筒转速与采煤机牵引速度相协调，为达到这一目的，可以在采煤机上配备直流电动机来驱动滚筒，据说在 苏联研制了这种机械，而关于使用结果还没有资料。 一般的采煤机都是沿机身的纵轴方向装置电动机，在两端都需要出轴以便把动力传递给机头。这样的采煤机需要复杂的传动系统，但是有个好处，就是电动机的动力能够按需要分配给两个滚筒和牵引部。像 EDW-150-2L 这样的新式采煤机装备有横置式电动机，他们直接安装在摇臂上。但是这个优点是有代价的，既不可能在两个滚筒之间分配动力，而承受较重载荷的那个滚筒由于达到了最大的功率，将决定采煤机的移动速度。 牵引部 采煤机的液压牵引部件到目前也使用了将近三十年。在这