How much impact does the self bonding core have on motor energy efficiency?

In this blog, we will discuss “How much impact does a self bonding core have on motor energy efficiency?”.  Understanding this impact is crucial because it has far-reaching implications for energy conservation, cost reduction, and environmental sustainability.

In the following exploration, we will delve into the technology behind self-bonding cores, their advantages over traditional counterparts(such as interlock, welding, and gluing), and their real-world applications.

Understanding Motor Iron Core

The iron core is also the magnetic core. The iron core (magnet core) plays a decisive role in the entire motor. It is used to increase the magnetic flux of the inductor coil and achieve the maximum conversion of electromagnetic power. It composite of two main parts: the stator core and the rotor core.

The stator core is the stationary part of the motor and plays a critical role in generating a rotating magnetic field when an electric current flows through it. This magnetic field interacts with the rotor core, which is the rotating part of the motor, causing it to spin and drive the mechanical load. The stator and rotor core are punched out of silicon steel sheets(electrical steel sheets).

The iron core serves as the pathway for the magnetic flux, facilitating efficient energy conversion. The magnetic properties of the core material directly influence the motor’s performance, with higher magnetic permeability leading to improved efficiency.

manufacturing motor iron core

Welding Iron Core

Welding iron cores joining individual laminations of the iron core together using welding seam techniques. The main welding processes include TIG+MIG welding, laser welding, resistance welding, etc., which have the advantages of mature technology, low cost, low requirements for lamination, and low requirements for equipment.

However, welding iron cores also comes with its set of challenges and disadvantages.  The thermal reaction zone is large, resulting in reduced motor performance; it is not environmentally friendly; it requires high operating requirements for workers; it has defects in appearance and rough welds.

Moreover, the precision required in welding can make it a costly and complex manufacturing process, particularly for small-scale production.

laser welding

Interlock Iron Core

The interlocking iron core uses automatic stacking riveting technology on the progressive die. The formation process of the interlocking iron core is to make the convex part of the stacking riveting point of the previous piece correctly align with the stacking riveting point of the lower piece at the blanking station.

The dot concave holes are overlapped together. When the upper piece is subjected to the pressure of the blanking stamp, the lower piece uses the reaction force generated by the friction between its shape and the wall of the die to cause the two pieces to overlap. 

Through continuous punching by a high-speed automatic punching machine, a neat iron core with a certain stack thickness is formed.

The interlocking iron core stacking riveting points include cylindrical stacking riveting points, V-shaped stacking riveting points, L-shaped stacking riveting points, trapezoidal stacking riveting points, etc.

In interlock iron cores, the stacking and interlocking points are strategically positioned to ensure maximum stability and alignment of the laminations. This precise placement reduces the potential for energy loss due to eddy currents and hysteresis, leading to improved motor energy efficiency.

Bonding Iron Core

The bonded core replaces the traditional welding and stack riveting methods. The purpose of this improvement is to improve the electromagnetic performance of the motor and reduce iron damage to the stator and rotor cores.

Gluing Iron Core

Traditional motor cores have often relied on glue bonding to hold laminations together.

Bonded stator and rotor cores are ideal for ultra-thin laminations, where the glue holds the stack together without lamination deformation. The adhesive between the bonded iron core steel plates forms an insulating layer, which can significantly reduce electromagnetic losses. The bonded iron core has stronger earthquake resistance and waterproof performance.

While gluing iron cores can produce sturdy and reliable cores, it is not without its drawbacks. Adhesive layers can introduce inconsistencies and irregularities, affecting the core’s magnetic properties and potentially leading to energy losses over time.

Moreover, adhesive bonding can be labor-intensive and may require additional curing time, which can slow down the manufacturing process.


Self-Bonding Iron Core

Self bonding iron cores represent a significant evolution in motor core technology. Unlike traditional gluing methods, self-bonding cores utilize specialized materials and manufacturing processes to create laminations that inherently bond together without the need for additional adhesives.

One of their primary advantages is the reduction in core loss and eddy currents, thanks to the absence of adhesive and riveting materials that can introduce inefficiencies. This translates to significantly improved motor energy efficiency, ultimately lowering energy consumption and operating costs.

Additionally, the self-adhesive iron cores exhibit enhanced magnetic properties, ensuring a more consistent and efficient conversion of electrical energy into mechanical motion. Their inherent mechanical strength eliminates the risk of delamination.

Thin plate material (0.1 mm) can control core loss and heat generation to a minimum, reduce vibration during rotation, smooth lamination, reduce wind noise, and have excellent heat dissipation, which can extend the life of the motor.

Furthermore, the self-adhesive process streamlines manufacturing, reducing assembly time and costs.

Overall, they can be used as the preferred iron core for new energy vehicle motors to improve the core strength and effectively improve the external characteristics and NVH level of the drive motor.

self-bonding motor laminiation

Our Capability For Self-Bonding Iron Core

From stamping to stacking motor lamination stacks, we innovate step by step. Lamination bonding is a new technology in our company.

Motorneo offers glue dot bonding and self-bonding process to bond stator and rotor laminations. We have multiple various types of high-speed punching machines and multiple disc motor stator punching machines. The largest high-speed punching machine is 350 tons and can produce iron cores with a maximum outer diameter of 1250mm.

We also have three-dimensional coordinate inspection, two-dimensional inspection, core iron loss inspection, stator component voltage withstand inspection, inter-turn inspection, CRH inspection, insulation resistance inspection, and other performance and size inspection capabilities to meet different customer needs.


Most electrical steel sheets are assembled into cores through welding, bolting, self-fastening, cleating, or riveting. However, welding and fixing methods can cause short circuits at the edges of the core, reduce insulation, and cause various problems such as deterioration of magnetic properties due to thermal deformation.

Whether it is welding, bolting self-fastening, cleating, or riveting fixation, the iron core is partially fixed at a point. The connection force is not high, and it is difficult to meet the requirements for high fastening strength. In addition, welding and riveting are not suitable for many micro motors.

Self-bonding iron cores address critical challenges faced by traditional adhesive-bonded cores, eliminating the risk of inefficiencies introduced by adhesives and enhancing the overall performance of electric motors.

By streamlining the manufacturing process and eliminating the need for additional binding agents, they not only reduce production costs but also contribute to a more environmentally friendly and sustainable future.


What is a self-bonding iron core, and how does it differ from Adhesive iron cores?

Here are the key differences between self-bonding iron cores and gluing iron cores:

Bonding Mechanism:

Self-bonding cores rely on the inherent magnetic attraction or bonding force between laminations to hold them together. No external adhesives are required.

Adhesive cores depend on adhesives to create a bond between laminations. These adhesives must be carefully applied and allowed to cure.


Self-bonding cores are known for their high efficiency because there are no additional materials (adhesives) that can introduce energy losses.

Adhesive cores may introduce inefficiencies due to the presence of adhesive materials, which can lead to losses over time.

Manufacturing Process:

The manufacturing process for self-bonding cores involves specialized techniques to ensure laminations bond together inherently.

Adhesive cores involve the application of adhesive materials during the stacking process, requiring careful attention to adhesive quality and application.


Self-bonding cores often offer enhanced mechanical strength because they rely on the inherent magnetic attraction, reducing the risk of delamination.

Adhesive cores may be susceptible to delamination or degradation of adhesive bonds over time.

Are self-bonding iron cores suitable for all types of electric motors?

Self-bonding cores are versatile and can be used in various types of electric motors. Such as pump motors, drone motors, rail transportation linear motors, permanent magnet synchronous elevator motors, fans motors, robotic motors, and new energy vehicle motors, including those wheel motors.

Do self-bonding iron cores require specialized manufacturing equipment or processes?

Yes, manufacturing self-bonding iron cores typically involves specialized processes and equipment to ensure precise bonding between laminations.

Try to contact us for high-quality motor cores in China.