rotor weight impact motor performance

How Insufficient Rotor Weight Impacts Motor Performance?

Have you ever wondered how the weight of a rotor affects motor performance? Understanding the significance of rotor weight is crucial for optimizing motor efficiency. In this blog, we’ll explore the consequences of an insufficient rotor weight and the factors contributing to this issue.

Effects of Rotor Is Not Heavy Enough

When the rotor core’s weight is insufficient, it results in a reduced net length of the rotor core. This reduction decreases the cross-sectional area of the rotor teeth and yoke, leading to an increased magnetic flux density. The performance impacts include:

Increased Excitation Current: A lighter rotor demands more excitation current, leading to a decreased power factor.

Higher Stator Current: The motor stator current rises, which increases the stator copper loss and decreases efficiency.

Temperature Rise: The motor operates at higher temperatures, which can affect its longevity and reliability.

Causes of Rotor Is Not Heavy Enough

Several factors can contribute to the rotor core being lighter than necessary:

1. Uneven Thickness of Silicon Steel Sheets

Variations in the thickness of silicon steel sheets can lead to an uneven rotor core weight.

2. Excessive Rotor Punching Burrs

Large punching burrs on the rotor can affect its overall weight and balance.

3. Inadequate Press-Fitting Pressure

Insufficient pressure during the press-fitting process can result in aluminum filling into the punching room, reducing the net rotor core length.

4. Rusty or Dirty Rotor Stampings

Contaminated or corroded rotor stampings can compromise the rotor’s weight and performance.

5. Overheating During Preheating

If the preheating temperature of the cast aluminum rotor core is too high or prolonged, it can severely burn the core, reducing its net length.


Maintaining the correct rotor is not heavy enough is essential for optimal motor performance. Ensuring the even thickness of silicon steel sheets, controlling punching burrs, applying adequate press-fitting pressure, keeping rotor stampings clean, and monitoring preheating temperatures are all crucial steps. By addressing these factors, you can enhance the efficiency and longevity of your motors.

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