Design improvement of synchronous reluctance machines with internal rotor flux barriers for high-speed drives

2003 ◽  
Author(s):  
E. Schmidt ◽  
W. Brandl ◽  
C. Grabner
Keyword(s):  
High Speed ◽  
Design Improvement ◽  
Rotor Flux ◽  
Internal Rotor

Internal Rotor Friction Induced Instability in High-Speed Rotating Machinery

1993 ◽  
Author(s):  
James F. Walton ◽  
Michael R. Martin
Keyword(s):  
Internal Friction ◽  
Natural Frequency ◽  
High Speed ◽  
Critical Speed ◽  
Rotating Machinery ◽  
Rotor System ◽  
Analytical Models ◽  
Interference Fit ◽  
Internal Rotor

Abstract Results of a program to investigate internal rotor friction destabilizing effects are presented. Internal-friction-producing joints were shown to excite the rotor system first natural frequency, when operating either below or above the first critical speed. The analytical models used to predict the subsynchronous instability were also confirmed. The axial spline joint demonstrated the most severe subsynchronous instability. The interference fit joint also caused subsynchronous vibrations at the first natural frequency but these were bounded and generally smaller than the synchronous vibrations. Comparison of data from the two test joints showed that supersynchronous vibration amplitudes at the first natural frequency were generally larger for the interference fit joint than for the axial spline joint. The effects of changes in imbalance levels and side loads were not distinguishable during testing because amplitude-limiting bumpers were required to restrict orbits.

scholarly journals Analysis and design improvement of high class roads’ arched sections in Poland

2018 ◽  
Vol 63 ◽  
pp. 00003
Author(s):  
Joanna Żukowska ◽  
Paweł Słomiński
Keyword(s):  
Road Safety ◽  
High Speed ◽  
Road Network ◽  
Social Consequences ◽  
Road Accidents ◽  
Vertical Alignment ◽  
Complex Issue ◽  
Analysis And Design ◽  
Design Improvement ◽  
Road Geometry

Although Polish road network standards, in particular higher classes of roads are improving dynamically the number of fatalities on the network is still higher that EU’s average. Ensuring road safety and high maintaining standards is a complex issue and one that poses a major challenge for all road authorities. Road accidents at high speed roads characterize specially serious material and social consequences, thus research into road safety is of a special interest and numerous analyses and debates are being conducted worldwide as well as in Poland. In this paper the authors provide the results and recommendations coming from the analysis of accidents which happened on high speed roads during the heavy rainfall. The analysis of incidents which happened on sections with changing vertical alignment shows that a properly designed road geometry does not eliminate road accidents or conflicts.

The Influence of Internal Friction on the Stability of High Speed Rotors With Anisotropic Supports

1969 ◽  
Vol 91 (4) ◽  
pp. 1105-1113 ◽  
Author(s):  
E. J. Gunter ◽  
P. R. Trumpler
Keyword(s):  
Internal Friction ◽  
High Speed ◽  
Equations Of Motion ◽  
Three Dimensional ◽  
Analog Computer ◽  
Three Dimensional Model ◽  
Stiffness Properties ◽  
Stiffness Characteristics ◽  
The Stability ◽  
Internal Rotor

This paper evaluates the stability of the single mass rotor with internal friction on damped, anisotropic supports. The paper shows under what conditions the rotor stability may be improved by an undamped support with anisotropic stiffness properties. A three dimensional model is presented to show the influence of rotor and support stiffness characteristics on stability. Curves are also presented on how support damping may also improve or even reduce rotor stability. An analog computer solution of the governing equations of motion is presented showing the shaft transient motion for various speed ranges, and also plots of the rotor steady state motion are given for various speeds up to and including the stability threshold. The analysis is used to explain many of the experimental observations of B. L. Newkirk concerning stability due to internal rotor friction.

DOE-FEM based design improvement to minimize thermal errors of a high speed spindle system

2018 ◽  
Vol 8 ◽  
pp. 525-536 ◽  
Author(s):  
An-Shik Yang ◽  
Xin-Han Yu ◽  
Jyun-Rong Zhuang ◽  
Chun-Ying Lee ◽  
Wen-Hsin Hsieh
Keyword(s):  
High Speed ◽  
Spindle System ◽  
Design Improvement ◽  
Thermal Errors
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