Magnetic coupling is a transmission device that uses the magnetic force of permanent magnets or electromagnets to achieve non-contact torque transmission, and can complete power transmission without mechanical connection. The following is a comprehensive analysis of it:   1. Core Principle Magnetic coupling The torque transmission between the active end and the driven end is achieved through the interaction of the magnetic field generated by permanent magnets (such as NdFeB, SmCo) or electromagnets. Non-contact transmission There is a physical gap (air gap) between the two components to avoid mechanical friction. The typical gap is 0.1~10mm, depending on the design.   2. Main Types Synchronous magnetic coupling Structure: The inner and outer rotors are inlaid with permanent magnets, and the N-S poles are arranged alternately. Features: Torque is synchronized with speed, but may lose step (slip) when overloaded. Application: Scenarios that require precise transmission such as pumps and fans. Eddy current magnetic coupling (asynchronous type) Structure: The conductor disk (copper/aluminum) rotates in the magnetic field to generate eddy currents and form torque. Features: With soft start and overload protection capabilities, but there is slip (speed difference). Application: High-power speed regulation or buffer start equipment. Axial and radial magnetic circuit design Axial: The magnets are arranged along the axial direction, suitable for small torque and high speed. Radial: The magnets are arranged along the radial direction, with greater torque but complex structure.   3. Key Advantages Zero leakage: The sealing field (such as chemical pumps) eliminates medium leakage. Maintenance-free: No wear parts, long life. Vibration reduction and noise reduction: Isolate vibration and reduce system noise. Overload protection: Automatically slip when the torque exceeds the limit to protect the equipment. Adapt to harsh environments: Corrosion resistance, high temperature (Samarium Cobalt magnets can reach 350℃).   4. Performance Parameters Parameter Typical Range / Description Torque 0.1 Nm ~ 50 kNm (Customizable for high torque) Efficiency Synchronous type > 95%, Eddy-current type 80%~90% Maximum Speed Up to 50,000 rpm (Requires high-precision balancing) Temperature Limit -50°C ~ +300°C (Depends on magnet material)   5. Selection Points Torque requirements: Start torque, working torque and peak torque need to be calculated. Air gap requirements: The larger the air gap, the more significant the decrease in torque transmission capacity (inversely proportional to the square of the distance). Environmental factors: Corrosive media need to be encapsulated in stainless steel; samarium cobalt magnets are used in high temperature environments. Out-of-step torque: Select a rated value 20%~30% higher than the working torque to prevent slippage.   6. Typical Application Scenarios Chemical/pharmaceutical: magnetic pump, reactor stirring (leakage prevention). Vacuum system: semiconductor equipment transmission (pollution-free). Food machinery: avoid lubricant contamination. New energy: fuel cell circulation pump, wind power generation variable pitch system.   7. Limitations High cost: Permanent magnetic materials (especially rare earth magnets) are expensive. Axial force problem: The influence of axial attraction between magnets on bearings needs to be considered at high power. Torque limitation: Super large equipment requires multi-magnetic circuit parallel design.   8. Future Trends High temperature superconducting magnets: Improve torque density and reduce magnet volume. Intelligent control: Combine sensors to achieve real-time torque monitoring and adjustment. Composite materials: Lightweight and corrosion resistance optimization.

In recent years, driven by the growing demand for industrial automation, wall-climbing robots have emerged as vital tools in industries such as petrochemicals, power generation, and shipbuilding, thanks to their ability to operate on vertical surfaces.  Among their core components, magnetic wheels stand out for their high stability, strong load-bearing capacity, and adaptability, pushing the industry toward greater efficiency and safety.When paired with wheeled or tracked drive systems, they enable the robot to move with agility.--Strong load capacity: For example, our standard magnetic wheel (model KMW160) can provide up to 2940N of vertical pulling force, making it suitable for heavy-duty operations.--Adaptation to complex surfaces: Optimized designs allow magnetic wheels to conform to various curved steel surfaces such as those found on ships and storage tanks.--Low energy consumption: With no need for constant vacuuming, they reduce energy usage and extend the operating time of the robot.Application Cases of Magnetic Wheels in Wall-Climbing Robots：1)Shipbuilding and MaintenanceThe WRobot series developed by the Guangdong Academy of Sciences' Institute of Intelligent Manufacturing utilizes magnetic wheel technology and can carry loads exceeding 50 kg.  It has performed exceptionally in tasks like hull welding and rust removal.2)Wind and Nuclear Power InspectionMagnetic wheel wall-climbing robots are used for non-destructive testing (NDT) of wind turbine towers and nuclear pressure vessels.  A model developed by Shandong University of Science and Technology has demonstrated stable climbing on vertical and cylindrical walls during factory tests, improving inspection efficiency and reducing manual risks.3)Petrochemical Tank MaintenanceIn tasks like flaw detection and painting of large storage tanks, magnetic wall-climbing robots offer a safer and more efficient alternative to manual labor.  For example, robots from Portugal's OmniClimbers use specially designed magnetic wheels to adapt to varying curvatures and magnetic properties of steel surfaces.Future Development TrendsWith continued advances in materials science and magnetic circuit optimization, magnetic wheel technology is evolving toward being lighter, more powerful, and smarter:Material Innovation: The use of high-performance neodymium-iron-boron (NdFeB) magnets increases magnetic force density while reducing volume and weight.Conclusion the maturation of magnetic wheel technology is providing critical support for the application of wall-climbing robots in hazardous and challenging operational scenarios.  With the continuous advancement of modern industry and intelligent manufacturing, magnetic wheels are expected to be applied in more industries and become an important part of professional service robots.

Electromagnetic chuck working based on electromagnetic principles which is a machine tool accessory. When the internal coil is energized, it generates a magnetic force that is transmitted through a magnetic conductive panel to firmly hold ferrous workpieces on its surface. Once the power is cut off, the magnetic force disappears, allowing for demagnetization and release of the workpiece. Its mechanism seems simple, but it is a complex combination of electromagnetism and materials science.   Modern electromagnetic chucks use direct current (DC) power supply, offering advantages such as high stability, strong magnetic force, and low residual magnetism. Based on magnetic force, they are classified into standard magnetic chucks (magnetic force of 10–12 kg/cm²) and high-power electromagnetic chucks (magnetic force not less than 14 kg/cm²). Depending on their applications, there are various types including chucks for grinding machines, chucks for milling and planing machines, and chucks for knife grinders.   Electromagnetic chuck is a kind of machine tool accessory equipment based on electromagnetic principle. Through the internal coil energized to generate magnetic force, and then through the conductive panel will be contacted in the panel surface of the iron workpiece tightly adsorption, power failure after the disappearance of the magnetic force to achieve demagnetization, so as to complete the workpiece fixed and release. Seems to be a simple principle behind the electromagnetic and material science is a subtle combination.  

Electromagnetic chucks were initially developed as a replacement for clamps and bolts to secure workpieces on grinding machines. These early chucks were relatively simple and primarily used to hold flat workpieces, which greatly limited their application. With the development of industry, the demand for more advanced electromagnetic tools in the industry is constantly increasing, which has driven the continuous innovation and improvement of chuck technology.Electromagnetic chucks have a wide variety of pole arrangements. The cross-sectional shape and distribution of the magnetic core varies from workpiece to workpiece. Common types of construction include rectangular and circular. Rectangular poles can be arranged longitudinally or transversely, with the longitudinal arrangement being suitable for holding larger workpieces and the transverse arrangement being more suitable for holding smaller workpieces.  .Performance improvement has been a key breakthrough area in recent years. Conventional electromagnetic chucks suffer from the defects of uniform distribution of magnetic lines of force on the surface, non-concentration of magnetic force, and low magnetic field strength per unit area. At the same time, the direction of the magnetic force is perpendicular to the surface of the suction cup and is difficult to change. Only one magnetic force can be generated for the workpiece with the same suction area. These problems cause the problem such as low positioning accuracy, weak clamping force, narrow application range and low production efficiency during processing.To solve these problems, a new generation of electrically controlled powerful suction cups has emerged, whose features include:1) It has an extremely strong holding force, up to 16kg/cm², and the magnetic force distribution is uniform and adjustable. The holding force does not need to be maintained by connecting to a power supply. Continuous operation does not generate heat, avoiding the deformation of the workpiece due to heat.2) It can work continuously for more than 20 hours every day and requires almost no maintenance.3) It has an automatic auxiliary positioning function, and it only takes 0.3 seconds to clamp or release the workpiece.4) In contrast, the magnetic force of a common electromagnetic chuck requires a continuous current supply. After working for a period of time, it generates heat, which not only causes the workpiece to deform due to heat but also reduces the magnetic force of the chuck, making it impossible to ensure processing accuracy.Besides, ordinary electromagnetic chucks can only work for a few hours each day, the equipment is easy meet problems so it need to replacement and maintenance of internal components frequently.