scholarly journals An Investigation of Viscous Torque Loss in Ball Bearing Operating in Various Liquids

Water ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1414
Author(s):  
Martin Dobrovolný ◽  
Vladimír Habán ◽  
Jana Tancjurová ◽  
Jan Zbavitel
Keyword(s):  
Experimental Investigation ◽  
Cfd Simulation ◽  
Input Power ◽  
Ball Bearings ◽  
Lower Efficiency ◽  
Real Time Measurement ◽  
Hydraulic Machines ◽  
Torque Loss ◽  
Viscous Torque ◽  
Efficiency And Reliability

The limited functionality of seals that are used in hydraulic machines to prevent the liquid from leaking into the bearings may result in decrease in machine efficiency and reliability and may cause an accident of the whole hydraulic machine. However, not every damage of seals must result in a shutdown of the whole machine. In case of partially or fully flooded bearings, the machine can temporarily operate with significantly increased input power and with lower efficiency. Such a limited operation of the machine shortens its lifetime and is accompanied by the presence of torque loss on the shaft. The measurement of torque loss can be helpful during the design process of new machines as well as for an analysis of hydraulic losses and efficiency of prototypes. Moreover, the real-time measurement of torque loss can be used for remote online monitoring of hydraulic machines. The aim of this paper is to present primarily an experimental investigation of the viscous torque loss for ball bearings submerged into liquid. The CFD simulation is also included to distribute the total torque loss between the hub and the bearing. The main goal is to modify the drag coefficient, respectively the friction loss coefficient in SKF’s and Palgrem’s empirical model. The new coefficients may provide a prediction of torque loss in the fully flooded bearings which is not possible with existing models. The torque loss characteristics are determined for specific ball bearings too. In contradiction to partially flooded bearing situation, it is obvious from a experiment, that some coefficients in Palgrem’s model and SKF model are dependent on revolutions when bearings are fully flooded. The experimental investigation of viscous torque loss are carried out for various types of ball bearings, all fully submerged into two various liquids, i.e., oil and water.

Experimental Investigation and CFD Simulation of Hydrocarbon Pool Fire

2012 ◽  
Vol 22 (2) ◽  
pp. 201-222
Author(s):  
Pramod C. Ramteke ◽  
Akhilesh Gupta ◽  
Ravi Kumar ◽  
A. K. Gupta ◽  
Pawan K. Sharma
Keyword(s):  
Experimental Investigation ◽  
Cfd Simulation ◽  
Pool Fire ◽  
Hydrocarbon Pool

Theoretische Analyse eines neuen Loslagerkonzepts*/Theoretical analysis of a new floating bearing - The simulated operational behavior of FRB bearings in comparison to reference bearings

2015 ◽  
Vol 105 (05) ◽  
pp. 285-290
Author(s):  
C. Brecher ◽  
M. Fey ◽  
J. Falker
Keyword(s):  
Experimental Investigation ◽  
Theoretical Analysis ◽  
High Speed ◽  
Contact Point ◽  
Ball Bearings ◽  
Roller Bearings ◽  
Cylindrical Roller ◽  
Bearing System

Das Floating-Roller-Ball (FRB)-Lager ist ein Konzept für Radiallager als Loslager für Hochgeschwindigkeits-Motorspindeln, das die Vorteile von Zylinderrollenlagern und angestellten Mehrpunktlagern in einer neuen Wälzkörpergeometrie kombiniert. Zur Auslegung des ersten Prototyps wurde mithilfe eines Berechnungstools das theoretische Betriebsverhalten untersucht. Die Berechnungsergebnisse liefern Randbedingungen als Grundlage zur experimentellen Untersuchung des Lagerkonzepts.   Floating roller ball bearings provide a new floating bearing system for high-speed motor spindles, combining the advantages of both cylindrical roller bearings and elastically mounted multi-contact point bearings in a new roller geometry. To design the first prototype, the operational behavior of the bearing system was analyzed theoretically by a new calculation tool. The results provide the basis for the experimental investigation of the bearing concept.

Experimental Investigation on the Use of Bispectral Analysis in Detecting Nonlinear Faults in Hydraulic Machines

2014 ◽  
Vol 606 ◽  
pp. 147-151 ◽  
Author(s):  
M.S. Somia Alfatih ◽  
M. Salman Leong ◽  
L.M. Hee
Keyword(s):  
Experimental Study ◽  
Experimental Investigation ◽  
Signal Processing ◽  
Spectral Analysis ◽  
Centrifugal Pump ◽  
Nonlinear Behavior ◽  
Suction Side ◽  
Bispectral Analysis ◽  
Detection And Identification ◽  
Hydraulic Machines

Bispectral analysis is one of the relatively more recent tools in signal processing used for detection and identification of higher harmonics in a signal. It is also acknowledged to be one of Higher Order Spectral Analysis (HOSA) effective tools for detecting nonlinear behavior in mechanical systems. In this study, vibration sources in a hydraulic machine which may have features of nonlinear behavior were investigated. An experimental study was undertaken to formulate a more sensitive and effective method using Bispectral analysis to diagnose cavitation in a centrifugal pump facility. Cavitation was induced on the suction side of the pump. The cavitation signal was analyzed with and without induced cavitation conditions at different locations on the pump, and analyzed using FFT and bispectrum methods. It was observed that bispectral analysis could be used as an early indicator of cavitation with changes for severity of cavitation.

scholarly journals Experimental investigation energy balance and distribution of a turbocharged GDI engine fuelled with ethanol and gasoline blend under transient and steady-state operating conditions

2020 ◽  
Vol 24 (1 Part A) ◽  
pp. 243-257 ◽  
Author(s):  
Xiongbo Duan ◽  
Yiqun Liu ◽  
Xianjie Zhou ◽  
Peng Zou ◽  
Jingping Liu
Keyword(s):  
Experimental Investigation ◽  
Steady State ◽  
Thermal Efficiency ◽  
Cfd Simulation ◽  
Design Procedure ◽  
Operating Conditions ◽  
Fuel Injector ◽  
Gdi Engine ◽  
Rotating Injector ◽  
Transient And Steady State

Improving the performance and reducing emissions in a Diesel engine is the single most objective in current research. Various methods of approach have been studied and presented in literature. A novel but not so pursued study is on the performance of a rotating diesel injector. To date, there has been very little study by implementing a rotating injector. Studies have shown an improvement on the performance of an engine, but with a complicated external rotating mechanism. In the present research, a novel self-rotating fuel injector is designed and developed that is expected to improve the performance without the need for a complicated rotating mechanism. The design procedure, CFD simulation along with 3- D printing of a prototype is presented. Numerical modelling and simulation are performed to study the combustion characteristics of the rotating injector viz-a-viz a standard static injector. Comparison based on heat release, efficiency, and emissions are presented. While the proposed 9-hole injector had slight loss in thermal efficiency, the modified 5-hole had a slight increase in thermal efficiency when compared to the static baseline readings. The NOx reduced by 13% and CO increased by 14% compared baseline emissions for the 5-hole version.

scholarly journals Experimental Investigation of Clearance Influences on Cage Motion and Wear in Ball Bearings

2021 ◽  
Vol 11 (24) ◽  
pp. 11848
Author(s):  
Baogang Wen ◽  
Meiling Wang ◽  
Xu Zhang ◽  
Jingyu Zhai ◽  
Wei Sun
Keyword(s):  
Experimental Investigation ◽  
Vital Role ◽  
Operating Conditions ◽  
Ball Bearings ◽  
Test Rig ◽  
The Stability ◽  
The Relationship ◽  
Ring Frequency

Clearances of cages in ball bearings, including pocket and guiding clearances, play a vital role in the stability and reliability of bearings. In this paper, experiments on the cage motion and wear were carried out to investigate the influence of clearances in ball bearings. Firstly, the cages with a series of pocket and guiding clearances were specially designed and tested for prescribed operating conditions on a bearing test rig in which the cage motions were measured, and corresponding wear was also observed. Then, the normalized trajectory, waveform, and spectra of cage motion were constructed and compared to illustrate the effects of clearances on the cage motion and then to establish the relationship between cage motion and wear. Results reveal that the cage motion and wear are both significantly affected by its clearances. The increment of cage guiding clearance makes the whirl trajectories of the cage regular and the motion frequency of cage motion significantly change. However, the increment of cage pocket clearance make the whirl trajectories change from well-defined patterns to complicated ones, and the frequency of cage motion apparently changes. Additionally, the bearing wear is closely related to the cage motion. If the inner ring frequency is of domination for the cage motion, the cage guiding surface will wear seriously. While cage motion is dominated by two times cage frequency in spectrum domain, the cage pocket will wear more seriously.

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