There is no unified standard for quality inspection of non-standard automated production lines for motors, which needs to be customized based on motor type, application scenarios, and customer requirements. The following introduces common quality inspection standards from different stages of motor production:

1.Raw Material and Component Inspection

1.Silicon Steel Sheet

Material Inspection: Check the silicon content, iron content, and other chemical components to ensure compliance with motor design requirements and guarantee electromagnetic performance. For example, high silicon content can reduce core losses but may increase material brittleness.

Thickness Tolerance: The general tolerance range is controlled at±0.02mm±0.05mm, ensuring the dimensional accuracy and magnetic permeability uniformity after the core is stacked.

Flatness: Use flatness detection equipment, requiring the warpage within each square meter not to exceed0.1mm0.3mm, to prevent uneven silicon steel sheets from affecting core assembly and motor performance.

2.Enamelled Wire

Wire Diameter Tolerance: The tolerance is controlled at±0.005mm±0.01mm, as the wire diameter deviation affects winding resistance, current density, and motor performance.

Coating Thickness: The uniformity and thickness value of the coating must meet the standards, such as the coating thickness of enamelled wire for ordinary motors being0.02mm0.05mm, to ensure insulation performance.

Insulation Performance: Tested with an insulation resistance tester, requiring the insulation resistance not to be lower than the specified value at a certain voltage, such as100MΩ500M, to prevent inter-turn short circuits.

3.Bearing

Dimensional Accuracy: The tolerances for inner diameter, outer diameter, and width must meet the corresponding grade standards, such asP5level bearing inner diameter tolerance at ±0.005mm±0.01mm, ensuring the fit accuracy with the motor shaft and end cover.

Clearance: Appropriate clearance ensures normal operation of the bearing, with the radial clearance of rolling bearings for general motors being0.01mm0.03mm.

Rotational Accuracy: Check the radial runout and axial movement of the bearing during rotation, with radial runout not exceeding0.02mm0.05mm, and axial movement not exceeding.0.01mm0.03mm.

2.Motor Manufacturing Process Inspection

1.Core Manufacturing

Stacking Coefficient: Generally at0.950.98, a low stacking coefficient affects the effective magnetic permeability of the core and motor performance.

Core Outer Diameter: Tolerance controlled at±0.05mm±0.1mm, ensuring a tight fit with the housing.

Core Length: Tolerance controlled at±0.1mm±0.2mm, ensuring consistency in the motor magnetic circuit length.

2.Winding Winding

Number of Turns: The error in the number of turns is controlled at±1%.±2%., as the deviation in the number of turns affects the strength and performance of the motor's magnetic field.

Winding Uniformity: Checked through a visual inspection system to ensure that the enamelled wire is neatly arranged on the winding mold, with no crossing or overlapping, to avoid affecting insulation and heat dissipation.

3.Winding Insertion

Slot Filling Rate: Generally controlled at75%85%.A high slot filling rate affects insulation treatment and motor heat dissipation.

Insulation Treatment: The insulation resistance of the winding to ground should not be less than500MΩ after varnish immersion and drying, to prevent leakage.

4.Motor Assembly

Integrity of Component Assembly: Ensured through a visual recognition system or manual inspection to confirm that all components are fully assembled without omissions.

Assembly Gap: The fit gap between the end cover and the housing is controlled at0.05mm0.1mm, ensuring the motor's sealing and operational stability.

Bolt Tightening Torque: Controlled using a torque wrench according to design requirements, with an error of±5%.±10%., to prevent performance issues due to loose bolts.

3.Finished Motor Inspection

1.Electrical Performance

Insulation Resistance: Cold insulation resistance not less than500MΩ, hot insulation resistance not less than100MΩ, to ensure good insulation performance of the motor.

DC Resistance: The DC resistance deviation of each phase winding of the three-phase motor does not exceed±2%., to ensure three-phase current balance.

Withstand Voltage Test: Apply a certain voltage (such as1500V3000V), sustained for1min2min, with no breakdown or flashover, to test the voltage withstand capability of the motor's insulation structure.

2.Performance Testing

No-load Performance: No-load current deviation does not exceed±10%., and no-load loss does not exceed the specified value, to assess the motor's performance under no load.

Load Performance: Under rated load, the motor's output power, efficiency, speed, and other performance indicators must meet design requirements, such as efficiency deviation not exceeding±3%..

Locked rotor performance: Measure the locked rotor current and locked rotor torque, the locked rotor current generally does not exceed the rated current of5times7times, and the locked rotor torque must meet the motor starting requirements.

3.Vibration and noise

Vibration: At rated speed, the effective value of vibration displacement in all directions of the motor does not exceed the specified value, such as for small motors, the vibration displacement does not exceed0.05mm0.1mm.

Noise: Measured using a sound level meter, at a distance of1mfrom the motor, the noise level does not exceed the specified standard, such as for general small and medium-sized motors, the noise does not exceed60dB80dB.

4.Appearance and dimensions

Appearance: The surface has no obvious scratches, bumps, paint loss, or other defects, and the markings are clear and complete.

Dimensions: The motor's external dimensions must comply with the design drawing requirements, with key dimension tolerances controlled within±0.1mm±0.5mm.