The YL series large and medium electric motors are designated according to GB/T4831, with the motor model consisting of a product code and a specification code arranged in sequence. The product code is represented by the motor series designation, with meanings as follows:
YL-----Squirrel-cage rotor horizontal three-phase asynchronous motor
YLS--Closed-type squirrel-cage rotor vertical three-phase asynchronous motor with water-air cooler
YLKK---Closed-type squirrel-cage rotor vertical three-phase asynchronous motor with air-air cooler
Structural description:
The new series of motors adopts the internationally popular box-type structure. Its square frame is welded from steel plates, offering advantages of high rigidity and light weight. By changing the covers or water-air coolers on both sides of the frame, different series of YL or YLSK motors can be formed.
The stator adopts either an external or internal press-fit structure. Its stator windings use Class F insulation materials and anti-corona materials, and the end windings are secured with special binding techniques for firm and reliable fixation. The entire stator is treated with vacuum pressure impregnation (VPI) using Class F solventless varnish, providing excellent and reliable insulation performance as well as moisture resistance and impact resistance.
The rotor adopts a single-cage or double-cage copper bar structure. Regardless of the rotor structure used, its design and manufacturing process ensure reliable motor operation.
The upper bearing structure of the motor includes a plain thrust bearing and a guide bearing, capable of withstanding axial thrust caused by the load and the radial force of the motor itself. The upper bearing is a sliding bearing, which can be further divided into traditional thrust bearings and self-leveling thrust bearings, with oil lubrication; the lower bearing structure is a rolling bearing with grease lubrication, equipped with a device for adding and draining oil without stopping the machine. The main terminal box has a sealed structure with an ingress protection rating of IP54. The cable entry holes of the terminal box face downward, and a separate grounding terminal is provided inside the box.
For YL (IP21 or IP23) motors with traditional structure, the frame is a circular welded structure. The motor can be installed on pump bases, concrete foundations, or within concrete foundation pits; Class F insulation is used. Its bearing structure includes a thrust bearing and upper and lower guide bearings. The motor thrust bearing is a sliding bearing, which can be further divided into traditional thrust bearings and self-leveling thrust bearings, with oil lubrication. The lower guide bearing structure is a sliding bearing with oil lubrication, while for some motors, the lower guide bearing is a rolling bearing with grease lubrication. The rotor structure is also a copper bar rotor, and the stator terminal box is of a protective cover type.
