The Effect of Drain Orifice Damping on the Performance Characteristics of a Servovalve Flapper/Nozzle Stage

1987 ◽  
Vol 109 (1) ◽  
pp. 19-23 ◽  
Author(s):  
J. Watton
Keyword(s):  
Steady State ◽  
Dynamic Characteristics ◽  
High Frequency ◽  
Performance Characteristics ◽  
Sufficient Condition ◽  
Supply Pressure ◽  
Design Characteristics ◽  
Possible Cause ◽  
Steady State Performance ◽  
Motor Dynamics

The effect of a return line orifice on the steady-state performance and dynamic characteristics of a servovalve flapper/nozzle stage is investigated. Generalized design characteristics are initially developed and a specific application is then pursued by including torque motor dynamics. The possible cause of high frequency whistle within such systems is then discussed. A sufficient condition for valve whistle is established and shown to be critically dependent upon the supply pressure.

Steady State Performance Characteristics of a Tilting Pad Thrust Bearing

2000 ◽  
Vol 123 (3) ◽  
pp. 608-615 ◽  
Author(s):  
Sergei B. Glavatskikh
Keyword(s):  
Steady State ◽  
Film Thickness ◽  
Thrust Bearing ◽  
Operating Conditions ◽  
Performance Characteristics ◽  
Shaft Speed ◽  
Oil Film ◽  
Tilting Pad ◽  
Bearing Load ◽  
Steady State Performance

The paper reports results of the experimental investigation into the steady state performance characteristics of a tilting pad thrust bearing typical of design in general use. Simultaneous measurements are taken of the pad and collar temperatures, the pressure distributions, oil film thickness, and power loss as a function of shaft speed, bearing load, and supplied oil temperature. The effect of operating conditions on bearing performance is discussed. A small radial temperature variation is observed in the collar. A reduction in minimum oil film thickness with load is approximately proportional to p−0.6, where p is an average bearing pressure. It has also been found that the oil film pressure profiles change not only due to the average bearing load but also with an increase in shaft speed and temperature of the supplied oil.

scholarly journals Performance Characteristics of Single-Phase Self-Excited Induction Generators with an Iron Core of Various Non-Grain Oriented Electrical Sheets

Energies ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3166
Author(s):  
Krzysztof Makowski ◽  
Aleksander Leicht
Keyword(s):  
Steady State ◽  
Single Phase ◽  
Magnetic Core ◽  
Performance Characteristics ◽  
Iron Core ◽  
The Core ◽  
Induction Generators ◽  
Different Types ◽  
Load Characteristics ◽  
Steady State Performance

This paper deals with the computation of the performance characteristics of the single-phase self-excited induction generator by field–circuit method. It presents and compares previously unpublished results—self-excitation and no-load characteristics of the generator for different rotor speeds, and complete load steady-state performance characteristics for various types of the core materials. The discrepancies between the performance characteristics of the generator for the catalog’s magnetization curves of different types of electrical sheets and for an actual magnetic core of the generator for self-excitation transients and load steady-state are presented. The results may be useful for designing new constructions of single-phase self-excited induction generators.

Steady State Performance Characteristics of Single Pad Externally Adjustable Fluid Film Bearing in the Laminar and Turbulent Regimes

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
B. S. Shenoy ◽  
R. Pai
Keyword(s):  
Steady State ◽  
Performance Characteristics ◽  
Fluid Film ◽  
Radial Clearance ◽  
Wide Range ◽  
Tilting Pad ◽  
Load Carrying ◽  
Static Performance ◽  
Laminar And Turbulent Regimes ◽  
Steady State Performance

In an externally adjustable fluid film bearing, the hydrodynamic conditions can be changed as required in a controlled manner. The principal feature of the bearing is the facility to adjust its radial clearance and circumferential film thickness gradient. Unlike a tilting pad bearing, this bearing can have radial adjustments. The tilt adjustments are obtained by providing flexibility to the pad at one corner. This paper deals with the effect of turbulence on the steady state performance characteristics of a centrally loaded 120 deg single pad externally adjustable fluid film bearing. The bearing has an aspect ratio of 1 and operates over a wide range of eccentricity ratios with different radial and tilt adjustments. The Reynolds equation is solved numerically using the finite difference method. The linearized turbulence model of Ng and Pan (1965, “A Linearized Turbulent Lubrication Theory,” ASME J. Basic Eng., 87, pp. 675–688) as well as the simplified adiabatic model of Pinkus and Bupara (1979, “Adiabatic Solutions for Finite Journal Bearings,” ASME J. Lubr. Technol., 101, pp. 492–496) are incorporated in the solution scheme. The static performance characteristics calculated are presented in terms of load carrying capacity, attitude angle, friction variable, and Sommerfeld number. A comparative study with the combination of adjustments predicts that the static performance of the bearing is superior with negative radial and tilt adjustments.

An Analysis of the Steady State and Dynamic Characteristics of a Spherical Hydrodynamic Journal Bearing

1989 ◽  
Vol 111 (3) ◽  
pp. 459-467 ◽  
Author(s):  
P. S. Leung ◽  
I. A. Craighead ◽  
T. S. Wilkinson
Keyword(s):  
Steady State ◽  
Dynamic Characteristics ◽  
Journal Bearing ◽  
Axial Forces ◽  
Design Charts ◽  
Spherical Surfaces ◽  
Recent Developments ◽  
Hydrodynamic Journal Bearing ◽  
Bearing Design ◽  
Steady State Performance

With recent developments in N. C. manufacturing processes it is relatively straightforward to produce a journal bearing with spherical surfaces. Such a bearing offers two main advantages over a conventional bearing: it can tolerate much larger misalignment and it can resist axial forces. In this paper, the steady state performance of a spherical journal bearing is studied by using a finite bearing theory. The dynamic characteristics of the bearing are represented by eight displacement and velocity force coefficients and the boundary of bearing stability is determined. The effect of superlaminar flow upon the bearing performance is also studied, and typical bearing design charts are provided. In comparison, the behavior of the spherical journal bearing is found to be similar to that of an equivalent cylindrical bearing.

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