Experimental Investigations of Multiple Faults in Ball Bearing

2019 ◽  
pp. 151-162
Author(s):  
S. P. Mogal ◽  
S. N. Palhe
Keyword(s):  
Ball Bearing ◽  
Experimental Investigations ◽  
Multiple Faults

Experimental Investigations of Single and Multi-Fault in Rotor System

2014 ◽  
Vol 541-542 ◽  
pp. 628-634
Author(s):  
S.P. Mogal ◽  
D.I. Lalwani
Keyword(s):  
Fourier Transform ◽  
Fast Fourier Transform ◽  
Real Life ◽  
Rotor System ◽  
Vibration Response ◽  
Experimental Investigations ◽  
Multiple Faults ◽  
Single Fault ◽  
Vibration Behavior ◽  
Combined Action

Many researchers dealt with single fault but in real life situations, combined action of two or more single faults are usually present. Multi-faults (two and three combinations) were studied by few researchers. Researchers have mostly studied the vibration behavior of a rotor with misalignment, unbalance and rub separately. This paper presents one such case, where multiple faults are considered together in a rotor system, i.e. misalignment, unbalance and rub. The objective of this paper is to experimentally investigate the vibration response of combined of three faults misalignment, unbalance and rub using Fast Fourier Transform (FFT). FFT spectrum of combination of three faults misalignment, unbalance and rub show 1 X and 2 X are predominant and many sub harmonics are generated.1X peak represent unbalance, 2X peak represents misalignment and sub harmonics shows rub fault.

Mapping the Domain of Electronic Repair Shops: A Field Study in Fault Diagnosis

1995 ◽  
Vol 39 (9) ◽  
pp. 464-468 ◽  
Author(s):  
Dal Vernon C. Reising ◽  
Penelope M. Sanderson
Keyword(s):  
Fault Diagnosis ◽  
Concept Maps ◽  
Field Work ◽  
Problem Definition ◽  
Experimental Investigations ◽  
Simple Explanation ◽  
Field Observations ◽  
Multiple Faults ◽  
Technological Advances ◽  
In Series

Recent experimental research has indicated that different multiple faults impose differing levels of objective and subjective difficulty on human troubleshooters. Technological advances suggest that systems are becoming more complex and integrated, in which case multiple components will fail. Operators will have to be able to deal with these more complex failures. In this paper we report field work conducted in order to build and substantiate a model of the factors influencing fault diagnosis in the field. By conducting field observations and by constructing concept maps, we investigated how expert troubleshooters handle the difficulty associated with diagnosing multiple faults. The troubleshooters were expert electronic technicians in departmental repair shops on a large university campus. The end product of the research is a model of fault diagnosis that is grounded in field data. Our results suggest that diagnostic difficulty arises from several factors: (1) organizational structure, (2) technicians' strategies for fault diagnosis, and (3) equipment design. The field observations and concept maps indicate that technicians approach the diagnostic task with standard, ritualistic methods that they have developed over years of experience. They generally go through two phases of troubleshooting: (1) the problem definition phase and (2) what we call the At-the-Equipment-TroubleShooting (AETS) phase. Technicians also reason about multiple failures in series, considering one simple explanation at a time. Our principal conclusion is that in real-world settings the three previously mentioned factors have evolved to avoid situations in which technicians must engage in prolonged functional reasoning. These findings will be used (1) to develop further the model of fault diagnosis, and (2) to guide future experimental investigations studying the influences of fault diagnosis.

Investigation of Dynamic Processes in Ball Bearings with Defects

2013 ◽  
Vol 198 ◽  
pp. 651-656 ◽  
Author(s):  
Marijonas Bogdevičius ◽  
Viktor Skrickij
Keyword(s):  
Mathematical Model ◽  
Ball Bearing ◽  
Dynamic Processes ◽  
Experimental Investigations ◽  
Ball Bearings ◽  
Outer Race ◽  
Rolling Element ◽  
Inner Race

The paper considers the dynamics of ball bearings with defects. A mathematical model of a ball bearing with defects is offered. The performed theoretical and experimental investigations of ball bearings with defects are described. Five cases of various defects are investigated, including the defective outer race, the defective inner race, the defective rolling element, the defective inner and outer races, the rolling element and a separator, the worn-out ball bearing.

scholarly journals A Cylinder-Type Multimodal Traveling Wave Piezoelectric Actuator

2020 ◽  
Vol 10 (7) ◽  
pp. 2396
Author(s):  
Dalius Mažeika ◽  
Andrius Čeponis ◽  
Daiva Makutėnienė
Keyword(s):  
Piezoelectric Actuator ◽  
Traveling Wave ◽  
Ball Bearing ◽  
Rotation Speed ◽  
Experimental Investigations ◽  
Vibration Modes ◽  
Wave Type ◽  
Bending Vibration ◽  
Piezoceramic Ring ◽  
Electric Signals

Numerical and experimental investigations of a multimodal piezoelectric traveling wave actuator are presented. The actuator consists of a cylindrical stator with a conical hole and piezoceramic rings that are located at the node of the first longitudinal and second bending vibration modes; one piezoceramic ring is also placed at the bottom of the actuator. The actuator is clamped at the bottom using a special supporting cylinder and a ball bearing. Traveling-wave-type vibrations are excited at the top surface of the cylinder by employing a superposition of the first longitudinal and second bending vibration modes of the stator. The conical hole of the stator is used to amplify the vibration amplitudes of the contact surface. Four electric signals with phase difference of π/2 are used to drive the actuator. Numerical and experimental investigations showed that the proposed actuator is able to generate up to 115 RPM rotation speed at constant preload force.

Vibration analysis of a multi-fault transient rotor passing through sub-critical resonances

2017 ◽  
Vol 24 (14) ◽  
pp. 2986-3009 ◽  
Author(s):  
Heba H El-Mongy ◽  
Younes K Younes
Keyword(s):  
Transient Response ◽  
Identification Problem ◽  
Vibration Response ◽  
Fault Detection And Diagnosis ◽  
Experimental Investigations ◽  
Critical Limit ◽  
Simple Method ◽  
Multiple Faults ◽  
Critical Response ◽  
Detection And Diagnosis

Various faults may simultaneously occur in a rotor dynamic system. It is crucial to detect and monitor these faults to ensure the safe operation of machinery. Usually, vibration response is utilized for fault diagnosis; however, the identification process becomes more challenging when multiple faults exhibit similar symptoms in the vibration response. In this paper, the vibrational transient response of a cracked rotor is analyzed in the presence of unbalance and coupling misalignment. The study focuses on investigating the possibility, advantages and limitations of using the sub-critical startup response in solving the fault identification problem. Numerical simulations using finite element modeling and experimental investigations are carried out for different individual and multi-fault conditions. Various factors are taken into consideration, including sub-critical limit speed, crack parameters, unbalance parameters and misalignment severity. Numerical and experimental investigations showed that the sub-critical transient response is suitable for the fault detection and diagnosis of the simultaneously existing faults studied. Compared to the critical response, the sub-critical response is more informative and each fault shows a unique feature that can be extracted without the need for sophisticated post signal processing. The study provides useful insights on the interaction between the various fault effects on the vibratory response and presents a simple method for condition monitoring of industrial equipment.

Experimental investigations of the use of cartilage in tympanic membrane reconstruction

2000 ◽  
Vol 21 (3) ◽  
pp. 322-328 ◽  
Author(s):  
T ZAHNERT ◽  
K HUTTENBRINK ◽  
D MURBE ◽  
M BORNITZ
Keyword(s):  
Tympanic Membrane ◽  
Experimental Investigations

EXPERIMENTAL INVESTIGATIONS OF THE QUANTUM PHOTOVOLTAIC EFFECT IN InAs-GaSb SEMICONDUCTOR SUPERLATTICES

1987 ◽  
Vol 48 (C5) ◽  
pp. C5-183-C5-186
Author(s):  
J. BLEUSE ◽  
P. VOISIN ◽  
M. VOOS ◽  
L. L. CHANG ◽  
L. ESAKI
Keyword(s):  
Photovoltaic Effect ◽  
Experimental Investigations ◽  
Semiconductor Superlattices

Ball bearing turbocharger vibration management: application on high speed balancer

2020 ◽  
Vol 21 (6) ◽  
pp. 619
Author(s):  
Kostandin Gjika ◽  
Antoine Costeux ◽  
Gerry LaRue ◽  
John Wilson
Keyword(s):  
Dynamic Behavior ◽  
High Speed ◽  
Internal Combustion Engines ◽  
Ball Bearing ◽  
Squeeze Film ◽  
Design And Technology ◽  
Squeeze Film Damper ◽  
Damping Coefficients ◽  
Bearing Loads ◽  
Stiffness And Damping

Today's modern internal combustion engines are increasingly focused on downsizing, high fuel efficiency and low emissions, which requires appropriate design and technology of turbocharger bearing systems. Automotive turbochargers operate faster and with strong engine excitation; vibration management is becoming a challenge and manufacturers are increasingly focusing on the design of low vibration and high-performance balancing technology. This paper discusses the synchronous vibration management of the ball bearing cartridge turbocharger on high-speed balancer and it is a continuation of papers [1–3]. In a first step, the synchronous rotordynamics behavior is identified. A prediction code is developed to calculate the static and dynamic performance of “ball bearing cartridge-squeeze film damper”. The dynamic behavior of balls is modeled by a spring with stiffness calculated from Tedric Harris formulas and the damping is considered null. The squeeze film damper model is derived from the Osborne Reynolds equation for incompressible and synchronous fluid loading; the stiffness and damping coefficients are calculated assuming that the bearing is infinitely short, and the oil film pressure is modeled as a cavitated π film model. The stiffness and damping coefficients are integrated on a rotordynamics code and the bearing loads are calculated by converging with the bearing eccentricity ratio. In a second step, a finite element structural dynamics model is built for the system “turbocharger housing-high speed balancer fixture” and validated by experimental frequency response functions. In the last step, the rotating dynamic bearing loads on the squeeze film damper are coupled with transfer functions and the vibration on the housings is predicted. The vibration response under single and multi-plane unbalances correlates very well with test data from turbocharger unbalance masters. The prediction model allows a thorough understanding of ball bearing turbocharger vibration on a high speed balancer, thus optimizing the dynamic behavior of the “turbocharger-high speed balancer” structural system for better rotordynamics performance identification and selection of the appropriate balancing process at the development stage of the turbocharger.

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