scholarly journals A Review of the High-speed Permanent Magnet Rotor Stress Analysis used for Automotive Air-handling Machines

2020 ◽  
Vol 5 (4) ◽  
pp. 448-456
Author(s):  
Levi Ryan Mallin ◽  
Simon Mark Barrans
Keyword(s):  
Permanent Magnet ◽  
Plane Strain ◽  
High Speed ◽  
Element Analysis ◽  
Interference Fit ◽  
Centrifugal Load ◽  
High Speed Rotation ◽  
Speed Rotation ◽  
Rotor Assembly ◽  
Analytical Approaches

Machines incorporating high-speed electrical machines (HSEM) are becoming increasingly common place in applications including air handling, energy storage and medical devices. They are of increasing interest within the automotive field for air handling applications. HSEM’s use surface-mounted permanent magnet (PM) rotors, manufactured from rare earth metals. However, these PM’s have low tensile strength and are susceptible to failure under the centrifugal load produced at high speed rotation. Retaining sleeves which are an interference fit around the magnets, provide compression and hence resistance to tensile stress. The ability to predict the stresses within the rotor assembly is essential for robust design. This review paper examines existing analytical calculations and finite element analysis (FEA) models. The analytical approaches include both plane stress and plane strain models and the limitations of these are discussed. For relatively long rotors, a generalised plane strain approach is suitable, however it is seldom used. In addition, this latter approach has not been extended to assemblies where the magnets are assembled onto a carrier or shaft. Optimisation of rotors has been addressed in a relatively small number of papers. However, further work is required in this area to ensure that the optimised rotors can be manufactured.

Study on Interference Fit of Composite Flywheel Rotor

2012 ◽  
Vol 215-216 ◽  
pp. 302-306
Author(s):  
Shao Bo Wen
Keyword(s):  
Stress Distribution ◽  
Calculation Method ◽  
High Speed ◽  
Material Failure ◽  
Interference Fit ◽  
Composite Flywheel ◽  
Press Fit ◽  
High Speed Rotation ◽  
Speed Rotation ◽  
Flywheel Rotor

The combination of composite rotor and mounting shaft is mainly realized by press fit. In the paper, the initial stress distribution of interference fit between composite rotor and mounting shaft, the centrifugal stress due to high speed rotation are studied systematically. Based on the principles of material failure and detachment constraint at high speed rotation, a calculation method for the appropriate interference is proposed. Finally, specific example is analyzed to verify the feasibility of this method.

scholarly journals Comparison of theoretical approaches to determine the stresses in surface mounted permanent magnet rotors for high speed electric machines

2021 ◽  
pp. 030932472110076
Author(s):  
Levi Mallin ◽  
Simon Barrans
Keyword(s):  
Permanent Magnet ◽  
Plane Strain ◽  
Plane Stress ◽  
High Speed ◽  
Electric Machines ◽  
Mechanical Transmission ◽  
Element Analysis ◽  
Theoretical Approaches ◽  
Rotor Design ◽  
Stress Plane

High-speed electrical machines (HSEMs) are becoming more popular in applications such as air handling devices. Using surface-mounted permanent magnet (PM) rotors manufactured from rare earth metals, they provide benefits over their mechanical transmission counterparts. However, these PMs have low tensile strength and are prone to failure under large centrifugal loads when rotating. Therefore, retaining sleeves are used to hold the PMs in compression to eliminate tensile stress and reduce failure risk. The magnets are also often held on a back iron or carrier, forming an assembly of three cylinders. The ability to predict these stresses is extremely important to rotor design. Current published work shows a lack of exploration of analytical methods of calculating these stresses for three-cylinder assemblies. This paper shows the development of plane stress, plane strain and generalised plane strain (GPS) theories for three cylinders. For a range of rotor designs, these theories are compared with finite element analysis (FEA). GPS is shown to be more accurate than plane stress or plane strain for the central region of long cylinders. For short cylinders and for the ends of cylinders, all three theories give poor results.

Finite-Element Analysis of Arranging Intermediate Cuttings Tool of Circular Saw Web and Wedge Disc

2013 ◽  
Vol 631-632 ◽  
pp. 1068-1072
Author(s):  
Yan Wu ◽  
Yan Ma
Keyword(s):  
Finite Element Analysis ◽  
High Speed ◽  
Working Condition ◽  
Three Dimensional ◽  
Element Analysis ◽  
Three Dimensional Modeling ◽  
Circular Saw ◽  
Dimensional Modeling ◽  
High Speed Rotation ◽  
Speed Rotation

When the intermediate cuttings cut the wood, the efficiency of the vibration of the circular saw web was low so that the saw web always broke off. Moreover, the high-speed rotation would cause the vibration of the complete machine and result in the initial failure of the machine. Therefore, seeing from the problems from the analysis above and practice, the new design of the current micro intermediate cuttings seemed especially important. In the thesis, the author made a new arrangement of the micro intermediate cuttings of machinery tools, carrying out three-dimensional modeling and simulation of the complete machine and made an analysis of the dynamic cutting process by means of analyzing the working condition of circular saw web.

Energy Conversion for Gas Isentropic Compression Process with High Speed Rotation

2013 ◽  
Vol 336-338 ◽  
pp. 899-906
Author(s):  
Haakon Karlsen ◽  
Tao Dong
Keyword(s):  
Energy Conversion ◽  
High Speed ◽  
Stokes Equations ◽  
Ideal Gas ◽  
Navier Stokes ◽  
Compression Process ◽  
Element Analysis ◽  
Isentropic Compression ◽  
High Speed Rotation ◽  
Speed Rotation

Energy conversion from rotational to thermal is investigated for a compressible ideal gas. The high speed rotation is considered as the driven force of the isentropic compression. The analytical model explaining the thermodynamic parameters (pressure, pressure gradient, density, and especially temperature) are developed. The analytical results are compared with the simulation data obtained from Finite Element Analysis, which employs compressible Navier-Stokes equations and heat equation. A good accordance between the analytical and FEA results has been observed. And it shows a predictable beginning and end state for the isentropic rotation process.

The Performance of the Hydraulic Expansion Toolholder in High-Speed Rotation

2011 ◽  
Vol 188 ◽  
pp. 457-462 ◽  
Author(s):  
Shu Lin Wang ◽  
Wei Zhan Zhang ◽  
Qin Zhang ◽  
G. Liu ◽  
Z.J. Yang
Keyword(s):  
Finite Element Analysis ◽  
High Speed ◽  
Rotation Speed ◽  
Analysis Software ◽  
Element Analysis ◽  
Fluid Analysis ◽  
High Speed Rotation ◽  
Speed Rotation ◽  
High Rotation Speed ◽  
Pressure Changes

On the basis of finite element analysis, the static transmitted torque of Hydraulic Expansion Toolholder is validated. At the same time fluid analysis software is used to investigate the oil pressure changes in oil chamber wall because of different rotation speed. Then through the fluid-solid coupling, the article analyzes the chuck clamping performance on the factors of expansion chuck and tool clearance, rotation speed, and hydraulic oil pressure when toolholder on the state of high rotation speed.

Performance analysis of magnetic gear with Halbach array for high power and high speed

2020 ◽  
Vol 64 (1-4) ◽  
pp. 959-967
Author(s):  
Se-Yeong Kim ◽  
Tae-Woo Lee ◽  
Yon-Do Chun ◽  
Do-Kwan Hong
Keyword(s):  
Permanent Magnet ◽  
Eddy Current ◽  
High Power ◽  
High Speed ◽  
Torque Ripple ◽  
Eddy Current Loss ◽  
Element Analysis ◽  
Current Loss ◽  
Halbach Array ◽  
Magnetic Gear

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.

scholarly journals Sound Noise Generated from Ball Bearing in High Speed Rotation

1978 ◽  
Vol 21 (158) ◽  
pp. 1306-1310 ◽  
Author(s):  
Akio NAGAMATSU ◽  
Masaho FUKUDA
Keyword(s):  
High Speed ◽  
Ball Bearing ◽  
High Speed Rotation ◽  
Speed Rotation

Analysis of the Lubrication Regimes at the Small End and Big End of a Connecting Rod of a High Performance Motorbike Engine

2012 ◽  
Author(s):  
Luca Bertocchi ◽  
Matteo Giacopini ◽  
Daniele Dini
Keyword(s):  
Rotational Speed ◽  
High Speed ◽  
High Performance ◽  
Hydrodynamic Lubrication ◽  
Vertical Axis ◽  
Connecting Rod ◽  
Lubrication Regimes ◽  
High Speed Rotation ◽  
Speed Rotation ◽  
Squeeze Effect

In the present paper, the algorithm proposed by Giacopini et. al. [1], based on a mass-conserving formulation of the Reynolds equation using the concept of complementarity is suitably extended to include the effects of compressibility, piezoviscosity and shear-thinning on the lubricant properties. This improved algorithm is employed to analyse the performance of the lubricated small end and big end bearings of a connecting rod of a high performance motorbike engine. The application of the algorithm proposed to both the small end and the big end of a con-rod is challenging because of the different causes that sustain the hydrodynamic lubrication in the two cases. In the con-rod big end, the fluid film is mainly generated by the relative high speed rotation between the rod and the crankshaft. The relative speed between the two races forms a wedge of fluid that assures appropriate lubrication and avoids undesired direct contacts. On the contrary, at the con-rod small end the relative rotational speed is low and a complete rotation between the mating surfaces does not occurs since the con-rod only oscillates around its vertical axis. Thus, at every revolution of the crankshaft, there are two different moments in which the relative rotational speed between the con-rod and the piston pin is null. Therefore, the dominant effect in the lubrication is the squeeze caused by the high loads transmitted through the piston pin. In particular both combustion forces and inertial forces contribute to the squeeze effect. This work shows how the formulation developed by the authors is capable of predicting the performance of journal bearings in the unsteady regime, where cavitation and reformation occur several times. Moreover, the effects of the pressure and the shear rate on the density and on the viscosity of the lubricant are taken into account.

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