【導讀】1795年，他申請并獲得了液壓機的相關專利，從此布拉瑪液壓機聲名鵲起。非常廣泛的應用。液壓幫助操作員完成許多重要工作(抬沉重的負荷、轉向軸、孔。毫無損失地傳遞至流體的各個部分和容器壁（圖1）。磅的力，那么整個容器內的每平方英寸上將產(chǎn)生100磅的力。在100平方英寸的面上產(chǎn)生1000磅的力。液壓系統(tǒng)是對帕斯卡定律的合理運用，它通過液壓油在兩點間傳遞能量。液壓系統(tǒng)的主要組成部分是液壓缸，液壓泵，閥和執(zhí)行機構。統(tǒng)中游離液體或氣體的釋放。液壓泵通過作為傳輸媒介的液壓油的運動，將機械能轉化為液壓能。以通過液壓缸轉換為直線運動，或用液壓馬達將其轉化為旋轉運動。接到驅動軸上后裝入定子，同時使其與軸保持偏心。用途廣泛且造型復雜，能應對各種類型系統(tǒng)的用途及要求。柱塞式液壓泵正常工作的運動粘度值為10到160cSt。內嚙合式齒輪液壓泵所能產(chǎn)生的壓力高達3000至3500帕斯卡。于水基液壓油的特點，需要隨時監(jiān)控以防出現(xiàn)問題。溫度升高將導致液壓油內的水

　　

【正文】 includes collecting all the design limitations and optimum operating characteristics from the manufacturer. What you are looking for is the optimum operating viscosity range for the pump in question. Minimum viscosity is 13 cSt, maximum viscosity is 54 cSt, and optimum viscosity is 23 cSt. 2. Check the actual operating temperature conditions of the pump during normal operation. This step is extremely important because it gives a reference point for paring different fluids during operation. Pump normally operates at 92186。C. 3. Collect the temperatureviscosity characteristics of the lubricant in use. The ISO viscosity rating system (cSt at 40186。C and 100186。C) is remended. Viscosity is 32 cSt at 40186。C and cSt at 100186。C. 4. Obtain an ASTM D341 standard viscositytemperature chart for liquid petroleum products. This chart is quite mon and can be found in most industrial lubricant product guides or from lubricant suppliers. 5. Using the viscosity characteristics of the lubricant found in Step 3, start at the temperature axis (xaxis) of the chart and scroll along until you find the 40 186。C line. At the 40186。C line, track upward until you find the line corresponding to the viscosity of your lubricant at 40186。C as published by your lubricant manufacturer. When you find the corresponding line, make a small mark at the intersection of the two lines (red lines, Figure 3). 6. Repeat Step 5 for the lubricant properties at 100186。C and mark the intersection point (dark blue line, Figure 3). 7. Connect the marks by drawing a line through them with a straight edge (yellow line, Figure 3). This line represents the lubricant’s viscosity at a range of temperatures. 8. Using the manufacturer’s data for the pump’s optimum operating viscosity, find the value on the vertical viscosity axis of the chart. Draw a horizontal line across the page until it hits the yellow viscosity vs. temperature line of the lubricant. Now draw a vertical line (green line, Figure 3) to the bottom of the chart from the yellow viscosity vs. temperature line where it is intersected by the horizontal optimum viscosity line. Where this line crosses, the temperature axis is the optimum operating temperature of the pump for this specific lubricant (69186。C). 9. Repeat Step 8 for maximum continuous and minimum continuous viscosities of the pump (brown lines, Figure 3). The area between the minimum and maximum temperatures is the minimum and maximum allowable operating temperature of the pump for the selected lubricant product. 10. Find the normal operating temperature of the pump on the chart using the heat gun scan done in Step 2. If the value is within the minimum and maximum temperatures as outlined on the chart, the fluid is suitable for use in the system. If it is not, you must change the fluid to a higher or lower viscosity grade accordingly. As shown in the chart, the normal operating conditions of the pump are out of the suitable range (brown area, Figure 3) for our particular lubricant and will have to be changed. Figure 3 Also, observe the following hydraulic fluid management practices. ? Implement a procedure for labeling all ining lubricants and tagging all reservoirs. This will minimize crosscontamination and assure that critical performance requirements are met. ? Use a FirstInFirstOut (FIFO) method in your lubricant storage facility. A properly executed FIFO system reduces confusion and storageinduced lubricant failure. Hydraulic systems are plicated fluidbased systems for transferring energy and converting that energy into useful work. Successful hydraulic operations require the careful selection of hydraulic fluids that meet the system demands. Viscosity selection is central to a correct fluid selection. There are other important parameters to consider as well, including viscosity index, wear resistance and oxidation resistance.