外文翻译--小型玉米脱粒机的设计

附 录 1 小型玉米脱粒机的设计 1、 引言 玉米脱粒机是我国粮食收获的重要农业机械之一。轴流式玉米脱粒机 ,全机有入料斗、脱粒、风选、筛选、机架等五个重要部分。脱粒部分由钉齿滚筒、凹板、螺旋板组成。凹板下方有流斗。风选部分有风扇和出糠口。筛选部分有筛子和偏心滚轮振动器，筛子由偏心滚轮振动器带动做往复运动，将玉米芯中夹带的子粒筛出，由筛孔漏下。其加工流程如下：玉米穗通过料斗进入滚筒，在高速回转滚筒的冲击和玉米穗、滚筒、凹板的相互作用下被脱粒。脱下的子粒大部分通过凹板孔，由子粒滑板滑出机外。穗轴则沿滚筒轴向往后移 动，通过筛子表面流出机外。夹带在穗轴中的部分子粒经过筛孔漏下。风扇的作用是将夹在子粒中的轻杂带走。 2、 喂入口和排出口的设计 为保证玉米穗顺利喂入而不堵塞滚筒，料斗底板应有一定的斜度；进入滚筒的入口应偏向滚筒向下回转的一侧。轴流式滚筒式脱粒装置的喂入口和排出口设置在径向位置时，其设计原理与切流式脱离装置基本相同。根据需要也可配置喂入轮和逐稿轮。在现有的一些脱粒机上，喂入口宽约 400-500mm，排出口宽约 300mm。有的脱粒装置上的排出口宽度可以调节，用来改变作物的脱粒时间，以适应不同作物需要。穗轴排出口 与子粒排出口的配置应保持一定的距离，以免穗轴于子粒混杂。轴流式滚筒上方的顶盖与凹板镶接组成圆筒行的脱粒室。圆柱形轴流滚筒的顶盖内壁应有螺旋线导向板，用以控制作物轴向移动的速度。导向板的螺旋升角约为 20度到 50 度，升角过大导向板起不到轴向导送的作用，作物易滞留、积聚、使秸草破碎严重。导向板高度一般为 50-70mm.喂入量大、作物层厚、导向板高度取最大值。导向板与滚筒间隙大多为 10-15mm，间隙过大，作物轴向流动不畅，使生产率降低，甚至可能发生堵塞。间隙太小，碎秸草多，功率消耗大，作物湿度较大时还易引起堵塞。 因作物层沿轴向逐渐变薄，滚筒与导向板的间隙也可沿轴方向由大变小，以提高脱粒分离的效果。 3、 脱粒装置的设计 、滚筒类型的设计 轴流式脱粒装置主要由滚筒、凹板、导板和盖（或罩）等部分组成。工作时，作物由滚筒的一端喂入（顺着滚筒轴向或径向喂入），随着滚筒的旋转，作物贴着凹板与盖（或罩）组成的圆筒内弧面作螺旋运动。沿着滚筒轴线方向流过脱粒装置。谷粒、颍壳、碎秸、碎叶等谷粒混合物在滚筒离心力的作用下同时由凹板筛孔（或分离筛孔）落下，秸草则由滚筒的另一端（轴向或径向）排出。大部分生长成熟、饱满的谷粒在滚筒前半段脱下 分离，一些生长不好和不太成熟的谷粒到后半段才被脱下 ,后半段滚筒还把其余混在碎秸里的谷粒分离出来。因作物在脱粒装置内的时间长（约 2-3秒），能充分的进行分离，故比传统使用的切流式脱粒装置脱净率高，而且有可能把脱粒调整的柔和些。使受损伤的的谷粒减少。但碎秸杆多，脱粒消耗的功率也相应较大。 滚筒的直径、转速和长度的设计 常用的圆柱形钉齿滚筒的齿顶圆直径为 200-300 mm。这里取 224 mm。轴流滚筒式脱粒装置对作物的脱粒时间比较长，故滚筒的脱粒速度可比切流滚筒式的稍底些，脱粒间隙可以大些，而不同的作物所 要求的脱粒速度与脱粒间隙在调节。 4、 清选装置的设计、清选装置的功用 通过总体设计方案选用吹出型清选装置。清选风道位于风扇出口的前面，谷粒混合物沿滑板在出风口前落下，轻杂物沿风道被吹走，谷粒靠重力穿过气流场进入集谷装置。清选风道下眼保证轻杂物的吹出通畅，并能截留被气流吹出的少量谷粒，减少损失。清选风道的截面积一般比风扇出口的面积大很多，以便在出风口处把谷粒混合物吹散。 5、 带轮传动 鉴于带传动的优点和在应用中的广泛性。在一般的机械传动中，应用最广泛的是 V 带传动。 V 带的横截面呈等腰梯形， V 带轮上也做出相应 的轮槽。传动时带只和轮槽的两个侧面接触，即以两侧面为工作面。根据槽面摩擦的原理，在同样的张紧力下， V 带传动较平带传动等产生更大的摩擦力。这是 V 带传动性能上最主要的优点。再加上 V带传动允许的传动比较大，结构紧凑，以及 V带多以标准化并大量生产的优点，因而 V带传动的应用比平带传动应用广泛的多。所以综合以上 V带种种的优点和实际操作的可行性， V带传动是最佳的选择。 6、 带轮的材料 带轮的材料主要采用铸铁，常用的材料牌号为 HT150 或者为 HT200；转速比较高的时候采用铸钢（或者用钢板冲压后焊接而成）；小功率时可以用 铸铝或者塑料。 附 录 2 Small corn Sheller design One、 Introduction Corn Sheller is Chinas grain harvest of one of the important agricultural machinery. Axial-flow corn Sheller, the whole machine into the hopper, threshing and winnowing, screening, rack and important parts. Threshing in part by the nail tooth drum, concave, Helix Board composition. Concave bottom stream bucket. Some fans and winnowing out chaff. Filtering is a sieve and eccentric wheel vibrators, shaken by the eccentric wheel vibrators driven do reciprocating motion, the corncob entrainment of grain screening out from under the sieve leakage. The process is as follows: maize ears by hopper into the cylinder at high-speed rotary drum of shock and maize ears, roller, concave plate interactions are threshed. Off most of the grain through concave bore, from grain skateboard slide-out machines. Cobs along drum shaft yearning after moving through a sieve surface flow out of the machine. The aim of the section in the Spike-grain through the sieve leakage. The fan is enclosed in the grain of miscellaneous away. Two、 feeding inlet and outlet of design In order to guarantee the smooth feeding corn without clogging rollers, hopper bottom should get some angle； enter the drums of entry should be in favor of the drum down one side of the revolution. Axial-flow type threshing equipment feeding inlet and outlet settings in radial position, their design principles and cut streaming out of the device is basically the same. Depending on your needs or you can configure the automatic feeder round and round-by-draft. Some of the existing threshers feed entry on approximately 400-500mm, is a 300mm outlet. The threshing of outlet width is adjustable, used to change the threshing time, crop to fit the needs of different crops. Cobs outlet and grain exports configuration should keep a certain distance, to avoid spike in the grain mix. Axial-flow top on the top of the drum and concave inlay-composition of threshing drum line. Cylindrical drums of the top wall-flow should have the Helix design, to control crop axial movement speed. Guide plate of spiral up-angle is approximately 20 to 50 , the angle too large guide plate is the role of axial rushed, crop and the accumulation of stranded, spiked broken serious. Guide plate height typically 50-70mm-feed capacity, crop guide plate thickness, height for maximum value. Guide plates and rollers gap most 10-15mm, gap is too large, crop axial flow, reducing productivity, and perhaps even blocked. Gap is too small, much grass stubble, power consumption, is the larger crop humidity also easily cause blockage. Because of the crop layer along the axial gradually becomes thin, drum and guide plate of clearance or direction along the axis, to improve the effectiveness of threshing. separation Three、 threshing equipment、 drum type design Axial-flow by threshing drum, concave, plate and cover (or mask). As you work, the end of the crop by the drum cutter (axial down the drum or radial feed), with the drum rotation, the crop with a concave plate and cover (or cover) the cylinder arc for spiral motion. Along the axis through the threshing drum. Grain, one-piece shell, straw, broken leaf, grain mixture in the cylinder at the same time under the effects of centrifugal force by the concave sieve (or separate sieve) fall, spiked by the other end of the drum (axial and radial). Most of the growth of mature, full of grain in the roller first took off, some growth is not good and not too mature grains to the latter part is off, the latter part of the drum also mixed in the grain stubble. As a result of crops in the threshing equipment a long time (about 2-3 seconds), the separation adequately, therefore, cut than traditional use of flow cytometry threshing equipment net rate is high, and the gentleness of threshing adjustment. The injury of grain. But broken straw, threshing consumption power is appropriate. drum diameter, speed and length of design Common cylindrical spike tooth drum of addendum circle with a diameter of 200-300 mm. Here take the 224 mm. Axial-flow type threshing equipment on crop of threshing a long time, the drum of threshing than tangential flow slightly bottom barrel, threshing clearance can be bigger, but different crops may be requested by the threshing speed and threshing gaps in regulated. Four、 device design、 device functions The overall design scheme selection by blowing out of the device. Cleaning the air duct is located at the front of the fan export grain mixtures along skateboards in the air, light before falling debris along the duct was blown away, grain by gravity through the flow field enter set Valley. Cleaning the air duct eyes that light the patency of the blow out debris and interception is a small amount of airflow blown out of the grain, minimize the loss. Cleaning the air duct of sectional area is generally lower than that of the fan area of export much more so that in the grains outlet and a cool the mixture. Five、 swith wheel In view of the advantages of the belt drive and the universality of the application. In typical mechanical transmission, the most widely used is the V-belt drive. V-belt of the cross section is isosceles trapezoid, V belt pulley also make the appropriate wheel slot. Transmission belt sheave and only two side contact, that is, w