【正文】 ed material is delivered to the buckets to make the scooping scraper is secured underneath the screw elevator of the multibucket loader usually dischanges the material onto belt conveyers that deliver it to tiansport facilities. Some loaders discharge the handle material into tranport facilities through hoppers or chutes. 4 裝載機 在建筑施工中，材料的裝卸是用裝載機和寫在機進行的。實踐證明，在采石場和非金屬材料的倉庫作業(yè)中，挖掘機的裝在效率要比裝載機高。 根據(jù)所裝載材料的種類，裝載機可以 分為叉式裝載機，用于裝在整塊物料；鏟斗式裝載機，用于裝載松散物料。鏟斗裝載機分為單斗裝載機和連續(xù)作業(yè)多斗裝載機。單斗裝載機式通用機械，適用于多種條件下作業(yè)。多斗裝載機用于大型倉庫、公路工程以及需要連續(xù)作業(yè)的工作。 按照行走裝置的類型，可以分為履帶行走裝載機和輪胎式裝載機。履帶行走式裝載機具有良好的通過性，能產(chǎn)生很大的推進力。輪胎裝載機機動性能良好。行走速度快，對公路路面和存活地面從不產(chǎn)生破壞作用。 裝載機用來卸掉火車車廂里的砂子、礫石、碎石和水泥。 卸載機分為機動卸載和氣動卸載機。既定卸載機用于從平板貨車或 敞蓬車上卸貨；氣動卸載機用于卸水泥。 叉車的主要工作裝置是用于裝卸整件貨物的叉子。這些裝載機有不同的換裝部件。當(dāng)裝上鏟斗或抓斗時，可用語裝卸松散和小塊物料，叉架機構(gòu)使這些裝載機能適于把貨物舉升到一個不大的高度，有時也適于建筑安裝工程。 因為叉車在硬路面上作業(yè)，因此，主要用于倉庫并作為工廠物料的裝卸設(shè)備。這些裝載機是根據(jù)卡車的原理制造的，所以也叫卡車裝載機，他們以內(nèi)燃機或帶有蓄電池的電動機為動力。 以發(fā)動機為動力的卡車用于大型倉庫和材料搬運工作，用于一般的堆放場和車輛裝卸。液力變距傳動系統(tǒng)使運動平穩(wěn)。還可以選 配動力轉(zhuǎn)向及全天候駕駛室。 單斗裝載機以履帶拖拉機或輪胎拖拉機作為行走機架。該裝載機可使裝載作業(yè)、建筑施工、安裝工程實現(xiàn)機械化。在這些換裝裝置中，主要附件是鏟斗。裝載設(shè)備有三種不同的形式，即前卸式、翻轉(zhuǎn)式和側(cè)卸式。前卸式機構(gòu)只允許從裝料的一側(cè)卸料；側(cè)卸式機構(gòu)是側(cè)面卸料；翻轉(zhuǎn)式機構(gòu)則從后面卸料。 目前，具有變量液壓驅(qū)動的工作裝置的前卸式裝載機使用得最為廣泛。 多斗裝載機的產(chǎn)量比同一額定功率的單斗裝載機的產(chǎn)量高 40%~60%。多斗裝載機適于磚廠、混泥土預(yù)制品廠及裝卸量大的火車站，也同樣適用于裝載松散5 物料。此外， 該機還適用于對松散物料的顆粒分級，為此，可以安裝一個專用的振動篩。 用多斗裝載機為側(cè)邊卸料的平板車卸料，其效率很高。多斗裝載機可用于混凝土預(yù)制品廠的生產(chǎn)線中，也可用于筑路。在筑路中，用于將砂子和礫石裝入烘干筒和攪拌機里。 該裝載機的工作機構(gòu)是兩個左右螺旋桿組成的螺旋給料器，安裝在斗式提升機的兩側(cè)。當(dāng)給料器旋轉(zhuǎn)時，物料被送入各個鏟斗內(nèi)，使得裝料比較容易。刮板固定在螺旋給料器的下方。多斗裝載機的提升機把物料卸在傳送帶上，再由傳送帶將物料運送到設(shè)備中。 有些裝載機用漏斗或料槽把物料送進運輸設(shè)備中。 Pneumatic Motors and Tools Compressde air can be used for a wide variety of operations,such as:to drive air motors and air hammers,to operate air cylinders,to atomize liquids,to convery materials,to displace and agitate liquids,to serve as a cushion,to create a vacuum,to accelerate bustion,and to serve as a coolant and lubricant. An electric motor is a device in which electrical energy is converted into mechanical fluid motor is a device for converting fulid energy into mechanical this chapter,the main features of pneumatic motors and pneumatic tools are discussed. GENERAL TYPES OF AIR MOTORS Air motors may be divided into tow general type: (1) the rotary type and (2) the reciprocating type. The bination of a piston and cylinder is an example of the reciprocating type of example of the rotary motor are the vanetype and geartype motors. A rotary vanetype motor is rotating member,with its sliding vanes,it is trapped between the vane(which ride on the inside of the housing)and pushes to the the pressed air drives a rotating member. A geartype motor is pair of meshed gears rotate inside 6 a housing,As the gears rotate,the air is trapped between the gear teeth and housing,and pushes from the inlet to the the pressed air drives the gears. CHARACTERISTICS OF AIR MOTORS An air motor operates safely in an explosive atmosphere,and has a low installation cost,a rapid acceleration,and a high starting is pact,and its cariable speed can be changed. A typical curve for torque versus speed(rpm)for a rotarytype air motor is speed can be caried,in small steps,from zero a maximum by varying the air flow to the air flow rate to the motor can be varied by means of a valve in the inlet pressedair pressure at the air motor inlet can be contolled with an adjustable pressure regulator in the air inlet line。thus torque can be controlled by means of the pressure air motor can be arranged to be recersible in speed direction,by means of a four