以ZL10裝載機(jī)為底盤設(shè)計(jì)挖掘裝載機(jī)含3張CAD圖.zip,ZL10,裝載,底盤,設(shè)計(jì),挖掘,CAD 英文原文 Mine hoisting in deep shafts in the 1st half of 21st Century Alfred Carbogno Key words: deep shaft, mine hosting, Blair winder, rope safety factor, drum sizing, skip factor Introduction The mineral deposits are exploited on deeper and deeper levels. In connection with this, definitions like “deep level” and “deep shaft” became more and more popular. These definitions concern the depth where special rules regarding an excavation driving, exploitation, rock pressure control, lining construction, ventilation, underground and vertical transport, work organization and economics apply. It has pointed out that the “deep level” is a very relative definition and should be used only with a reference to particular hydro-geological, mining and technical conditions in a mine or coal-field. It should be also strictly defined what area of “deep level” or “deep shaft” definitions are considered. It can be for example: (1)mining geo-engineering, (2)technology of excavation driving, (3) ventilation (temperature). It is obvious that the “deep level” defined from one point of view, not necessarily means a “deep level” in another area. According to [5] as a deep mine we can treat each mine if: (1)the depth is higher than 2300 m or (2)mineral deposit temperature is higher than 38 oC. It is well known that the most of deep mines are in South Africa. Usually, they are gold or diamonds mines. Economic deposits of gold-bearing ore are known to exist at depths up to 5000 m in a number of South Africa regions. However, due to the depth and structure of the reef in some areas, previous methods of reaching deeper reefs using sub-vertical shaft systems would not be economically viable. Thus, the local mining industry is actively investigating new techniques for a single-lift shaft up to 3500 m deep in the near future and probably around 5000 m afterwards. When compared with the maximum length of wind currently in operation of 2500 m, it is apparent that some significant innovations will be required. The most important matter in the deep mine is the vertical transport and the mine hoisting used in the shaft. From the literature [1-12] results that B.M.R. (Blair Multi-Rope) hoist is preferred to be used in deep mines in South Africa. From the economic point of view, the most important factors are: (1)construction and parameters of winding ropes (safety factor, mainly), (2)mine hoisting drums capacity. This article of informative character presents shortly above-mentioned problems based on the literature data [1-12]. Especially, the paper written by M.E. Greenway is very interesting [3]. From two transport systems used in the deep shaft, sub-vertical and the single-lift shaft systems, the second one is currently preferred. (Fig.1.) [6] Hoisting Installation The friction hoist (up to 2100 m), single drum and the double drum (classic and Blair type double drum) hoist are used in deep shafts in South Africa. Drum winders Drum winders are most widely used in South Africa and probably in the world. Three types of winders fall into this category (1)Single drum winders, (2)Double drum winders, (3)Blair multi-rope winders (BMR). Double drum winders Two drums are used on a single shaft, with the ropes coiled in opposite directions with the conveyances balancing each other. One or both drums are clutched to the shaft enabling the relative shaft position of the conveyances to be changed and permitting the balanced hoisting from multiple levels The Blair Multi-Rope System (BMR) In 1957 Robert Blair introduced a system whereby the advantage of the drum winder could be extended to two or more ropes. The two-rope system developed incorporated a two-compartment drum with a rope per compartment and two ropes attached to a single conveyance. He also developed a rope tension-compensating pulley to be attached to the conveyance. The Department of Mines allowed the statutory factor of safety for hoisting minerals to be 4,275 instead of 4,5 provided the capacity factor in either rope did not fall below the statutory factor of 9. This necessitated the use of some form of compensation to ensure an equitable distribution of load between the two ropes. Because the pulley compensation is limited, Blair also developed a device to detect the miscalling on the drum, as this could cause the ropes to move at different speeds and so affect their load sharing capability. Fig.2 shows the depth payload characteristics of double drum, BMR and Koepe winders. The B.M.R. hoist is used almost exclusively in South Africa, probably because they were invented there, particularly for the deep shaft use. There is one installation in England. Because of this hoist's physical characteristics, and South African mining rules favouring it in one respect, they are used mostly for the deep shaft mineral hoisting. The drum diameters are smaller than that of an equivalent conventional hoist, so one advantage is that they are more easily taken underground for sub-shaft installations. A Blair hoist is essentially a conventional hoist with wider drums, each drum having a centre flange that enables it to coil two ropes attached to a skip via two headsheaves. The skip connection has a balance wheel, similar to a large multi-groove V-belt sheave, to allow moderate rope length changes during winding. The sheaves can raise or lower to equalize rope tensions. The Blair hoist's physical advantage is that the drum diameter can be smaller than usual and, with two ropes to handle the load, each rope can be much smaller. The government mining regulations permit a 5 % lower safety factor at the sheave for mineral hoisting with Blair hoists. This came about from a demonstration by the% permits the Blair hoists to go a little deeper than the other do. On the other hand, the mining regulations require a detaching hook above the cage for man hoisting. The balance wheel does not suit detaching hooks, so a rope-cutting device was invented to cut the ropes off for a severe overwind. This was tested successfully but the Blair is not used for man winding on a regular basis. The B.M.R. hoist has been built in three general styles similar to conventional hoists. The three styles are (Fig. 3 and 4): The gearless B.M.R. hoist at East Dreifontein looks similar to an in-line hoist except that the drums are joined mechanically and they are a little out of line with each other. This is because each drum directly faces its own sheaves for the best fleet angle. The two hoist motors are fed via thyristor rectifier/inverter units from a common 6.6-KV busbar. The motors are thus coupled electrically so that the skips in the shaft run in balance, similar to a conventional double-drum hoist. Each motor alternates its action as a DC generator or DC motor, either feeding in or taking out energy from the system. The gearless Blair can be recognized by the offset drums and the four brake units. A second brake is always a requirement, each drum must have two brakes, because the two drums have no mechanical connection to each other. Most recent large B.M.R. hoists are 4.27 or 4.57 m in diameter, with 44.5 ÷ 47.6 mm ropes [1]. In arriving at a drum size the following parameters have been used: (1) The rope to be coiled in four layers, (2)The rope tread pressure at the maximum static tension to be less than 3,2 MPa, (3) The drum to rope diameter ratio (D/d) to be greater than 127 to allow for a rope speed of 20 m/s. With the above and a need to limit the axial length of the drums, a rope compartment of 8,5 m diameter by 2,8 m wide, was chosen. The use of 5 layers of coiled rope could reduce the rope compartment width to 2,15 m but this option has been discarded at this stage because of possible detrimental effects on the rope life. One problem often associated with twin rope drum hoists is the rope fleeting angle. The axial length of the twin rope compartment drums requires wide centres for the headgear sheaves and conveyances in the shaft. To limit the diameter of the shaft, the arrangement illustrated in Fig. 4 has been developed and used on a hoist still to be installed. Here, an universal coupling or Hooke’s Joint has been placed between the two drums to allow the drums to be inclined towards the shaft center and so alleviate rope fleeting angle problem, even with sheave wheels at closer centres [11]. The rope safety factor The graphs in Fig. 5 illustrate the endload advantage with reducing static rope safety factors. While serving their purpose very well over the years, the static safety factor itself must now be questioned. Static safety factors, while specifically relating to the static load in the rope were in fact established to take account of: a. Dynamic rope loads applied during the normal winding cycle, particularly during loading, pull-away, acceleration, retardation and stopping, b. Dynamic rope loads during emergency braking, c. Rope deterioration in service particularly where this is of an unexpected or unforeseen nature. If peak loads on the rope can be reduced so that the peak remains equal to or less than that experienced by the rope when using current hoisting practices with normal static rope safety factor, the use of a reduced static rope safety factor can be justified. The true rope safety factor is not reduced at all. This is particularly of importance during emergency braking which normally imposes the highest dynamic load on the rope. Generally, the dynamic loads imposed during the skip loading, cyclic speed changes and tipping will be lower than for emergency braking but their reduction will of course improve the rope life at the reduced static rope safety factor. The means, justification and safeguards associated with a reduced static safety factor are discussed in [4,7,9,12]. Based on the static rope safety factor of 4, the rope endload of 12843 kg per rope can be achieved. With twin ropes, this amounts to an endload of 25686 kg. With a conveyance based on 40 % of payload of 18347 kg with a conveyance of 7339 kg. There are hoisting ropes of steel wires strength up to Rm = 2300 MPa (Rm up to 2600 MPa [6] is foreseen) used in deep shafts. There are also uniform strength hoisting ropes projected [2,8]. Conveyances The winding machines made from a light alloy are used in hoisting installations in deep shafts. The skip factor (S) has been defined as the ratio of empty mass of the skip (including ancillary equipment such as rope attachments, guide rollers, etc) to the payload mass. If the rope end load is kept constant, a lower skip factor implies a larger payload – in other words, a more efficient skip from a functional point of view. However, the higher the payload for the same rope end load, the larger the out-of-balance load –implying a more winder power going hand in hand with the higher hoisting capacity. If, on the other hand, the payload is fixed, a lower skip factor implies a lower end load and a smaller rope-breaking load requirement. Under these conditions, an out-of-balance load attributable to the payload would remain the same, but that due to the rope would reduce slightly. The sensitivity of depth of wind and hoisting capacity to skip the factor is illustrated in Fig. 6 and 7. A reduction of skip factor from 0,5 to 0,4 results in a depth gain of about 40 m for Blair winders and 50 m for single-rope winders. The increase of hoisting capacity for a reduction of skip factor by about 0,1 is about 10 %. Typical values for the “skip factor” are about 0,6 for skips and about 0,75 for cages for men and material hoisting. Reducing skip factors to say about 0,5 is a tough design brief and the trade-offs between lightweight skips and maintainability and reliability soon become evident in service. The weight can be readily reduced by omitting (or reducing in thickness) skip liner plates but this could reduce skip life by wear of structural plate leading to the high maintenance cost or more frequent maintenance to replace thinner liner plates. Similarly, if the structural mass is saved by reducing section sizes or changing the material from steel to aluminium for example, the structural reliability is generally reduced and the fatigue cracking becomes more efficient. Some success has been achieved in operating large capacity all – aluminium skips with low skip factors but the capital cost is high and a very real hoisting capacity constrain must exist before the additional cost is warranted. It would appear that the depth and hoisting capacity improvements are better made by reducing the rope factor of safety and increasing the winding speed. The philosophy of the skip design should be to provide robust skips with reasonable skip factors in the range of 0,5 to 0,6 that can be hoisted safely and reliably at high speeds and that are tolerant to the shaft guide misalignment. It should be noted that some unconventional skips have been proposed (but not yet built and tested) that could offer skip factors as low as 0.35. Conclusions The first installation of Blaire hoists took place in 1958. From that time we can observe a continuous development of this double-rope, double-drum hoists. Currently, they are used up to the depth of 3 150 m (man/material hoist at the Moab Khotsong Mine, to hoist 13 500 kg in a single lift, at 19,2 m/sec, using 2 x 7400 kW AC cyclo-convertor fed induction motors). The Blair Multi-Rope system can be use either during shaft sinking or during exploitation. The depth range for them is 715 to 3150 m and the maximum skip load is 20 tons. In South Africa in deep shafts single lift systems are preferred. References [1] BAKER. T.J.: New South African Drum Hoisting Plants. CIM Bulletin, No 752, December 1994, p. 86-96. [2] CARBOGNO, A.: Winding Ropes of Uniform Strength. 1st International Conference LOADO 2001. Logistics and Transport. Hotel Permon, High Tatras, June 6th – 8th 2001 p.214-217. [3] GREENWAY, M.E.: An Engineering Evaluation of the Limits to Hoisting from Great Depth. Int. Deep Mining Conference: Technical Challenges in Deep Level Mining, Johannesburg, SAIMM, 1990 p.449-481. [4] HECKER, G.F.K.: The Safety of Hoisting Ropes in Deep Mine Shafts. International Deep Mining Conference: Technical Challenges in Deep Level Mining. Johannesburg, SAIMM, 1990 p. 831-838. [5] HILL, F.G, MUDD J,B: Deep Level Mining in South African Gold Mines. 5th International mining Congress 1967, Moscow, p. 1 –20. [6] LANE, N.M: Constraints on Deep-level Sinking – an Engineering Point of View. The Certificated Engineer, vol. 62, No6, December 1989/January 1991 p. 3-9. [7] LAUBSCHER, P.S.: Rope Safety Factors for Drum Winders – Implications of the Proposed Amendments to the Regulations. Gencor Group, 1995 Shaft Safety Workshop. Midrand, Johannesburg, November 1995, paper No 5 p.1-11. [8] MAC DONALD, D.H., PIENAAR, F.C.: State of the Art and Future Developments of Steel Wire Rope in Sinking and Permanent Winding Operations. Gencor Group, Shaft Safety Workshop Magaliesberg, 1994, paper No 13, p. 1-21. [9] MCKENZIE, I.D.: Steel Wire Hoisting Ropes for Deep Shafts. International Deep Mining Conference: Technical Challenges in Deep Level Mining. Johannesburg, SAIMM, 1990 p. 839-844. [10] SPARG, E.N.: Development of SA- Designed and Manufactured Mine Winders. The South African Mechanical Engineer vol.35, No 10, October 1985 p. 418-423. [11] SPARG E,N.: Developments in Hoist Design Technology Applied to a 4000 m Deep Shaft. Mining Technology, No 886, June 1995, p. 179-184. [12] SYKES, D.G., WIDLAKE, A.C.: Reducing Rope Factors of Safety for Winding in Deep Levels Shafts. International Deep Mining Conference. Technical Challenges in Deep Level Mining. Johannesburg, SAIMM, 1990 p. 819-829. 中文譯文 21世紀(jì)前半葉礦井挖掘機(jī)在深井中的應(yīng)用 關(guān)鍵詞: 深井，礦井挖掘機(jī)，布萊爾挖掘機(jī)，鋼絲繩安全要素，滾筒尺寸，驟變要素 介紹 礦物沉淀物在越來越深的水平上被開采。關(guān)于這方面，像“深水平面”和“深井”的定義變得越來越流行了。這些定義與有關(guān)特殊規(guī)則方面的深度有關(guān)，涉及到挖掘操縱、開采、巖石壓力控制、內(nèi)層建造、通風(fēng)，地下和垂直的運(yùn)輸, 勞動(dòng)組織和經(jīng)濟(jì)學(xué)應(yīng)用。 “深水平面”已經(jīng)被指出是一種非常相對(duì)的定義，這個(gè)定義應(yīng)當(dāng)只能用于采礦或煤領(lǐng)域有關(guān)特殊的水-地質(zhì)學(xué), 采礦和技術(shù)條件方面的參考。它也應(yīng)當(dāng)用于嚴(yán)格定義已經(jīng)公認(rèn)的有關(guān)“深水平面”或“深井”領(lǐng)域的定義?？梢耘e例來說: （1）采礦工程技術(shù), （2）開采操縱技術(shù), （3）通風(fēng) (降低溫度). 明顯的是，從一方面得到的“深水平面”定義,在其他領(lǐng)域并不意味著“深水平面” 。 根據(jù)第5段提到的“深井”，我們可以設(shè)想每一個(gè)礦井： （1）深度超過2300米深或者 （2）礦石沉積物的溫度超過38攝氏度。 廣為人知的是大部分深井在南非。通常，它們是金礦或者鉆石礦井。人們都知道像黃金方面礦石的經(jīng)濟(jì)沉淀物存在于南非一些深達(dá)5000米的深井領(lǐng)域。然而，在一些區(qū)域中，存在暗礁的深度和結(jié)構(gòu)要素，先前在垂直的深井中使用的到達(dá)深度暗礁的方法在經(jīng)濟(jì)上不可取。因此，當(dāng)?shù)氐牟傻V業(yè)正在積極地研究在不久的將來能夠用于深度達(dá)到3500米或者未來深度在5000米左右的礦井中的單一挖掘技術(shù)。相對(duì)于當(dāng)今深度達(dá)2500米的礦井中的挖掘技術(shù)，它的一些創(chuàng)新在將來會(huì)有很大的意義。 在深井中最重要的事件是垂直運(yùn)輸以及礦井挖掘技術(shù)在井中的應(yīng)用。參考文獻(xiàn)的1至12篇可以得出這樣的結(jié)論:布萊爾多繩挖掘機(jī)在南非的深井應(yīng)用中是首選的。從經(jīng)濟(jì)學(xué)的觀點(diǎn)看, 最重要的要素是: （1）挖掘繩索的構(gòu)造和參數(shù)(主要是安全要素)； （2）礦井挖掘絞車的承載能力。 這篇見聞廣博性質(zhì)的文章簡(jiǎn)略的介紹了上述基于參考文獻(xiàn)1至12篇所反映的問題。尤其, M.E. Greenway寫的文獻(xiàn)【3】非常有趣。從被應(yīng)用于深井中的雙運(yùn)輸系統(tǒng)，接近垂直的以及單一的井中挖掘系統(tǒng)，第二種系統(tǒng)是目前首選的。參見插圖1/參考文獻(xiàn)【6】。 挖掘裝置： 挖掘機(jī)（挖掘深度達(dá)2100米），單獨(dú)的和雙滾筒挖掘機(jī)（第一流的和布萊爾形式的雙滾筒挖掘機(jī)）廣泛應(yīng)用于南非地區(qū)。 1 Carbogno Alfred Ing 博士, 來自波蘭格利維策市西里西亞技術(shù)大學(xué)，采礦機(jī)械化學(xué)會(huì)，Akademicka 2，PL 44-101 Gliwice, (他于2002年8月5日修訂了先前被公認(rèn)為是標(biāo)準(zhǔn)的版本)。 滾筒挖掘機(jī)： 滾筒挖掘機(jī)被廣泛應(yīng)用于南非或許全世界。三種類型的挖掘機(jī)屬于這樣的類型： （1）單一滾筒挖掘機(jī), （2）雙鼓挖掘機(jī), （3）布萊爾多繩繞線機(jī) (BMR)。 雙滾筒挖掘機(jī)： 雙滾筒應(yīng)用于單井，鋼絲繩以相對(duì)的方向纏繞在它的上面，以保持運(yùn)輸工具的平衡。單一或者雙滾筒附著于井，使得運(yùn)輸工具能夠在相對(duì)于井的位置上變換以及從不等高的水平面平穩(wěn)的挖掘。 布萊爾多繩系統(tǒng) (BMR)在1957年，布萊爾羅伯特引進(jìn)了一種挖掘系統(tǒng)，這種系統(tǒng)可以將滾筒的優(yōu)勢(shì)擴(kuò)大到能夠纏繞兩根或多根鋼絲繩。這種雙繩系統(tǒng)發(fā)展成為二合一的滾筒，每一部分一根繩以及兩根繩附著在單一的運(yùn)輸工具上。他也開發(fā)了一種張緊滑輪裝置，把它附著在運(yùn)輸工具上。礦山部門說：倘若任何一根繩的承載能力要素不能降至法定要素9以下，將允許挖掘機(jī)械的法定安全要素從4275更改為45。這樣一種補(bǔ)償?shù)谋匾允沟锰幱趦筛K之間的載荷能夠平衡分配。因?yàn)榛喌难a(bǔ)償作用有限，布萊爾同樣發(fā)明了一種裝置來監(jiān)測(cè)滾筒的誤差，因?yàn)檫@樣可以使得鋼絲繩能夠以不同的速度移動(dòng)以及干預(yù)兩根繩能夠按他們的實(shí)際承載能力分配。圖2描述了雙滾筒的深度有效載荷的特性，布萊爾和Koepe挖掘機(jī)。 布萊爾挖掘機(jī)幾乎專一性的應(yīng)用于南非地區(qū)，或許由于這些機(jī)器是在那兒發(fā)明的，尤其是應(yīng)用于深井。在英國(guó)有一套設(shè)備。因?yàn)檫@種挖掘機(jī)的物理性能好，以及南非地區(qū)的礦井規(guī)程在某一方面特別親賴于它，他們主要被應(yīng)用于深井挖掘系統(tǒng)。這種滾筒的直徑比普通相當(dāng)規(guī)格的挖掘機(jī)小，因此一方面的優(yōu)點(diǎn)是它們更加便于在井下安裝。 布萊爾挖掘機(jī)本質(zhì)上是帶有寬鼓的常規(guī)挖掘機(jī)，每個(gè)滾筒有一個(gè)中心凸輪，以使得兩根繩子能夠纏繞在上面，用來急速改變兩個(gè)主導(dǎo)輪。急變系統(tǒng)擁有一個(gè)平衡輪, 類似于大的多凹槽形的V帶滑輪, 以允許在挖掘過程中繩索長(zhǎng)度的適度變化?；喣苌鸹蛘呓档鸵允沟娩摻z繩的張緊力相等。 布萊爾挖掘機(jī)的物理性能優(yōu)勢(shì)表現(xiàn)在滾筒的直徑比普通的小，以及兩根繩子同時(shí)承載載荷，使得每根繩子能夠變得更加小些。政府部門的采礦規(guī)則允許使用布萊爾挖掘機(jī)的礦井在滑輪安全要素方面低于正常5％。這從發(fā)明家羅勃特布萊爾的演示可以看出, 一根嚴(yán)格符合要求的鋼絲繩,以額定速度運(yùn)轉(zhuǎn)，由剩余的鋼絲繩承擔(dān)負(fù)載。這5%的安全要素允許布萊爾挖掘機(jī)比其他挖掘機(jī)稍微深入一些。 另一方面,采礦規(guī)則要求為方便人們的升降，在罐籠的上方必須安裝有可分離的吊鉤。平衡輪不適合用于分離吊鉤，因此，發(fā)明了一種可以切斷繩索的裝置用來切斷旋得很緊的繩索。這種裝置順利通過試驗(yàn)，但是布萊爾挖掘機(jī)不是用于人類規(guī)范準(zhǔn)則的挖掘機(jī)。 布萊爾挖掘機(jī)已經(jīng)被應(yīng)用于三種類似于傳統(tǒng)挖掘機(jī)的普通風(fēng)格的類型中。這三種風(fēng)格可見圖3和圖4。 在Dreifontein東部的無傳動(dòng)裝置的B.M.R.挖掘機(jī)除滾筒連接以及它們相互不在同一中心外，從外表上看似同軸挖掘機(jī)。這是因?yàn)槊總€(gè)滾筒直接地面對(duì)自己的滑槽輪而獲得最佳的深淺角度。兩個(gè)挖掘機(jī)的馬達(dá)通過6.6千伏的半導(dǎo)體閘流管整流換流器/反用換流器來反饋。馬達(dá)與電相連接以便軸中的急變能夠保持平衡，類似于傳統(tǒng)的雙滾筒挖掘機(jī)。每臺(tái)馬達(dá)交替變換它們的作用相當(dāng)于直流發(fā)電機(jī)或者直流電動(dòng)機(jī)任意的從系統(tǒng)中輸入或者輸出能量。無傳動(dòng)裝置的布萊爾挖掘機(jī)能夠被偏移滾筒和四種剎車裝置所檢驗(yàn)。第二種剎車永遠(yuǎn)是必要的，每個(gè)滾筒必須有兩個(gè)剎車，因?yàn)閮蓚€(gè)滾筒之間沒有機(jī)械連接。大部分最新的布萊爾挖掘機(jī)直徑達(dá)到4.27或者4.57米，附帶有直徑達(dá)44.5至47.6毫米的鋼絲繩。 在達(dá)到滾筒的尺寸方面，以下的參數(shù)已經(jīng)被采用: （1）鋼絲繩被纏繞成四層， （2）鋼絲繩的最大靜態(tài)壓力要小于32兆帕， （3）滾筒與鋼絲繩的直徑比（大徑比小徑）要大于12，以保證鋼絲繩的速度達(dá)到20米/秒。 綜上所述為限制滾筒的軸的長(zhǎng)度的需要，鋼絲繩減速箱的尺寸選擇為直徑85米、寬28米。 5層纏繞的鋼絲繩的利用可以使鋼絲繩間隔間的寬度減少到215米，但是這種想法在此階段已經(jīng)被放棄，是因?yàn)樗鼈兛赡軐?duì)鋼絲繩的壽命有負(fù)面影響。 經(jīng)常與雙繩滾筒挖掘機(jī)有關(guān)的一個(gè)問題是鋼絲繩的短暫角度，雙繩間隔間滾筒的軸長(zhǎng)為了挖掘機(jī)能夠在礦井中順利的運(yùn)輸，需要寬敞的中心區(qū)。為了限制井的直徑，在圖4中安排的插圖直到挖掘機(jī)被安裝才被證實(shí)是正確的。這里，通用的或者Hooke的結(jié)合點(diǎn)已經(jīng)在雙滾筒之間安置，這是為了允許滾筒在礦井中心被連接以及能夠減小鋼絲繩的角度問題，以及槽輪在靠近的中心問題。 鋼絲繩的安全要素： 在圖5中的圖表舉例說明了鋼絲繩在減少靜態(tài)安全要素方面的負(fù)載優(yōu)勢(shì)。當(dāng)數(shù)年以來很好的滿足它們的目的，靜態(tài)安全要素現(xiàn)在本身一定會(huì)被質(zhì)疑的。靜態(tài)安全要素，雖然在鋼絲繩上與靜態(tài)負(fù)載有明確的關(guān)聯(lián)，事實(shí)上已經(jīng)有了明確的考慮： a、動(dòng)態(tài)的繩索負(fù)載應(yīng)用于正常的纏繞循環(huán)周期中，尤其在加載、離開、加速、延遲以及停止， b、動(dòng)態(tài)繩索負(fù)載在緊急制動(dòng)中， c、工作期間的繩索變化尤其處于以外的或者無法預(yù)料的狀態(tài)。 如果鋼絲繩的最大負(fù)載能夠減少以便最大負(fù)載殘余應(yīng)力能夠平擔(dān)或者少于曾經(jīng)承受過的負(fù)載，當(dāng)使用的當(dāng)前的挖掘?qū)嶋H能力以及普通的靜態(tài)繩索安全要素，靜態(tài)繩索安全要素降低的利用被證實(shí)是正確的。真正的繩索安全要素實(shí)質(zhì)上并沒有減少。這在鋼絲繩處于最大動(dòng)態(tài)負(fù)載的緊急制動(dòng)中尤其重要。通常，在負(fù)載急變瞬間的動(dòng)態(tài)加載， 循環(huán)的速度變化將會(huì)緊急制動(dòng)的情況，但是它們的減少一定會(huì)在減少的靜態(tài)繩索安全要素方面改善鋼絲繩的壽命。那些與降低的靜態(tài)安全要素相關(guān)的合理的以及安全的手段在參考書[4，7，9，12]中有相關(guān)的討論。 基于第四篇文獻(xiàn)中涉及的靜態(tài)繩索安全要素，每一根鋼絲繩所能承受的最大負(fù)載為12843千克。對(duì)于雙繩來說，最大負(fù)載量達(dá)到25686千克。基于18347千克的運(yùn)輸量的40％的有效載荷為7339千克。在深井中挖掘鋼絲繩的力量最大可以達(dá)到2300兆帕（在第六篇參考文獻(xiàn)中所估計(jì)的可以達(dá)到2600兆帕）。在第2，8篇參考文獻(xiàn)中提到的挖掘機(jī)鋼絲繩被設(shè)計(jì)成統(tǒng)一的額定載荷。 運(yùn)輸 纏繞機(jī)器由閃光合金制成廣泛使用于深井挖掘設(shè)備中。急變要素作為空載對(duì)有效載荷的比例已經(jīng)被詳細(xì)的論述（包括輔助設(shè)備，例如鋼絲繩附加裝置、引導(dǎo)滾筒等等）。如果鋼絲繩的最大載荷保持不變，一種低級(jí)的急變要素暗示著有更大的有效載荷，換句話說，是來自于功能觀點(diǎn)的更有效率的急變特征。然而，同一鋼絲繩的有效最大載荷越高，來自平衡的載荷越大，意味著與挖掘高能量相關(guān)的纏繞能量越來越高。另一方面，如果有效載荷被確定，更低的急變要素意味著更低的最大負(fù)載以及更小的繩索制動(dòng)加載設(shè)備。在這些條件下，來自于平衡外的負(fù)載雖然仍然歸于有效載荷，但是應(yīng)歸于繩索的少量降低。在圖6、7中描述了纏繞和挖掘機(jī)容量的深度靈敏性。急變要素從0.5降低到0.4，導(dǎo)致布萊爾挖掘機(jī)深度增加大約40米，單繩挖掘機(jī)增加大約50米。急變要素降低了0.1使得挖掘機(jī)容量大約增加了10％。 急變要素的典型價(jià)值體現(xiàn)在人和材料挖掘運(yùn)輸方面，急變方面為0.6，罐籠方面為0.75。在工作中輕量級(jí)以及可維護(hù)性和可靠性迅速變得明顯之間，急變要素的降低被認(rèn)為與0.5有關(guān)，其實(shí)是一種很難的規(guī)劃設(shè)計(jì)。 重量可以很容易的通過省略(或者在厚度方面減少)急變襯墊金屬板 ，但是這