The difference between hoisting metallurgical motors and ordinary motors
Compared with ordinary motors, lifting metallurgical motors have some special requirements. In the naming of the motor series, the heavy pinyin initial letter "Z" is used as the classification code, such as the more common YZ, YZR, and YZP are all motor series used for lifting conditions. This type of motor is suitable for various types of hoisting machinery and other similar equipment. It requires the motor to have high overload capacity and mechanical strength. It is suitable for short-time or intermittent cycle work. The motor must be able to withstand frequent starting, braking Moving, forward and reverse, and larger vibration and shock conditions.
 
In order to achieve the target performance requirements of this type of motor, the design and manufacture of the motor must be different from the motor under normal working conditions, including the following aspects:
 
1 Insulation class. Because of frequent start-stop and forward-reverse working conditions, the motor current has large fluctuations, especially the large current impact during each start-up process, resulting in a high temperature rise of the motor, so the motor winding is required to have a higher insulation level. That is, it can withstand the test of higher temperature. Therefore, the general lifting metallurgical motor is one or two insulation grades higher than ordinary motors. Class H insulation.
 
2 The matching relationship between the stator core and the frame. The stator core and frame of ordinary motors adopt interference fit. For relatively larger motors, one or two fixed jackscrews are added, but the stator and frame, rotor and shaft of lifting and metallurgical motors all use long keys. The circumferential position is fixed to meet the mechanical effects caused by frequent start-stop and forward and reverse operation conditions.
 
3 Connection method of stator winding. The lifting metallurgical motors all adopt the star connection method. We have described the reasons for using this connection method in a special article, so I won’t repeat them here; while ordinary motors have no strict requirements. The connection method of the stator is clearly stipulated in the technical conditions of the YZR series motor.
 
4 Cooling fans. The cooling fans of ordinary motors mostly use non-metallic fans. For lifting and metallurgical motors where the operating environment temperature is relatively high, if the insulation level of its windings reaches Class H, it must be matched to withstand high temperatures without failure. Deformed metal fan.
 
5 shaft extension. Most of the lifting metallurgical motors use conical shaft extensions, while ordinary motors mostly use cylindrical shaft extensions.