Detailed interpretation of the industrial control industry three common actuators

中英合資天蝶閥門帶大家來認識一下，工控行業中，三款常用的執行器。并詳細解讀他們之間有何不同。今后我們在工業控制系統中，該如何選擇執行器，便會一目了然。

In the industrial control industry, the three most commonly used actuator.And explain in detail how they differ.
In the future, it will be clear how to select the actuator in the industrial control system.

執行器是接受調節器輸出信號對調節對象施加作用的裝置。通常用在驅動閥門等機械設備中。根據執行器使用的控制介質不同，可以分為：氣動、液動和電動執行器三種。按輸出位移的形式，執行器有轉角型和直線型兩種。按動作規律，執行器可分為開關型、積分型和比例型三類。按輸入控制型號，執行器分為可以輸入空氣壓力信號、直流電流信號、電接點通斷信號、脈沖信號等幾類。
The actuator is the device that accepts the output signal of the regulator to adjust the object.It is usually used in driving valves and other mechanical equipment.According to the different control medium used by actuators, it can be divided into three kinds: pneumatic, electric and hydraulic actuators.According to the form of output displacement, there are two types of actuators: rotary and linear.According to the law of motion, actuators can be divided into switch type, integral type and proportional type.According to the input control model, the actuator is divided into input air pressure signal, DC current signal, electrical contact on-off signal, pulse signal and other types.

三種執行器的優缺點
The advantages and disadvantages of the three actuators

1.液動執行器
1.Hydraulic actuator

液動執行器是以液壓油為動力源來完成預定運動要求和實現各種機構功能的機構。
Hydraulic actuator is a mechanism that uses hydraulic oil as a power source to fulfill predetermined motion requirements and realize various functions of institutions.

優點：
The advantages:
（1）在輸出同等功率的條件下，機構結構緊湊，體積小、重量輕、慣性小。
 (1) under the condition of equal output power, the mechanism has compact structure, small volume, light weight and small inertia.
（2）工作平穩，沖擊、振動和噪音都較小，易于實現頻繁的啟動、換向，能夠完成旋轉運動和各種往復運動。
(2) The work is stable, the impact, vibration and noise are small, and it is easy to realize frequent start-up and reversal, and it can complete rotary motion and various reciprocating motions.
（3）操縱簡單、調速方便，并能在大的范圍內實現無級調速，調速比可達5000。
(3) The operation is simple, the speed is convenient, and stepless speed regulation can be realized in a large range, and the speed ratio can reach 5000.
（4）可實現低速大力矩傳動，無需減速裝置。
(4) It can realize low-speed and high-moment transmission without deceleration device.
缺點：
The disadvantages:
（1）油液的粘性受溫度變化的影響大，不宜用于低溫和高溫環境中。
 (1) The viscosity of oil is greatly affected by temperature changes and should not be used in low temperature and high temperature environments.
（2）液壓組件的加工和配合要求精度高，加工工藝困難，成本高。
(2) The hydraulic components require high precision in processing and fitting, and the processing technology is difficult and the cost is high.

2.氣動執行器
2.Pneumatic actuator

優點：
The advantages:
(1)以空氣為工作介質，工作介質獲得比較容易，用后的空氣排到大氣中，處理方便，與液壓傳動相比不必設置回收的油箱和管道。
(1)Using air as the working medium, the working medium is relatively easy to obtain, the used air is discharged into the atmosphere, and the handling is convenient. Compared with the hydraulic transmission, it is not necessary to set the recovered oil tank and pipeline.
(2)因空氣的粘度很小（約為液壓油動力粘度的萬分之一），其損失也很小，所以便于集中供氣、遠距離輸送。外泄漏不會像液壓傳動那樣嚴重污染環境。
(2)Because the viscosity of the air is very small (about 1/10000 of the dynamic viscosity of the hydraulic oil), its loss is also very small, so it is convenient for centralized gas supply and long-distance transportation. Leakage will not seriously pollute the environment like hydraulic transmission.
(3)與液壓傳動相比，氣壓傳動動作迅速、反應快、維護簡單、工作介質清潔，不存在介質變質等問題。
(3)Compared with the hydraulic transmission, the pneumatic transmission has the advantages of rapid action, quick response, simple maintenance, clean working media, and no deterioration of medium.
(4)工作環境適應性好，特別在易燃、易爆、多塵埃、強磁、輻射、振動等惡劣工作環境中，比液壓、電子、電氣控制*。
(4)The adaptability of the working environment is good, especially in the bad working environment, such as flammable, explosive, multi dust, strong magnetic, radiation, vibration and so on, which is superior to the control of hydraulic, electronic and electrical control.
(5)成本低，過載能自動保護。
(5)The cost is low and the overload can be automatically protected.
缺點：
The disadvantages:
(1)由于空氣具有可壓縮性，因此工作速度穩定性稍差。但采用氣液聯動裝置會得到較滿意的效果。
(1)Because of the compressibility of the air, the working speed is slightly worse. But the use of gas-liquid linkage will get satisfactory results.
(2)因工作壓力低（一般為0.31.0MPa），又因結構尺寸不宜過大，總輸出力不宜大于10～40kN。
(2)Due to low working pressure (generally 0.31.0MPa), and the size of the structure should not be too large, the total output power should not be greater than 10 ~ 40kN.
(3)噪聲較大，在高速排氣時要加消聲器。
(3)The noise is large, and mufflers should be added at high speed.
(4)氣動裝置中的氣信號傳遞速度在聲速以內比電子及光速慢，因此，氣動控制系統不宜用于元件級數過多的復雜回路。
(4)The gas signal transmission speed in the pneumatic device is slower than the speed of electrons and light within the speed of sound. Therefore, the pneumatic control system should not be used in the complex circuit with too much element series.

3.電動執行器
3.Electric actuator

優點：
The advantages:
(1)取用能源方便容易、傳輸信號速度快、信號傳輸距離遠、以便于集中操作控制。
(1)Energy consumption is easy and convenient, and the speed of signal transmission is fast, and the distance of signal transmission is far away, so as to facilitate centralized operation and control.
(2)度、靈敏度相對較高，與其他電動調節儀表配合方便易操作，接線安裝簡單。
(2)The accuracy and sensitivity are relatively high. It is convenient and easy to operate with other electric regulating instruments, and the wiring and installation are simple.
(3)使用效果證明，電動執行器抗偏離能力很好，所輸出的力矩或推力基本恒定，能做到很好的克服介質的不平衡力，確保達到相關工藝參數的控制，因此該產品控制精度相比氣動執行器要稍高一些。
(3)The use effect proves that the electric actuator has a good anti deviation ability and the output torque or thrust is basically constant. It can overcome the imbalance force of the medium well and ensure the precise control of the related process parameters. Therefore, the control precision of the product is slightly higher than the pneumatic actuator.
(4)若配備伺服放大器，能夠輕易實現正、反作用的互換，亦可輕松設定信號閥位狀態，如在出現故障時，一定是停留在原位，這種能力是氣動執行器產品所無法達到的，因為氣動執行器須借助于配備組合保護系統來實現保位功能。
(4)If equipped with a servo amplifier, it can easily achieve positive and reverse interchangeability, and it can also easily set the state of signal valve position, If a fault occurs,, it must stay in situ, this ability is not achieved by the pneumatic actuator products, because the pneumatic actuator is required to be equipped with a combination protection system to protect the position. Function.
缺點：
The disadvantages:
(1)僅適用于防爆要求不高，氣源缺乏的場所。結構相對復雜，推力小，平均故障率比氣動執行機構較高，而由于結構復雜性的問題，對于現場維護人員的技術要求也相對較高。
(1)It is only applicable to places where explosion-proof is not high and gas sources are scarce.the structure is relatively complex, the thrust is small, the average fault rate is higher than the pneumatic actuator, and the technical requirements of the field maintenance personnel are relatively high due to the complexity of the structure.
(2)電機運行會產生熱量，調節頻率大的話，易造成電機過熱，也增加了減速齒輪的磨損。
(2)The motor will generate heat when running. If the adjustment frequency is large, it will cause overheating of the motor and increase the wear of the reduction gear.
(3)還有運行較慢，從調節器輸出信號開始，到調節閥響應而運動至位置，往往耗時較多，以上是較之氣動或液動執行器所表現不足的地方。
(3)The operation is slow, from the output signal of the regulator to the response of the regulator to the specified position, which is often more time-consuming, and the above is a place where the pneumatic or hydraulic actuator is insufficient.

三種執行器的對比

Comparison of executive agencies

①氣動執行器
①pneumatic actuator
執行器和調節機構是統一的整體，執行器有薄膜式和活塞式兩類。活塞式行程長，適用于要求有較大推力的場合；而薄膜式行程較小，只能直接帶動閥桿。由于氣動執行器有結構簡單，輸出推力大，動作平穩可靠，并且安全防爆等優點，在化工，煉油等對安全要求較高的生產過程中有廣泛的應用。
 Actuators and regulators are a unified entity. Actuators have two types: diaphragm and piston.The piston stroke is long and is suitable for applications where there is a need for high thrust; while the film-type stroke is small and can only directly actuate the valve stem.Because the pneumatic actuator has the advantages of simple structure, large output thrust, stable and reliable operation, safety and explosion proof, etc., it is widely used in the chemical industry, oil refining and other high-security production processes.
②液動執行器
②Hydraulic actuator
推力大，現在一般都是機電一體化的，但比較笨重，所以現在很少使用，比如三峽的船閥用的就是液動執行器。
Thrust is the largest, but now it is generally electromechanical integration, but it is cumbersome, so it is rarely used now, for example, the Three Gorges ship valve uses hydraulic actuator.
③電動執行器
③Electric actuator
安全防爆性能差，電機動作不夠迅速，且在行程受阻或閥桿被扎住時電機容易受損。盡管近年來電動執行器在不斷改進并有擴大應用的趨勢，但從總體上看不及氣動執行器應用得普遍。
The safety and explosion-proof performance is poor, the motor is not fast enough, and the motor is easily damaged when the stroke is blocked or the stem is tied.Although electric actuators have been continuously improved in recent years and there is a tendency to expand applications,they are generally not as widely applied as pneumatic actuators.

執行器的選擇
Choice of executive agencies

主要考慮因素
Main considerations

①可靠性；

① reliability;
②經濟性；

② economy;

③動作平穩、足夠的輸出力；

③ a stable and sufficient output force;

④重量外觀；

④ the appearance and weight;

⑤結構簡單、維護方便。

⑤The simple structure and the convenient maintenance  

電動執行器與氣動執行器的選擇比較
Selection and comparison of electric actuator and pneumatic actuator
 (1)氣動執行器簡單可靠
 (1)The pneumatic actuator is simple and reliable
老式電動執行器可靠性差是它過去的一貫弱點，然而在90年代電子式執行器的發展*解決了這一問題，可以在5~10年內免維修，它的可靠性甚至超過了氣動執行器。正由于此，筆者認為，它將成為下世紀調節閥的主流。
The poor reliability of the old electric actuator is the weakness in the past. However, in 90s, the development of the electronic actuator completely solved the problem, and it could be avoided in 5~10 years, and its reliability was even more than the pneumatic actuator. Because of this, I believe that it will become the mainstream of regulatory valve in the next century.
 (2)驅動源
 (2)Drive source
氣動執行器的大不足就是需別設置氣源站，增加了費用；電動閥的驅動源隨地可取。
The biggest deficiency of pneumatic actuators is is to set up gas source station and increase the cost; the driving source of electric valves is desirable everywhere.
(3)價格方面
(3)Price
氣動執行器必須附加閥門定位器，再加上氣源，其費用與電動閥不相上下（進口電氣閥門定位器與進口電子式執行器價格相當；國產定位器與國產電動執行器不相上下）。
Pneumatic actuators must be equipped with a valve positioner and plus gas source, the cost of which is comparable with that of the electric valve (imported electric valve positioner is equivalent to imported electronic actuator; domestic positioner is comparable to domestic electric actuator) .
 (4)推力和剛度兩者相當。
 (4)Both thrust and stiffness are comparable.
 (5) 防火防爆
 (5)Fire and explosion protection
氣動執行器+電氣閥門定位器”略好于電動執行器。
“Actuator + Electric Valve Positioner" is slightly better than the electric actuator.

推薦意見
Suggestions
 (1) 在可能的情況下，建議選用進口電子式執行器配國產閥（如全功能超輕型閥）以用于國產化場合、新建項目等。
 (1) in the case of possible, it is suggested that imported electronic actuators should be selected with domestic valves (such as full function ultra light valves) for domestic applications and new projects.
(2)薄膜執行器雖存在推力不夠、剛度小、尺寸大的缺陷，但其結構簡單，所以，目前仍是使用多的執行器。但這里我們強調的是應該選用ZHA、ZHB型的精小型薄膜執行器去代替ZMA、ZMB型的老式薄膜執行器，以獲得更輕的重量、更小的尺寸和大的輸出力。
(2)Thin film actuator has the defects of insufficient thrust, small stiffness and large size, but its structure is simple, so it is still the most used actuator at present.But we emphasize that it is best to use ZNA, ZHB fine small-film actuators instead of ZMA, ZMB type of old film actuators to get lighter weight, smaller size and large output force.
 (3)活塞執行器選擇注意方面：
 (3)Piston actuator selection Note:
①氣動薄膜執行器推力不夠時，選用活塞執行器來提高輸出力；對大壓差的調節閥（如中壓蒸汽切斷），當DN≥200時，甚至要選雙層活塞執行器；
 ① When the thrust of the pneumatic diaphragm actuator is not enough, the piston actuator is used to increase the output force; for large pressure differential regulators (such as medium pressure steam cutoff), when the DN ≥ 200, even the double piston actuator must be selected;
②對普通調節閥，還可選用活塞執行器去代替薄膜執行器，使執行器的尺寸大大減小，就此觀點而言，氣動活塞調節閥使用會更多；
②For ordinary regulating valves, the piston actuator can be used to replace the film actuators, so that the size of the actuator is greatly reduced. In this view, the pneumatic piston regulating valve will be used more.
③對角行程類調節閥，其角行程執行器，典型的結構是雙活塞齒輪齒條轉動式。
③ For diagonal-type control valves, the angular-stroke actuator is typically a dual-piston rack-and-pinion type.