Generalized Three-Dimensional Mathematical Models for Force and Stiffness in Axially, Radially, and Perpendicularly Magnetized Passive Magnetic Bearings With “n” Number of Ring Pairs

2016 ◽  
Vol 138 (3) ◽  
Author(s):  
Siddappa I. Bekinal ◽  
Soumendu Jana

This work deals with generalized three-dimensional (3D) mathematical model to estimate the force and stiffness in axially, radially, and perpendicularly polarized passive magnetic bearings with “n” number of permanent magnet (PM) ring pairs. Coulombian model and vector approach are used to derive generalized equations for force and stiffness. Bearing characteristics (in three possible standard configurations) of permanent magnet bearings (PMBs) are evaluated using matlab codes. Further, results of the model are validated with finite element analysis (FEA) results for five ring pairs. Developed matlab codes are further utilized to determine only the axial force and axial stiffness in three stacked PMB configurations by varying the number of rings. Finally, the correlation between the bearing characteristics (PMB with only one and multiple ring pairs) is proposed and discussed in detail. The proposed mathematical model might be useful for the selection of suitable configuration of PMB as well as its optimization for geometrical parameters for high-speed applications.

2017 ◽  
Vol 139 (3) ◽  
Author(s):  
Siddappa I. Bekinal ◽  
Mrityunjay Doddamani ◽  
Soumendu Jana

This work deals with optimization of axially magnetized stack structured permanent magnet (PM) thrust bearing using generalized three-dimensional (3D) mathematical model having “n” number of ring pairs. The stack structured PM thrust bearing is optimized for the maximum axial force and stiffness in a given cylindrical volume. matlab codes are written to solve the developed equations for optimization of geometrical parameters (axial offset, number of ring pairs, air gap, and inner radius of inner and outer rings). Further, the results of proposed optimization method are validated using finite element analysis (FEA) and further, generalized by establishing the relationship between optimal design variables and air gap pertaining to cylindrical volume constraint of bearing's outer diameter. Effectiveness of the proposed method is demonstrated by optimizing PM thrust bearing in a given cylindrical volume. Mathematical model with optimized geometrical parameters dealt in the present work helps the designer in developing PM thrust bearings effectively and efficiently for variety of applications.


Author(s):  
Ömer Faruk Güney ◽  
Ahmet Çelik ◽  
Ahmet Fevzi Bozkurt ◽  
Kadir Erkan

This paper presents the electromagnetic and mechanical analysis of an axial flux permanent magnet (AFPM) motor for high speed (12000 rpm) rotor which is vertically suspended by magnetic bearings. In the analysis, a prototype AFPM motor with a double-sided rotor and a coreless stator between the rotors are considered. Firstly, electromagnetic analysis of the motor is carried out by using magnetic equivalent circuit method. Then, the rotor disk thickness is determined based on a rotor axial displacement due to the attractive force between the permanent magnets placed on opposite rotor disks. Hereafter, an analytical solution is carried out to determine the natural frequencies of the rotor-shaft system. Finally, 3D finite element analysis (FEA) is carried out to verify the analytical results and some experimental results are given to verify the analytical and numerical results and prove the stable high-speed operation.


Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5872 ◽  
Author(s):  
Nai-Wen Liu ◽  
Kuo-Yuan Hung ◽  
Shih-Chin Yang ◽  
Feng-Chi Lee ◽  
Chia-Jung Liu

Different from the design of conventional permanent magnet (PM) motors, high-speed motors are primarily limited by rotor unbalanced radial forces, rotor power losses, and rotor mechanical strength. This paper aimed to propose a suitable PM motor with consideration of these design issues. First, the rotor radial force is minimized based on the selection of stator tooth numbers and windings. By designing a stator with even slots, the rotor radial force can be canceled, leading to better rotor strength at high speed. Second, rotor power losses proportional to rotor frequency are increased as motor speed increases. A two-dimensional sensitivity analysis is used to improve these losses. In addition, the rotor sleeve loss can be minimized to less than 8.3% of the total losses using slotless windings. Third, the trapezoidal drive can cause more than a 33% magnet loss due to additional armature flux harmonics. This drive reflected loss is also mitigated with slotless windings. In this paper, six PM motors with different tooth numbers, stator cores, and winding layouts are compared. All the design methods are verified based on nonlinear finite element analysis (FEA).


Author(s):  
Siddappa Iranna Bekinal ◽  
Mrityunjay Doddamani ◽  
Mohan Vanarotti ◽  
Soumendu Jana

Optimization of rotational magnetized direction permanent magnet thrust bearing configuration is carried out using generalized three-dimensional mathematical model. The bearing features namely axial force and stiffness are maximized using in-house developed mathematical expressions solved using MATLAB. The design variables selected for the optimization are axial offset, number of ring pairs, air gap and inner radius of inner and outer rings. The maximized axial force values of the optimized configuration are validated with the finite element analysis results. To overcome the high computational cost associated with three-dimensional equations, generalized method of optimization is sucessfully demonstrated using plots representing variation of optimal design variables as a function of air gap with respect to bearing’s outer diameter. Simple and useful method of using the generalized plots for the process of optimization is presented by dimension optimization of representative bearing configuration with a particular aspect ratio. The proposed optimization using mathematical model and generalized approach assists designer in selecting optimized geometrical parameters of rotational magnetized direction thrust bearing configurations easily for variety of high-speed applications.


2016 ◽  
Vol 65 (2) ◽  
pp. 249-261 ◽  
Author(s):  
Adrian Mlot ◽  
Marian Lukaniszyn ◽  
Mariusz Korkosz

Abstract This paper presents a finite element investigation into the proximity losses in a high-speed permanent magnet (PM) machine for traction applications. A three-dimensional (3D) finite element analysis (FEA) is employed to evaluate and identify the endwinding contribution into the overall winding power loss generated. The study is focused on the end-winding effects that have not been widely reported in the literature. The calculated results confirm that the end-winding copper loss can significantly affect the eddycurrent loss within copper and it should be taken into account to provide reasonable prediction of total losses. Several structures of the end-winding are analyzed and compared in respect to the loss and AC resistance. The results clearly demonstrate that the size of the end-winding has a significant impact on the power loss. The calculated results are validated experimentally on the high-speed permanent magnet synchronous machine (PMSM) prototype for selected various winding arrangements.


2020 ◽  
Vol 64 (1-4) ◽  
pp. 959-967
Author(s):  
Se-Yeong Kim ◽  
Tae-Woo Lee ◽  
Yon-Do Chun ◽  
Do-Kwan Hong

In this study, we propose a non-contact 80 kW, 60,000 rpm coaxial magnetic gear (CMG) model for high speed and high power applications. Two models with the same power but different radial and axial sizes were optimized using response surface methodology. Both models employed a Halbach array to increase torque. Also, an edge fillet was applied to the radial magnetized permanent magnet to reduce torque ripple, and an axial gap was applied to the permanent magnet with a radial gap to reduce eddy current loss. The models were analyzed using 2-D and 3-D finite element analysis. The torque, torque ripple and eddy current loss were compared in both models according to the materials used, including Sm2Co17, NdFeBs (N42SH, N48SH). Also, the structural stability of the pole piece structure was investigated by forced vibration analysis. Critical speed results from rotordynamics analysis are also presented.


Author(s):  
Jifeng Wang ◽  
Qubo Li ◽  
Norbert Mu¨ller

A mechanical and optimal analyses procedure is developed to assess the stresses and deformations of Novel Wound Composite Axial-Impeller under loading conditions particular to centrifuge. This procedure is based on an analytical method and Finite Element Analysis (FEA, commercial software ANSYS) results. A low-cost, light-weight, high-performance, composite turbomachinery impeller from differently designed patterns will be evaluated. Such impellers can economically enable refrigeration plants using water as a refrigerant (R718). To create different complex patterns of impellers, MATLAB is used for creating the geometry of impellers, and CAD software UG is used to build three-dimensional impeller models. Available loading conditions are: radial body force due to high speed rotation about the cylindrical axis and fluid forces on each blade. Two-dimensional plane stress and three-dimensional stress finite element analysis are carried out using ANSYS to validate these analytical mechanical equations. The von Mises stress is investigated, and maximum stress and Tsai-Wu failure criteria are applied for composite material failure, and they generally show good agreement.


Author(s):  
Dinh Hai Linh

In this paper, a type interior permanent magnet synchronous motor designs is proposed for sport scooter application to improve constant torque wide speed performance. Interior Permanent Magnet machines are widely used in automotive applications for their wide-speed range operation and low maintenance cost. An existing permanent magnet motor (commercial QS Motor) is 3 kW-3000 rpm. In order to improve torque and power in wide speed range, a IPM electric motor 5.5 kW -5000 rpm can run up to 100 km/h: An Step-Skewing Interior Permanent Magnet motor alternatives is designed and optimized in detail with optimal magnetic segment V shape. The electromagnetic charateristics of Interior Permanent Magnet motors with V shape are compared with the reference Surface Permanent Magnet motor for the same geometry parameter requirements. Detailed loss and efficiency result is also analyzed at rate and maximum speeds. A prototype motor is manufactured, and initial experimental tests are performed. Detailed comparison between Finite Element Analysis and test data are also presented. It is shown that it is possible to have an optimized Interior Permanent Magnet motor for such high-speed traction application. This paper will figure out optimal angle of magnetic V shape for maximum torque and minimum torque ripple.


2010 ◽  
Vol 129-131 ◽  
pp. 256-260
Author(s):  
Yi Shu Hao ◽  
Chuang Hai ◽  
Xin Xing Zhu

Treating high speed milling theory as the guidance, this paper researched high speed milling process of bracket part based on UG NX. Combined with the structural features of bracket part, three dimensional model is built by UG NX CAD and machining processes are worked out after analysis. UG CAM module was applied to fabricate tool paths. At last, finite element analysis method is introduced to study the processing deformation by UG NX NASTRAN module, based on which measures to restrain processing deformations is advanced and processing sequences are optimized.


Author(s):  
L. Goteti ◽  
J. Choi ◽  
J. Park

Snap-fit integral attachments are used widely for joining plastic parts. The proliferated use of integral attachment in the form of snap-fit features in designs is due to the ability to mould such parts of great complexity at little cost. The exceptional diversity of part geometry and integral snap-fit features has made it seem that design possibilities may be unlimited. Thus, attempts at optimization might be intractable. A design of experiments (DOE) approach coupled with three-dimensional, geometrical non-linear finite element analysis (FEA) was used to calculate the insertion and retention responses on such parts for various geometrical parameters like length, width and angles. A statistical technique was employed to formulate empirical relationships among the geometrical dimensions, to investigate the effect of these parameters on the design as well as to obtain optimal insertion and retention forces or strains. Design equations obtained from this methodology were verified within the DOE domain and it was observed that the predicted responses were ranged within 30% of the FEA results. During this investigation, it was observed that geometrical features of a block, which exert force on the snap-fit features, have a considerable effect on the results. Therefore, the effects of the block parameters on the various responses were also studied. An attempt was also made to understand the effect of the block parameters such as corner radius and thickness on the design formula, which depicts the geometrical parameters of the snap-fit part as a function of insertion and retention forces. It is expected that the results help to find optimal design parameters in order to enhance the performance of such snap-fit features.


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