【正文】 (5) 結(jié)合第三步研究潤(rùn)滑油粘度特性所得到的結(jié)論，首先在圖表的溫度軸 （ x軸）上找出溫度所對(duì)應(yīng)的線如 40 186。C 的線，再根據(jù)潤(rùn)滑油廠商提供的潤(rùn)滑油在 40186。C時(shí)的粘度在圖上找出對(duì)應(yīng)的粘度線，然后標(biāo)記兩條直線的交點(diǎn)（圖 3 中紅線）。 (6) 在潤(rùn)滑油溫度為 100 186。C 時(shí)，重復(fù)第五步，并標(biāo)記點(diǎn)（圖 3 中深綠色線）。 (7) 用直線連接這些標(biāo)記點(diǎn)（圖 3 中黃線）。這條線表示了在一系列溫度時(shí)，潤(rùn)滑油的粘度。 (8) 在表中的粘度軸上找出廠商提供的相應(yīng)潤(rùn)滑油最佳粘度值之對(duì)應(yīng)點(diǎn)，然后在該點(diǎn)上畫一條水平線與黃色線相交。接著從此交點(diǎn)引一條垂直線（圖 3 中綠線）至表底部。上述黃線倍幾條溫度線分割，這條線所 穿過的區(qū)域是泵中特定潤(rùn)滑劑的最佳工作溫度（ 69186。C）。 (9) 當(dāng)粘度分別為泵所需粘度的最大值和最小值時(shí)，重復(fù)步驟 8 畫出線（圖 3中棕色線）。介于最高溫度和最低溫度間的區(qū)域是為泵選擇理想潤(rùn)滑油的根據(jù)既算選潤(rùn)滑油的溫度范圍必須在這個(gè)區(qū)域內(nèi)。 (10) 在圖表上找出步驟 2 所述測(cè)出溫度所對(duì)應(yīng)的值，如果這一值落在最高溫度和最低溫度所形成的區(qū)域之間，則表明該液壓油適合這個(gè)系統(tǒng)。否則，就要更換液壓油。因此，從表上可以看出，所舉液壓油的正常工作條件超出了合適范圍，需要更換。 圖 3 粘度 溫度表 此外， 請(qǐng)遵守以下液壓 油的管理 原則 : (1) 標(biāo)記所有的輸入液壓油和液壓油箱 。這將最大限度地減少交叉污染，確保關(guān)鍵性能得到滿足。 (2) 在液壓油的存儲(chǔ)設(shè)備中采用先入先出的方式 。 這種先入先出的系統(tǒng)將減少由于使用混亂和存儲(chǔ)問題造成的液壓油 失效 。 液壓系統(tǒng) 是 以流體為基礎(chǔ) 的 相對(duì)復(fù)雜的系統(tǒng)，它能輕松地將能量轉(zhuǎn)變?yōu)橛杏玫膭?dòng)作。但是只有根據(jù)系統(tǒng) 要求 選擇了合適的液壓油，液壓系統(tǒng)才能 正常 工作。在選擇液壓油時(shí)，要合理考慮到液壓油的粘度。當(dāng)然需要考慮的重要參量還有很多，包括粘度指數(shù)、耐磨性和抗氧化性等。 附件 2：外文原文 Hydraulic Systems and Fluid Selection It wasn’t until the beginning of the industrial revolution when a British mechanic named Joseph Bramah applied the principle of Pascal’s law in the development of the first hydraulic press. In 1795, he patented his hydraulic press, known as the Bramah press. Bramah figured that if a small force on a small area would create a proportionally larger force on a larger area, the only limit to the force that a machine can exert is the area to which the pressure is applied. What is a Hydraulic System? Hydraulic systems can be found today in a wide variety of applications, from small assembly processes to integrated steel and paper mill applications. Hydraulics enable the operator to acplish significant work (lifting heavy loads, turning a shaft, drilling precision holes, etc.) with a minimum investment in mechanical linkage through the application of Pascal’s law, which states: “Pressure applied to a confined fluid at any point is transmitted undiminished throughout the fluid in all directions and acts upon every part of the confining vessel at right angles to its interior surfaces and equally upon equal areas (Figure 1).” Figure 1 By applying Pascal’s law and Brahma’s application of it, it is evident that an input force of 100 pounds on 10 square inches will develop a pressure of 10 pounds per square inch throughout the confined vessel. This pressure will support a 1000pound weight if the area of the weight is 100 square inches. The principle of Pascal’s law is realized in a hydraulic system by the hydraulic fluid that is used to transmit the energy from one point to another. Because hydraulic fluid is nearly inpressible, it is able to transmit power instantaneously. Hydraulic System Components The major ponents that make up a hydraulic system are the reservoir, pump, valve(s) and actuator(s) (motor, cylinder, etc.). Reservoir The purpose of the hydraulic reservoir is to hold a volume of fluid, transfer heat from the system, allow solid contaminants to settle and facilitate the release of air and moisture from the fluid. Pump The hydraulic pump transmits mechanical energy into hydraulic energy. This is done by the movement of fluid which is the transmission medium. There are several types of hydraulic pumps including gear, vane and piston. All of these pumps have different subtypes intended for specific applications such as a bentaxis piston pump or a variable displacement vane pump. All hydraulic pumps work on the same principle, which is to displace fluid volume against a resistant load or pressure. Valves Hydraulic valves are used in a system to start stop and direct fluid flow. Hydraulic valves are made up of poppet’s or spools and can be actuated by means of pneumatic, hydraulic, electrical, manual or mechanical means. Actuators Hydraulic actuators are the end result of Pascal’s law. This is where the hydraulic energy is converted back to mechanical energy. This can