【正文】 大連交通大學(xué)信息工程學(xué)院 畢業(yè)設(shè)計(jì) (論文 )外文翻譯 學(xué)生姓名 專業(yè)班級(jí) 機(jī)械 班 指導(dǎo)教師 職 稱 所在單位 機(jī)械工程學(xué)院 教學(xué)部主任 完成日期 20 年 6 月 16 日 大連交通大學(xué)信息工程 學(xué)院 2020 屆本科生畢業(yè)設(shè)計(jì)（論文）外文翻譯 1 Pneumatic Transmission Similar to hydraulic transmission, pneumatic transmission performs the function of energy transfer and control by the medium of flow. They have a great deal in mon in the aspects of working principle, ponents’ structure, system position and graphic symbol. The readers should notice their pneumatic system incorporates the following ponents and devices: (1)Air supply devices: They include pressure generation devices, air regeneration and storing devices, F. R. L. (air filter, pressure reducing valve and oil mist lubricator) bination, etc. It provides qualified pressed air for pneumatic systems. (2)Actuators: They convert the pressed air pressure into mechanical energy, such as air cylinders and air motors. (3)Control elements: They are used to control the pressure, flow rate and moving direction for the ponents, such as valves. (4)Pneumatic attachments: They incorporate the ponents which are used to cool, silence, purify, and lubricate pressed air and those to joint each ponent. Air Supply Devices Air supply devices are used to provide pressed air for pneumatic systems. An air supply device is an important part of a pneumatic system, which supplies qualified pressed air (with a certain lever of pressure, flow rate and purification) for the pneumatic system. Generally, for the delivery surpasses or equals 6 12m179。/min, a pressed air station is needed. But for the delivery less than 6 12m179。/ air pressor can be mounted besides the pneumatic equipment directly. An air supply device incorporates four parts: pressure generation devices, air regeneration and storing devices, air lines and F. R. L. bination. Normally the first two parts are located in pressed air station as a center to supply gas in industry or workshop. Air pressor: pressurize atmospheric air。 Cooler: cool pressed air。 condense water and hydrocarbon vapours。 Oil and water separator: remove gross solid and liquid particulates。 Receivers: air storage。 settling chamber for particulates。 cool air。 Air dryer: further reduce water and oil vapour content。 Air filter: further remove desiccant dust and fines. In a pneumatic system, the pressed air flowing out from receiver is for general use and that from another receiver is for special use (such us the control circuits posed by 大連交通大學(xué)信息工程 學(xué)院 2020 屆本科生畢業(yè)設(shè)計(jì)（論文）外文翻譯 2 pneumatic meters or fluidic elements). Pressure generation devices Compressor is one type of pressure generation devices, which converts mechanical energy into pressure energy. Compressors can be classified according to their working principles, structures or performance properties. (1) According to working principles: Displacement and dynamic。 (2) According to structures (3) According to output pressures: Low pressure ( ), medium pressure ( 10MPa), high pressure (10 100MPa), super high pressure (100MPa). (4)According to output flow rates(delivery): Mini (1m179。/min), small (1 10 m179。/min), medium (10 100 m179。/min), large (100 m179。/min). Purification and storing devices and equipments for pressed air Normally, purification equipments for pressed air involve: cooler, a moisture separator, a receiver and an air dryer. Cooler:cooler is usually set at the outlet port of the pressor and serves as a heat exchanger to cool pressed air after leaving the pressor. Cooling can reduce an air temperature of 120 150176。C to 40 50176。C. Coolers can be further classified based on their arrangement: coil tubular type, series tubular type, thermosyphon system and tube drive type. There are two types of cooling: water cooling and air cooling. Moisture separator: it is used to separate the impurities such as condensed water and oil stain from the pressed air to gain an initial purified pressed air. When pressed air enters the separator, its flow rate and velocity will change sharply and the impurities with a higher density initially purified. The configurations of separators incorporate: ring revolving type, strike and return type, centrifugal rotary type, waterbath type, etc. This is a strike and return type moisture separator. When the pressed air enters the separator, it strikes against the baffle and turns sharply before falling down. When air falls down, it again strikes the case bottom and then rises up. The water droplets and oil are then separated from the pressed air by the centrifugal force produced by the sharp turning action. Receiver: it is used to store a certain amount of pressed air, reduce its pressure fluctuation and provide gas continuously and stably. There are two types of receivers: horizontal and vertical. Vertical type receivers are more often adopted to save room. Nowadays, the arrangement with the bination of cooler, moisture separator and receiver has f