Fusion - Active Magnetic Bearings
From Magnetic Bearings
Fully integrated magnetic bearing control system – the controller is built into the bearing housing, simplfying installation. Compact controller can be mounted on or near the machine, simplifies installation and reduces cable length and losses. Standard Ethernet port for ease of communications. Optimized magnetic structure reduces bearing size. Integrated eddy current sensors reduce length of bearing. Health monitoring of coils and amplifiers. Vibration and position monitoring. Rotordynamic condition monitoring and protection. MTBF > 110,000 hour. Synchrony advanced control algorithms for stability under diverse and adverse conditions: Dynamic Force Compensation™, Flux Command™, Inertial Balance™, Magnetic Balance™, Communications protocol: Modbus TCP/IP provides remote monitoring capability. Easy to optimize bearing parameters reduces start-up and commissioning time.
A typical Fusion magnetic bearing system contains the following components:
- Two radial bearings, each consisting of a rotor and a stator, and built-in AMB controller
- One thrust bearing, consisting of a stator and thrust disk, and built-in AMB controller
- Position sensors
- Bearing Power supply
- Uninterruptible Power Supply (battery backup)
- Auxiliary bearings / bushings
- Reduced size
- Onboard AMB controller - built into the bearing housing
- Split thrust bearings
- Motors as prime mover
- High-speed blowers
- Gas turbine engines
- Expansion turbines
- High-speed generators
Reducing The Size Of The Magnetic Bearing
The load capacity of a radial bearing is the product of the rotor diameter, the active length, and the equivalent bearing pressure. Because the bearing pressure of a magnetic bearing is many times less than the bearing pressure of alternatives such as oil-lubricated fluid film bearings, the size will in general be greater for the same load capacity. Also, the end windings and position sensors increase the length of the magnetic bearing beyond the active length.
Through recent design innovations, the size of radial magnetic bearings has been reduced by more than 30 percent. The bearing pressure for radial bearings has been improved by increasing the amount of electrical steel at the bore of the stator where the force is created. At the same time, the outer diameter of the stator has been reduced by splitting the flux paths and isolating the electromagnets. Finally, the length of the radial magnetic bearing has been reduced by developing position sensors that can be integrated into the electromagnets.