Electric devices: basic performance ZD series has the following deficiencies

This phase roughly between 1964 to 1980, is still in its early understanding of the electrical device, cognition, the demand for domestic electric valve spawned a series of electric devices of the first products that ZD Series multi-turn electric actuators . It is under the planned economic environment industry department, research and collaboration crystal manufacturing units, reflecting a set of resources for all sectors of society era characterized by self-developed products, so there is more ZD series of electric devices historical significance. 

ZD series output torque range 220N · m ~ 2400N · m, stroke control of movement leads from the output shaft of the Ministry of deceleration torque control mechanism acting on the slope spiral spring clutch structure, hand / electric switch structure is completely manual and electric type mechanical transmission control operation of the manual operation is not separated, using the method of connecting the valve output shaft Portland jaw structure, the use of an ordinary motor power input. 

Due to the time limitations of information sources and related conditions, with the current standard analysis, the presence of the basic properties of ZD series certain deficiencies, in particular to the following points: 

● Motion stroke control mechanism from the low speed shaft (output shaft) came on deceleration, resulting in lower electric control valve stroke accuracy and precise adjustment difficulties. Since the operation of the clutch under action of the coil spring contact with two inclined surfaces is not so unstable movement distance and speed, motor torque control device causes low accuracy. These two points was also the main reason for the poor reliability of electric valve control. 

● Use an ordinary motor-powered, small starting torque and running torque motor is too large. This situation not only the torque characteristics and the load characteristics of the electric valve means of a difference, but also a tremendous impact on the time when the valve jamming and thus affect the safety of the electric valve. 

● hand / electric switching mechanism using completely manual type, and non-electrical interlocking mechanical structure, namely electric control panel and manually operated mechanical transmission without electrical separation between the state and the state of the manual. If you switch (built-in micro-switch) fails, and the manual mode and the power is turned on by mistake will lead to high-speed rotary hand wheel, then the operator constitutes a safety hazard with the electrical components. 

● electrical products control box cover flat paper gasket, poor outdoor performance, no proof type and other special features. 

● electrical control type is simple, basically no additional control functions. 

● The design concept has not yet recognized the short-term electric load characteristics of the device, its design and calculation basis for the common mechanical transmission method, and thus a larger machine size, shape slightly clumsy (especially the small and medium torque specifications). 
With the increase in the amount of electric valve applications in the late stages of the manufacturers and have developed several multi-turn electric actuator products. Some of these products form a series, some only a single base, but has a good application performance, technically also reflects the depth understanding of electric devices. 

These products are technically solve the following problems: 

● In order to improve the precision and adjustment of the stroke control accuracy, the stroke movement of the electric control device designed to try to take over drive leads and electrically controlled actuators in a batch-off counter gear mechanism. At this point precision stroke control electric devices have been able to meet the wedge gate valve, globe valve, ball valve for precise control. 

● The disc spring and ring rack gear torque signal lead agency, the torque significantly improved product performance, has been able to ensure the wedge gate valve, globe valve, valve seat torque torque control and protection. 

● hand / electric switching mechanism, mostly semi-automatic electric priority structure, safe and reliable, and have attention to resolving the low speed shaft (output shaft) to get started / electric switching force the issue. 

● products have been used for motor valves, valves meet its load torque characteristic features of the structure of the wire leads flange face began to apply. 1977 implemented a special ministerial standard valve motor, that motor YDF early technical conditions, the standard for the development of electric devices provide the necessary conditions. 

● The main cabinet, electrical housing parts have been sealed with a circular spigot, outdoor product performance improved significantly, up to IP65. 

● successful development of outdoor, anti-corrosion, anti-fog products. 

● has successfully developed a flameproof electrical equipment, explosion-proof rating for the then standard B2d. 

● Additional features electrical control products gradually increased, reference ROTORKA series products have been developed with the overall type control. 

● planetary bodies of two small reducer rotation torque specifications section Q series products have been put into use. Has developed a stand-alone part of the rotary electric device, but very little practical use. 

Products and applications by increasing the initial stages of independent research and extensive amount of electric valves, electric equipment products of technology has been rapid development. The late stage, it has been recognized not only replace human power device open and close the valve tool, it is primarily the execution unit pipeline system automation and control, reliability and control technology performance of their work is an important basis for assessing product quality. 
Because it is from scratch, so the initial stages of the development process of China's electric system is more difficult. At that time an electric device products from research and development to production to go through a lot of links, including initial design, prototype process planning, parts selection of design, prototype trial, the type test prototype, design finalization, prototype identification, process equipment design, tooling manufacturing, small batch verification, industrial test products, product identification, production and so on. Thus, the previously mentioned these products fully reflects the dedication of pioneers, especially scientists and trial frontline staff, who work year laid a good foundation for the development of electric devices. 

■ to introduce technology as the representative of the rapid development stage 

This phase roughly between 1981 and 2000. Social environment of reform and opening to understand the foreign advanced technology and integrated electric device status provides favorable conditions for industry manufacturers have send personnel abroad study, combined with the introduction of the national situation analysis of object technology screening. During this time, our electric device products and technologies have been able to rapidly develop and was closely related to the successful introduction of foreign advanced technology. The most typical introduction of the project are: the introduction of the early 1980s, the United States LIMITORQUE technology, has introduced the 1990s in Germany and the UK ROTORKA series SIEMENS technology techniques. These digestive absorption of imported technology has shortened the distance of the electric device technology with the international advanced level, as well as product design selection theory has also been improved, technical infrastructure work outstanding achievements. 

In addition, between 1990 to 2000, rapid economic development driving the demand for electric valves, and a market economy has prompted a corresponding increase in the electric device manufacturers, more professionals involved in the study of the product and its application technology. So, in addition to the introduction of technology leading products, this time also emerged in many economic products to enrich the varieties and specifications of electric devices, expanding the user's choice. 

Technical characteristics of the phase leading products and important technical foundation work are: 

● Complete product specifications, base product binning reasonable. For multi-turn actuators, the output torque range 50N · m ~ 27000N · m, the output speed range between ~ 120r/min in 5r/min selected; For part-turn product, output torque range 50N · m ~ 200000N · m, the output speed can be selected between 0.25r/min ~ 2.0r/min, high torque motor means wherein the performance is significantly improved. 

● have a series of explosion-proof enclosure B3d and ExdIIBT4. Improved protection class outdoor products, is generally IP65 ~ IP67. Independent research and development of products for rapid development of nuclear power, it also has some special electric devices, such as high temperature and high type, cold type, fire type, marine type, diving type. 

● Performance stroke and torque control mechanism is more comprehensive and reliable, there has been contact made with silver inlay stroke and torque control mechanism. Stroke and torque control are already a number of passive contacts for users to choose, the overall control type (Integrated Control) applications and standards and receiving continuous electrical feedback control requirements increasing year by year. 

● Advanced mechanical transmission structures, such as the structure of the output shaft equipped stem nut, counter intermittent gear sealed transmission structure, non-friction ring rack drive torque signal leads institutions, which are to improve the reliability and applicability from important role. 

● advanced manufacturing and testing equipment and processing technology has been applied, such as the main cabinet machining centers, special gear and worm Machine 
Bed, special heat treatment equipment, precision steel complex parts, aluminum die-cast body parts, computer and sensor technology in applications such as test equipment products, which are to improve the quality of products play an important role. 

● 1981, on the basis of independent research and development stage to build on our first release and implementation of the ministerial standard two electric devices, namely JB2920-81 "valve actuators Types, basic parameters and dimensions" and JB2921-81 "valves electric device technology, "connection size JB2920-81 thermal power requirements currently still the main connection parameters of the product. Implementation of these standards to regulate the orderly development of China's electric devices play an important role. 

● With the introduction of technology, localization, technical parameters LIMITORQUE electric device has become the main reference index of valve electric device technology, and in 1987 enacted the updated ZBJ16002-1987 "valve electric device technology", as amended in 1997 JB/T8528-1997 "common type valve electric device technology", 2010 and will be revised and upgraded to GB that is currently used GB/T24923-2010 "common type valve electric device technology." The development and promulgation of the standards so that our electric device design, manufacturing, testing, inspection and other more standardized, its provisions technical indicators also reflects a higher level of electric device technology have.