The Production Process of the YE-112M-2 4kW Induction Motor

As a commonly used power device in industrial production, the YE-112M-2 4kW motor's production process integrates precision machining, electromagnetic technology application, and strict quality control. Every step directly affects the motor's performance, efficiency, and service life. From raw material selection to finished product delivery, it undergoes dozens of standardized processes, adhering to stringent industrial motor production standards throughout.

The production process begins with the prefabrication of raw materials and core components. The motor base, as the basic load-bearing structure, is made of high-strength gray cast iron HT200, formed through sand casting. During casting, the molten iron temperature must be strictly controlled between 1380-1420℃ to ensure that the casting is free of defects such as porosity and sand holes. After forming, it undergoes aging treatment to eliminate internal stress, and then the end face, outer diameter, and bearing seat holes are precision machined on a CNC lathe to ensure that the verticality and coaxiality error of the base does not exceed 0.02mm. The rotor core is made of 0.35mm thick cold-rolled silicon steel sheets, which are stamped into uniformly distributed slots using a high-speed punch press. These slots are then stacked and fixed using argon arc welding to form a core body with an outer diameter of 112mm. The stacking factor of the silicon steel sheets must reach at least 0.95 to reduce eddy current losses.

The stator fabrication is a crucial step in ensuring the electromagnetic performance of the motor. First, insulating material (polyimide film) is evenly wrapped around copper enameled wire, with the wire diameter precisely controlled at 1.08mm to meet the 4kW power requirement. Then, an automatic winding machine winds the enameled wire into the stator core slots using a specific winding method (double-layer lap winding). The number of turns per phase winding is strictly controlled to 36 turns. During the winding process, the coils must be neatly arranged to avoid damage to the insulation layer. After the windings are completed, the stator undergoes impregnation. It is placed in a vacuum impregnation tank, filled with solvent-free epoxy resin, and immersed for 2 hours under a vacuum of 0.08 MPa, followed by curing at 150℃ for 4 hours to form a dense insulating layer, improving the motor's insulation performance and mechanical strength.

The rotor is also meticulously machined. The shaft is made of high-quality 45# carbon steel, forged and tempered, and then CNC-machined with journals, keyways, and other structures. The journal surface roughness must reach Ra0.8μm to ensure the precision of the fit with the bearings. The rotor core is then heat-fitted onto the shaft at a temperature controlled at 200-220℃, utilizing the principle of thermal expansion and contraction to achieve an interference fit, with a tolerance controlled within 0.03-0.05mm. Afterwards, the fan blades and balance weights are installed, and the rotor is calibrated using a dynamic balancing machine to ensure that the rotor imbalance does not exceed 2g・mm, reducing vibration and noise during motor operation.

The final assembly of the motor emphasizes precise coordination and standardized procedures. First, the bearings are press-fitted into the bearing housing holes at both ends of the motor frame, and high-temperature grease is applied. Then, the rotor assembly is smoothly installed into the stator, and the air gap between the stator and rotor is adjusted to ensure uniformity and a clearance controlled between 0.25-0.35mm. Next, end covers, bolts, and other components are installed, with bolt tightening torque meeting specified standards to prevent loosening during operation. After final assembly, a preliminary mechanical inspection is performed, including rotor rotation flexibility and the reliability of all component connections, ensuring no jamming, abnormal noise, or other issues.

Final testing and calibration are crucial for ensuring the motor leaves the factory. Electrical performance testing includes insulation resistance testing (requires insulation resistance ≥10MΩ), DC resistance testing (three-phase resistance imbalance ≤2%), no-load testing, and load testing. During the no-load test, the motor's no-load current, no-load loss, and speed are measured to ensure the speed reaches 2900 r/min (corresponding to a synchronous speed of 3000 r/min for a 2-pole motor). During the load test, the load is gradually applied, and parameters such as the motor's output power, power factor, and efficiency are measured to ensure that under a rated power of 4 kW, the motor efficiency is ≥88% and the power factor is ≥0.85. Simultaneously, a temperature rise test is conducted, running the motor under rated load for 2 hours and measuring the winding temperature to ensure it does not exceed 120℃ (F-class insulation standard). In addition, vibration, noise, and appearance quality inspections are performed. After all indicators pass, a qualified label is affixed, and the motor is stored for shipment.

The production process of the YE-112M-2 type 4 kW motor is an organic combination of machining, electromagnetic technology, and quality control. Strict control over each process provides a solid guarantee for the motor's stable operation and high energy efficiency, ultimately meeting the stringent requirements of industrial production for power equipment.