三梁四柱式液壓壓力機(jī)的設(shè)計(jì)【含CAD圖紙和說明書】
三梁四柱式液壓壓力機(jī)的設(shè)計(jì)【含CAD圖紙和說明書】,含CAD圖紙和說明書,三梁四柱式,液壓,壓力機(jī),設(shè)計(jì),cad,圖紙,以及,說明書,仿單
參考文獻(xiàn)
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[15] 秦勇.液壓機(jī)技術(shù)的現(xiàn)狀與發(fā)展趨勢[J].煤礦機(jī)械，2002，（11），10-12.
液 壓 機(jī)
水由高處下降到一個(gè)低的高度的時(shí)候能產(chǎn)生能量, 可以用來驅(qū)動(dòng)水輪和渦輪等機(jī)械.最高和最低水位之間的落差決定了每磅水的能量。水力可以來自很多自然資源, 例如瀑布和建有大壩的河流等.在沒有自然資源的情況下, 可以修建人工水庫。當(dāng)能量充足的時(shí)候可以抽水到水庫來儲存水能, 當(dāng)能量不足的時(shí)候, 這些儲存起來的水可提供能量來驅(qū)動(dòng)渦輪。
工業(yè)的液壓機(jī)械的某些稱作儲蓄器的機(jī)械裝置被用來短時(shí)間的提供高效的功率.活塞負(fù)載重量后裝入缸體中, 然后水被緩慢的壓入缸體, 活塞和活塞負(fù)載的重物給強(qiáng)迫的升到一個(gè)高的位置, 當(dāng)放下他們是,他們強(qiáng)迫缸體中的水迅速的流出, 為機(jī)器提供水的壓力能。
液壓機(jī)是由一種液體,特別是水的壓力來操縱。他們在工程領(lǐng)域的廣泛應(yīng)用,例如: 地層移動(dòng)、礦業(yè)、建筑機(jī)械、汽車工程、紡織工業(yè)、電站、農(nóng)業(yè)機(jī)械等。
1 液壓設(shè)備
水、油壓力是常用的動(dòng)力源, 比如壓力機(jī)、鉚機(jī)、起錨機(jī)、絞盤等機(jī)械. 水壓或者靜水力壓是約瑟夫布拉瑪(Joseph Bramah)發(fā)現(xiàn)的, 因此優(yōu)勢也稱布拉瑪壓力. 他主要包括連個(gè)缸體, 一個(gè)是用液體填充, 一個(gè)用活塞. 兩個(gè)缸體用管子連接起來, 也同樣用液體填充。一個(gè)缸體是小直徑的, 另一個(gè)是大直徑的. 根據(jù)帕斯卡定律, 外界作用在小活塞上壓強(qiáng)通過液體毫無損失的傳到被迫上升的大活塞的表面。對于兩個(gè)活塞來說, 壓強(qiáng)(單位面積壓力)是相同, 作用在大活塞上向上的壓力是作用在小活塞的幾倍, 因?yàn)榇蠡钊拿娣e是小活塞的幾倍. 比如, 舉個(gè)例子, 小活塞的面積是2平方英寸, 100lb的壓力作用在它上面, 于是作用在具有50平方英寸面積的大活塞上的壓力就會(huì)有25000lb(100×50/2=2,500). 然而, 讓活塞一定時(shí), 小活塞一定的距離也成比例的大于大活塞移動(dòng)的距離, 這滿足能量轉(zhuǎn)換定律。如果小活塞移動(dòng)25 英寸,大的活塞就會(huì)只移動(dòng)1英寸。水壓被使用了, 比如, 使三維的物體從一片金屬壓縮成一個(gè)大的物體。
壓力起重器, 同樣是帕斯卡定律的一項(xiàng)應(yīng)用, 用來施加大的壓力或者提升重物。
液壓機(jī),也是實(shí)施帕斯卡爾的定律,是用來產(chǎn)生大力量和負(fù)重。像水壓機(jī),它是由兩個(gè)不同尺寸的活塞筒中,由管道相連。當(dāng)小活塞來回移到了相關(guān)處理,但液體泵入較大的圓筒活塞,迫使大型活塞議案。這樣力量薄弱的小型活塞可以應(yīng)用于提高了一大沉重負(fù)擔(dān)。 液壓電梯也是適用Pascal的定律。象水壓一樣, 它的汽缸中包括兩個(gè)用管子連接起來的不同大小的活塞, 當(dāng)小些的活塞靠連在他上面的手柄來回移動(dòng)的時(shí)候, 壓迫液體進(jìn)入大活塞的汽缸, 強(qiáng)制大活塞移動(dòng)。這樣, 小力氣可以使用小活塞升起很重的負(fù)載。壓力電梯同樣是帕斯卡定律的一項(xiàng)應(yīng)用。
2 壓力機(jī)的特征
1. 這些壓力機(jī)提供快捷的方式緩慢的積壓&快速的返回。變化速度可以人工進(jìn)行預(yù)定；
2. 該結(jié)構(gòu)經(jīng)過超聲波質(zhì)量測試，能承受長時(shí)間的負(fù)載和重壓；
3. 通過計(jì)算機(jī)半自動(dòng)的結(jié)構(gòu)設(shè)計(jì)和有限元分析達(dá)到了極大化結(jié)構(gòu)剛度；
4. 額外的長期的，精確的操縱進(jìn)一步縮小磨損的額外精度設(shè)計(jì)；
5. 關(guān)閉或一拳打在液壓阻尼系統(tǒng)可以安裝壓力。 這將有效突破,通常產(chǎn)生噪音的科學(xué)手段穿上這種行動(dòng)；
6. 低噪音包水電設(shè)計(jì)單位按國際慣例,國際知名的科學(xué)組裝部件作。按統(tǒng)計(jì)學(xué)的印刷設(shè)計(jì)準(zhǔn)則,因而標(biāo)準(zhǔn)印章、灌木使用；
7. "邏輯控制器"(PLC)是在符合國際標(biāo)準(zhǔn)的壓力也使ABB/艾倫-布拉德利/西門子/Telemacqnice/Keyance提供最大的靈活性和收購生產(chǎn)完全符合國際標(biāo)準(zhǔn)；
8. 精確的機(jī)械結(jié)構(gòu)都是正?；蟮玫降乃璧臏?zhǔn)確度及與PLATEN科學(xué)之間的角度提出的PLATEN；
9. 潤滑油: 方式/可以從油孔中心注油；
10. 移動(dòng)PLATEN:這是假想的、重型的、工程測試板焊接性能最高的負(fù)荷重量.。PLATEN全是壓力減輕后焊接.。按platen標(biāo)準(zhǔn)規(guī)定't'時(shí)間。 液壓系統(tǒng)或機(jī)械操作按內(nèi)部RAM要求也提供選擇性的請求或申請；
11.卡死或鐵軌滑動(dòng)的安排方式也提供了支持選擇性信息的一種重要應(yīng)用工具。
3 液壓缸
液壓缸是被用來加壓的液壓元件，它是依靠液體使元件產(chǎn)生線性運(yùn)動(dòng)和應(yīng)力的驅(qū)動(dòng)設(shè)備。液壓缸被使用在各種各樣的力的應(yīng)用中。經(jīng)營的規(guī)格、配置或架置、建筑材料, 和特點(diǎn)是選擇液壓缸首要的考慮因素。
液壓缸的重要規(guī)格包括圓筒類型、沖程、最大工作壓力、打擾直徑, 和標(biāo)尺直徑。
選擇為圓筒類型包括連接桿,焊接和填塞。使用一個(gè)或更多連接桿提供另外的穩(wěn)定的連接桿是圓筒液壓缸。連接桿通常典型地被安裝在圓筒型的外部直徑處。在許多應(yīng)用中, 圓筒連接桿承受多數(shù)的應(yīng)用的裝載次數(shù)。使用一套耐用被焊接的圓筒可提供穩(wěn)定的應(yīng)用數(shù)據(jù)。液壓缸是一個(gè)被焊接的光滑的圓筒。填塞圓筒是作為填塞類型的液壓缸。一個(gè)液壓油缸的里活塞標(biāo)尺斷面是超過二分之一的部分，是可移動(dòng)的斷面的設(shè)備。液壓油缸主要被使用推擠而不是拉扯, 而且通常是在高壓環(huán)境中應(yīng)用。沖程是活塞在缸筒中運(yùn)動(dòng)的最大距離。液壓缸可能有各種各樣的沖程長度, 從一英寸的分?jǐn)?shù)到許多英尺。最大工作壓力是圓筒可能承受的最大工作壓力。缸筒直徑缸筒內(nèi)圓的直徑。標(biāo)尺直徑是被使用在圓筒的標(biāo)尺或活塞的直徑。選擇為圓筒配置是簡單的配置或望遠(yuǎn)鏡形。一種簡單的結(jié)構(gòu)液壓缸包括唯一圓柱形缸筒和內(nèi)部元件。一種望遠(yuǎn)鏡配置液壓缸使用"擠撞" 圓柱形缸筒來擴(kuò)大圓筒的長度。望遠(yuǎn)鏡配置圓筒被使用在要求對一個(gè)長的圓筒的用途在一個(gè)空間特殊的環(huán)境里的不同應(yīng)用。液壓缸可能是單一行程或雙重行程。一次唯一運(yùn)動(dòng)液壓缸只在一個(gè)方向上施加壓力。一次雙重行動(dòng)液壓缸可能行動(dòng)沿水平(Ｘ軸) 面, 垂直的(Ｙ軸) 飛運(yùn)動(dòng)沿其他方向運(yùn)動(dòng)。選擇架構(gòu)的方法包括耳輪緣、耳軸, 穿線, U-形鉤或目測。登上地點(diǎn)可能是缸蓋、兩端或中間體。生產(chǎn)材料包括鋼、不銹鋼和鋁。共同的特點(diǎn)為液壓缸包括缺一不可的傳感器、雙重末端標(biāo)尺、液壓缸數(shù)據(jù)表和可調(diào)整的沖程。
液壓缸是使用在使被施加壓力液體的液壓機(jī)產(chǎn)生線性行動(dòng)和動(dòng)力的驅(qū)動(dòng)設(shè)備。液壓缸被使用在各種各樣的動(dòng)力應(yīng)用。
區(qū)別在氣缸和液壓缸之間是他們供給動(dòng)力的方式。當(dāng)空氣圓筒引起線性行動(dòng)和力量通過氣動(dòng)力學(xué)的力量, 液壓缸用途加壓了流體。液壓缸是可利用的在三主要型(微型液壓缸也可使用): 連接桿, 被焊接和填塞。
連接桿液壓缸使用一個(gè)或更多連接桿增加穩(wěn)定性。連接桿典型地被安裝在圓筒的外部。在許多應(yīng)用, 連接桿在這些精確度液壓缸里負(fù)擔(dān)應(yīng)用的裝載的多數(shù)。被焊接的圓筒提供光滑的運(yùn)動(dòng)，由于他們的使用被焊接的圓筒, 提供穩(wěn)定性。液壓油缸有活塞標(biāo)尺的一個(gè)斷面, 是超過二分之一移動(dòng)的組分的斷面。液壓油缸主要被使用推擠而不是拉扯, 而且是最常用在高壓應(yīng)用。
除他們的類型之外, 液壓缸可能被根據(jù)了他們的配置區(qū)分。二種主要配置是簡單和望遠(yuǎn)鏡的(習(xí)慣液壓缸配置再是可利用的) 。簡單的配置液壓缸包括唯一圓柱形住房和內(nèi)部元件。這是基本的液壓缸設(shè)計(jì)由多數(shù)液壓缸制造商使用。望遠(yuǎn)鏡液壓缸使用"擠撞" 圓柱形住房擴(kuò)大圓筒的長度。擠撞液壓缸被使用在要求對一個(gè)長的圓筒的用途在一個(gè)空間拘束的環(huán)境里的各種各樣的應(yīng)用。
根據(jù)行動(dòng), 液壓缸可能是唯一行動(dòng)或雙重行動(dòng)設(shè)計(jì)。唯一行動(dòng)圓筒被加壓為行動(dòng)在只一個(gè)方向。頻繁地被使用帶來圓筒活塞回到原始位置。雙重行動(dòng)液壓缸可能行動(dòng)沿水平(Ｘ軸) 面, 垂直的(Ｙ軸) 方向或沿其他方向運(yùn)動(dòng)。圓筒活塞的雙方可能被加壓為反復(fù)性行動(dòng)。力量規(guī)定值可能不同，有些在相反方向。
4 一般液壓機(jī)構(gòu)的組成
電源單位提供必要的液體壓力- 從主驅(qū)動(dòng)電動(dòng)機(jī)轉(zhuǎn)換機(jī)械動(dòng)力。
4.1 電源部分:
最重要的組成部分在動(dòng)力源是泵。這畫在液壓機(jī)液體油箱旁邊，并且由它通過線性系統(tǒng)在液體壓力下抵抗負(fù)載力。壓力不加強(qiáng)直到流動(dòng)的液體遇到負(fù)載。油液過濾單位經(jīng)常也包含在電源部分。雜質(zhì)可能進(jìn)入系統(tǒng)由于是熱或冷的機(jī)械磨損、油, 或外在環(huán)境影響。因此, 過濾器被安裝在水力電路從液壓機(jī)液體去除土微粒。水和氣體在油是還破裂物質(zhì)并且必須采取特別措施防止他們的產(chǎn)生。加熱器和致冷機(jī)被安裝來調(diào)節(jié)液壓機(jī)液體。這對液壓機(jī)實(shí)際應(yīng)用中的需要有著特殊的作用。
油箱的作用在于儲存液壓機(jī)需要的工作液體:
-- 過濾和氣體分離由相應(yīng)的部件；
-- 通過他們的表面是使液體冷卻。?
4.2 液壓部分
流體這是轉(zhuǎn)移準(zhǔn)備的能量電源單位到驅(qū)動(dòng)部分的工作媒介(圓筒或馬達(dá)) 。液壓機(jī)液體有各種各樣的特征。所以, 他們必須被選擇適合應(yīng)用在考慮中。按不同情況進(jìn)行調(diào)整，液壓機(jī)液體在一個(gè)礦物油基地頻繁地被使用; 這些指壓力油。
4.3閥門
閥門是設(shè)備為控制能量流程。他們能控制和調(diào)控液壓機(jī)液體、壓力、流速和, 因而, 流程速度的流程方向。
有四種閥門類型被選擇與問題符合在考慮中。直通控制閥這些閥門控制流程液壓機(jī)液體和, 因而, 方向行動(dòng)和安置的方向運(yùn)作的組分。定向控制閥用手工, 機(jī)械上, 電子, 氣動(dòng)力學(xué)來控制開動(dòng)或液壓.他們改變位置和放大信號(手工, 電或氣動(dòng)力學(xué)) 形成一個(gè)接口在電能控制部分和信號控制段之間。
4.3.1壓力閥工作在一種完全液壓機(jī)構(gòu)或在系統(tǒng)的部份，他們能夠影響工作壓力。操作方法這些閥門的根據(jù)事實(shí)有效的壓力從系統(tǒng)行動(dòng)在表面在閥門?？傊盗颗c負(fù)載平衡。
4.3.2流程控制閥門這交互式與壓力閥影響流速。他們使成為可能控制或調(diào)控運(yùn)動(dòng)速度力量組分的。那里流速是恒定的, 流程變化必須發(fā)生。這一般被影響通過流程控制閥門的互作用與壓力閥。
4.3.3單向閥門在這類型閥門情況下, 分別被做在普通的單向閥門和被控制的單向閥門之間。在被控制的單向閥門情況下, 流程在封鎖的方向可能由信息控制。圓筒是轉(zhuǎn)換水力成機(jī)械動(dòng)力的驅(qū)動(dòng)組分。他們引起線性運(yùn)動(dòng)通過壓力在可移動(dòng)的活塞的表面。
4.3.4缸筒(線性執(zhí)行機(jī)構(gòu))單作用圓筒可變的壓力只能向活塞的一邊作用，驅(qū)動(dòng)運(yùn)動(dòng)只導(dǎo)致在活塞的一個(gè)方向.回歸沖程在一個(gè)彈簧的外力作用下產(chǎn)生。例子: Hydraulic ；Telescopic。駕駛運(yùn)動(dòng)被生產(chǎn)在二個(gè)方向的雙作用圓筒可變的壓力可能向或者活塞意思的一邊被應(yīng)用。例子: Telescopic 有差別的圓Synchronous。
正如液壓缸一樣, 水力馬達(dá)是驅(qū)動(dòng)組分由閥門控制。他們太轉(zhuǎn)換水力成機(jī)械動(dòng)力以區(qū)別, 他們引起轉(zhuǎn)臺式或轉(zhuǎn)體運(yùn)動(dòng)代替線性運(yùn)動(dòng)。
Hydrostatic Devices
Water or oil under pressure is commonly used as a source of power for many types of presses, riveting machines, capstans, winches, and other machines. The hydraulic press, or hydrostatic press, was invented by Joseph Bramah and is therefore sometimes called the Bramah press. It consists essentially of two cylinders each filled with liquid and each fitted with a piston; the cylinders are connected by a pipe also filled with the liquid. One cylinder is of small diameter, the other of large diameter. According to Pascal lows pressure exerted on the smaller piston is transmitted undiminished through the liquid to the surface of the larger piston, which is forced upward. Although the pressure (force per unit of area) is the same for both pistons, the total upward force on the larger piston is as many times greater than the force on the smaller piston as the area of the larger piston is greater than the area of the smaller piston. If, for example, the smaller piston has an area of 2 sq in. and a force of 100 lb is exerted on it, then the force on the larger piston having an area of 50 sq in. would be 2,500 lb (100×50/2=2,500). However, when the pistons move, the distance the smaller piston travels is proportionately greater than the distance the larger piston travels, satisfying the law of conservation of energy. If the smaller piston moves 25 in., the larger one will only move 1 in.
The hydraulic press is used, for example, to form three-dimensional objects from sheet metal and plastics and to compress large objects.
The hydraulic jack, also an application of Pascal's law, is used to exert large forces or to lift heavy loads. Like the hydraulic press it consists essentially of two different-sized pistons contained in cylinders that are connected by a pipe. When the smaller piston is moved back and forth by a handle connected to it, it pumps a liquid into the cylinder of the larger piston, forcing the larger piston to move. In this way a weak force applied to the smaller piston can raise a heavy load on the larger one. The hydraulic elevator is also an application of Pascal's law..
Salient Features of hydraulic presses:
1. These presses provide fast approach slow pressing & fast return speeds. The change in speed can be manually preset to take place at any point of the stroke with the help of limit switches / proximity switches.
2. The frame is fabricated by ultrasonically tested quality profiles & plates of suitable thickness to with stand the load & longer life of the press. The frames are stress-relieved.
3. Maximum frame rigidity is achieved through computer aided frame design & finite element analysis.
4. Extra long, precision machined & hardened guides to face slides offer exceptional accuracy & alignment which further reduced to wear.
5. In blanking or punching hydraulic presses a damping system can be fitted. This effectively reduces breakthrough noise & tool wear normally generated by such operations.
6. The low noise hydraulic power pack unit is designed as per international practices & assembled with internationally reputed make components. The presses are designed as per ISI guidelines, hence standard seals, bushes are used.
7. "Programmable logical controls" (PLC) is provided in our presses of international standard make i.e. ABB/Allen-Bradley/Siemens/Telemacqnice / keyance, offering maximum production flexibility & Full compatibility with international standards.
8. Precise machining of the structural members is done after normalising to get the required accuracies like parallelism between platen & bed & right angularity between bed and the moving platen.
9. Lubrication: Ram slides / guides/ guide bushes are lubricated from a centralised lubrication arrangement.
10. Moving platen: It is a fabricated, heavy duty, tested welded plate construction for highest stiffness under heavy loads. The whole platen is stress-relieved after welding. 'T' slots provided in the platen are as per DIN standards. Hydraulic or mechanical ejector pins to operate from inside the ram is also provided as optional on request or depending on the application.
11. Die transfer rails or bolster sliding arrangement is also provided as optional in front side of the press for heavy tools applications.
About Hydraulic Cylinders
Hydraulic cylinders are actuation devices that utilize pressurized hydraulic fluid to produce linear motion and force.? Hydraulic cylinders are used in a variety of power transfer applications.? Operating specifications, configuration or mounting, materials of construction, and features are all important parameters to consider when searching for Hydraulic cylinders .
Important operating specifications for Hydraulic cylinders include the cylinder type, stroke, maximum operating pressure, bore diameter, and rod diameter.? Choices for cylinder type include tie-rod, welded, and ram.? A tie-rod cylinder is a Hydraulic cylinders that uses one or more tie-rods to provide additional stability.? Tie-rods are typically installed on the outside diameter of the cylinder housing.? In many applications, the cylinder tie-rod bears the majority of the applied load.? A welded cylinder is a smooth Hydraulic cylinders that uses a heavy-duty welded cylinder housing to provide stability.? A ram cylinder is a type of Hydraulic cylinders that acts as a ram.? A hydraulic ram is a device in which the cross-sectional area of the piston rod is more than one-half the cross-sectional area of the moving component.? Hydraulic rams are primarily used to push rather than pull, and are most commonly used in high pressure applications.? Stroke is the distance that the piston travels through the cylinder. Hydraulic cylinders can have a variety of stroke lengths, from fractions of an inch to many feet.? The maximum operating pressure is the maximum working pressure the cylinder can sustain.? The bore diameter refers to the diameter at the cylinder bore.? The rod diameter refers to the diameter of the rod or piston used in the cylinder.
Choices for cylinder configuration are simple configuration or telescopic figuration.? A simple configuration Hydraulic cylinders consists of a single cylindrical housing and internal components.? A telescopic configuration Hydraulic cylinders uses "telescoping" cylindrical housings to extend the length of the cylinder. Telescopic configuration cylinders are used in a variety of applications that require the use of a long cylinder in a space-constrained environment.? Hydraulic cylinders can be single action or double action.? A single action Hydraulic cylinders is pressurized for motion in only one direction.? A double action Hydraulic cylinders can move along the horizontal (x-axis) plane, the vertical (y-axis) plane or along any other plane of motion.? Choices for mounting method include flange, trunnion, threaded, clevis or eye, and foot.? The mount location can be cap, head, or intermediate.? Materials of construction include steel, stainless steel, and aluminum.? Common features for Hydraulic cylinders include integral sensors, double end rod, electro- Hydraulic cylinders and adjustable stroke.
Hydraulic cylinders are actuation devices that use pressurized hydraulic fluid to produce linear motion and force. Hydraulic cylinders are used in a variety of power transfer applications.
The difference between air and Hydraulic cylinders is the manner by which they are powered. While air cylinders generate linear motion and force via pneumatic power, Hydraulic cylinders use pressurized fluid. Hydraulic cylinders are available in three main types (with custom and miniature Hydraulic cylinders also available): tie-rod, welded and ram.
Tie-rod Hydraulic cylinders use one or more tie-rods to provide additional stability. Tie-rods are typically installed on the outside diameter of the cylinder housing. In many applications, the tie-rods in these precision Hydraulic cylinders bear the majority of the applied load. Welded cylinders provide smooth motion because of their heavy-duty welded cylinder housing, which provides stability. Hydraulic rams have a cross-sectional area of the piston rod, which is more than one-half the cross-sectional area of the moving component. Hydraulic rams are primarily used to push rather than pull, and are most commonly used in high-pressure applications.
In addition to their type, Hydraulic cylinders can be differentiated based upon their configuration. The two main configurations are simple and telescopic (again custom Hydraulic cylinders configurations are available). Simple configuration Hydraulic cylinders consist of a single cylindrical housing and internal components. This is the basic Hydraulic cylinders design used by most Hydraulic cylinders manufacturers. Telescopic Hydraulic cylinders use "telescoping" cylindrical housings to extend the length of the cylinder. Telescoping Hydraulic cylinders are used in a variety of applications that require the use of a long cylinder in a space-constrained environment.
In terms of motion, Hydraulic cylinders can be of single action or double action design.
Single action cylinders are pressurized for motion in only one direction. A spring is frequently used to bring the cylinder piston back to the original position. Double action Hydraulic cylinders can move along the horizontal (x-axis) plane, the vertical (y-axis) plane or along any other plane of motion. Both sides of cylinder piston can be pressurized for reversible motion. Force ratings can differ somewhat in opposite directions.
Components of a hydraulic system
The power supply unit provides the necessary hydraulic power – by converting the mechanical power from the drive motor.
1. Power supply section
The most important component in the power supply unit is the hydraulic pump. This draws in the hydraulic fluid from a reservoir (tank) and delivers it via a system of lines in the hydraulic installation against the opposing resistances. Pressure does not build up until the flowing liquids encounter a resistance. The oil filtration unit is also often contained in the power supply section. Impurities can be introduced into a system as a result of mechanical wear, oil which is hot or cold, or external environmental influences. For this reason, filters are installed in the hydraulic circuit to remove dirt particles from the hydraulic fluid. Water and gases in the oil are also disruptive factors and special measures must be taken to remove them. Heaters and coolers are also installed for conditioning the hydraulic fluid. The extent to which this is necessary depends on the requirements of the particular exercise for which the hydraulic system is being used.
The reservoir itself also plays a part in conditioning the hydraulic fluid:
--Filtering and gas separation by built-in baffle plates,
--Cooling through its surface.
2. Hydraulic fluid
This is the working medium which transfers the prepared energy the power supply unit to the drive section (cylinders or motors). Hydraulic fluids have a wide variety of characteristics. Therefore, They must be selected to suit the application in question. Requirements vary from problem to problem. Hydraulic fluids on a mineral oil base.
frequently used; these are referred to as hydraulic oils.
Hydraulic fluid
3．Valves
Valves are devices for controlling the energy flow. They can control and regulate the flow direction of the hydraulic fluid, the pressure, the flowrate and, consequently, the flow velocity.
There are four valve types selected in accordance with the problem in question.
－Directional control valves
These valves control the direction of flow of the hydraulic fluid and, thus, the direction of motion and the positioning of the working components.
Directional control valves may be actuated manually, mechanically, electrically, pneumatically or hydraulically.They convert and amplify signals (manual, electric or pneumatic) forming an interface between the power control section and the signal control section.
Pressure valves
These have the job of influencing the pressure in a complete hydraulic system or in a part of the system. The method of operation of these valves is based on the fact that the effective pressure from the system acts on a surface in the valve. The resultant force is balanced out by a counteracting spring.
Flow control valves
These interact with pressure valves to affect the flow rate. They make it possible to control or regulate the speed of motion of the power components. Where the flow rate is constant, division of flow must take place. This is generally effected through the interaction of the flow control valve with a pressure valve.
Non-return valves
In the case of this type of valve, a distinction is made between ordinary non-return valves and piloted non-return valves. In the case of the piloted non-return valves, flow in the blocked direction can be released by a signal.
Cylinders are drive components which convert hydraulic power into mechanical power. They generate linear movements through the pressure on the surface of the movable piston. Distinction is made between the following types of cylinder:
Cylinders? (linear actuators)
Single-acting cylinders
The fluid pressure can only be applied to one side of the piston with the result that the drive movement is only produced in one direction.The return stroke of the piston is effected by an external force or by a return spring.
Examples:
－Hydraulic ram
－Telescopic cylinder
Double-acting cylinders
The fluid pressure can be applied to either side of the piston meaning that drive movements are produced in two directions.
Examples:
－Telescopic cylinder
－ Differential cylinder
－Synchronous cylinder
Like cylinders, hydraulic motors are drive components controlled by valves. They too convert hydraulic power into mechanical power with the difference that they generate rotary or swivel movements instead of linear movements.
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