Induction Motor Core Lamination Stacks Manufacturer

As Sino, a top Chinese maker of motor laminations, we know the very important part that core laminations play in how well electric motors work, how much energy they save, and how long they last. Our goal is to help motor makers everywhere, in many different fields, with the newest and best lamination products. We want to show the way to better energy use, more power in a smaller size, and better heat handling, while also looking at the big changes that can come from new materials and ways of making things.

The Sino Material Advantage

Sino predominantly utilizes high-grade silicon steel, often referred to as electrical steel for adding a small percentage of silicon (typically between 1-4%) to the iron alloy significantly boosts its electrical resistivity. This intrinsic property of the material itself gives eddy currents another hurdle to overcome, further diminishing their impact.

But silicon steel brings more to the table:

Excellent Magnetic Permeability: This means the material readily allows magnetic flux to pass through it, which is essential for a strong and effective magnetic field in the motor.
Reduced Hysteresis Losses: Silicon steel alloys are formulated to minimize these losses too, contributing further to overall motor efficiency.

By carefully selecting the grade of silicon steel, Sino ensures that your induction motor core – whether it’s for the stator core of an induction motor or the rotor core of an induction motor – possesses the optimal magnetic properties with the lowest possible core losses.

New Induction Motor Lamination Materials We Use

when EV motors run at very high speeds (hundreds of Hz to several kHz) and under strong magnetic fields, regular silicon steels have problems. This is because they lose more energy as heat, especially from eddy current losses and anomalous losses. To get past the problems with regular steels, new and better materials are becoming more popular. They offer better magnetic abilities at high speeds.

Amorphous Metals

Amorphous metals, like those from Metglas and Hitachi Amorphous, are made of atoms arranged randomly, like glass, not in a neat crystal pattern. This special structure gets rid of grain boundaries, which are a big reason for energy loss and the creation of eddy currents.

Less Core Loss: Amorphous metals have energy losses that are 70–80% lower than regular silicon steel at speeds above 400 Hz. This makes them a very good choice for high-speed EV motors (10,000–20,000 rpm). This could make the whole motor 1–2% more efficient, especially when it isn’t running at full power or is at high speeds.
Saturation Flux Density (Bs): They can’t handle as much magnetic field as silicon steel, around 1.2 T. This can mean the core needs to be bigger to get the same amount of turning force.
Mechanical Problems: Amorphous metals are naturally brittle and break easily. This makes it very hard to stamp, stack, and handle them when building a core. Because they are brittle, the layers can’t be too thin (usually 20–30 μm), and it’s harder for machines to stack them. This means more material gets wasted and you need special tools.
Stacking Factor: The stacking factor for amorphous layers is usually 0.85–0.88. This is lower than the 0.95 for silicon steel because of the insulation coatings and the uneven surfaces of the thin strips.
Heat Transfer: Amorphous metals are much worse at moving heat (5–10 W/m·K) compared to silicon steel (about 25–30 W/m·K). This stops heat from escaping easily and makes it more likely for small areas to get too hot.

Nanocrystalline Alloys

Nanocrystalline alloys, like Finemet (Fe73.5Si13.5B9Nb3Cu1), Vitroperm, and Nanoperm, are made mostly of iron and have a structure of extremely tiny crystals held within a random, non-crystal structure. This special structure brings together the good points of both amorphous and regular crystal materials.

Saturation Flux Density (Bs): They can handle a magnetic field of about 1.2–1.35 T. This is better than amorphous alloys but not as good as high-quality silicon steels.
Permeability: They are very responsive to magnetic fields. This ability stays high even at very high speeds (up to several hundred kHz), much better than silicon steels. This makes them perfect for fast, high-frequency motor systems.
Core Loss: At 1.5 T and 400 Hz, their energy loss is very low (10–20 W/kg), much lower than the best NOES grades (30–50 W/kg). At 10 kHz, nanocrystalline losses are still under 100 W/kg, while the energy loss in silicon steel becomes too high to be practical (>500 W/kg).
Temperature Stability: They keep their good magnetic abilities up to 120–150°C. New research shows they can be stable up to 180°C by adding small amounts of other metals.
Manufacturing: They are made as thin strips (18–30 μm), like amorphous metals, which makes stacking and handling them difficult. Laser welding and special glue are making it possible to create stacks with many layers.
Annealing: They need a very specific heat treatment (500–600°C in a magnetic field) to get the best performance.
Cost: Right now, they cost 3–5 times more per kg than high-quality NOES. But, we are seeing that they can save money for the whole system (by making motors smaller and lighter, and needing less cooling).

Our Induction Motor Core Lamination Products

Advantages of Laminations from Sino

Reduced Operating Costs

Lower energy consumption means smaller electricity bills.

Enhanced Reliability

Cooler operation leads to longer motor life and less frequent maintenance or replacement.

Improved Performance

Motors can deliver their rated power more effectively without being hampered by excessive losses.

Design Flexibility

For motor designers, low-loss cores can mean the possibility of creating more compact motors for a given power output, or achieving higher power from an existing frame size.

Stator and Rotor Cores by Sino

An induction motor has two main core components that benefit immensely from Sino’s precision laminations:

The Stator Core of an Induction Motor

This is the stationary part that holds the stator windings. When energized, these windings create the rotating magnetic field. The stator core of an induction motor, built from Sino’s laminations, serves several vital functions:

Provides a Low-Reluctance Path: It guides and concentrates the magnetic flux produced by the windings, ensuring it’s efficiently directed across the air gap to the rotor.
Minimizes Core Losses: Our high-quality, insulated laminations ensure that eddy currents and hysteresis losses within the stator core are kept to an absolute minimum, preventing energy waste and overheating.
Structural Support: It provides a robust framework for the stator windings. Sino ensures precise slot dimensions and stacking for easy and secure winding insertion.

The Rotor Core of an Induction Motor

This is the rotating part of the motor. In squirrel-cage induction motors (the most common type), the rotor core of an induction motor houses conductive bars (usually aluminum or copper) that are short-circuited by end rings.

Carries Induced Currents: The stator’s rotating magnetic field induces currents in these rotor bars, and it’s the interaction between this rotor current and the stator field that produces torque.
Efficient Flux Path: Just like the stator core, the laminated rotor core provides an easy path for magnetic flux.
Loss Reduction is Key: Even though the frequency of the magnetic flux changes in the rotor core is typically lower (slip frequency) during normal operation, minimizing losses here is still important, especially during startup or under heavy load conditions. Sino’s rotor laminations ensure these losses are controlled.

Induction Motor Lamination Manufacturing Methods

The way laminations are made has a big effect on their final magnetic and physical qualities. Sino uses the most modern methods and keeps putting money into new ways of making things to deliver better products.

Stamping

Stamping is the most common way to make laminations because it’s fast and doesn’t cost too much for making a lot of them. However, the cutting process bends the metal and leaves stress in it at the cut edge. This makes the magnetic abilities a bit worse, usually increasing energy loss by 5–15% compared to the original material. Afterwards, a step like a special heat treatment (stress relief annealing) is often needed to fix these problems.

Laser Cutting

Laser cutting is very exact and can be used for many different shapes, especially for making samples and complex parts. However, it heats up a small area, creating a Heat-Affected Zone (HAZ) that is usually 10–100 μm wide. This HAZ has changes in its tiny internal structure and leftover stress, all of which together make the magnetic abilities worse. Studies show this can increase energy loss by 10–30%. How much worse it gets depends on the laser settings (power, speed, gas used, etc.).

Sino's Commitment: Precision, Quality, and Partnership

At Sino, manufacturing induction motor core laminations is more than just stamping steel. It’s a science and an art we’ve honed through years of dedication.

Cutting-Edge Manufacturing

We employ advanced, high-speed stamping presses and precision carbide dies to ensure every lamination meets exacting dimensional tolerances. This precision is vital for uniform stacking, minimizing air gaps within the core, and ensuring consistent magnetic properties.

Material Mastery

We source only high-quality electrical steel from reputable mills, with traceable certifications. We understand the nuances of different steel grades and their suitability for various motor designs and operational demands.

Insulation Integrity

The interlaminar insulation is paramount. We utilize various coating types (like C5 or C6) applied and cured under controlled conditions to guarantee high electrical resistance between laminations, preventing short circuits that would negate their benefits. Rigorous testing, including inter-laminar resistance checks (Franklin tests), is part of our standard quality control.

Annealing Expertise

For certain grades of electrical steel, a carefully controlled annealing process after stamping is crucial to relieve mechanical stresses induced during punching and to restore optimal magnetic properties. Sino has the in-house capability to perform this critical step.

Quality at Every Stage

From raw material inspection to final stack dimensional checks, quality control is embedded in our process. We adhere to international standards (e.g., ISO 9001) to give you complete confidence in our products.

Power Up Your Performance with Sino

When you choose Sino for your induction motor core laminations, you’re not just buying a component; you’re investing in the heart of your motor’s performance and reliability. Whether you’re designing the next generation of energy-efficient industrial motors, specialized servo motors, or robust traction motors, our laminations for the stator core of an induction motor and the rotor core of an induction motor provide the foundation for excellence.

We understand that one size rarely fits all. That’s why we work closely with our clients, offering:

Custom Designs: Tailored lamination profiles, slot configurations, and stacking arrangements to meet your unique motor specifications.
Prototyping Services: Helping you test and validate your designs quickly.
Technical Support: Our experienced team is ready to discuss your specific scenario and recommend the best lamination solutions.

Contact Sino Today!

Don’t let outdated core technology hold your motors back. Embrace the efficiency, durability, and performance that Sino’s precision-engineered induction motor core laminations deliver. Let’s work together to build motors that are not just powerful, but also smart and sustainable.

Ready to give your motors the core they deserve? Contact Sino today, and let’s discuss how we can energize your next project!

Note: To speed up your project, you can label Lamination Stacks with details such as tolerance, material, surface finish, whether or not oxidized insulation is required, quantity, and more.

Let Sino's Lamination Stacks Empower Your Project!