This paper shows how simulation of screw rotor profile manufacturing can be used in the design phase to assess profile alternatives. To do this, variations in manufacturing parameters are studied to illustrate how these deviations affect different rotor profile shapes and the resulting rotor pair clearances. INTRODUCTION Clearances between rotors in a twin screw compressor play a key role in de...

Rotating electrical machines play an important role in the world’s industrial life. Hence there is a strong demand on their reliable and safe operation. Their faults and failures can lead to excessive downtimes and generate enormous costs in reduced output, emergency maintenance and lost revenues. Therefore the fault detection methods of electrical machines are of real interest. For the rotor f...

Some large wind turbines use a low speed synchronous generator, directly-coupled to the turbine, and a fully rated converter to transform power from the turbine to mains electricity. This paper considers the condition monitoring and diagnosis of mechanical and electrical faults in such a variable speed machine. The application of wavelet transforms is investigated because of the disadvantages o...

The most severe damage of the turbine rotor is its distortion. The rotor straightening process must lead, at the first stage, to removal of the stresses from the material by annealing and next, to straightening of the plastic distortion without leaving any stress by hot spotting. The straightening method does not produce stress accumulations and the heating technique, developed specifically for...

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The behavior of a railway traction squirrel cage induction motor under rotor fault conditions is simulated by a complete phase model. A simple and direct procedure for model parameters identification by finite elements method (FEM) is described.

A rotor that accepts and automatically processes a bulk aliquot of a single blood sample into multiple aliquots of plasma has been designed and built. The rotor consists of a central processing unit, which includes a disk containing eight precision-bore capillaries. By varying the internal diameters of the capillaries, aliquot volumes ranging 1 to 10 mul can be prepared. In practice, an unmeasu...

Abstract: Bottom-fixed vertical rotating devices are widely used in industrial and civilian fields. The free upside of the rotor will cause vibration and lead to noise and damage during operation. Meanwhile, parameter uncertainties, nonlinearities and external disturbances will further deteriorate the performance of the rotor. Therefore, in this paper, we present a rotor orientation control sys...

The internal structure and dynamics of rotors that form in the lee of topographic ridges are explored using a series of high-resolution eddy-resolving numerical simulations. Surface friction generates a sheet of horizontal vorticity along the lee slope that is lifted aloft by the mountain lee wave at the boundary layer separation point. Parallel-shear instability breaks this vortex sheet into s...

Friction between contacting surfaces of metal materials restricts the application of mechanical support in the high-precision inertial device of a rotational gyroscope. Instead, a diskor ring-shaped rotor is electrostatically or magnetically suspended. However, stability of the rotor suspension restricts further improvement of the measurement precision. In the developed rotational gyroscope, a ...