Magnetic levitation keeps cooling fans quiet

Sunonwealth Electric Machine Co has been developing fans, blowers, thermal management and micromotors for 22 years, and has become synonymous with precision micromotor cooling devices.

Sunonwealth Electric Machine Co has been developing fans, blowers, thermal management and micromotors for 22 years, and has become synonymous with precision micro-motor cooling devices in professional fields.

Sunon's cooling products are used in a broad variety and growing number of computer, networking, industrial electronics applications, telecommunications equipment and consumer electronics.

Today, Sunon provides the industry's broadest range of fans and blowers with award-winning innovative technologies such as MagLev, which helps create a low-noise, space-saving, cost-effective cooling environment.

Between Q4 of 1999 and 2002, 50 million Sunon MagLev motor fans were sold to the market.

Innovation is Sunon's cornerstone.

Alex Hong the company's CEO places research and development above all else to create market leading precision miniature cooling fans.

520 patents have been obtained in 23 countries and another 520 are pending.

Among all the technologies developed, MagLev technology could be viewed as Sunon's most advanced and unrivalled innovation.

For decades, friction and noise have been the root defects for conventional fan motors.

Usually after long-term operation, abrasions can be caused by the rub between the shaft and the inner surface of the bearing, creating the noise and sway common in many convention fan motors.

Sunonwealth set out to develop a new motor structure to breakthrough this impasse and root out the imperfections of conventional fan motors.

From this commitment and background MagLev has come in to its own.

When motor with MagLev technology is in operation, the magnetic force between the permanent magnet in the hub and the magnetic plate mounted on the PCB helps to attract the impeller rotor towards the end point of shaft.

The weight of the rotor is entirely neutralised by the magnetic force and enables the shaft to turn without being affected by the gravity.

In this way, a constant distance between bearing and shaft is maintained naturally without causing any contact between the two surfaces.

Therefore, when the fan is operating, the highly balanced rotor assembly rotates in nearly a perfect circular motion in a consistent orbit.

The centre of rotation of the rotor shaft is the true centreline of the shaft and the bearing assembly.

This phenomenon eliminates any rotational vibration and abrasions between the shaft and the inner surface of the bearing even in any mounted position.

Accordingly, the MagLev system creates unprecedented vibration-free (and therefore noise-free) operating conditions for the fan.

This is particularly interesting to both the PC and IT sectors of industry for thermal management control.

Because the shaft rotates evenly in a constant orbit and the rotor is held at a fixed centreline of rotation, no contact occurs.

No matter how the fan is mounted, during operation there is no friction or noise, and no slanting or wobbling.

Which means the bearing life is greatly extended.

The Sunon MagLev system can be used in conjunction with all kinds of conventional motors, regardless of whether it uses sleeve bearings or ball bearings.

It also works particularly well with Sunon's proprietary Vapo bearing, which features a specially treated inner surface for wear and impact resistance.

Furthermore, the use of the Vapo bearing with MagLev system removes the need to use oil rings and Mylar washers.

This reduces not only excess friction, but also helps to evaporate and release from the assembly the high temperature gas which originates from the lubricating oil.

(If not released properly before being solidified, the oil would release nitride particles and clog the gap between shaft and bearing bore).

By adopting the new design, it is very easy to prevent problems of sticking rotors and excessive noise generation.

Because of the outstanding performance while operating, Vapo bearings (with the MagLev system inside) are now widely applied throughout Sunon's motors.

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