外文翻譯--長臂式采煤用的采煤機

1、<p><b>　　附錄一（英文）</b></p><p>　　I.SHEARER LOADERS FOR LONGWALL MINING</p><p>　　In Europe， longwall mining is comprehensively mechanized by the almost exclusive use of shearer

2、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

3、.It accounted for 36 percent of the total national output in October 1977.</p><p>　　There are a number of convincing reasons why shearer loaders are gaining ground. Their operation is essentionly more indepe

4、ndent 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 fav

5、our of shearer loaders.</p><p>　　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

6、 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.</p><p>　　Sheare

7、r 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

8、accordance with the unit principle of construction.</p><p>　　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 2

9、30 kw units will be available soon.</p><p>　　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 oper

10、ate on various voltages and frequencies generally used ，with various haulage methods and speeds， and different drum speeds and drum design for various machine heights.</p><p>　　Contrary to former years the m

11、anufacturers 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

12、 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.</p>&l

13、t;p>　　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

14、 view to meet the following future requirements：</p><p>　　(1)—increased outputs (and at the same time a further improvement in operational safety )，</p><p>　　(2)—Extension of the working range (

15、e.g. into steeply inclined seams )，</p><p>　　(3)—Improvement of the ergonomical conditions (e.g. reduction of dust make and noise ).</p><p>　　Increased Outputs</p><p>　　The current

16、trend is for more coal to be extracted from fewer faces.</p><p>　　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

17、 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 .</p><p

18、>　　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 eventua

19、lly full automation.</p><p>　　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 .</p><p>　　Outputs can als

20、o 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 mus

21、t be crushed manually.</p><p>　　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 t

22、he introduction of higher voltages.</p><p>　　Extension of the Working Range </p><p>　　Comprehensive experience has been gained with shearer loaders in level and slightly inclined seams or workin

23、gs to the rise.</p><p>　　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

24、 .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

25、traveling track only. A solution eventually found was to trap the machine against the conveyor. Th</p><p>　　In steeply inclined seams the use of shearer loaders has been limited due to haulage difficulties，

26、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 ha

27、ve extended the working range of shearer loaders into steeply inclined seams .</p><p>　　The cost of roadway drivage and maintenance increase considerably with the depth of the workings. The development of ad

28、vanced 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 purpos

29、e 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 .</p><p>　　Improvement of Ergonomical Condition

30、s Underground</p><p>　　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

31、 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 .</p><p>　　For many years the problem o

32、f 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

33、 of water jets for assisting conventional mining machine .</p><p>　　Underground operations are continuously jeopardized by the occurrence of fire damp .To eliminate such hazards hollow shaft ventilation is f

34、requently used in the U.K. for feeding water and air into the depth of cut by means of Venturi spray jets.</p><p>　　The operation of shearer loaders is also improved by the provision of controls at each end

35、of the machine by radio control ，and by automatic control enabling independent operation of the shearer on the face .</p><p>　　COMPONENTS OF SHEARER LOADERS </p><p>　　The targets of development

36、outlined in the foregoing call for continuous improvement and further development of all machine components.</p><p><b>　　Motors：</b></p><p>　　High outputs require high motor ratings

37、.An optimum machine adaptation must be employed for each particular type of coal to keep the specific energy at a minimum .</p><p>　　The accommodation of high ratings within the limited space necessitates th

38、e 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 f

39、urther within a given space by cooling the shafts.</p><p>　　The motors used so far for longwall power loading machinery are three-phase induction motors which due to their design are sufficiently robust to m

40、eet 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

41、 machine equipped with d.c. motors for powering the drums which is said to have been developed in the USSR， although there is no info</p><p>　　The motors of conventional shearer loaders are positioned in the

42、 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 p

43、ower can be divided among the two drums and the haulage box as required .</p><p>　　New machines such as ， for instance ，the EDW-150-2L are equipped with transverse motors fitted direct to the ranging arm .Th

44、e 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 m

45、arking full use of its motor power .</p><p>　　Haulage Units </p><p>　　Hydraulic haulage units for power loaders have been used for nearly 30 years now .In the course of the decades they have bee

46、n 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 .</p><p>　　However ，th

47、e 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 thyrist

48、ors .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 alte

49、rations than hydraulic haulage units . Amongst th</p><p>　　Chainless Haulage Systems </p><p>　　After the use of haulage ropes and chains ，chainless haulage systems are now gaining ground .They o

50、ffer the advantages of greater safety ，of a steadier machine operation ，and of multi-machine operation on a face .</p><p>　　In Great Britain， a number of various designs are used .A problem connected with so

51、me chainless haulage systems is the fact that they impede the flexibility of the face conveyor and can cause operational restrictions.</p><p>　　The Eicotrack system of Gebr. Eickhoff has overcome this proble

52、m， 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 natu

53、rally entails higher costs .</p><p>　　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 accessorie

54、s ，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 p

55、oints along the face.</p><p>　　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 ar

56、e 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

57、motor and with the follow up train of gear wheels .The oil flow from the pump in the main haulage unit i</p><p>　　Gear Boxes </p><p>　　Shearers powered by longitudinal motors need gearboxes to w

58、hich 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

59、cooling is required for high ratings .Intermediate ，two-speed gearboxes are available when a lower drum speed is required .</p><p>　　It is unavoidable ，however， that low drum speeds result im a higher torque

60、 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

61、obvious ，and new developments must be planned from the beginning to transmit the full motor power at low speeds.</p><p>　　Ranging Arms</p><p>　　Ranging Arms in many different lengths are availab

62、le 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 transm

63、ission 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 lo

64、ads must b</p><p>　　Electrical Equipment </p><p>　　With the almost universal use of shearer loaders for longwall mining and the demand for increased productivity the demand for monitoring and co

65、ntrol functions has become extremely urgent .</p><p>　　The realization of this however ，has only become feasible after the introduction of instrinsically safe electronics . The latest machines are therefore

66、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 rela

67、yed to function indicators which provide the facility for obtaining the desired information by means of selective push-buttions </p><p>　　Considerable progress still has to be achieved in the field of horizo

68、n 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

69、 far have not had the expected success ，although the height control of the drums of s shearer is now possible .</p><p>　　A programmed shearer loader was already shown by Eickhoff during the 1976 mining exhib

70、ition 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 ，pro

71、gramming the shearer so that the cutting profile is respeated during successive shears .</p><p>　　Electrical supply to shearer loaders has ben improved in the course of the last years .The shearer cables ori

72、ginally 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

73、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 armo</p><p>　　The cable carrier operatin

74、g 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 f

75、irst 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

76、maintaining an even pull. Hence ，t</p><p><b>　　附錄二（譯文）</b></p><p>　　長臂式采煤用的采煤機</p><p>　　長臂式采煤在歐洲已普遍機械化，幾乎全部使用采煤機和刨煤機。在德意志聯(lián)邦共和國，刨削式采煤比其他國家用得更為廣泛，盡管如此，用采煤機采出煤炭時的比率穩(wěn)步增加。在19

77、77年10月，他的產(chǎn)量占全國總產(chǎn)量的36%。</p><p>　　采煤機之所以得到發(fā)展有許多令人信服的理由。采煤機的運轉(zhuǎn)比刨煤機受頂?shù)装鍡l件，夾石和煤層厚度的變化影響更小。截高適應(yīng)性強，截深穩(wěn)定、頂板易于控制，是傾向于使用采煤機的另一些理由。</p><p>　　1976年10月，刨煤機工作面的有效工作時間在35%左右，相比之下，采煤機工作面為48%。平均日產(chǎn)量也反映了上列數(shù)字（在德意志聯(lián)

78、邦共和國1977年10月刨煤機工作面平均日產(chǎn)煤1180噸，采煤機工作面采煤1678噸）。但是，這里必須指出，采煤機通常是在厚度較大的煤層中使用。</p><p>　　目前采煤機的適用范圍是厚度從0.75米到4.5米的煤層。適用于可能遇到的不同工作條件的各種形式的采煤機是根據(jù)積木式結(jié)構(gòu)原理由許多主要部件組裝而成的。例如，Eickhoff采煤機分別備有縱置式電動機，功率為170，200，300千瓦，而450千瓦的不久

79、即將問世。橫置式電動機目前為150千瓦，230千瓦的也即將供貨。</p><p>　　采煤及騎在輸送機上面或者貼著輸送機移動。搖臂有不同長度，從740毫米至2230毫米，各種采煤機可以制造成在常用的各種電壓和頻率下運轉(zhuǎn)，可以用各種的牽引方法和速度，可以有不同的滾筒速度以及為各種高度的機型作出不同的滾筒設(shè)計。與前些年不同，這類機械的制造廠商不再大批生產(chǎn)同型號的機械設(shè)備，而不得不根據(jù)不斷修正與改進的原則利用現(xiàn)有的大量

80、組件組裝采礦機械，并根據(jù)所遇到的采掘條件使這些機械與工作面輸送機和頂板支護設(shè)備配套，形成完整的系統(tǒng)。盡管對于惡劣的井下工作條件來說已經(jīng)取得了很大的技術(shù)發(fā)展并達到了很高的工作安全性，為了滿足下列的要求，尚需進一步做出努力來發(fā)展采掘機械：增加產(chǎn)量（同時進一步改進操作安全性）；擴大工作范圍（例如，開采急傾斜煤層）；改善工人工作條件（例如，減少粉塵產(chǎn)生和噪音）。</p><p><b>　　增加產(chǎn)量</b

81、></p><p>　　當前的趨勢是從更少的工作面中采出更多的煤炭。</p><p>　　某些工作面的產(chǎn)量已經(jīng)很高，以致工作面工作稍有停頓，即會造成大量損失產(chǎn)量的后果。因此，采煤機產(chǎn)量的提高就與提高運轉(zhuǎn)安全性、提高利用率，以及更方便的監(jiān)控機械所有的功能密切相關(guān)。</p><p>　　因此性能的改進就不僅限于研制更大功率的電動機、牽引部、機頭和搖臂，而且還包括研

82、制機器的電器監(jiān)控系統(tǒng)，最終實現(xiàn)全面自動化。這也適用于截齒的改進，因為截齒的壽命和價格決定采煤機的性能。提高產(chǎn)量，還可以通過在一個工作面使用多臺采煤機的辦法實現(xiàn)。這樣，由于免開切口，避免因大塊煤從工作面脫落不得不用人力破碎等原因而造成的停頓，就可以提高效率。還有一個很明顯的問題，那就是把工作電壓限制在1000伏以內(nèi)限制了采煤機的性能發(fā)揮，要進一步增大電動機的額定功率，就必須采用更高的電壓。</p><p><

83、b>　　擴大應(yīng)用范圍</b></p><p>　　在水平煤層，緩傾斜煤層或仰斜開采中，采煤機的應(yīng)用已經(jīng)取得全面經(jīng)驗。薄煤層的開采受到難以克服的限制，這是由于輸送機的高度，采煤機下應(yīng)留有必要的間隙，以及采煤機本身高度的限制。因此只有當采煤機貼著輸送機移動式薄煤層的煤才能被采出。這就造成一個導向問題，僅僅利用行走道軌上的導向設(shè)備是解決不了問題的。一個新近發(fā)現(xiàn)的解決辦法是使采煤機卡住輸送機滑行。這就使

84、得把采煤機運用于到目前為止只適用于使用刨煤機的煤層厚度成為可能。大量的EDW-170-LN型采煤機正在工作，特別是在英國，用于開采高品位煉焦煤的薄煤層。在急傾角的煤層，采煤機的使用受到牽引困難的限制，而且不易找到一種能把采煤機保持在坡道上的使用裝置。一些新的設(shè)計，無需在采煤機以外另設(shè)安全裝置，它備有必要的牽引裝置，已把采煤機的工作范圍擴大到急傾斜煤層。</p><p>　　隨著作業(yè)深度增加，巷道的掘進與維護費大量

85、增加。掘進超前平巷一向妨礙采煤工作面的推進。目前用于采煤機的無鏈牽引系統(tǒng)允許使用多機操作。專門設(shè)計的工作面端頭采煤機可以在此種系統(tǒng)中使用，它不僅可以免開切口，還可以切割巷道部分，因此產(chǎn)量提高，結(jié)果導致生產(chǎn)效率的提高。</p><p>　　改善井下工人工作條件</p><p>　　與其他工業(yè)活動相比，在井下工作特別勞累而且危險。因此目前正在致力于減輕勞作負擔和提高井下作業(yè)的安全性，這不僅是由

86、于有嚴格的規(guī)程，而且還處于能招募到愿意開采煤機的工人的需要。這一點也促進了不斷改進技術(shù)的必要性。</p><p>　　多年以來，采煤機工作面的防塵問題一直是個至關(guān)重要的問題，至今在這方面還有許多工作要做。為此最近常常有人議論用水槍進行水力開采，或是用水槍協(xié)助傳統(tǒng)的采煤機。</p><p>　　井下作業(yè)不斷地受到爆炸性氣體的威脅。為了消滅這類事故，在英國常常采用空心軸通風法，用文丘里噴嘴把水

87、和空氣注入截槽深部。</p><p>　　采煤機的操作改進，還包括在采煤機的兩端配備了控制設(shè)備，用無線電控制，還可用自動控制使采煤機在工作面獨立運轉(zhuǎn)。</p><p><b>　　采煤機的部件</b></p><p>　　上文簡要談到的發(fā)展目標不斷改善和進一步發(fā)展采煤機的所有部件。</p><p><b>　　

88、電 動 機</b></p><p>　　提高產(chǎn)量要求強大的電動機功率。每一特定的煤種應(yīng)該使用一種最適用的機械設(shè)備以便使單位能耗（千瓦小時/立方米）最低。在有限的空間內(nèi)容納很高的功率需要采用水冷式電機。目前，冷卻電機定子已作為既定標準，最新設(shè)計的電動機已有了端罩冷卻，此外，為了進一步提高一定空間內(nèi)的電動機功率還正在試驗冷卻主軸。</p><p>　　到目前為止，長臂采煤機所用的電

89、動機都是三相感應(yīng)電動機，由于它的結(jié)構(gòu)足夠堅固，可以應(yīng)付井下運轉(zhuǎn)條件。為盡量把單位能耗（千瓦小時/立方米）降至最小，就必須使?jié)L筒轉(zhuǎn)速與采煤機牽引速度相協(xié)調(diào)，為達到這一目的，可以在采煤機上配備直流電動機來驅(qū)動滾筒，據(jù)說在蘇聯(lián)研制了這種機械，而關(guān)于使用結(jié)果還沒有資料。</p><p>　　一般的采煤機都是沿機身的縱軸方向裝置電動機，在兩端都需要出軸以便把動力傳遞給機頭。這樣的采煤機需要復雜的傳動系統(tǒng)，但是有個好處，就是

90、電動機的動力能夠按需要分配給兩個滾筒和牽引部。像EDW-150-2L這樣的新式采煤機裝備有橫置式電動機，他們直接安裝在搖臂上。但是這個優(yōu)點是有代價的，既不可能在兩個滾筒之間分配動力，而承受較重載荷的那個滾筒由于達到了最大的功率，將決定采煤機的移動速度。</p><p><b>　　牽引部</b></p><p>　　采煤機的液壓牽引部件到目前也使用了將近三十年。在這三

91、十年當中，液壓牽引已改進到高度完善的程度。目前已可以把采煤機的牽引速度作為電動機和牽引部負荷的函數(shù)來控制（Eicomatic）。這樣的牽引部可以避免過負荷，并可采用難燃液安全運行。</p><p>　　但近十年來半導體技術(shù)已發(fā)展到一定階段，目前已有可能以直流電動機驅(qū)動牽引部，其速度由可控硅整流器控制。與液壓牽引部相比，電氣牽引部比較簡單和牢固耐用，電氣部件容易通過使用控制插件進行檢查和維護。此外，它的各種功能可以

92、得到監(jiān)視，他的變速反應(yīng)比液壓牽引快。在第一批配備了這種電力牽引部的采煤機中，有Eickhoff EDW-150-2L型雙端可調(diào)高滾筒采煤機，首次安裝試用以來，其電力牽引部完全滿足預期的要求。</p><p><b>　　無鏈牽引系統(tǒng)</b></p><p>　　繼牽引繩和牽引鏈之后，無鏈牽引系統(tǒng)使用日益廣泛。這類系統(tǒng)的優(yōu)點是更為安全，機械運轉(zhuǎn)穩(wěn)定，并可以在一個工作面使

93、用多臺采煤機。</p><p>　　目前有若干種不同結(jié)構(gòu)形式在英國使用。對于某些無鏈牽引系統(tǒng)來說，有一個問題是他們妨礙工作面輸送機的彎曲性能，可能使運行受到約束。Eickhoff 工廠出產(chǎn)的Eicotrack 系統(tǒng)解決了這個問題。因為與其他系統(tǒng)不同，他的導軌節(jié)段長度只用輸送機槽的一半，所以兩輸送機槽之間的錯位和折角對兩個導軌節(jié)段之間只有一半的影響。這一優(yōu)越性能自然需要較高的成本。然而在某些場合，工作面輸送機的彎曲

94、性能還是顯得不夠。在這些場合，導軌節(jié)段就不固定在工作面的設(shè)備上，而是根據(jù)情況滑裝在導槽中或?qū)Ч苌稀＿@就徹底的消滅了對輸送機彎曲性能的任何影響。根據(jù)條件，可沿工作面全線在一個或幾個點上把導軌的節(jié)段固定起來?，F(xiàn)有的牽引不可以經(jīng)改裝試用Eicotrack系統(tǒng)。目前常用的采煤機牽引力可高達300千牛頓。但即使這樣大的力對于急傾斜煤層的重型采煤機來說有時還是不夠。如在現(xiàn)有的牽引部中加上助推裝置，內(nèi)設(shè)一個輔助液壓馬達和齒輪傳動系統(tǒng)，就可以得到更大的

95、牽引力，油液從主牽引部的油泵中流出，然后分配到兩個液壓馬達，這兩個液壓馬達再把動力傳遞給兩個導軌齒輪。這樣的液壓裝置可以保證兩個導軌齒輪對導軌施加的力相等。因此，更大的牽引力是以相</p><p><b>　　變 速 箱</b></p><p>　　裝有縱置式電動機的采煤機需要齒輪箱，行星齒輪傳動的搖臂可以與它接裝。根據(jù)現(xiàn)有電動機的不同，齒輪箱可以做成不同的尺寸，

96、內(nèi)裝傘齒輪，潤滑泵和液壓泵。如果功率大，則需要冷卻油液。如果滾筒需要較低轉(zhuǎn)速，可采用雙速的中間齒輪箱。在一定的功率下滾筒速度低必然會造成扭矩負荷的增加。因此目前所有的兩速齒輪箱都不能滿載運轉(zhuǎn)，必須有過負荷保護。可是，降低滾筒速度的趨勢是很明顯的，新的設(shè)計應(yīng)該從一開始就考慮以低速傳遞電動機的全部功率。</p><p><b>　　搖 臂</b></p><p>　

97、　采煤機可配備各種不同長度的搖臂。例如，工作面端頭采煤機就可以安裝用超長搖臂，通常是用螺栓把兩個搖臂接在一起。為了傳遞大的功率，油液的循環(huán)和冷卻在這里也是必要的。目前終于做到了以行星傳動把很低的滾筒速度傳遞到搖臂末端。如果將來要求繼續(xù)降低滾筒速度，那么行星傳動裝置就要負擔更高的減速比與載荷。此外，假如由于為了通過足夠的空氣流量以改善通風而使用空心軸來加大尺寸，那么唯一可行的解決辦法似乎就是使用雙級行星傳動裝置。要滿足這些要求，機構(gòu)勢必復

98、雜昂貴。</p><p><b>　　電 器 設(shè) 備</b></p><p>　　由于采煤機在長臂采煤方面日益廣泛使用和提高生產(chǎn)率的要求，對于監(jiān)視和控制性能的要求也變得極為迫切。然而這個要求的實現(xiàn)，只有在引用了本質(zhì)安全型電子器件之后才切實可行。所以，最新型的采煤機都配備了大量的傳感器，分布于機體不同部位，檢視與指示溫度、壓力、流速、環(huán)流量、電壓等各種狀態(tài)參數(shù)。在Eic

99、khoff采煤機中各種壓力的監(jiān)視都通過功能指示器實現(xiàn)，它具有獲取所需信息的能力，這是通過選擇性按鈕和數(shù)字顯示實現(xiàn)的。在層位控制方面，尚有待于取得更大進展。截至目前，還沒有一種可靠的、操作安全的，可以使采煤機能沿頂板或底板分界線自動截割的層位控制方法。雖然采煤機滾筒的調(diào)高控制現(xiàn)已解決，目前所設(shè)想的或試驗過的概念和設(shè)計都沒有取得預期效果。1976年杜塞爾多夫采礦展覽會上，Eickhoff公司展出了一種程序控制采煤機。這種采煤機還是沒有一套全