立式成型铣加工专用机床液压动力系统设计——执行元件设计【含CAD图纸、说明书】
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压缩包内含有CAD图纸和说明书,咨询Q 197216396 或 11970985摘 要液压传动是通过流动液体的压力能来实现运动的。液压传动在各个领域都有着非常广泛的运动,尤其在工业生产中,它的效率相比于刨床要高出许多,而且,越高科技的设备,运用的液压部分就越多。本设计是机床液压动力系统设计-执行元件设计,本机床是立式成型铣加工专用机床。我的设计内容是铣床,主要是其执行元件,也就是液压缸的设计,工作内容是设计主液压缸,确定其主要尺寸,还要设计其他辅助元件。并完成液压系统的制图。关键词 立式铣床;执行元件;液压系统;专用机床IIABSTRACTHydraulic fluid is flowing through the pressure energy to achieve movement. Hydraulic transmission in various fields have a very wide range of sports, especially in industrial production, its efficiency is much higher compared to the planer, and, the higher the technological equipment, the more use of hydraulic part. This machine is designed hydraulic power system design - actuator design, this machine is a vertical form-milling specific machine.My design content is milling machines, mainly in the implementation of components, namely hydraulic cylinder design, design work content is the master cylinder to determine its main dimensions, but also design other auxiliary components. And complete mapping of the hydraulic system.Key words Vertical Milling Machine;hydraulic pressure actuator;hydraulic system;Special Machines目 录摘 要IABSTRACTII目 录III绪 论- 1 -1.1技术要求- 4 -1.2系统功能设计- 4 -1.2.1 工况分析- 4 -1.2.2 确定主要参数,编制工况图- 5 -1.2.3 拟定液压系统原理图- 9 -1.2.4组成液压系统- 10 -1.3系统液压元件、辅件元件的设计- 12 -1.3.1 液压泵及其驱动电机的选用- 12 -1.3.2 液压控制阀和部分液压辅助元件的选择- 12 -1.3.3 其他辅助元件及液压油液的选用- 14 -1.3.4 计算液压系统技术性能- 15 -1.4 定位缸和夹紧缸的设计- 16 -1.4.1定位缸的设计- 16 -1.4.2 夹紧缸的设计- 17 -第二章 专用铣床液压系统中主液压缸的设计- 18 -2.1液压缸主要尺寸的确定- 18 -2.1.1 缸工作压力的确定:- 18 -2.1.2 液压缸内径D和活塞杆直径d的确定- 18 -2.1.3 液压缸壁厚和外径的计算:- 18 -2.1.4 液压缸工作行程的确定- 19 -2.1.5 缸盖厚度的确定- 19 -2.1.6 最小导向长度的确定- 19 -2.1.7 缸体长度的确定- 20 -2.1.8 活塞杆稳定性的验算- 20 -小 结- 21 -致 谢- 22 -参考文献- 23 -IX第一章 专用铣床液压系统设计绪 论CAD技术大约诞生于上个世纪60年代,当时的美国麻省理工学院提出了交互式图形学的研究计划,以此为基础CAD技术得以产生。但是由于当时的硬件设施过于昂贵以及其他诸多原因,仅有美国通用汽车公司和美国波音航空公司有能力去使用自行开发的交互式绘图系统,因此在当时并没有普及。cad制图软件广泛地应用于计算机辅助设计领域内,这个软件由于功能齐全、运用简便、所需花费的金钱较少等优点,在全球许多诸如机械、建筑、家居、纺织等行业都有使用到CAD技术,使用的人非常之多。cad制图软件的用户交流界面很友好,主要是以交互式的菜单和命令行的方式来进行交流和绘制图形。它的设计环境也是多文档性的,由于此优点,那些并非计算机专业的人也可以较快的学习和使用。在不断的运用过程之中我们可以学习并了解到它的各种应用以及开发技巧等等,这样也可以提高我们绘图的工作效率。cad制图软件具有以下的优点:(1)图形绘制功能十分完善。(2)可以进行图形编辑修改。(3)支持二次开发和用户定制,服务于特殊用户。(4)可以绘制多种格式的图纸,应用面就很广了。(5)硬件设备支持得很广泛。(6)操作平台支持得很广泛。工程制图主要用于建筑工程、环境设计、水电工程设计、土木施工设计等等。工业制图主要用于绘制精密零件和磨具的草图和正式图。电子工业之中也会用到CAD来绘制电路图。随着生产工艺的发展和科学技术的发展,人们对高功率、高效率、高精度、高响应的工业领域和技术领域的追求更大,液压控制系统的需求量正在逐步矿大,尤其在液压系统中使用越来越多的就是反馈控制,它将先进的液压技术与电子技术结合在了一起,这一技术无论在元件系统还是在理论运用上,都已经变得完善和成熟,并使液压系统在当今机械设计中拥有着重要的位置。利用液体做为工作的介质,依靠液体地压力能以实现运动和力地传递地传动称为液压传动。液压传动不仅可以传递能量,还可以有效地对系统实施控制。液压传动的原理是根据帕斯卡提出的液体静压力传动,也算是一门相对新兴的技术了。现在已经广泛地应用于工业制造之中了,并且其水平的高低已经成为衡量一个国家工业能力的重要指标。 1795年的伦敦,约瑟夫布拉曼用水作为传动的介质,制成了历史上第一台液压机,标志着液压技术正式运用于工业之中。到了1905年的时候,人们用油取代了水,使之成为新的传动介质,这就是现代液压设备的最初形态。在十九世纪初,石油工业逐渐发展壮大,从而推动了近代液压技术的发展,然而战舰上的炮塔转位器是最早应用液压的,随后又出现了一些简单的通用机床,在第二次世界 大战期间,美国的机床广泛地使用了液压技术,正是液压技术的广泛应用,使得美国的工业生产能力达到了世界最高水平,期间生产的诸多物资,为战争的胜利提供了可能性。而我们的近邻日本,他们的液压技术要比欧美这些国家晚发展近20年,可是在1955年时候,由于制造业的需求,日本的液压技术得到了飞速发展,在1956年的时候,更是创立了“液压工业会”。在其后的二三十年间,他的液压技术就跃升到了世界领先水平,这就非常值得我国借鉴学习了。二十世纪五十年代,随着世界各国的经济逐渐恢复,自动化水平越来越高,从而导致液压技术运用到了民用工业上,在机械、航空等众多领域得到了广泛而深入的应用。二十世纪六十年代以来,核能、航天技术得到飞速发展,以至于液压技术有了更广泛的应用,国民经济的各个方面有了空前的提高。,如今机械设备的发展方向就是机电液气一体化。尽管液压传动是机械传动学里面的一门新兴技术,可是经过多年的改进和发展,伴随着液压油以及液压元件的改进和升级,使得液压系统发展得更为简单方便以及安全可靠,成本也趋向低廉,更加适合大规模应用。在许多领域之中都有液压传动的身影。比较常见的有起重机,千斤顶,混凝土搅拌机,钻井用的液压泵,发动机之中也会用到。在机床中就更加广泛了,比如我设计的铣床之中就大量的用到了液压装置。近年来液压技术取得了许多重大进步,首先是压强的加大,速度加快,功率以及效率的增加,噪音污染减少,液压元件和系统的耐用性也大大加强并且高度集成化。在完善比例、伺服和数字控制等关键技术上也有诸多成就。板料折弯机中也大量运用到了液压技术,这样使得机器的能源利用方式得到了很大的改善,进而减少成本支出,减少噪声污染,可以更方便地进行控制,可靠性和安全性也得到了保障,操作也更加简单。几乎在各个部门都能看到液压系统的影子,在工业方面应用的更为广泛。首先是制造零件的机床上,其次是各种零件的制造以及加工。由于液压系统重量比较轻,所以可以用于航天事业,液压系统的结构普遍比较简单却可以输出较大的功率,所以可以用于工程机械上。液压系统还有许多其他的优点,所以他的普及也就不足为奇了。第一章 专用铣床液压系统设计1.1技术要求该机床工作循环是:工件上位-夹具定位夹紧-工作头垂直快进-成型铣刀进给加工-工作台快退-夹具松开-手工卸料。定位缸推力1000N,行程50mm;夹紧缸夹紧力5000N,行程60mm;定位、夹紧运动时间都约为1s。铣削加工进给缸负载4000N,运动部件总重量约5500N,快进、快退速度为5m/min,工进速度0.030m/min。快进、工进、快退行程分别为300mm、10mm、310mm。启动和制动时间都为0.5s。滑台均采用平导轨,动、静摩擦系数分别为0.1和0.2。把数据计入一下表格表1.1铣床工作台的运动参数和动力参数工况行程(mm)速度(m/min)时间t(s)运动部件重力G(N)铣削负载Fe(N)启动、制动t(s)快速3005t15500-0.53.6工进100.03t2400020快退3105t3-3.721.2系统功能设计1.2.1 工况分析启动加速阶段 快进或快退阶段工进阶段按公式计算出结果后填入表1-2表1-2工进阶段速度v/(m/min)负载F/N启动加速1326快进5611工进0.035056快退5611根据上面算出的数据作出液压缸的行程特性(L-t)图、速度特性(v-t)图和负载特性(F-t)图。图1.1液压缸的L-t图、v-t图和F-t图1.2.2 确定主要参数,编制工况图 阅读参考书籍,根据书中表格给出的数据初选液压缸的设计压力P1=3MPa.因为工作台快进和快退的时候他的速度应当保持一致且液压泵的流量应尽可能的小,所以选择液压缸的无杆腔作为主工作腔,且快进时的连接选择差动连接,故液压缸无杆腔的有效面积A1 与A2应当满足A1=2A2(即液压缸内径D和活塞杆直径d间应满足:D=d.) 如果液压缸不维持一定的回油背压,那么在工进结束的时候就会发生前冲现象。为避免出现这种情况,查阅参考书籍,根据书中给出的参考取背压为0.8MPa,并取定液压缸的机械效率cm=0.9。从表1-2之中可以看出,工进阶段会出现最大负载,这时的负载F=5056N,则有:查找相应的设计手册按液压缸内径系列圆整计算值为标准直径,取D=50mm。故活塞杆直径为同上,查找相应的设计手册按液压缸内径系列圆整计算值为标准直径,取d=36mm。则液压缸的实际有效面积为工进若采取调速节流阀调速,查询产品样本,调速阀的最小稳定流量值,因最小工进速度则:不满足低速稳定性要求。重新查阅参考资料选取更大的D值,经验算后发现D=63mm,d=45mm时可以满足要求。故取:D=63mm,d=45mm。此时A1=31.2cm2,A2=15.9cm2由于选取的是差动连接,所以在快进的时候,液压缸有杆腔的压力P2必须大于无杆的腔压力P1;在这里取并且取快退时候的回油压力损失为0.5MPa。根据以上数据计算出压力。流量和功率,再画出工况图。如图(1.2)表1.3 液压缸工作循环中各阶段的压力、流量和功率工作阶段计算公式负载F(N)回油腔压力P2(MPa)工作腔压力P1(MPa)输入流量q(L/min)输入功率P(W)快进6110.50.9647.65122.9工进50560.82.2070.0943.46快退6110.51.4087.95186.6图1.2液压缸的工况图1.2.3 拟定液压系统原理图1) 选择液压回路调速回路与动力源的选择 确定液压油缸的形式后就需要选择液压运动的控制方向与速度的回路,当流量较小时,一般选用常规的阀来实现配合,当流量较大时,就需要利用插装阀与先导控制阀的逻辑组合去实现。由上面算出的数据可以得到以下结论:在快进和快退时,系统的压力小而流量大,这个阶段的持续3.6秒;工进阶段时真好相反,这个阶段持续20秒。根据这个结论结论,查阅参考文献后选用回油路调速阀节流调速回路。选择该液压回路可以保证进给运动的平稳性,进给的速度也不会有太大的浮动。由于选用的是差动连接,所以液压泵的流量会比较小,考虑到设计时要尽可能的经济实惠,所以选用单定量泵供油的供油方式。 由于液压回路为节流调速回路,所以只能选择开式循环方式。 考虑到在工作台中点位置的定位精度要求不高、此工作台既可以手动也可以自动,并且系统的压力比较低流量也比较小、工作台换向过渡的位置不应当出现等因素,所以选用“Y”型中位机能的电磁滑阀做为系统的。因为采用的是差动连接,所以选用电磁。通过电气行程来控制换向阀电磁铁的电,这样就可以自动换向了。 为了实现系统的定压溢流,可以在泵的出口处并联一个先导式溢流阀,并且在溢流阀的口处连接一个二位二通的换向阀,这样可以方便一个工作后,在等待装卸工件的时候,卸载,这样做还有一个是便于液压泵处于状态下可以迅速得。 1.2.4组成液压系统 选定了主回路后,再添加一些就可组成完整的液压系统。比如:在液压泵(吸油口)可以设置一个过滤器来液压油;为了观测液压泵的压力,可以口处配置一个压表。图1.3 专用铣床工作台液压系统快进回路:油从1流入2流入7流入8再流入11,回油时从10流入8。工进回路:油从1流入2流入7流入8再流入11;回油:从10到9再到8最后流回油箱。快退回路:油从1流入2流入7流入9再流入10;回油:从11到8再流回油箱。卸载:油的流向是1到2到5到6最后流回油箱。1.3系统液压元件、辅件元件的设计 1.3.1 液压泵及其驱动电机的选用 通过以上计算结果可以发现工进时的最大工作压力为2.52Mpa。此时的输入流量非常之小且进油路元件很少,查阅选取泵至缸间的进油路压力损失估值为.由此计算出液压泵的最高工作压力pp为由于系统还需要压力储备,所以液压泵的最高压力取1.25倍的计算值计算最大供油量,这里取泄露系数K=1.1只要液压泵的额定流量大于系统计算的最大流量都是可以的。查表后决定选用单级叶片泵,型号是YB1-10。该泵的额定压力为,公称排量,额定转速。查阅资料后估取泵的容积效率,选用转速的驱动电动机,可以计算出泵的流量为由上面的计算结果并查表可得泵的总效率,则可计算出功率。电动机功率不应低于这个数值。查阅参考资料,选用的电动机为型封闭式三相异步电动机,主要参数如下:其转速为,额定功率为。根据上面所选择的并考虑到系统的工作,可以计算出液压缸在各个阶段的、输出流量,运动以及持续时间计入表1.5,可以以此为基础其他液压元件并对系统的性算提供帮助。 1.3.2 液压控制阀和部分液压辅助元件的选择根据计算得到的工作压力与最大流量,查询产品样本所选择的元件型号规格如表1.6所列。工作阶段流量(L/min)速度(m/s)时间(s)无杆腔有杆腔快 进工进快 退注:工进阶段只计算了调速上限时的参数。1.3.3 其他辅助元件及液压油液的选用 1)管件 由上述计算可知,无杆腔的最大流量为18L/min而的实际最大流量为9L/min。查询取油管内油液的允许流速是4 L/min,则可以计算出有杆腔和无杆腔的直径如下查阅相关资料,两根油管均选用182(外径18毫米,壁厚2毫米)的10号冷拔无缝钢管();查设计管材的抗拉强度为,查表取安全系数n=8,校核此管子的强度,计算如下:所选的管子壁厚安全。其他直接按所连接的液压元、的接口尺寸决定其大小。2) 油箱的容积与流量有关,选取=6,可以计算出液压系统中的油箱容量V3)根据所选用的液压泵类型,选取牌号是的液压油,其运动粘度是。1.3.4 计算液压系统技术性能(1) 验算压力损失查找相关资料得到估算公式:以此可以估算出阀类元件的压力损失。由于差动连接,有杆腔的油液经阀后流入无杆腔,根据上面计算得到的数值,不难求出有杆腔压力p2与无杆腔p1之差:油路上阀类元件的总压力损失为:工进阶段进油路上阀类元件的总压力损失:快退阶段进油路上阀类元件的总压力损失:经检验符合要求。(2) 确定系统调整压力 溢流阀的调整压力等于工进阶段的系统工作压力加上压力损失,即(3) 估算系统效率、发热和升温 通过计算可得,快进和快退之和仅占总时长的26.8%而工进阶段却占73.2%的时长,所以系统的可以用工进阶段的数值来表示。 工进阶段的回路效率 之前已选取液压泵的总效率和液压缸的总效率,则可算得本的效率由于溢流损失和节流损失,工进阶段的效率很低。根据系统的发可以计算得工进阶段的发热查阅参考资料取散热系数K=15W/(m)来计算系统温升查阅资料可知许用温升t=35,显然当前情况不符合要求。这时可以采取以下措施来降低温升,采用加风扇冷却的方式增加散热即取K=20W/(m2)。这样就满足了许用温升的要求。1.4 定位缸和夹紧缸的设计1.4.1定位缸的设计负载F=1000N,速度v=50mm/s。可以求得,查设计手册按标准内径系列取D=25mm。,可以求得d=17.68mm,圆整后取18mm。定位缸所需流量。1.4.2 夹紧缸的设计负载F=5000N,速度v=50mm/s。可以求得,圆整后取D=50mm,d=0.7D,所以d=35mm,按标准尺寸取d=36mm.夹紧缸所需流量- 17 -第二章 专用铣床液压系统中主液压缸的设计第二章 专用铣床液压系统中主液压缸的设计由上一章的计算可知数据:1. 液压缸的工作压力:。2. 无杆腔的有效面积:31.2cm23. 有杆腔的有效面积:,其中:。4. 内径D=63mm,活塞杆直径d=45mm.5. 行程:L=310mm。6. 最大外负载:F=5056N。2.1液压缸主要尺寸的确定2.1.1 缸工作压力的确定:由上面可知p=3Mpa。2.1.2 液压缸内径D和活塞杆直径d的确定保持一定的回油背压可以有效防止工进结束时发生前冲现象,取背压为,机械效率为。 D=63mm, d=45mm, 其中。经验算满足速度稳定要求。2.1.3 液压缸壁厚和外径的计算:液压缸的壁厚也许满足设计要求,否则缸体的安全性就不达标。可以通过以下公式进行计算:PyD/2式中:表示液压缸壁厚(m);表示液压缸内径(m);表示试验压力,一般是1.251.5倍的最大工作压力 为缸筒材料的许用应力。由于此缸体的压力比较小所以在这里选用高强度铸铁,其值取=60Mpa.计算可得:=2.63 (取Py=1.5p=4.5Mpa).则缸体的外径D1应满足以下要求: 2.1.4 液压缸工作行程的确定由毕业设计任务书可得到L=310mm。2.1.5 缸盖厚度的确定前缸盖:后缸盖:2.1.6 最小导向长度的确定 用以下公式进行计算:式中:L指液压缸的最大行程; D表示液压缸的内径。 图2.1 液压缸的导向长度活塞的宽度B一般取:(0.61.0)D;缸盖滑动支承面的长度,根据液压缸内径D而定:当时,取=(0.61.0)D;当时,取=(0.61.0)d.计算隔套长度:取=0.8D=56mm,B=0.6D=42mm则:C=32.1.7 缸体长度的确定计算如下:式中D表示活塞的行程,t表示活塞宽度。缸体长度不应大于内径的2030倍。显然,满足所需条件。2.1.8 活塞杆稳定性的验算 活塞杆长度L与其直径d的比值不应大于15。进行验算。L/d=310/45=6.8915。不难发现活塞杆稳定性好。故满足要求。- 20 -小 结历时三个多月的毕业设计也已经接近了尾声,在这三个月的毕业设计之中,我也学会了许许多多新的知识并且也提高了自己设计的能力。回想做毕业设计的这几个月,其中有苦也有甜,不仅有艰辛,其中也充满了乐趣,还有依靠自己独立解决问题的自豪感。总的来说,毕业设计的过程还算比较顺利的,没有遇到过份困难的问题,在毕业设计期间,指导老师也给予了我很大的帮助。给处于困境中的我指出了明路。这次的毕业设计给我最大的感觉是和以往的课程设计相比,需要思考的问题要多许多,不再是像课程设计时那样只需要用到所学课本中的只是就能解决问题了。毕业设计要用到的东西非常之多。在这次的毕业设计之中,我也查阅了大量的资料,参考了网上相似设计内容的模板,思考他们在设计时用到的思路,再结合自身实际情况进行修改,老师也给予了我很多的帮助,在多方面的努力之下才完成了这次的毕业设计。通过这次毕业设计,我明白了许多以前不懂的道理,让我知道了自己在以往学习中的不足之处,自己的知识太理论化了,面对单独的课题就陷入了迷茫之中,自己需要学习的东西还有许多,以前老是觉得自己会的东西很多,现在才知道其实自己还是有许多不足的地方的。我也从中学会要谦虚。学习是一种长期积累的过程,绝不会一蹴而就,在学习之中我们要脚踏实地,在以后的工作生活之中我也要牢牢紧记这条宝贵的经验,努力提高自身的知识储备。完成这次毕业设计的过程就是再次学习的过程,在做毕业设计的过程中,我发现了许多以前学习时没有注意到的问题,还有许许多多的知识没有掌握。这次的毕业设计其实也是一次复习的过程,整个期间我又翻阅了以前的课本,学习了以前漏掉的知识。毕业设计也是一次拓展知识的机会,期间我还翻阅了许多课外的参考书,知道了解到许多在课本上没有的知识。总之这次的毕业设计让我成长了许多。致 谢毕业设计已然到了最后的时刻,这也意味着我的大学生涯也就到此为止了,学习生活一晃而过,回首过往的日子,心中感慨良多。感怀岁月匆匆,不着痕迹。也有一丝的后悔,后悔当初没有好好的学习,没有积极的参与学校的各种活动,我的大学生活好似就这样虚度了一般。以至于在做毕业设计时许多问题都无法自己一个人解决。在整个毕业设计期间,许许多多的人给予了我帮助与支持。首先,我要感谢我的指导老师赵新老师,在整个毕业设计中,赵新老师给予我的帮助是最多的。做毕业设计是很艰辛的,期间我也碰到了许多自己一个人无法解决的问题,而在这些时候我会向赵老师寻求帮助,而每次去找赵老师的时候,老师无论是忙还是闲,都会抽出时间来解答我的疑惑。有时赵老师还会找我面谈,询问我毕业设计中有没有什么不会做的地方。赵老师平日里工作繁忙,但在我做毕业设计的每个阶段,从选题到查阅资料,论文提纲的确定,开题报告的书写,中期论文的修改,后期论文格式调整等各个环节中都给予了我悉心的指导。所以我要对赵老师表达最真诚的谢意。其次我要感谢这四年来教授我知识的各位老师,如果没有他们,我想我会在做毕业设计时寸步难行,有了他们教给我的知识,我才能顺利的完成毕业设计。再次我要感谢我的同学,在毕业设计中他们也给予了许多帮助。 以上。参考文献杨培元、朱福元。液压系统设计简明手册。机械工业出版社。官忠范。液压传动系统第三版。机械工业出版社。煤炭工业部、煤炭科学研究院上海研究所。液压传动设计手册。上海科学技术出版社。刘新德。袖珍液压气动手册第二版。机械工业出版社。高等工程专科学校机制及液压教学研究会液压组。液压传动课程设计指导书。何存兴、张铁华。液压传动与气压传动第二版。华中科技大学出版社。章宏甲。金属钻削机床液压传动。江苏科学技术出版社。李芳民。工程机械液压与液力传动。人民交通出版社。雷天觉。新编液压工程手册。北京理工大学出版社。10周士昌。液压系统设计图集。机械工业出版社。11 吴宗泽. 机械零件设计手册M. 北京: 机械工业出版社,2004. 12 闻邦椿. 机械设计手册M. 北京: 机械工业出版社,2010.13 赵如福.金属机械加工工艺人员手册M.上海:上海科学技术出版社,1990.14 陈立德.机械制造装备设计M.北京:高等教育出版社,2010.15 周鹏翔. 工程制图M. 北京: 高等教育出版社,2000.16 王伯平. 互换性与测量技术基础M. 北京: 机械工业出版社,2009.毕 业 设 计(论 文)外 文 参 考 资 料 及 译 文译文题目: Hydraulic System 液压系统 学生姓名: 学 号: 专 业: 所在学院: 指导教师: 职 称: 20xx年 2月 27日Hydraulic SystemHydraulic presser drive and air pressure drive hydraulic fluid as the transmission is made according to the 17th century, Pascals principle of hydrostatic pressure to drive the development of an emerging technology, the United Kingdom in 1795 Braman Joseph (Joseph Braman ,1749-1814), in London water as a medium to form hydraulic press used in industry, the birth of the worlds first hydraulic press. Media work in 1905 will be replaced by oil-water and further improved.After the World War I (1914-1918) ,because of the extensive application of hydraulic transmission, especially after 1920, more rapid development. Hydraulic components in the late 19th century about the early 20th century, 20 years, only started to enter the formal phase of industrial production. 1925 Vickers (F. Vikers) the invention of the pressure balanced vane pump, hydraulic components for the modern industrial or hydraulic transmission of the gradual establishment of the foundation. The early 20th century G Constantimscofluct- uations of the energy carried out by passing theoretical and practical research; in 1910 on the hydraulic trans- mission (hydraulic coupling, hydraulic torque converter, etc.) contributions, so that these two areas of development.The Second World War (1941-1945) period, in the United States 30% of machine tool applications in the hydraulic transmission. It should be noted that the development of hydraulic transmission in Japan than Europe and the United States and other countries for nearly 20 years later. Before and after in 1955, the rapid development of Japans hydraulic drive, set up in 1956, Hydraulic Industry. Nearly 20 to 30 years, the development of Japans fast hydraulic transmission, a world leader.Hydraulic transmission There are many outstanding advantages, it is widely used, such as general industrial use of plastics processing machinery, the pressure of machinery, machine tools, etc.; operating machinery engineering machinery, construction machinery, agricultural machinery, automobiles, etc.; iron and steel indu-stry metallurgical machinery, lifting equipment, such as roller adjustment device; civil water projects with flood control and dam gate devices, bed lifts installations, bridges and other manipulation of institutions; speed turbine power plant installations, nuclear power plants, etc.; ship from the deck heavy machinery (winch), the bow doors, bulkhead valve, stern thruster, etc.; special antenna technology giant with control devices, measurement buoys, movements such as rotating stage; military industrial control devices used in artillery, ship antirolling devices, aircraft simulation, aircraft retractable landing gear and rudder control devices and other devices.A complete hydraulic system consists of five parts, namely, power components, the implementation of components, control components, auxiliary components and hydraulic oil. The role of dynamic components of the original motive fluid into mechanical energy to the pressure that the hydraulic system of pumps, it is to power the entire hydraulic system. The structure of the form of hydraulic pump gears are generally pump, vane pump and piston pump. Implementation of components (such as hydraulic cylinders and hydraulic motors) which is the pressure of the liquid can be converted to mechanical energy to drive the load for a straight line reciprocating movement or rotational movement.Control components (that is, the various hydraulic valves) in the hydraulic system to control and regulate the pressure of liquid, flow rate and direction. According to the different control functions, hydraulic pressure control valve can be divided into valves, flow control valves and directional control valve. Pressure control valves are divided into benefits flow valve (safety valve), pressure relief valve, sequence valve, pressure relays, etc.; flow control valves including throttle, adjusting the valves, flow diversion valve sets, etc.; directional control valve includes a one-way valve , one-way fluid control valve, shuttle valve, valve and so on. Under the control of different ways, can be divided into the hydraulic valve control switch valve, control valve and set the value of the ratio control valve. Auxiliary components, including fuel tanks, oil filters, tubing and pipe joints, seals, pressure gauge, oil level, such as oil dollars. Hydraulic oil in the hydraulic system is the work of the energy transfer medium, there are a variety of mineral oil, emulsion oil hydraulic molding Hop categories. The concept of gear pump is very simple, that it is two of the most basic form of the same size gear in a close cooperation of mutual engagement with the rotating shell, the shells internal similar 8 shape, the two gears mounted inside , the diameter of gear and work closely with both sides and shell. From the extruder the material inhaled into the mouth of two intermediate gears, and full of the space, with the teeth along the shell of the rotary movement, the final two hours from the meshing teeth. Speaking in terms of gear, also known as positive displacement pump device, that is, inside the cylinder like a piston, when a tooth to another tooth space of the fluid, the liquid was squeezed mechanically to row out. Because the liquid is incompressible, so the liquid and the tooth at the same time will not be able to occupy the same space, so that the liquid has been ruled out. Because of the constant mesh gear, this phenomenon occurs on a row and, therefore, the pump provides a continuous export to exclude the amount of a turn each pump, the volume of discharge is the same. With the continuous rotation of the driveshaft, pump fluid is continuously discharged. Pump flow directly to the speed of the pump. In fact, there is little pump of the fluid loss, which makes the operation of pumps can not achieve 100% efficiency, as these fluids are used to on both sides of bearing and gear lubrication, and the pump body is also not possible with no gap, it can not be so that 100% of fluid discharged from the export, so a small amount of fluid loss is inevitable. However, a good pump can be run out of material for the majority, will still be able to achieve 93% 98% efficiency. For the viscosity or density change in the process fluid, the pump will not be affected too much. If there is a damper, for example, in the export side, one row or a limiter filter, pumps will push fluid through them. If the damper changes in their work, that is, if the filters become dirty, blocked, or limiter on the back of the hypertension, the pump will maintain a constant flow, until the device in the weakest parts of the mechanical limit (usually equipped with a torque limiter). For a pump speed, in fact, there are restrictions, which mainly depends on the process fluid, if the transmission is oil, pump can rotate at high speed, but when the fluid is a high viscosity of the polymer melt, such restrictions will be significantly reduced. Promote blood flow into the intake side of the two tooth space is very important, if not fill in this space is full, the pump will not be able to discharge the flow of accurate, so the value of PV (pressure velocity) is also a limiting factor, and is a process variable. As a result of these restrictions, gear pump manufacturers will provide a range of products, that is, different specifications and emission (perweek to the emission of volume). These pumps will fit the specific application of technology to enable the system to achieve optimal capacity and price. PEP-II pump shaft gear and a total of one species hardened using technology, will be a longer working life. D-type bearing a combination of forced lubrication mechanism, so that the polymer surface by the bearing, and return to the import side of pump to ensure effective lubrication of the rotation axis. This feature reduces the degradation of polymers and the possibility of being stranded. Precision machining of the pump body can D-type gear shaft with precision bearings to ensure noneccentric gear shaft to prevent gear wear. Structure and Parkool PTFE sealing lip sealed water cooled sealed together. This shaft seal does not actually contact the surface, it is the principle of the sealing polymer to a semimolten state cooling and the formation of self sealing. Can also be used Rheoseal sealing, seal it inside the table are reverse spiral groove processing, the polymer can be imported back to the antipressure. In order to facilitate the installation, the manufacturer has designed the installation of a ring bolt, so that the flange and install other equipment line, which makes the manufacture of tube flange easier. PEP-II with a gear pump with the pump to match the specifications of the heating elements for the user matching, which ensures rapid heating and heat control. Heating the body and pump in different ways, the damage to these components is limited to a board, the pump has nothing to do with the whole. Gear pump by an independent motor drive, to be effective in blocking the upper reaches of the pressure pulsation and flow fluctuations. Gear pump in the outlet of the pressure fluctuation can be controlled within 1%. In the extrusion production line using a gear pump, can increase the output flow rate of material in the extruder to reduce the shear and residence time to reduce the extrusion temperature and pressure fluctuation in order to enhance productivity and product quality.The role of the hydraulic system is to help humanity work. Mainly by the implementation of components to rotate or pressure into a reciprocating motion. Hydraulic principle :it consists of two cylinders of different sizes and composition of fluid in the fluid full of water or oil. Water is called hydraulic press; the said oilfilled hydraulic machine. Each of the two liquid a sliding piston, if the increase in the small piston on the pressure of a certain value, according to Pascals law, small piston to the pressure of the pressure through the liquid passed to the large piston, piston top will go a long way to go. Based cross-sectional area of the small piston is S1, plus a small piston in the downward pressure on the F1. Thus, a small piston on the liquid pressure to P = F1/SI, Can be the same size in all directions to the transmission of liquid. By the large piston is also equivalent to the inevitable pressure P. If the large piston is the cross-sectional area S2, the pressure P on the piston in the upward pressure generated F2 = PxS2 Cross-sectional area is a small multiple of the piston cross-sectional area. From the type known to add in a small piston of a smaller force, the piston will be in great force, for which the hydraulic machine used to suppress plywood, oil, extract heavy objects, such as forging steel. Hydraulic system and hydraulic power control signal is composed of two parts, the signal control of some parts of the hydraulic power used to drive the control valve movement. Part of the hydraulic power means that the circuit diagram used to show the different functions of the interrelationship between components. Containing the source of hydraulic pump, hydraulic motor and auxiliary components; hydraulic control part contains a variety of control valves, used to control the flow of oil, pressure and direction; operative or hydraulic cylinder with hydraulic motors, according to the actual requirements of their choice.In the analysis and design of the actual task, the general block diagram shows the actual operation of equipment. Hollow arrow indicates the signal flow, while the solid arrows that energy flow. Basic hydraulic circuit of the action sequence Control components (two four-way valve) and the spring to reset for the implementation of components (double-acting hydraulic cylinder), as well as the extending and retracting the relief valve opened and closed. For the implementation of components and control components, presentations are based on the corresponding circuit diagram symbols, it also introduced ready made circuit diagram symbols.Working principle of the system, you can turn on all circuits to code. If the first implementation of components numbered 0, the control components associated with the identifier is 1. Out with the implementation of components corresponding to the identifier for the even components, then retracting and implementation of components corresponding to the identifier for the odd components. Hydraulic circuit carried out not only to deal with numbers, but also to deal with the actual device ID, in order to detect system failures.DIN ISO1219-2 standard definition of the number of component composition, which includes the following four parts: device ID, circuit ID, component ID and component ID. The entire system if only one device, device number may be omitted. Practice, another way is to code all of the hydraulic system components for numbers at this time, components and component code should be consistent with the list of numbers. This method is particularly applicable to complex hydraulic control system, each control loop are the corresponding number with the system.With mechanical transmission, electrical transmission compared to the hydraulic drive has the following advantages: 1, a variety of hydraulic components, can easily and flexibly to layout. 2, light weight, small size, small inertia, fast response. 3, to facilitate manipulation of control, enabling a wide range of stepless speed regulation (speed range of 2000:1). 4, to achieve overload protection automatically. 5, the general use of mineral oil as a working medium, the relative motion can be self-lubricating surface, long service life. 6, it is easy to achieve linear motion. 7, it is easy to achieve the automation of machines, when the joint control of the use of electro-hydraulic, not only can achieve a higher degree of process automation, and remote control can be achieved.The shortcomings of the hydraulic system: 1, as a result of the resistance to fluid flow and leakage of the larger, so less efficient. If not handled properly, leakage is not only contaminated sites, but also may cause fire and explosion. 2, vulnerable performance as a result of the impact of temperature change, it would be inappropriate in the high or low temperature conditions. 3, the manufacture of precision hydraulic components require a higher, more expensive and hence the price. 4, due to the leakage of liquid medium and the compressibility and can not be strictly the transmission ratio. 5, hydraulic transmission is not easy to find out the reasons for failure; the use and maintenance requirements for a higher level of technology.In the hydraulic system and its system, the sealing device to prevent leakage of the work of media within and outside the dust and the intrusion of foreign bodies. Seals played the role of components, namely seals. Medium will result in leakage of waste, pollution and environmental machinery and even give rise to malfunctioning machinery and equipment for personal accident. Leakage within the hydraulic system will cause a sharp drop in volumetric efficiency, amounting to less than the required pressure, can not even work. Microinvasive system of dust particles, can cause or exacerbate friction hydraulic component wear, and further lead to leakage.Therefore, seals and sealing device is an important hydraulic equipment components. The reliability of its work and life, is a measure of the hydraulic system an important indicator of good or bad. In addition to the closed space, are the use of seals, so that two adjacent coupling surface of the gap between the need to control the liquid can be sealed following the smallest gap. In the contact seal, pressed into self-seal-style and self-styled self-tight seal (ie, sealed lips) two.The three hydraulic system diseases 1, as a result of heat transmission medium (hydraulic oil) in the flow velocity in various parts of the existence of different, resulting in the existence of a liquid within the internal friction of liquids and pipelines at the same time there is friction between the inner wall, which are a result of hydraulic the reasons for the oil temperature. Temperature will lead to increased internal and external leakage, reducing its mechanical efficiency. At the same time as a result of high temperature, hydraulic oil expansion will occur, resulting in increased compression, so that action can not be very good control of transmission. Solution: heat is the inherent characte -ristics of the hydraulic system, not only to minimize eradication. Use a good quality hydraulic oil, hydraulic piping arrangement should be avoided as far as possible the emergence of bend, the use of high-quality pipe and fittings, hydraulic valves, etc.2, the vibration of the vibration of the hydraulic system is also one of its malaise. As a result of hydraulic oil in the pipeline flow of high-speed impact and the control valve to open the closure of the impact of the process are the reasons for the vibration system. Strong vibration control action will cause the system to error, the system will also be some of the more sophisticated equipment error, resulting in system failures. Solutions: hydraulic pipe should be fixed to avoid sharp bends. To avoid frequent changes in flow direction, can not avoid damping measures should be doing a good job. The entire hydraulic system should have a good damping measures, while avoiding the external local oscillator on the system.3, the leakage of the hydraulic system leak into inside and outside the leakage leakage. Leakage refers to the process with the leak occurred in the system, such as hydraulic piston-cylinder on both sides of the leakage, the control valve spool and valve body, such as between the leakage. Although no internal leakage of hydraulic fluid loss, but due to leakage, the control of the established movements may be affected until the cause system failures. Outside means the occurrence of leakage in the system and the leakage between the external environment. Direct leakage of hydraulic oil into the environment, in addition to the system will affect the working environment, not enough pressure will cause the system to trigger a fault. Leakage into the environment of the hydraulic oil was also the danger of fire. Solution: the use of better quality seals to improve the machining accuracy of equipment. Hydraulic components will be high-performance, high-quality, high reliability, the system sets the direction of development; to the low power, low noise, vibration, without leakage, as well as pollution control, water based media applications to adapt to environmental requirements, such as the direction of development; the development of highly integrated high power density, intelligence, mechatronics and micro-light mini-hydraulic components; active use of new techniques, new materials and electronics, sensing and other high-tech.Hydraulic coupling to high-speed high-power and integrated development of hydraulic transmission equipment, development of water hydraulic coupling medium speed and the field of automotive applications to develop hydraulic reducer, improve product reliability and working hours MTBF; hydraulic torque converter to the development of high-power products, parts and components to improve the manufacturing process technology to improve reliability, promote computeraided technology, the development of hydraulic torqu
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