터보맥스

Air Bearing

The core technology of turbo blowers is air bearing. During high-speed rotation, a hydrodynamic pressure is formed between the shaft and the journal bearing. The air bearing is a non-contact that does not cause friction in the rotor, so suitable for semi-permanent operation because no wear occurs during rotation. Clean air can be produced since air acts as a lubricant instead of oil.

During On/Off

Bearing supports shaft, which forms small preload between the shaft and bearing, and the shaft comes into contact with the journal bearing surface in case of on/off.

Acceleration

When the rotor begins to accelerate, the air foil between the shaft and the journal bearing levitates the shaft by Dynamic Pressure, which generates a Wedge effect.

High Speed Rotation

The support force of the air foil bearing increases in proportion to the rotational speed. At this time, the air foil acts as cooling and lubrication, so continuous operation is possible without additional cooling system.

Nano Silver Triple treatment Bearing

The air bearing is the integral parts that determine the reliability and durability of the high speed turbo blower. NSTB+ technology sets apart from other competing air bearings. By Nano Silver particle coating and 3 stage OTT heat treatment, the durability, elasticity and abrasion characteristic of the air bearing significantly improved. In addition, its reversible rotation feature added more resistant to damage caused by reverse rotation that occurs during initial startup and the mechanical surge.

Nano Silver Coating

Adding the Nano Silver particle coating layer to the existing Teflon(PTFE) coating to lower the abrasion. Nano-silver coating reduces the wear rate of the bearing surface by 1/5 with excellent lubrication function, actually increasing the number of on/off times, extending the bearing life.

Optimized 3-stage Heat Treatment

The mechanical property of the typical bump bearing material was formed from 2-stage heat treatment. When there are frequent on/offs required in the applications, the over-worked bump material could be fatigued, cracked or deformed. On the other hand, TurboMAX NSTB+ went through 3-stage OTT(Optimized Triple Heat Treatment) to increase the hardness and the yield strength of the bump material. The NSTB+ has significantly improved the recovery elasticity and material durability for the frequent on/offs needed in today’s processes.

Improvement of Abrasion, Elasticity and Durability

Because of the outstanding elasticity of NSTB+, the bearing curvature form and contact area of NTSB+ can be maximized compared to other bump bearings even at the frequent On/Offs.

Reversible rotation bearing

Reverse rotation in the surge

Reverse rotation occurs when PMSM detects polarity.

The previous generation of air bearing could only be rotated in one direction. Therefore, it was vulnerable to damage due to the characteristics of a permanent magnet synchronization motor (PMSM), which rotates minutely to find polarity when starts up. Also, against a sudden surge which inhaled air is discharged in reverse. To overcome the vulnerability, TurboMAX has developed NSTB+ allowing the reverse rotation. The feature improved the durability of large horsepower products (300hp to 1,000hp).

Drastically increased bearing On/Off life

When tested NSTB+ in 400hp model, there was 30% wore on the coating without any deformation of the bearing after 55,000 On/Offs.
The expected On/Off life of the NSTB+ is over 100,000 on 400hp model. The On/Off life of smaller models are much higher.