The air inlet and outlet of the motor ventilation duct shall be set in a safe place without explosion hazard. If the exhaust outlet is located in an explosion hazardous area, the exhaust outlet shall be equipped with a device for blowing fire flowers, electric arcs and inflammables out of the shell. If there is a risk of sparks from the clearance between rotating shafts and the joints of pipes, sparks can be artificially created, such as igniting some combustible substances, and then ventilation normally to observe whether the sparks can be blown out from the gaps.
The motor shell is filled with hydrogen (nitrogen or carbon dioxide) with a concentration of 60% ± 1%. Conduct ventilation and purging with the air volume of 5 times of the total volume of the motor shell and auxiliary pipes or according to the air volume and time specified in the product operation manual, and then use the gas analyzer to measure at 3-5 of the estimated ventilation dead angle. The above gas concentration ≤ 1% is qualified.
One of the advantages of steel castings is the flexibility of design. Designers have great freedom to choose the shape and size of castings, especially for parts with complex shape and hollow section. Steel castings can be manufactured by the unique process of core assembly. Its forming and shape change are very easy, and the transformation from drawing to finished product is very fast, which is conducive to rapid quotation response and shortening of delivery time. The perfect design of shape and quality, small stress concentration factor and strong overall structure all reflect the flexibility and process advantages of steel casting design.
Casting technology of Dalian motor shell. Cast steel has high melting point, poor fluidity and easy oxidation and gas absorption of molten steel. At the same time, its volume shrinkage is 2 ~ 3 times that of gray cast iron. Therefore, the casting performance of cast steel is poor, and it is easy to produce defects such as insufficient pouring, porosity, shrinkage, hot cracking, sand sticking, deformation and so on. In order to prevent the above defects, corresponding measures must be taken in the process.
Motor efficiency is an important index to evaluate motor performance. The motor efficiency directly affects the economic interests of users. Today, energy conservation and emission reduction are strongly advocated throughout the country, which shows its importance. Excessive input power is an important reason for low efficiency. If it is operated for a long time, it will accelerate the aging of winding insulation, damage the motor, reduce the service life of the motor and cause accidents. Too small output power is also an important reason for the low efficiency of the motor. The important reason for this phenomenon is that the motor randomly raises the product performance parameters and the machining accuracy is not enough to cause excessive loss.
