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<正> 东风-50拖拉机制动器压盘上有五个球窝(图1),过去我们用整球形高速钢刀加工,刀具磨损较快,始终达不到球窝与斜面接刀处光滑平整的技术要求。后来经改进设计制造了如图2所示的新型硬质合金球头刀,解决了生 相似文献
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上海-50型拖拉机采用的是干摩擦片盘式制动器,现将其使用中常见故障及排除方法介绍如下: 1.制动力矩不足或制动失灵 表现为踩下制动器踏板后,不能把拖拉机刹住,且路面无拖印,严重时拖拉机继续行驶,制动失效,其故障主要原因及排除方法如下: (1)摩擦片磨损严重 制动器压盘与摩擦片、摩擦片与制动器盖及制动器壳体之间都有一定的间隙,其总间隙为1~1.2毫米,且间隙大小可用制动器盖上的 相似文献
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<正>东方红-75型拖拉机离合器主要由主动部分、从动部分、压紧装置、操纵机构、小制动器等组成。1.主动部分发动机的动力经过飞轮与压盘的摩擦面传给从动盘。飞轮上有甩油孔,以便在离心力的作用下将漏入离合器中的油甩到离合器室内,从放油孔放出。压盘用灰铸铁制成,有足够的刚度,可防止变形;同时,为了有效地吸收滑磨过程中产生的热量,压盘有足够的厚度和体积。压盘与飞轮一起旋转,并在离合器分离或接合过程 相似文献
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<正>一、问题的提出我厂曾接受石油部门一批177.8mm(7″)和139.7mm(5(1/2)″)可钻耐热封隔器中心管加工任务,材质为QT600—3.这批零件属长筒管类件,结二、工艺方案的制订可钻耐热封隔器中心管有177.8mm和139.7mm两种,从图1可看出,零件最大直径为φ120—φ101mm,长度为840—683mm,结构比较复杂,技术要求高,铸件及机加工难度都很大,特别是管件要承压20MPa,铸件不能有渗漏现象发生,这就要求铸件绝对不能产生缩松气孔和夹渣缺陷.因此,要保证上述缺陷不产生,必须采用先进可靠工艺方法来保证. 相似文献
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本文针对离合器盖及压盘总成总装线动平衡工序产品初始不平衡量大的现象,通过对离合器盖及压盘总成产品结构及工艺过程的分析,提出离合器压盖内腔同轴度、盖与传动片铆接件传动片装配孔位置度的工艺过程控制措施。试验证明,采取这些措施后,大大降低了离合器盖及压盘总成初始不平衡量。 相似文献
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经拆修后的拖拉机制动器在重新装配中 ,必须要按装配技术要求进行 ,以确保有效制动 ,防止因制动失效而发生事故。一、盘式制动器的重新装配1 制动摩擦盘及与摩擦盘接触的平面必须保持清洁 ,摩擦盘总成在半轴上能自由地作轴向移动 ,无卡滞现象。2 双头螺栓拉杆总成的螺栓 ,必须拧到压盘后回至1~ 2圈 ,然后再拧紧锁紧螺母。3 摩擦盘与制动压盘及制动器壳体摩擦表面应存在适当的间隙。4 左右制动踏板的联动块及停车锁爪应能扳动灵活。5 左右制动踏板的行程为 6 0~ 6 5mm ,有效行程为 30~ 4 0mm ,当外力除去后应能迅速回位 ,不得有卡滞现… 相似文献
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一、制动系
制动系是拖拉机安全行驶的保障,也是田间拐弯的必要操纵机构.本地区大部分上海-50型拖拉机的机龄在8年以上,制动器内部进油或泥水的相当多,导致制动压盘生锈,回位弹簧失效,钢球锈死在压盘槽中,造成制动失灵或制动力不足,此时必须注意检修制动器部分,在检修时须几个问题:1.一般情况下制动的回位弹簧在拆卸后都需更换.2.摩擦片根据情况更换.3.制动器总间隙不能过小,否则易发生自行制动现象,可适当增加制动器盖的调整垫片,满足制动器总间隙要求.4.左右制动踏板自由行程不一致应重新调整.…… 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