TBM离合器摩擦片失效成因及对策

TBM离合器摩擦片失效成因及对策 徐明新 杜立杰 石家庄铁道学院 河北 石家庄 050043 摘要:西康铁路秦岭隧道TBM驱动离合器摩擦片磨损严重，平均不到一公里就要更换，换件成本高且耽误掘进工期。文章从施工、维修过程和摩擦材料等方面了造成离合器摩擦片早期失效的原因，提出相应减磨措施，在西南线桃花铺隧道和磨沟岭隧道施工中成效显著。 关键词:TBM 离合器 摩擦片 失效 The invalidation reasons and countermeasures of TBM clutch’s friction piece Xu mingxin，Du lijie (Department of Mechanical Engineering,Shijiazhuang railway institute, Shijiazhuang 050043, China) Abstract: The clutch’s friction pieces of TBM, which were used in Xi’an to Ankang railway’s Qinling tunnel, were abraded seriously and replaced less than per kilometer. The cost of the replacement is great high. Moreover, It delayed the time of boring. In this paper, the reason, which caused clutch’s ribbing slice to invalidate in the initial stages, were analyzed on the way of construction, maintaining procedure and the rubbing materials. Furthermore, the according measures of lessening friction were presented. Key words: tunnel boring machine(TBM);clutch;friction disc ;invalidation 1 概述 TBM的驱动离合器摩擦片是全断面岩石掘进机传输动力易损的重要零部件。据统计:在西康铁道秦岭隧道施工过程中，由于隧道埋深大，地质条件复杂，高地应力、岩爆和围岩失稳等地质灾害繁多，TBM的工作条件非常恶劣，致使驱动离合器摩擦片非正常磨损严重，平均不到一公里就要更换，每片进口摩擦片平均折合人民币10000元，而TBM中共有24片摩擦片，全部更换一次费用高 [1]达24万元。通过长期工程实践，找到了摩擦片早期失效的成因。 2 成因分析 摩擦部件运用摩擦力原理进行工作，它能吸收动能并转化成热散发到空气中，材料本身无损害性磨损，摩擦部件不破坏，因而要求摩擦材料有足够高而稳定的磨擦系数、高的耐磨性、耐热性和 [2]机械强度，噪音低及不损伤对偶。由于TBM离合器在隧道内工作的特殊环境，TBM离合器的工作状况和摩擦条件实际上达不到理想的静摩擦状态。离合器在使用过程中会出现过度磨损等失效形式，成因很多，主要因素分析如下: 1)离合器打滑 ( 当地质条件较恶劣时，刀盘可能承受很大的负载扭矩，一旦超过离合器的最大传递扭矩(电驱summer of masonry construction, brick requires sufficient moist. 8.6.2.6 you must take the following measures to concrete construction in summer high temperature impact on concrete a. hardening speed up, vibrating difficulties reduced bleeding, fast drying, easy to crack (plastic), high early strength, fast early hydration heat, less cooling, temperature increases rapidly, due to temperature difference cracks. B. pouring daytime high temperatures, due to the high temperature effect of concrete strength, stability, in varying degrees, on mixing processes, perfusion vibration and moisture conservation, effective measures should be taken. 2) main measures taken by a. temperature control the water temperature in your standard mix proportion of concrete 2 degrees, the concrete temperature 0.5 degrees. B. with the controlled addition of retarder agent can reduce the effects of concrete under high temperature, but make some performance degradation of concrete, so when you are using additives must be implemented upon approval by the supervising engineer. C. time control suitable for work at night, should seek to reduce the mixing time and shipping time at high temperatures. D. strengthen the conservation and high temperatures after pouring in the early days of continuous water conservation to prevent surface drying and covering thin-film wet grass bag to make it moist State in 24 hours. 8.6.3 8.6.3.1 winter construction measures in winter construction preparation 1) required winter construction materials, equipment, planning ahead of time comes into 动95%传递效率时最大传递扭矩为5800kN?m、脱困扭矩为8700 kN?m)，离合器将出现打滑并导致摩擦片急剧磨损(见图1): 1)力释放较快、岩爆严重地段，因刀盘前部会有大块岩 块爆出卡滞刀盘的可能，从而导致过载停机，离合器打滑(例 如:1999 年4月19日9时，掘进里程为DK77+846，刀盘前部 3隧道中心坍落一3m巨大岩块，导致刀盘被卡滞，难于旋转，不 得不将刀盘强制后退1 m，才起动刀盘旋转)。 图1 TBM摩擦片严重磨损 2)大塌方地段，由于大量塌落的碎石挤紧刀盘和护盾，同样会造成刀盘卡滞，阻力矩过大刀盘转不动导致离合器打滑。 3)由于突然停电等偶发原因造成主机急停，由于刀盘旋转的惯性，离合器虽然失去驱动力矩依然旋转，而离合器接合油压释放缓慢，摩擦片与压盘若即若离，导致摩擦片持续打滑而急剧磨损。 4)更换离合器时，不慎将液压辅助驱动与电机驱动的制动油路接反，导致离合器接合时，变速箱制动油路无油压造成制动器制动闭锁，离合器打滑，旋转动力无法传递到刀盘，短时间内摩擦片急剧磨损直至报废。 )离合器不慎漏入油液、粉尘和水分。 5 6)离合器打滑后，产生巨大的滑摩功，不仅加剧自身的磨损，而且还将加剧温升的变化，进一步对离合器造成危害，加快离合器的失效。 (2)离合器接合、分离不彻底，摩擦片偏磨 离合器接合和分离过程中，由离合器零件的卡滞造成摩 擦片磨损原因如下: 1)离合器弹簧轴啃咬、磨损(最大深痕1.27mm):由于离 合器频繁接合分离，卡滞造成压盘之间偏斜、摩擦片偏磨(同 一面摩擦片圆周方向间隔120?三个测点厚度相差0.67mm)。 图2 TBM离合器弹簧轴啃咬现象 2)离合器工作过程中芯轴孔和芯轴的微动磨损(最大达0.32mm)，进而影响离合器接合分离时的运动精度(见图2)。 3)离合器两层主动压盘之间弹簧高差显著(同一批新弹簧自由状态高度差最大为3.68mm)、由于高温造成弹簧变性，刚度不一致，导致压盘间偏斜。 4)压盘翘曲变形(见图3)和烧损(见图4):由于离合器频繁接合、打滑或打滑持续时间太长，产生巨大滑磨功和压盘热变形(180?范围翘曲变形最大可达0.60mm)，加剧摩擦片偏磨和磨损，甚至引起压盘与摩擦片之间局部高温，发生粘着和材料转移。 5)离合器碟簧失效:由于打滑产生高温，促使碟簧失去弹性而失效，进而使离合器分离不彻底。 summer of masonry construction, brick requires sufficient moist. 8.6.2.6 you must take the following measures to concrete construction in summer high temperature impact on concrete a. hardening speed up, vibrating difficulties reduced bleeding, fast drying, easy to crack (plastic), high early strength, fast early hydration heat, less cooling, temperature increases rapidly, due to temperature difference cracks. B. pouring daytime high temperatures, due to the high temperature effect of concrete strength, stability, in varying degrees, on mixing processes, perfusion vibration and moisture conservation, effective measures should be taken. 2) main measures taken by a. temperature control the water temperature in your standard mix proportion of concrete 2 degrees, the concrete temperature 0.5 degrees. B. with the controlled addition of retarder agent can reduce the effects of concrete under high temperature, but make some performance degradation of concrete, so when you are using additives must be implemented upon approval by the supervising engineer. C. time control suitable for work at night, should seek to reduce the mixing time and shipping time at high temperatures. D. strengthen the conservation and high temperatures after pouring in the early days of continuous water conservation to prevent surface drying and covering thin-film wet grass bag to make it moist State in 24 hours. 8.6.3 8.6.3.1 winter construction measures in winter construction preparation 1) required winter construction materials, equipment, planning ahead of time comes into 图3 离合器压盘翘曲变形和偏磨 图4 离合器压盘烧损 6)离合器轴承失效:由于离合器打滑、高温和压盘翘曲变形，离合器轴承内润滑油脂流失，致使轴承缺油运转，进而烧损轴承保持架、滚子、内外圈和油脂护盖，严重时轴承与齿轮轴烧结粘连，离合器无法分离。 7)离合器液压接合油路故障:离合器接合油路微量泄漏或活塞缸螺塞松动，接合油压达不到额定值，使离合器接合处于若即若离状态,导致摩擦片快速磨损。 (3) 离合器频繁接合 )离合器接合次数增加后会导致其平均接合温升大。离合器磨损时，会产生很大的滑摩功，相应地1 会使离合器的温度升高。温度升高后，摩擦片材料的磨损性能变差，不仅削弱甚至完全破坏离合器的动力传递能力，而且形成磨损加剧的恶性循环。另外，温度过高会使润滑油的润滑性能变差，从而导致啮合摩擦力加大，并使从动摩擦片受载不均，于是油压压紧力不足，加大滑摩的机率。因此， 000离合器的工作环境温度范围规定为-20C,+80C(短时间允许100C)。因此，现场应监控离合器的工作温度，尽量减小离合器在连续工作过程中的接合次数，保证滑动过程的最小间隔时间大于10分钟。如果打滑现象严重，则要求掘进时控制最大扭矩或斟情控制工作进度，尽量延长离合器使用寿命，还应根据离合器的实际使用情况适时更换摩擦片，保证TBM正常工作。 2)离合器接合时具有一定的接合时间。在接合过程中，摩擦片间将发生很大的相对滑动。因此，应控制离合器的接合转速。如果转速太大，则接合过程将产生巨大的滑摩功，造成严重的温升现象，导致离合器的工作性能变差并缩短摩擦片的使用寿命，加快离合器的工作失效。为此，规定离合器的最大接合转速为1488rpm/744rpm。 (4) 使用保养问 1)液压油的渗漏可能造成摩擦片面被油污染，掘进时主机附近的烟尘也会逐渐沉积在离合器罩内，甚至淤积在压盘和摩擦片之间，从而降低离合器的动力传递能力。清洗机器时要特别注意，流进离合器里的脂类或腐蚀洗涤剂不仅降低其传递能力，而且会加快元件材料的失效导致离合器的工作失效;离合器工作之前，液压腔内如果有压力，则会造成如前所述的多余磨损。要适时检查液压管路，保证无漏油现象;应定期用压缩空气吹扫离合器，用专用清洗剂清洗摩擦片以保持离合器摩擦片的summer of masonry construction, brick requires sufficient moist. 8.6.2.6 you must take the following measures to concrete construction in summer high temperature impact on concrete a. hardening speed up, vibrating difficulties reduced bleeding, fast drying, easy to crack (plastic), high early strength, fast early hydration heat, less cooling, temperature increases rapidly, due to temperature difference cracks. B. pouring daytime high temperatures, due to the high temperature effect of concrete strength, stability, in varying degrees, on mixing processes, perfusion vibration and moisture conservation, effective measures should be taken. 2) main measures taken by a. temperature control the water temperature in your standard mix proportion of concrete 2 degrees, the concrete temperature 0.5 degrees. B. with the controlled addition of retarder agent can reduce the effects of concrete under high temperature, but make some performance degradation of concrete, so when you are using additives must be implemented upon approval by the supervising engineer. C. time control suitable for work at night, should seek to reduce the mixing time and shipping time at high temperatures. D. strengthen the conservation and high temperatures after pouring in the early days of continuous water conservation to prevent surface drying and covering thin-film wet grass bag to make it moist State in 24 hours. 8.6.3 8.6.3.1 winter construction measures in winter construction preparation 1) required winter construction materials, equipment, planning ahead of time comes into 洁净;开机前保证液压腔内无油压。 32) TBM离合器具有一定的磨损自动补偿能力。如果离合器接合时的冲程体积大于20cm，则离合器 3将发生分离时的多余磨损;如果在最小负载下工作时的冲程体积小于120cm，则离合器将发生打滑现象，不能有效传递动力，两种情况都会加快离合器的摩损失效。当摩擦片磨损现象非常严重时，活塞的自由行程不能完全补偿其磨损量，于是便不能实现离合器的接合，导致工作失效。维修保养时应经常检查摩擦片的磨损程度和摩擦片自由移动位移，一旦超过允许的设计值(接合元件的最大磨损量为15mm，挺杆座板与外摩擦片间的最大间隙为18+0.5mm)，则需更换内摩擦片。 3)离合器工作时，由于振动和温升的作用，其联接处可能生变形或松动现象，从而造成离合器的工作不稳定和端盖密封变差，导致杂质进入离合器，运动副间的配合能力下降，离合器的传递能力同样可能下降，工作寿命缩短，失效进程加快。因此，保养和维修离合器时，应仔细检查联接件的安装可靠性;检查润滑油的使用情况，适时更换或补充，根据需要选用VG460润滑油。 (5) 摩擦材料性能 经X射线能谱仪和金相组织分析，离合器摩擦片为石棉-金属-树脂基摩擦材料，该类型的摩擦材料摩擦系数高而稳定，磨损小。由于离合器工作时是靠内摩擦片(主动件)和外摩擦片(从动件)之间的摩擦来传递动力，而且要利用离合器主、从动部件的相对滑磨来保证刀盘平稳起步和防止过载，离合器的滑磨使摩擦表面产生大量的热，温度快速升高(100-350?)，摩擦系数μ急剧下降，摩擦片的磨损加剧，大大降低离合器的使用寿命，因而，要保证离合器良好的工作状况，要求其摩擦系数μ随温度的变化能保持稳定，进口摩擦片试验结果如下: 表1 TBM离合器进口摩擦片摩擦磨损性能测试结果 试验温度(?) 100 150 200 250 300 350 升温 0.516 0.433 0.350 0.333 0.333 0.316 摩擦系数μ 降温 0.383 0.383 0.366 0.366 0.366 0.386 磨损率0.211 0.207 0.311 0.399 0.461 0.412 -73V(10cm/Nm) 从表1看出，进口摩擦片的摩擦系数μ在100?时高达0.516，150?时达0.433，但随温度升高，摩擦系数下降很快，最大差值0.2,这是由于进口片采用了含石棉摩擦材料，而石棉低温摩擦系数高，但温度在250?以上石棉不断析出其结晶水，高温下摩擦系数下降很快，出现明显的热衰退现象。因此，离合器打滑在摩擦片表面将会产生严重擦伤和剧烈磨损，温度的升高会加速其失效。 3 减磨措施 为了避免上述现象的发生，在TBM的施工掘进过程中应采取下列防范措施，以尽可能的延长离合器的工作寿命，提高掘进的效率和效益。 (1)减少离合器打滑次数 summer of masonry construction, brick requires sufficient moist. 8.6.2.6 you must take the following measures to concrete construction in summer high temperature impact on concrete a. hardening speed up, vibrating difficulties reduced bleeding, fast drying, easy to crack (plastic), high early strength, fast early hydration heat, less cooling, temperature increases rapidly, due to temperature difference cracks. B. pouring daytime high temperatures, due to the high temperature effect of concrete strength, stability, in varying degrees, on mixing processes, perfusion vibration and moisture conservation, effective measures should be taken. 2) main measures taken by a. temperature control the water temperature in your standard mix proportion of concrete 2 degrees, the concrete temperature 0.5 degrees. B. with the controlled addition of retarder agent can reduce the effects of concrete under high temperature, but make some performance degradation of concrete, so when you are using additives must be implemented upon approval by the supervising engineer. C. time control suitable for work at night, should seek to reduce the mixing time and shipping time at high temperatures. D. strengthen the conservation and high temperatures after pouring in the early days of continuous water conservation to prevent surface drying and covering thin-film wet grass bag to make it moist State in 24 hours. 8.6.3 8.6.3.1 winter construction measures in winter construction preparation 1) required winter construction materials, equipment, planning ahead of time comes into 1)针对不同围岩条件，采用相应掘进参数，控制掘进推进速度和推进压力，应控制离合器的最大滑动时间不超过4秒钟，推荐采用表2掘进参数。 表2 不同围岩类型对应的掘进参数 -1岩石类别 刀盘推进速度/(m)h) 刀盘推力/MN 扭矩/kN)m 刀盘转速/rpm IV 70,80 10,12 70,80 5.4 V 25,35 16左右 20,30 5.4 断层地段 40,50 5,6 35,45 2.7 遇到大塌方，及时进行围岩支护，主机适当后退，减少刀盘旋转阻力矩和刀盘转速;尽量采用液压辅助驱动方式脱困，避免电机驱动脱困方式和利用电机旋转冲击惯性进行离合器接合方式。 2)加强责任心，减少人为失误造成的突然停电和主机急停，非紧急情况尤其不得随意拉动急停开关。 3)在TBM主机上维修和更换离合器时，主管技术人员应严格把关，仔细检查油路连接是否正确，避免离合器接合油路与变速箱制动油路接反，导致离合器接合而制动油路制动，进而迅速毁损摩擦片的恶性事故发生。 4)主机操作人员或相关施工人员在掘进过程中应密切观察设备运转情况，发现离合器冒烟、异味或离合器接合油压异常波动(<28bar)，立即报告并及时停机，避免摩擦片急剧磨损甚至更大损失。 (2)严格离合器组装工艺 1)检修离合器时，离合器弹簧轴、轴承、芯轴、弹簧、碟簧、压盘等零件明显磨损、变形失效者，一律更换新件。 2)严格离合器组装工艺:除遵守常规外，压盘安装前应做平面精度检查;同一层弹簧高度差不得大于0.5mm，弹簧刚度应保持一致;离合器修理时轴承一律换新(进口SKF 6218 2RS轴承的油脂防尘盖密封效果好)，轴承与孔的配合不得有明显松动，否则填充指定牌号锁固胶;安装、拆卸时避免锤击和强烈冲击，以免损伤压盘和轴承孔。 对从动摩擦片与齿轮轴齿轮的啮合也提出了相应的技术要求，以保护摩擦片避免不必要的打滑，并且避免技术安装造成离合器接合时间的增加。为此，要求啮合齿轮允许移动的径向距离为0.5mm;允许移动的角度为?0.5?;允许移动的轴向距离为?2mm。齿轮轴上的齿轮如有明显啃咬痕迹时，应将其仔细打磨修平。 (3)改进摩擦片材料 半金属摩擦材料是一种介于石棉摩擦材料和金属陶瓷摩擦材料之间的摩擦材料，一般可以在540?以下使用。半金属摩擦材料中含有较高的铁和石墨(典型配方中用量高达一半以上)，这一点类似于金属陶瓷摩擦材料。不过，它与烧结金属陶瓷摩擦材料不同之处是铁和石墨等组分要和有机树脂混合，并进行固化而粘结在一起，类似于通用的石棉摩擦材料。半金属摩擦材料的主要特点: summer of masonry construction, brick requires sufficient moist. 8.6.2.6 you must take the following measures to concrete construction in summer high temperature impact on concrete a. hardening speed up, vibrating difficulties reduced bleeding, fast drying, easy to crack (plastic), high early strength, fast early hydration heat, less cooling, temperature increases rapidly, due to temperature difference cracks. B. pouring daytime high temperatures, due to the high temperature effect of concrete strength, stability, in varying degrees, on mixing processes, perfusion vibration and moisture conservation, effective measures should be taken. 2) main measures taken by a. temperature control the water temperature in your standard mix proportion of concrete 2 degrees, the concrete temperature 0.5 degrees. B. with the controlled addition of retarder agent can reduce the effects of concrete under high temperature, but make some performance degradation of concrete, so when you are using additives must be implemented upon approval by the supervising engineer. C. time control suitable for work at night, should seek to reduce the mixing time and shipping time at high temperatures. D. strengthen the conservation and high temperatures after pouring in the early days of continuous water conservation to prevent surface drying and covering thin-film wet grass bag to make it moist State in 24 hours. 8.6.3 8.6.3.1 winter construction measures in winter construction preparation 1) required winter construction materials, equipment, planning ahead of time comes into 摩擦系数在400?以下非常稳定，热衰退小，热稳定性好;耐磨性好，使用寿命比石棉材料提高3,5倍;在高负荷下摩擦系数稳定，有良好的耐磨性;优良的能量吸收性能，使摩擦部件尺寸缩小，噪音小;导热性好，对环境污染小。 基于上述摩擦材料的研究现状和TBM离合器摩擦片的工作特点，其摩擦片的制作材料选用半金属摩擦材料为宜。通过TBM离合器摩擦片国产化研制后的现场考核试验，从材料组成配比和成型工艺等方面进行多次调整，确保了半金属摩擦材料的机械性能和摩擦磨损性能，完全满足了TBM驱动离合器摩擦片对摩擦材料的性能要求。 4 结论 通过对离合器摩擦片早期磨损原因的分析，根据不同围岩条件，改进掘进参数、从加强观测、减少急停、提高维修保养质量、严格离合器组装工艺等方面入手，积极采取措施，减轻了离合器摩擦片的磨损，改进摩擦片材料，有效延长了离合器使用寿命。 根据统计测算，按照正常离合器摩擦片更换规律(每掘进1000m，全部更换一次离合器摩擦片)，在剩下近4.78km隧道工程中，粗略计算，TBM离合器至少应全部更换四次即64个离合器共计192片摩擦片，而实际两个隧道只更换了15个离合器共计45片国产摩擦片，少用进口摩擦片147片，节省进口摩擦片资金1176000元。 参考文献 [1]付华.TB880E掘进机离合器摩擦片材料选用[J].石家庄铁道学院学报，15(2):16,18 [2]戴维杰.摩擦学基础[M].上海:上海科技出版社，1984.25,37 summer of masonry construction, brick requires sufficient moist. 8.6.2.6 you must take the following measures to concrete construction in summer high temperature impact on concrete a. hardening speed up, vibrating difficulties reduced bleeding, fast drying, easy to crack (plastic), high early strength, fast early hydration heat, less cooling, temperature increases rapidly, due to temperature difference cracks. B. pouring daytime high temperatures, due to the high temperature effect of concrete strength, stability, in varying degrees, on mixing processes, perfusion vibration and moisture conservation, effective measures should be taken. 2) main measures taken by a. temperature control the water temperature in your standard mix proportion of concrete 2 degrees, the concrete temperature 0.5 degrees. B. with the controlled addition of retarder agent can reduce the effects of concrete under high temperature, but make some performance degradation of concrete, so when you are using additives must be implemented upon approval by the supervising engineer. C. time control suitable for work at night, should seek to reduce the mixing time and shipping time at high temperatures. D. strengthen the conservation and high temperatures after pouring in the early days of continuous water conservation to prevent surface drying and covering thin-film wet grass bag to make it moist State in 24 hours. 8.6.3 8.6.3.1 winter construction measures in winter construction preparation 1) required winter construction materials, equipment, planning ahead of time comes into