Motor Stator and Rotor Cores
Oct 20, 2025
Leave a message
What Are the Stacking Rivet Points of Motor Cores?
The stacking rivet points of stator and rotor cores are mainly divided into three types:
Round buckle points: This type is commonly used in stepper motors. It has the advantage that the depth of the buckle point cannot be too deep; if it is too deep, it cannot be buckled properly. This is beneficial for reducing eddy currents in the motor and allows better control of temperature rise.
Square buckle points: Also called V-shaped rivet points, square buckle points are relatively common. Compared with round buckle points, they have lower requirements for the precision of the punch press. Their disadvantage is that they may be pressed too deep, causing certain damage to the insulating layer of the core stamped sheets. If the requirements are not too high, this type of square buckle point can be used.
Arc-shaped rivet points: These are used for twisted-slotted cores. To achieve proper lamination, an arc shape is usually required. Twisted-slotted cores are also used for cores with high requirements for dynamic balance; the twisting of the slots is performed after the rotation process.
Each of the three types of stacking rivet points has its own advantages and is selected based on specific needs.
Features of Motor Stator and Rotor Cores
Quality material and low loss: made by stacking cold-rolled electrical steel sheets with high magnetic permeability; the insulating varnish on the surface helps reduce energy consumption.
High precision and strong adaptability: the stator has slots for embedding windings; the rotor has different slot designs based on motor types (for example squirrel-cage). The air gap between stator and rotor must be evenly controlled at 0.2-1 mm.
Good working-condition resistance and stability: it can work at 55-130 deg C, resists overload and vibration, and suits applications such as home appliances and new energy vehicles.
Which Fields Are Motor Cores Used In?
They are used in home appliances, industrial automation, 5G base stations, and new energy vehicles. On a larger scale, they are used in the core drive motors of new energy vehicles, as well as in motors for car windows and steering wheel power assist. On a smaller scale, the vibration motor in mobile phones also belongs to this category of motors.
Core Material Specifications
The raw material is cold-rolled grain-oriented (CRGO) silicon steel sourced from established domestic steel mills, ensuring consistent quality for transformer and motor core laminations. Available grades include B30P120, B30P105, B30R100, 27QG120, 27QG100, 23Q110, 23QG100, 23QG095, 23RK090, 23RK085, 23QG085, 23RK080, 23RK075, B23R070, 20QG085, 20RK080, 20RK075, B20R070, B20R065, M0H, M1H, M2, M3, M4, M5, and the HP/CG series for motor and transformer cores.
| Type | Grade | Width | Max core loss at 1.7T/50Hz | Lamination factor (%) | Min induction at B800 |
|---|---|---|---|---|---|
| Common | 23Q110 | 35-1200 mm | 1.10 W/kg | 97.2 | 1.82 T |
| Common | 27Q120 | 35-1200 mm | 1.20 W/kg | 97.5 | 1.82 T |
| Common | 30G120 | 35-1200 mm | 1.20 W/kg | 98 | 1.82 T |
| High induction | B20P085 | 35-1200 mm | 0.85 W/kg | 97 | 1.86 T |
| High induction | B23P095 | 35-1200 mm | 0.95 W/kg | 97.2 | 1.88 T |
| High induction | B27P095 | 35-1200 mm | 0.95 W/kg | 97.5 | 1.89 T |
| High induction | B30P105 | 35-1200 mm | 1.05 W/kg | 98 | 1.89 T |
| Domain refined (laser) | B20R070 | 35-1200 mm | 0.70 W/kg | 97 | 1.86 T |
| Domain refined (laser) | B23R085 | 35-1200 mm | 0.85 W/kg | 97.2 | 1.88 T |
Manufacturing Process
The manufacturing process follows six steps: raw material sourcing, slitting to width, punching of laminations, laminating and stacking, core forming, and testing. Each step controls dimensions, burr, and insulation quality to meet the design specification.
Frequently Asked Questions
Q: What are the types of stacking rivet points? A> Round buckle, square (V-shaped) buckle, and arc-shaped rivet points.
Q: Why are motor cores laminated? A> Thin laminations reduce eddy current losses and temperature rise compared with a solid core.
Q: What is the typical air gap between stator and rotor? A> Evenly controlled at 0.2-1 mm.
Q: What materials are used? A> Cold-rolled grain-oriented silicon steel with insulating varnish on the surface.
Q: Where are motor cores used? A> Home appliances, new energy vehicles, 5G base stations, and industrial automation.
Q: What is the working temperature range? A> About 55-130 deg C.
Need motor stator and rotor cores for your application? Contact us with your drawings and grade requirements for a quotation.