Reciprocating compressors（往复式压缩机）
A great majority of reciprocating compressors which compress the refrigerant gas only on the forwards troke of a piston are built to be single acting in a large capacity range,up to hundreds of kilowatts.（大部份往复式压缩机,仅仅依靠活塞向前运动压缩制冷剂气体,它在往被用于大容量用途,高达数百千瓦｡）Models of these compressors may be single-cylinder or multicylinder in V,W,radial,or line form.（这些压缩机,可以是单气缸或在V､W､径向分布､交叉分布的多气缸｡）The power required for the compressor can be provided either directly by a motor or indirectly by a belt or a gear drive.（压缩机所需要的动力可以是直接由电动机驱动或间接由皮带､齿轮传动｡）In these compressors, cylinder clearance volume,compression ratio, amount of suction superheat, valve pressure drops, and the refrigerant-oil characteristics are the main parameters which affect their efficiencies.（在这些压缩机中,汽缸净容积､压缩比､吸气过热度､阀压降以及制冷剂-润滑油的特点是影响其效率的主要参数｡） The selection of cooling method is dependent on the discharge temperature.（冷却方式的选择依赖于排气温度｡）For example, when the discharge temperature is low, as in R-134a compressors, air cooling is usually chosen.Water cooling is used where high discharge temperatures occur.（举例来说,在 R134a 的压缩机中,当排气温度低,通常选择空气冷却的方式,水冷却是被用在排气温度过高的场合｡）
Note that Danfoss Maneurop hermetic reciprocating compressors are specially designed for applications with a wide range of operating conditions.（Danfoss Maneurop注意到全封闭往复式压缩机是专为较宽工况范围而设计的｡）The concept has proven its reliability and durability in low, medium and high temperature applications.（这种说法已经在低､中和高的温度环境下证明了它的可靠性和耐用性｡）Suction gas enters the compressor and cools the electrical motor.（制冷剂气体进入压缩机并且冷却电机｡）The circular valve design and profiled piston provide for an efficient compression process.（循环阀的设计及异型活塞提供了一个有效的压缩过程｡）Discharge gas passes through an internal muffler to eliminate gas pulsation which reduces sound level and vibration.（排出气体通过一个内部消声器,以消除气体脉动从而降低声级和振动｡）The internal discharge line runs through the oil sump taking care of an oil temperature high enough to evaporate eventual liquid refrigerant entering the compressor.（内部排气管贯穿了整个油箱,以便油温高到足以蒸发可能进入压缩机的液态制冷剂｡）
Rotary compressors（旋转式压缩机）
In reality,rotary compressors are of four general design configurations: (i) rolling piston, (ii)rotating vane, (iii) screw, and (iv) scroll.（在现实中旋转式压缩机有4种设计结构:(一)滚动活塞,(二)旋转叶片,(三)螺杆,以及(四)滚动｡）Therefore, rotary compressors have a rotary or circular motion instead of a reciprocating motion.（因此旋转式压缩机有旋转或圆周运动,而不是往复运动｡）They operate on rotors which rotate on an eccentric shaft.（他们是依靠一个有偏心轴的转子旋转｡）Gas enters through a space between the rotor and the cylinder through a suction port.（气体通过吸气阀进入转子及气缸之间的一个空腔｡）The gas is compressed as the rotor revolves due to the eccentrical assembly of the rotor and the cylinder.（由于转子和气缸偏心安装,使气体在转子转动时被压缩｡）A discharge port on the opposite releases the compressed air.（被压缩的气体通过对面的排气阀排出｡）The two more commonly used rotary compressors include the rolling piston-type and the rotating-vane-type.（两中较常用的旋转式压缩机包括滚动活塞式和旋转叶片式｡）Both are very similar in size, performance and applications.（两者在尺寸､性能和应用方面都非常相似｡）Rotary compressors are popular in domestic refrigeration and suited for applications where large volumes of vapor are circulated and where alow compression ratioisdesired.（旋转式压缩机在国内制冷领域非常受欢迎,适用于大量的气体循环和低压缩比的场合｡）In fact,these work as positive is placement pumps.（事实上,这些运动属于容积泵｡）
In a rotary compressor the rotor turns in a cavity.（旋转式压缩机的转子在一个空腔内运转｡）The refrigerant gas enters through a port,is compressed by the movement of the rotor after the rotor seals the port, and is moved to the discharge port.（制冷剂气体通过进气口进入,在转子密封住吸气口后气体被压缩,然后运动到排气口｡）This is known as the basic rotary principle and applies to both vane and screw compressors.（这就是所谓的旋转式原理,它被应用到叶片式和螺杆式压缩机中｡）
