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履带脱轨是履带拖拉机常见的故障,脱轨对行走系统零件损害极大,容易使前梁折断,后轴和导向轮轴弯曲等,主要原因是: 1.导向轮轴或后轴弯曲,使导向轮或驱动轮轴中轴线与拖拉机 相似文献
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李佩哲曹晨魏彩丽贾辉陈萌萌曹静琪 《拖拉机与农用运输车》2023,(4):78-82
拨叉是拖拉机变速箱中的关键零部件之一,采用尼龙涂覆工艺可有效解决传统加工方式使拨叉发生变形、磨损、失效的问题。通过试验,确定了试片及拨叉表面预处理、工件加热温度、涂覆方式等核心工艺参数,并经性能测试和台架试验,验证了涂层的可靠性。尼龙涂覆拨叉的各项技术指标满足技术装配要求及拖拉机使用性能,研究成果可推广应用于拖拉机及其他机械产品关键零部件的表面处理。 相似文献
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东方红—75型拖拉机行走机构主要由车架、履带、驱动轮、导向轮、支重台车及牵引装置等组成。在使用过程中,由于零件的磨损及紧固部分的松动,它们之间的配合间隙会发生变化。因此,机手必须对行走机构进行检查和调整。1.行走机构的调整(1)履带下垂度的检查方法和调整将拖拉机停放在平坦的地面上,取一根平直的木条置于两托带轮间一段履带两端的履带销上,测量下垂度最大处的履带销上端至木条下平面间的距离,履带正常的下垂度为30mm~50mm,这时张紧弹簧的压缩长度是260mm~265mm。履带下垂度过大时,可拧紧导向轮张紧螺栓的调整螺母,以使导向轮前… 相似文献
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履带式拖拉机、收割机、推土机在使用中,会出现履带脱轨现象,造成机车后桥传动装置及行走系零部件急剧磨损,甚至折弯引导轮轴和后轴,或折断前梁、损坏机件。应加以防范。 1.履带脱轨的原因 (1)使用和调整不当引起 ①履带拖拉机带负荷特别是满负荷作业时急剧转向,使履带板凸台中夹入泥土或石子,如不立即停车清除,便会脱轨。 ②履带拖拉机作业时横向严重倾斜,履带下边承受一个沿斜坡向下的机重分力,若此时履带中夹入泥土或石子,易于脱轨;同时 2侧履带上边各受 1个沿斜坡向下的履带自重的分力,作业中由于履带振动等原… 相似文献
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履带脱轨是覆带拖拉机常见的故障,脱轨对行走系统零件损害极大,容易使前梁折断,后轴和导向轮轴弯曲等,主要原因是: 一、导向轮轴或后轴弯曲,使导向轮或驱动轮轴中轴线与拖拉机纵向中轴线不垂直,履带在引导轮或驱动轮外倾斜,致使履带随时都有脱开引导轮或驱动轮的可能。 二、车架变形,尤其是两纵梁向一侧弯曲变 相似文献
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近年来,履带式拖拉机前梁断裂的现象时有发生。现分析其原因及预防方法。一、原因1.使用操作不当①拖拉机高速越过横垄地、沟渠、田埂或其他障碍物时不减速,使前梁受到剧烈的振动而断裂。②拖拉机在崎岖不平的路面上高速行驶或高速急转弯,前梁因受很大的颠簸和冲击力产生裂纹。③推土作业时猛推、硬冲,使前梁受到强烈的冲击而断裂。④经常猛起步、急制动,使前梁受到强大的冲击力而产生裂纹。⑤拖拉机履带经常掉轨,特别是机手用倒车或前进加转向强制复轨,履带张紧使导向轮拐轴孔处受张紧作用导致前梁断裂。2.维护保养不当①履带长度不当。因… 相似文献
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履带拖拉机前梁断裂多发生在前梁两侧串耳处,其原因主要有:(一)导向轮缓冲装置失调。如:张紧弹簧调整过短,失去缓冲作用;导向轮轴与轴套润滑不良,在超越障碍物时,其冲击力通过导向轮传导至前梁上。(二)履带复位方法不当,强行倒车或前进复轨,履带被拉紧,将弹簧压缩到死点而失去缓冲作用,使前梁导向轮轴座孔处直接受到履带的拉力而断裂。(三)车架变形,安装困难时就用撬杠硬拔,前梁受到附加扭矩。 相似文献
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履带式拖拉机、收割机、推土机在使用中,有时会出现履带脱轨现象,造成机车后桥传动装置及行走系零部件急剧磨损,甚至会折弯引导轮轴和后轴,或折断前梁、损坏机件。因此,必须找出履带脱轨的原因,并加以防范。 相似文献
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一、履带脱轨的原因 1.急剧回转。履带拖拉机在推土作业中急剧回转,履带上易夹进泥土、石子等物支垫起履带,支重轮会因悬空而脱出轨道。靠近导向轮 相似文献
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《Journal of Agricultural Engineering Research》1998,69(3):249-254
A model to represent the discolouration of dried powder of carrots as a function of temperature was developed. Two types of carrots, Asian and European, containing large amount of lycopene and β-carotene, respectively, were tested. The dried powder was stored under an atmosphere with O2and at three different temperatures, 5,20 and 35°C. The surface colour of the powder was monitored during storage by a Hunter colour ratioa/b. In the proposed model, the rate of oxidation was assumed to be represented by the product of the fraction of concentration of oxidized pigment at arbitrary time and a specific rate of oxidation of pigment. The rate parameters in the proposed model were calculated by fitting the experimental data with smooth curves by trial and error at the end of the induction period but before discolouration took place. The frequency constant and activation energy, expressing the temperature dependence of the rate parameters, were expressed by the Arrhenius relation. The simulation results of a Hunter colour ratioa/bof dried powder at 25°C showed good agreement with the experimental data, suggesting that the proposed model was effective for the prediction of discolouration of dried powder of both types of carrot. The use of the induction period in the manner described may enable the shelf life of dried powder to be predicted. 相似文献
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感官检验棉花的品级,这是农村常见的一种检测手段.它的一个主要特点就是存在不确定性.这是由于检验员的品级检验水平存在一定的差异,其中有很多因素制约着检验的结果.文章对影响感官检验结果的因素进行了系统的分析. 相似文献
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The fractional outflow rate of water from the rumen, measured as the rate of disappearance of the chromium complex of ethylenediamine tetra-acetic acid, was related to a number of dietary factors. A multiple regression equation was derived which expressed fractional outflow rate as a function of the intakes of dry matter, ash, acid-detergent fibre and crude protein.The data analysed consisted of 243 observations for sheep on 59 diets, including forage, concentrate and mixed diets. The ranges covered by the data were: fractional outflow rate 0.7–3.6 day?1; dry matter intake 560–1400g/day; ash 4–30%, acid-detergent fibre 7–41%, crude protein 5–26 % of dry matter; there were no observations for sheep of less than 34 kg liveweight.The equation accounted for 56·3 % of the total variance. Between-sheep variance could not be calculated for the whole of the data but was undoubtedly substantial since, for a sixth of the data, it was known to account for 38 % of the total variance. 相似文献
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从灾害经济学的角度探讨了城镇供水优化调度的必要性和可能性,认为在缺水不可避免的情况下,对供水进行优化调度可以减小缺水带来的损失,产生较好的减灾效益,特别是可以大大减小严重干旱的灾害效应。并根据水资源的特性,提出了缺水损失的计算模式以及优化调度的原则和方法。 相似文献