First, the foreword Impeller is the core part of the industrial pump, the different conditions of the configuration of the impeller type are very different. Full open impeller because it has no cover, the leaves in an open state, directly facing the static wear plate (fixed to the pump body and pump cover), when the transport containing fiber, high viscosity, crystallization, particles of the media will be Because the gap between impeller and wear plate end face is small, the relative speed of movement to the scraper-type effect, so that these easily wear-resistant plate, the impeller stay in the media, was forced to scrape away and take away, so open Many wheel applications, full-open impeller centrifugal pump structure shown in Figure 1. Figure 1 full-open impeller centrifugal pump structure 1. Pump 2. Wear front 3. Open impeller 4. After the wear plate 5. Pump cover Second, the open impeller machining clamping program Dalian dark blue pump limited The company's EAPK series pumps (design pressure 5.0MPa, center support) and ESHK series pump (design pressure 2.5MPa, foot support) of the impeller for the open structure, no front cover and the mouth ring, the pump body, pump cover A wear-resistant plate, suitable for containing particles of the working conditions, a wide range of applications, is one of the company's flagship product. Figure 1 for my company's ESHK series structure. One of the impeller (shown in Figure 2) as one of the core components, the machining accuracy of the performance of the pump has a key role. If the machining accuracy is poor, the gap between the blade and the wear plate will be uneven, and some parts of the gap is large, and some parts of the gap is small, will lead to head drop, reduce efficiency, so the impeller using the appropriate processing methods to ensure the processing accuracy is Very crucial. In the process of processing, because the import of non-processing umbilical child, and car workers need to find the process of clamping ring and blade welding, and then grinding away. Master craftsmen think this is a waste of time, welding power consumption, special materials to be dissimilar steel welding rod, the price is high, so put forward rationalization proposals, it is recommended to make a slight modification of the model, an increase in the import process umbilicus, easy lathe processing. Accordingly, the technology center sat down with the machining shop and foundry depot for analysis and research, and finally confirmed the plan of machining and opening the open impeller. Figure 2 full-open impeller 1. Option one (on the impeller blade welding a process clip ring) (1) the pattern may not be filled by the machine itself to solve, as shown in Figure 3. (2) the model does not move. (3) clamping chuck processing imported car ring, need to CW6163 lathe on the four-jaw chuck to find the outer diameter of the rear hub and the back of the impeller blade at the back of the blade, turn the rear hub to the size of the ministries; remove the impeller , With the angle grinder knocked the mouth ring; U-turn rear clamping hub, turning in front of the processing and the hole to ensure that the drawings of the dimensional tolerances and geometric tolerances. (4) Advantages Do not change the pattern, fixed model; turner their own way to find a suitable waste mouth ring spot welding to the blade can; clamping diameter, clamping stability, can ensure that the intermittent turning will not affect the processing quality. (5) the shortcomings of the turner to find their own waste ring, the inexperienced turner is a hassle; after use to be polished away, a little time; for mass production is in trouble; need ordinary or special electrode and additional power; high corrosion resistance Alloy impeller welding will destroy the microstructure. (6) clamping scheme to determine the state before this method has been in use. Figure 3 spot welding on the impeller blade a clamp ring 2. Option two (at the impeller inlet boss casting process boss) (1) the pattern required to add the casting process drawings as shown in Figure 4 casting process boss. Process boss diameter = (φd-5), φd for the impeller inlet hub diameter. Process boss extended out of the blade length L = 20 ~ 40mm, depending on the size of the impeller. (2) model to be modified. (3) the first clamp after the rear wheel hub turning the imported technology boss, the cylindrical wheel, as a clamping reference; U-turn clamping process boss imported, turning behind; and finally turn off turning process boss and processing In the hole, to ensure that the size of the drawings and the shape of tolerances. (4) Benefits Provides a permanent mounting solution. (5) Disadvantages A slight increase in the weight of the blank to increase the material costs; increase processing time, because more than a length of the process boss; the large impeller diameter fashion clip process boss may lead to chatter. (6) the clamping scheme to determine the state before the open impeller was basically no such process boss. Figure 4 casting boss at the impeller inlet boss 3. Scenario III (in the impeller round casting process ring) (1) drawings in the casting process drawings to add, as shown in Figure 5. (2) model to be modified. (3) vehicle processing and program two similar. (4) Benefits Provides a permanent clamping solution; large clamping diameter, stable clamping, you can ensure that the intermittent turning will not affect the processing quality. (5) shortcomings more significantly increase the weight of the blank, increase material costs; increase processing time. (6) clamping scheme to determine the state before the casting ring has not been applied at this time. Figure 5 in the impeller round cylindrical casting process Third, the conclusion Dalian dark blue pump technology center and the final conclusion of the relevant departments to form a unified opinion, to take the principle of discrimination: 1) open impeller nominal diameter ≤ 250 impeller with imported wheels plus casting Process boss (program one). 2) Nominal diameter of open impeller> 250) Welding clamp ring type is generally adopted (Scheme 2). 3) Open impeller nominal diameter> 250) Under special circumstances, such as welding performance is poor, the welding caused the blade to rupture, the corrosion resistance of the high corrosion resistant alloy caused by the welding is reduced, an integral process ring can be cast on the outer circumference of the impeller ). One of the first program and the second program is the most widely used. Practice has proved that open impeller machining fixture program to determine the problem has been plagued machining lathe problem, played a very good effect.