Function and coating requirements of Sima motor shell coatingSima motor technical data: motor shell technology has a history of 100 years. It can be seen from the development of this process that the billet coating plays an increasingly important role. In recent years, many scholars have pointed out that the stability of motor shell coating is one of the three major researches in the further development and application of motor shell technology, and emphasized the process control function of coating.
It is necessary to study and control the coating of motor shell and its performance test. At present, in the coating (coating) industry, the coating performance test method has formed a complete system, and has been upgraded from the Department standard to the Department standard. After decades of in-depth research, the coating performance test standard of common sand mold coating for casting has also been established. This paper summarizes the current situation of coating performance test of motor shell, and points out the development direction in the future.
1. Function of motor shell coating
The function of the motor shell coating is to improve the rigidity of the pattern at room temperature, so as to prevent the pattern from being damaged in the process of handling and modeling. Second, when the high temperature molten metal is filled, a barrier is established between the molten metal and the molding sand to prevent the casting from adhering to the sand. Meanwhile, the cracking products (gaseous and liquid) of the foam pattern and liquid polystyrene foam (polystyrene foam) were eliminated in time. It can be seen that the function of motor shell coating is different from that of ordinary sand mold coating, which also determines the different performance requirements of the two.
2. Different from ordinary sand mold coating
1) The requirements of physical and chemical properties of coatings are different. Due to different requirements of air permeability, the aggregate of single-phase motor coating is relatively coarse, which requires that the rheological properties of motor coating should be different. Moreover, the density of the foam pattern is smaller than that of the sand core, so as to reduce the resistance during the dip coating.
The density requirements of the coating are different, and the physical and chemical properties of the two coatings are compared.
2) Coating process performance requirements are different. In the casting process, the working surface of the ordinary sand mold coating is the exposed outer surface of the coating, while the working face of the motor shell coating is a non exposed inner surface which is contacted with the foam pattern. Therefore, the requirements for the convective levelness and permeability of the motor shell coating are low, but the wettability of the coating and the expanded polystyrene and the coating ability of the interstices between the foam beads are higher.
3) Due to the different casting forming principle, the working performance of motor shell coating is different from that of ordinary sand mold coating. In terms of air permeability requirements, sand coating requires high air permeability at room temperature, while the air permeability at room temperature has no effect on the motor shell process. The requirement of high temperature air permeability is just the opposite. The lower the sand mold coating requirements, the better, and the higher the motor shell coating requirements.
As far as the coating strength is concerned, the coating of Sima motor shell has very high requirements for enhancing the binding strength of pattern rigidity, the surface strength to resist the impact of sand filling and the adhesion strength between the coating and the pattern, because the three strength characteristics of the coating play an important role in the motor shell process than sand casting. Quantitative comparison of the strength and permeability of the two coatings. Although the data provided by various documents are inconsistent or even quite different due to different test systems, data processing methods and sizes, the differences between sand mold coating and EPC coating are still clear. In addition, there are some unique casting defects in the motor shell process, such as surface carbon, wrinkled skin, collapsed box, carbon deposition, etc. This requires that the coating of the motor shell should also have some special working properties, such as the adsorption capacity of liquid foam and liquid cracking products, the matching between the permeability of the coating and the coating strength (sand sticking resistance).
With the improvement of people's quality of life, they are more and more demanding on food, clothing, housing and other aspects. As the driver of machinery manufacturing industry, the motor requires pickiness, durability and energy saving. Therefore, more and more customized motor products, the demand for modern motor is also growing.
The motor housing plays two main roles in the motor:
1. The role of technology. The role of technology is of great significance. First of all, because the motor has different purposes and different requirements for different scenes, the requirements for the material and structure of the motor shell must be different. There must be a lot of friends here asking why. The reason is very simple, the use space of motor in different scenes is limited, and the performance requirements of motor are also high and low. Therefore, the reasonable design of the motor shell can bring infinite functions to the motor. Only when the design of the motor shell reasonably meets the requirements of the use scenario can the performance of the motor be brought into play. The motor housing can also effectively prevent the motor from grounding components.
2. Function of appearance. The reason is very simple. When we buy a motor, it is very important to see its appearance, both in appearance and appearance.
The motor end covers at both ends of the motor housing are mainly made of cast iron. The end cover is mainly used for fixing and supporting to ensure the stable operation of the motor at high speed. When machining the dimensional tolerance of the bearing chamber of the motor end cover parts, the dimensional tolerance required by the drawings and the surface roughness of the machined surface shall be ensured. In addition to preventing the size from being affected by too rough surface, it also ensures that the bearing will not be damaged due to insufficient surface finish during assembly.
When the motor shell is used for decoration or some special occasions, its surface needs to be anodized, painted and other treatment to obtain the corresponding color and surface texture. The casting of motor shell is widely used, and its production difficulty depends on its structure