I. Company Introduction
Wofu Permanent Magnet Technology Co., Ltd. is a national high-tech enterprise and provincial-level specialized, refined, unique and innovative enterprise integrating scientific research, design, production and sales. Founded in November 2010, the company has focused on permanent magnet transmission for nearly a decade, with subsidiaries or offices established in more than 30 key cities nationwide including Beijing, Shanghai, Hefei, Nanjing and Ningbo. Leveraging its professional expertise and mature technologies in the field of permanent magnet transmission, the company has risen rapidly in the industrial sector and gradually grown into an industry leader.
On the basis of fully introducing and absorbing advanced foreign technologies, we keep pursuing development and innovation, and have successfully developed a variety of series of permanent magnet products. These products are widely applied in energy-saving technological transformation of motors across numerous sectors such as electric power, metallurgy, chemical industry, cement, coal, iron and steel, and military industry, with over 1,000 application cases. The energy-saving rate of governors generally reaches 20-50%, and the company maintains a leading position in the industry in terms of market share, R&D strength and product quality of high-power permanent magnet governors.
At present, the company has obtained qualifications including National High-Tech Enterprise, Science and Technology Little Giant Enterprise, Gazelle Incubation Enterprise, and Provincial-level Specialized, Refined, Unique and Innovative Enterprise. It has also been recognized by the Ministry of Industry and Information Technology (MIIT) for its technology reaching the "domestic leading level" (Certificate No.: 202034ZK4474), awarded the Integration of Informatization and Industrialization certification, and certified by three major international ISO systems covering quality, environment and occupational health safety. Its products have obtained dual explosion-proof certifications from the National Explosion-proof Quality Inspection Center and the Petrochemical Industry Explosion-proof Quality Inspection Center, been recognized as provincial-level new products, and hold a work safety license.
The company has applied for a total of 139 patents, including 52 invention patents (26 authorized), 46 utility model patents (19 authorized), and 21 design patents (21 authorized). It also owns 17 software copyrights (all authorized) and 3 trademark registration certificates, with the annual number of newly applied intellectual property rights steadily increasing by more than 20 pieces each year. Additionally, the company has been accredited as a municipal-level enterprise with standardized intellectual property management and outstanding intellectual property advantages, and won the Provincial Excellent Patent Award and Provincial Excellent Design Patent Award.
Its independent patented invention products have been included in the MIIT National Industrial Energy-Saving Technology Catalogs of 2018 and 2020, the National Excellent Recommended Product and Technology Catalog for Electronic Energy Conservation and Environmental Protection, the Provincial "Five One Hundred" Promotion Catalog for Energy Conservation and Environmental Protection Industries in the Industrial Sector, as well as the Recommendation Catalog for Military-Civil Integration Enterprises and Product Technologies.
The company's projects have been invited to participate in major innovation and entrepreneurship competitions, including the Chuangye Jinling Nanjing Science and Technology Innovation Competition, Jiangsu Division of China Innovation and Entrepreneurship Competition, Ningbo Youth College Students Entrepreneurship Competition, China General Aviation and Aerospace Innovation and Entrepreneurship Competition, Anhui MBA Innovation and Entrepreneurship Competition, Maker China Anhui SME Innovation and Entrepreneurship Competition, and Chuangxiang China Innovation and Entrepreneurship Competition, winning numerous gold and silver awards. The core team members have been selected as high-level innovative and entrepreneurial talents for talent introduction in Hefei, Nanjing, Ningbo and other cities, earning high recognition and praise from all sectors of society.
At the end of 2019, the company received investment from district-level and provincial-level government-guided investment funds, fueling its rapid growth trajectory.
Today, all employees of Wofu adhere to the tenet of "Enterprising, Practical, Rigorous and United", continuously pursue innovation, take technology as the core and quality as the lifeblood. We wholeheartedly provide customers with cost-effective permanent magnet products, high-quality engineering renovation design and thoughtful after-sales service, striving to forge a profound brand imprint of "Wofu" in the process of energy-saving upgrading of high-power industrial motors in China.
II. Relevant Patent Certificates (Partial)
III. Overview
In the application of the cement industry, heavy-duty equipment such as elevators, chain conveyors and bucket elevators mostly adopt fluid coupling soft starting due to design safety considerations. However, fluid couplings feature outdated technology, numerous fault points and potential safety hazards, with explosion accidents occurring in the most severe cases. As work safety gains increasing attention nowadays, fluid couplings can hardly meet the needs of industrial development, and there is an urgent demand for superior alternative technology.
As a high-tech and multi-functional coupling, the permanent magnet coupling is designed targeting the transmission characteristics of various belt conveyors in the cement industry to replace traditional fluid couplings. It boasts a permanent magnet transmission efficiency as high as 98%, far exceeding that of fluid couplings. Additionally, it supports heavy-load start-up and buffer start-up, reduces starting current, solves installation alignment problems, lowers equipment vibration, eliminates oil leakage issues of fluid couplings, improves the reliability of motors and loads, cuts down equipment maintenance costs, and enhances the reliability of the entire system.
Permanent magnet drive technology is a groundbreaking new technology developed globally in recent years. Permanent magnet couplings are characterized by high reliability, torque transmission without rigid connection, adaptability to harsh working environments, substantial reduction of overall system vibration, lowered system maintenance requirements, extended system service life, and zero generation of high-order harmonics. These superior properties make them the optimal choice for the technical transformation of heavy-duty equipment represented by belt conveyors.
IV. Product Introduction
(I) Technical Principle of Permanent Magnet Coupler
Wolfer permanent magnet transmission technology is a revolutionary transmission device that transmits torque through an air gap. There is no need for mechanical connection between the rotating shafts of the motor and the load equipment. When the motor rotates, it drives the driving conductor rotor to cut magnetic lines of force in the strong magnetic field generated by the disc driven rotor equipped with high-power rare-earth magnets, thereby generating Eddy Current in the conductive disc. The eddy current induces a magnetic field on the driving conductor rotor. The magnetic attraction and repulsion between the induced magnetic field and the permanent magnetic field drive the driven rotor to rotate, realizing torque transmission between the motor and the load. The motor is connected to the driving rotor with a constant rotational speed.
By adjusting the air gap (distance) between the driven rotor and the driving rotor, the magnetic field strength at the position of the driven rotor can be regulated. The smaller the air gap, the stronger the magnetic field at the position of the driving rotor, the stronger the induced magnetic field generated by its high-speed rotation, the greater the torque produced, and the higher the load speed. Conversely, the larger the air gap, the weaker the magnetic field at the position of the driving rotor, the weaker the induced magnetic field generated by its high-speed rotation, the smaller the torque produced, and the lower the load speed.
Characteristics of Permanent Magnetic Transmission:
When the WF-CT torque-limiting permanent magnet coupling is overloaded or over-torqued, it disconnects the load with the fastest response time to protect the motor, bearings and load.
Scope of Application: Suitable for equipment requiring good cushioned start-up characteristics and prone to stalling. Examples include conveyor belts, elevators, zipper conveyors, bucket elevators and more, serving as a replacement for torque-limiting hydraulic couplings.
Product Features:
Cushioned soft start: Reduces motor inrush current and extends service life of equipment.
Torque limiting and automatic stall protection: When the load is overloaded, the air gap between the conductor disc and permanent magnet disc automatically widens, allowing the motor to run under light or no load without jamming, thus protecting the motor.
High tolerance for installation misalignment: Non-contact connection greatly simplifies installation and commissioning.
Overload protection: Improves the reliability of the entire motor drive system.
Low maintenance: Simple structure with minimal maintenance requirements, no bearings and no working medium needed.
Long service life: Designed service life of 25 years.
Excellent vibration damping: Torque transmission without mechanical connection.
Simple structure: Adaptable to various harsh environments, pollution-free and eco-friendly.
Easy installation: No modification to original processes required; only replace hydraulic couplings or shaft couplings without relocating the motor position, and no harmonic generation.
V. Comparative Introduction of Permanent Magnet Coupler Products
(I) Background Introduction
The first domestic application of permanent magnet speed regulators dates back to 2007, marking a development history of nearly 13 years. Disc-type structure is the mainstream design, while drum-type structure products are relatively rare. The fully magnetic synchronous permanent magnet coupling technology has emerged only in the past four years.
Wolfer Permanent Magnet's products are developed by a professional team engaged in permanent magnet speed regulator research and development for a long time. Its core technical backbones have over 10 years of experience in the permanent magnet industry, with its permanent magnet technology ranking absolutely leading domestically. The company holds more than 60 invention patents for permanent magnet technology and a total of 102 patents. It boasts the most complete product range, the highest power rating, and holds the world's largest operating power performance record to date.
(II) Permanent Magnet Coupler
1. Structure Diagram
Wolfer Permanent Magnet Coupler
2. Overload Protection Function of Coupling
Wolfer Torque-Limited Permanent Magnetic Coupling (Coupling Applied on Belt Conveyors)
The Vofer permanent magnetic coupling transmits load. When the load stalls, axial force is generated. Since the two internal magnetic discs are designed with an axially slidable structure, they will automatically pop apart to protect the motor, load, bearings, shafts, couplings and the permanent magnetic coupling, preventing system collapse. It can also reset automatically when the system fault is cleared. When the Drag system operates normally, the air gap between the magnetic discs and conductor discs is extremely small, enabling a transmission efficiency of 98%. When the motor is disconnected from the load, slip occurs, which realizes the soft start function.
When the system is overloaded, the permanent magnet discs automatically close toward the center, widening the air gap between the magnetic discs and the conductor discs. This disconnects torque transmission between the motor and the load, causing the discs to stop rotating (with the load remaining stationary) while the motor runs normally, thereby protecting the motor and reducer gears.
3. Performance
The Wofu permanent magnetic coupling is designed fully referencing the soft start characteristics of hydraulic couplings. After operation, it can effectively reduce the tension of the belt conveyor and the operating current of the motor, greatly extend the service life of the belt. It delivers better performance than hydraulic couplings and serves as a genuine alternative.
4. Mechanical Alignment Feature
The permanent magnetic part of the Wofu magnetic coupling adopts a disconnected structure, enabling simple and extremely convenient alignment, as well as vibration and noise isolation.
5. On-site Photos
Wofu Permanent Magnetic Coupling
VI. Summary
In summary, the disc type is currently the mainstream permanent magnetic coupling in the market. It is designed according to the actual working conditions on users' sites, capable of replacing the function of hydraulic couplings and providing automatic overload protection. Meanwhile, there are far more application cases of disc-type permanent magnetic speed regulators than drum-type and winding-type ones, and Wofu products account for almost all the maximum power applications in various fields.
