Analysis of a New Magnetic Bearing for Magnetic Levitation Stages

2011 ◽  
Vol 295-297 ◽  
pp. 2106-2111
Author(s):  
Yu Zhu ◽  
Yu Liu ◽  
Ming Zhang
Keyword(s):  
Current Sheet ◽  
Calculation Method ◽  
Magnetic Levitation ◽  
Levitation Force ◽  
Structural Parameters ◽  
Magnetic Bearing ◽  
Magnetic Bearings ◽  
Axial Stiffness ◽  
Equivalent Current ◽  
Ultra Precision

This paper proposed a new configuration of magnetic bearings used in magnetic levitation stages. The equivalent current sheet model is introduced to calculate the levitation force of the proposed magnetic bearing, and the experiment result validates the correctness of the calculation method. The relationships of structural parameters to the levitation force and axial stiffness are studied, which prove that the new magnetic bearing has larger levitation force with lower axial stiffness over the working stroke and could be applied in ultra-precision magnetic levitation stages.

scholarly journals Gain-Scheduled Control of Asymmetric Thrust Magnetic Bearing

Actuators ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 329
Author(s):  
Shuyue Zhang ◽  
Jihao Wu
Keyword(s):  
Control Method ◽  
Magnetic Levitation ◽  
Structural Parameters ◽  
Response Speed ◽  
Magnetic Bearing ◽  
Structure Design ◽  
Magnetic Bearings ◽  
And Performance ◽  
The Cost ◽  
Gain Scheduled

The thrust position of the magnetic levitation rotor can be changed, bringing convenience to the practical application of cold compressors. This paper derives the mathematical model of asymmetric thrust magnetic bearings for a cold compressor and analyzes the changes in the system characteristics with the equilibrium position. By constructing PID controllers associated with the structural parameters of the magnetic bearing, the adaptive adjustment of the control parameters under different balanced position commands is realized. The simulation and experimental results prove that the gain-scheduled control method proposed in this paper can achieve a robust stability of the rotor in the range of 50 to 350 μm, and not at the cost of the response speed, adjustment time, and overshoot. The research results have reference significance for the structure design of asymmetric thrust magnetic bearings and play an important role in the commissioning and performance improvement of cold compressors.

scholarly journals Stiffness Enhancement of a Superconducting Magnetic Bearing Using Shaped YBCO Bulks

2019 ◽  
Author(s):  
James Storey ◽  
Mathieu Szmigiel ◽  
Fergus Robinson ◽  
Stuart C. Wimbush ◽  
Rod Badcock
Keyword(s):  
Permanent Magnet ◽  
High Speed ◽  
Magnetic Levitation ◽  
Levitation Force ◽  
Lateral Force ◽  
Magnetic Bearing ◽  
Restoring Forces ◽  
Bearing Design ◽  
Lateral Displacements ◽  
Stiffness Characteristics

High-speed superconducting motors and generators<br>stand to benefit from superconductor magnetic levitation bearings if their stiffness characteristics can be improved. Here we investigate a novel thrust bearing geometry, comprising a conical frustum shaped permanent magnet and matching superconducting toroid and puck assembly, aimed at producing high stiffness coupled with high levitation force. To this end, we have constructed a bearing test rig enabling measurements of the levitation force and stiffness of the assembly of YBa<sub>2</sub>Cu<sub>3</sub>O<sub>7-d</sub> melt-textured bulks and Nd<sub>2</sub>Fe<sub>14</sub>B permanent magnet at temperatures down to 47 K. The experimental results are supported by finite element modeling that is validated against the experiment, and used to quantify the advantages of this configuration over a conventional cylindrical magnet and HTS puck arrangement.<br>For axial displacements, the assembly produces higher and more consistent stiffness together with stronger restoring forces. For lateral displacements, the assembly produces up to double the lateral force and up to four times the stiffness. Our study also shows that the force contribution to the assembly from the small inner puck is negligible and it can therefore be eliminated from the bearing design.

scholarly journals Stiffness Enhancement of a Superconducting Magnetic Bearing Using Shaped YBCO Bulks

2021 ◽  
Author(s):  
James Storey ◽  
M Szmigiel ◽  
F Robinson ◽  
Stuart Wimbush ◽  
Rodney Badcock
Keyword(s):  
Permanent Magnet ◽  
High Speed ◽  
Magnetic Levitation ◽  
Levitation Force ◽  
Lateral Force ◽  
Magnetic Bearing ◽  
Restoring Forces ◽  
Bearing Design ◽  
Lateral Displacements ◽  
Stiffness Characteristics

© 2002-2011 IEEE. High-speed superconducting motors and generators stand to benefit from superconductor magnetic levitation bearings if their stiffness characteristics can be improved. Here we investigate a novel thrust bearing geometry, comprising a conical frustum shaped permanent magnet and matching superconducting toroid and puck assembly, aimed at producing high stiffness coupled with high levitation force. To this end, we have constructed a bearing test rig enabling measurements of the levitation force and stiffness of the assembly of YBa_2Cu_3O_{7-\delta } melt-textured bulks and Nd_2Fe_{14}B permanent magnet at temperatures down to 47 K. The experimental results are supported by finite element modeling that is validated against the experiment, and used to quantify the advantages of this configuration over a conventional cylindrical magnet and HTS puck arrangement. For axial displacements, the assembly produces higher and more consistent stiffness together with stronger restoring forces. For lateral displacements, the assembly produces up to double the lateral force and up to four times the stiffness. Our study also shows that the force contribution to the assembly from the small inner puck is negligible and it can therefore be eliminated from the bearing design.

scholarly journals Stiffness Enhancement of a Superconducting Magnetic Bearing Using Shaped YBCO Bulks

2021 ◽  
Author(s):  
James Storey ◽  
M Szmigiel ◽  
F Robinson ◽  
Stuart Wimbush ◽  
Rodney Badcock
Keyword(s):  
Permanent Magnet ◽  
High Speed ◽  
Magnetic Levitation ◽  
Levitation Force ◽  
Lateral Force ◽  
Magnetic Bearing ◽  
Restoring Forces ◽  
Bearing Design ◽  
Lateral Displacements ◽  
Stiffness Characteristics

© 2002-2011 IEEE. High-speed superconducting motors and generators stand to benefit from superconductor magnetic levitation bearings if their stiffness characteristics can be improved. Here we investigate a novel thrust bearing geometry, comprising a conical frustum shaped permanent magnet and matching superconducting toroid and puck assembly, aimed at producing high stiffness coupled with high levitation force. To this end, we have constructed a bearing test rig enabling measurements of the levitation force and stiffness of the assembly of YBa_2Cu_3O_{7-\delta } melt-textured bulks and Nd_2Fe_{14}B permanent magnet at temperatures down to 47 K. The experimental results are supported by finite element modeling that is validated against the experiment, and used to quantify the advantages of this configuration over a conventional cylindrical magnet and HTS puck arrangement. For axial displacements, the assembly produces higher and more consistent stiffness together with stronger restoring forces. For lateral displacements, the assembly produces up to double the lateral force and up to four times the stiffness. Our study also shows that the force contribution to the assembly from the small inner puck is negligible and it can therefore be eliminated from the bearing design.

scholarly journals Stiffness Enhancement of a Superconducting Magnetic Bearing Using Shaped YBCO Bulks

2019 ◽  
Author(s):  
James Storey ◽  
Mathieu Szmigiel ◽  
Fergus Robinson ◽  
Stuart C. Wimbush ◽  
Rod Badcock
Keyword(s):  
Permanent Magnet ◽  
High Speed ◽  
Magnetic Levitation ◽  
Levitation Force ◽  
Lateral Force ◽  
Magnetic Bearing ◽  
Restoring Forces ◽  
Bearing Design ◽  
Lateral Displacements ◽  
Stiffness Characteristics

High-speed superconducting motors and generators<br>stand to benefit from superconductor magnetic levitation bearings if their stiffness characteristics can be improved. Here we investigate a novel thrust bearing geometry, comprising a conical frustum shaped permanent magnet and matching superconducting toroid and puck assembly, aimed at producing high stiffness coupled with high levitation force. To this end, we have constructed a bearing test rig enabling measurements of the levitation force and stiffness of the assembly of YBa<sub>2</sub>Cu<sub>3</sub>O<sub>7-d</sub> melt-textured bulks and Nd<sub>2</sub>Fe<sub>14</sub>B permanent magnet at temperatures down to 47 K. The experimental results are supported by finite element modeling that is validated against the experiment, and used to quantify the advantages of this configuration over a conventional cylindrical magnet and HTS puck arrangement.<br>For axial displacements, the assembly produces higher and more consistent stiffness together with stronger restoring forces. For lateral displacements, the assembly produces up to double the lateral force and up to four times the stiffness. Our study also shows that the force contribution to the assembly from the small inner puck is negligible and it can therefore be eliminated from the bearing design.

scholarly journals A Vibration Sensor-Based Method for Generating the Precise Rotor Orbit Shape with General Notch Filter Method for New Rotor Seal Design Testing and Diagnostics

Sensors ◽  
2021 ◽  
Vol 21 (15) ◽  
pp. 5249
Author(s):  
Karel Kalista ◽  
Jindrich Liska ◽  
Jan Jakl
Keyword(s):  
Notch Filter ◽  
Magnetic Bearing ◽  
Magnetic Bearings ◽  
Harmonic Vibration ◽  
Filter Method ◽  
Vibration Exciter ◽  
Active Magnetic Bearings ◽  
Rotor Vibration ◽  
Seal Design ◽  
Exact Shape

Verification of the behaviour of new designs of rotor seals is a crucial phase necessary for their use in rotary machines. Therefore, experimental equipment for the verification of properties that have an effect on rotor dynamics is being developed in the test laboratories of the manufacturers of these components all over the world. In order to be able to compare the analytically derived and experimentally identified values of the seal parameters, specific requirements for the rotor vibration pattern during experiments are usually set. The rotor vibration signal must contain the specified dominant components, while the others, usually caused by unbalance, must be attenuated. Technological advances have made it possible to use magnetic bearings in test equipment to support the rotor and as a rotor vibration exciter. Active magnetic bearings allow control of the vibrations of the rotor and generate the desired shape of the rotor orbit. This article presents a solution developed for a real test rig equipped with active magnetic bearings and rotor vibration sensors, which is to be used for testing a new design of rotor seals. Generating the exact shape of the orbit is challenging. The exact shape of the rotor orbit is necessary to compare the experimentally and numerically identified properties of the seal. The generalized notch filter method is used to compensate for the undesired harmonic vibrations. In addition, a novel modified generalized notch filter is introduced, which is used for harmonic vibration generation. The excitation of harmonic vibration of the rotor in an AMB system is generally done by injecting the harmonic current into the control loop of each AMB axis. The motion of the rotor in the AMB axis is coupled, therefore adjustment of the amplitudes and phases of the injected signals may be tedious. The novel general notch filter algorithm achieves the desired harmonic vibration of the rotor automatically. At first, the general notch filter algorithm is simulated and the functionality is confirmed. Finally, an experimental test device with an active magnetic bearing is used for verification of the algorithm. The measured data are presented to demonstrate that this approach can be used for precise rotor orbit shape generation by active magnetic bearings.

scholarly journals Design, Analysis and Test of a Hyperbolic Magnetic Field Voice Coil Actuator for Magnetic Levitation Fine Positioning Stage

Energies ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1830
Author(s):  
Yiheng Zhou ◽  
Baoquan Kou ◽  
He Zhang ◽  
Lu Zhang ◽  
Likun Wang
Keyword(s):  
Magnetic Field ◽  
High Precision ◽  
Magnetic Levitation ◽  
Structural Parameters ◽  
Industrial Applications ◽  
Degree Of Freedom ◽  
Force Density ◽  
Precision Positioning ◽  
Element Analysis ◽  
Voice Coil Actuator

The multi-degree-of-freedom high-precision positioning system (MHPS) is one of the key technologies in many advanced industrial applications. In this paper, a novel hyperbolic magnetic field voice coil actuator using a rhombus magnet array (HMF-VCA) for MHPS is proposed. Benefiting from the especially designed rhombus magnet array, the proposed HMF-VCA has the advantage of excellent force uniformity, which makes it suitable for multi-degree-of-freedom high-precision positioning applications. First, the basic structure and operation principles of the HMF-VCA are presented. Second, the six-degree-of-freedom force and torque characteristic of the HMF-VCA is studied by three-dimensional finite element analysis (3-D FEA). Third, the influence of structural parameters on force density and force uniformity is investigated, which is conducive to the design and optimization of the HMF-VCA. Finally, a prototype is constructed, and the comparison between the HMF-VCA and conventional VCAs proves the advantage of the proposed topology.

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