As the global leader in heat dissipation solutions, Sunonwealth Electric Machine Industry Co. has devoted itself to research in the field of fan motors. The firm has produced many innovative designs and technologies over the years. SUNON realizes the importance of breaking through the architectural bottleneck of traditional motors in order to sustain its competitive advantage in the realm of fan motors. Sunon's long term mission therefore has been to develop products capable of overcoming the problems of noise, abrasion, and short service life that beset traditional fan motors.

To achieve this goal and fulfill the commitment of providing the best heat dissipation solutions in the field, SUNON has invested huge amounts of capital and manpower in research and development work. The companywas proud to launch in the fourth quarter of 1999 the world's first MagLev motor fan featuring zero friction and no contact between the shaft and bearing during operation . On hitting the market, the new low-noise, long-life, and high temperature endurance fan quickly won plaudits from international leading manufacturers and became the world's most noticed high performance cooling fan.

Traditional fans apply the principle of like-pole repulsion to rotate. But with no control exerted over blade trajectory, the fan blades tend to produce irregular shuddering and vibrations. After long-term use, the shaft will cause severe abrasion on the bearings, distorting them into a horn shape. The worn-out fan then starts to produce mechanical noises and its life-time is shortened.

The unique feature of SUNON's MagLev motor fan is that the path of the flan blades during operation is magnetically controlled by Sunon's patented MagLev System. The result is that the shaft and bearing have no direct contact during operation and so experience no friction no matter how the fan is oriented. This means that the characteristic abrasion noises of worn-out components are not produced and also allows a service life of 50,000 hours or even longer at room temperature. Considering the distinctive internal structure of MagLev motor fans, SUNON has summarized the following two major features to help consumers identify and select the product.

MagLev Law

1. The MagLev system creates 360O attraction on the rotor, which results in stable rotation.
2. MagLev flux acts perpendicular to the standard magnetic flux.

In a traditional fan, the imbedded magnets of the rotor and the stator exert repulsive forces, and it is this continuous force of repulsion that makes the fan spin. This is the basic principle behind all cooling fans. If we visualize the magnetic forces between the stator and the rotor, we see only dense lines of standard magnetic flux running without any control mechanism to stabilize vibration of the blade rotor during the repulsion-driven operation. SUNON's MagLev motor fan includes just such a control mechanism in its design. This requires that each fan, in addition to standard magnetic flux, contains MagLev flux required to sustain for the unique MagLev orbit in its design.

Where does MagLev flux come from? A MagLev cross-section view reveals a uniquely designed set of conductive elements on the main board-the MagLev plate. This MagLev plate and the imbedded magnets in the fan blades together generate comprehensive vertical magnetic forces, which is the MagLev flux, the unique patented invention of MagLev motor fan. From the cross-section, the standard magnetic flux and MagLev flux form a 90-degree vertical angle, in others words, the MagLev flux acts perpendicular to the standard magnetic flux. This is the first key trait to use to identify a MagLev motor fan. The design of vertically intersected standard magnetic flux and MagLev flux ensures that the rotator is affixed to the MagLev orbit. Therefore, regardless of the mounting angle the fan, the shaft will always rotate around a fixed point and at a constant distance from the bearing without coming in contact with it to produce friction or mechanical noise. The problem of bearings being worn down into an oval shape or horn aperture after long use is effectively resolved.

The greatest benefit with MagLev flux is in fact the 360-degree complete force of attraction between the conductive element (MagLev plate) and the rotor above it. This ensures an evenly-distributed force of attraction to help keep the optimal balance of the rotor during operation and to avoid shuddering or instability. Fans with well-balanced blades not only last longer but produce a steady air flow. In short, the second easy trait for identification of the MagLev motor fan is that the Maglev system creates 3600 attraction on the rotor, which results in stable rotation.

Figure 1:Sleeve Bearing

• Advantages of Sleeve Bearing
  • More impact-resistant, less damage resulted during delivery.
  • Sleeve bearings cost much lower in comparison with ball bearings.
• Imperfections of Sleeve Bearing
  • Dust from outside may penetrated into bearing and mix with nitride particles to clog the motor, which may result in noise and much slower operation of the motor.The inner surface of bearing bore easily gets worn and influences the performance.The space between the shaft and sleeve-bearing bore is small this results in rough uneven start-ups.

   

Ball Bearing

Ball bearing workings utilize small metal balls for rotation. Since they have only point- contacts raotation can be started easily. With the use of springs to hold the outer metal ring of the ball bearing above, the weight of the entire rotor can sit on the ball bearing, indirectly supported by the springs. Therefore, ball bearings are ideal for use in portable devices with various mounting angles. However, caution should be used to prevent the product from falling and impact damaging the ball bearing, which could lead to noise and shortened product life-time.

Figure 2: Ball Bearing

• Advantages of Ball Bearing
  • Steel ball bearings have an operating life much longer than that of sleeve bearings.
  • However, the product must avoid rough handling or being dropped on the ground.
• Imperfections of Ball Bearing
  • Ball bearings are quite weak. It cannot bear any external impact.
  • When the fan motor is operating, the steel balls inside will generate a higher rotational noise than that of a sleeve bearing.
  • High price makes it uneasy to compete with sleeve bearings.
  • Limitation on both supply sources and supply quantities make it unacceptable for mass production needs.
  • The use of tiny assemblies such as springs, result in inefficiencies for mass production.

Sunon is renowned for its revolutionary MagLev System. Here is a good example to help in understanding the principle behind it. When a spinning top (a kind of toy) is thrown, the top continues to accelerate even as it hits the ground. During this acceleration the top tilts and sways until a consistent speed is obtained. At this point, the top will balance its self - e.g. the swaying and tilting have faded - and has become fixed perpendicular to the ground. This is the simple concept that Sunon's MagLev System roots from.

1. MagLev system helps the impeller to rotate evenly in a fixed orbit within the orbit center. Consequently, the shaft inside the Vapo bearing bore turns without creating friction. The bearing bore is hardly ever abraded into irregular or oval shapes such as seen in conventional fans. Hence the operating life of the bearing becomes very long.
2. The shaft inside the bearing bore is in friction with nothing except air, the fan motor starts up easily.
3. This new system removes the use of oil rings and washers, thus leaving space for the release of gas occured during normal operation. No more clogging problems. Hence, the fan motor may operates smoothly for quite a long time.
4. The use of magnet flux and supporting cap creates the same function as ball bearing, therefore, no matter how the fan is placed, no slanting and wobbling occured, which means it's suitable for design in portable applications.
5. Vapo bearings are made of a material specially treated for wear-resistance and impact-resistance. When used in conjunction with the MagLev, it creates a spring function, which helps the fan motor to bear impact.
6. For customized, Vapo bearing with MagLev is capable of an operating temperature of more than 70℃. It also performs very well in a low temperature environment.
7. The elimination of washer and oil ring may also allow the automatic production thus brings manufacturing efficiency.
8. The stable supply from Sunon prevents the inefficiency of supplying from abroad.
9. The Vapo bearing with MagLev design not only features its good quality but also its low cost.
10. The dust cap prevents dust penetrating into bearing and mixing with nitride particles to clog the motor, which may result in noise and slower motor operation.

With the combination of MagLev design and Vapo bearing, all the advantages of ball and sleeve bearings are maintained, while eradicating all the imperfections.

• The impeller rotor is influenced by a magnetic field originating from the MagLev system and is suspended, while rotating in a constant orbit and at a fixed point.
• The weak ball bearing is protected because it is firmly held between the copper ring and the impeller rotor.
• The MagLev flux creates a spring function; therefore, tiny components such as springs are not necessary.
• Dust cap prevents dust in and noise out.