Static Loading with Axial Channel for Hydrodynamic Journal Bearing Calculation Method

In this study, the calculation method required to transport the load in axial channel lubricated hydrodynamic journal bearings is the yield. Distortion analyzes of existing (designed) bearings can also be carried out with the method presented here, the performance of the bearing can be investigated and used to investigate what can be done to improve the performance of the bearing. The method presented here can be used for two axial grooved bearings to the right and left of the load direction. Alternative oil distribution patterns can also be negotiated. The journal bearing is statically loaded. But in applications where loads and speed change are slow, the calculation method can be used here. This study mainly consists of two parts. In the first part, the operation of a hydrodynamic journal bearing is defined and a method is given for estimating the required dimensions of the bearing and detailed information is given for bearing design parameters. In the second part, a method for the analysis of a journal bearing is given and necessary information is given for the safe operation of the bearing. Keywords: Axial Channel, Hydrodynamic Journal Bearing, calculation method DOI: 10.7176/JIEA/9-3-05 Publication date:May 31st 201

Investigation of effects of the rotational speeds on performance of a dynamically loaded journal bearing

In this study connecting rod journal bearing performance of the Ruston and Hornsby 4-cycle diesel engine was investigated under three different engine speeds (500,1500 and 2500 rpm). It was investigated how do the minimum journal bear-ing clearance, peak oil film pressure, friction torque, oil flow rate, journal orbit and the power losses on the dynamically loaded connecting rod bearing vary as the speed increases. Variations of the parameters affecting journal bearing per-formance with respect to the increase in engine speed are shown graphically

The effect on oil intake temperature at dynamicaly loaded radial journal bearings performance

İçten yanmalı benzinli ve dizel motorlarında, uçak motorlarında, kompresörlerde, pistonlu pompalarda, eksantrik presleri ve hadde merdaneleri gibi pek çok makinalarda milleri yataklamak için kullanılan radyal kaymalı yatakların, dinamik yük altında, farklı yağ giriş sıcaklıklarında gösterdiği performans yatak tasarımcıları açısından oldukça önemlidir. Bu çalışmada, önceden deneysel olarak belirlenen bir dinamik yük örneği (polar yatak yükü) kullanılmıştır. Yatak yükü ve diğer yatak parametreleri sabit kalmak şartıyla, yalnızca yatağa gönderilen yağın sıcaklığı $20^ oC, 40^ oC ve 60^ oC$ olarak alındığında yatağın performansında nasıl bir değişiklik olacağı araştırılmıştır. Sonuçlar irdelenerek yatak tasarımcılarına, yağ giriş sıcaklığı değişiminin yatak performansı üzerindeki etkileri konusunda pratik bilgi sunulmuştur.The performance that radial journal bearings, used for the bearing of many machines such as internal combustion gasoline and diesel engines, aeroplane engines, compressors, plunger pumps, eccentric presses and rolling cylinders, show under dynamic load and at different oil intake temperatures, is very much important for bearing designers. In this study, a dynamic load sample (polar bearing load) which was experimentally defined before was used. How the performance of bearing would be was investigated in the study, so long as bearing load and other bearing parameters stay stable, and when the temperature of oil poured only on bearing is designated as 20, 40 and 60 centigrade degrees. By analyzing results, bearing designers were given practical information about the effects of oil intake temperature change on the performance of bearing

Investigation of effects of oil additive on friction coefficient for statically loaded radial journal bearings

In this study, variation of friction coefficient under static loading on a radial journal bearing (Chrysler connecting rod bearing) is studied both theoretically and experimentally. The theoretical section of the study was conducted with the Kiss-SOFT program while the experimental part was conducted on a TM 290 hydrodynamic radial journal bearing experimental set. In this study we examine the effect of bearing loads and different proportion of poured additive in alkali-based lubrication oil on friction coefficient. Friction coefficient was calculated from the frictional torque. Consequently, theoretically calculated and experimentally tested friction coefficients were compared and the optimum oil additive ratio was determined

Theoretical and experimental determination of friction coefficient on statically loaded radial journal bearings

Bu çalışmada, statik yük altındaki bir radyal kaymalı yatakta (Chrysler biyel kolu yatağının) sürtünme katsayısı değişimi, teorik ve deneysel olarak belirlenmiştir. Çalışmanın teorik kısmında; yatak yükünün, yatak boşluğunun ve yağ viskozitesi değişiminin sürtünme katsayısına etkisi incelenmiştir. Deneysel kısımda ise; sürtünme momentine yatak parametrelerinin etkisi TM 290 hidrodinamik radyal kaymalı yatak deney setinden ölçülmüştür. Ölçülen sürtünme momentinden, sürtünme katsayısı hesaplanmıştır. Sonuç olarak teorik ve deneysel olarak belirlenen sürtünme katsayıları karşılaştırılmıştır.In this study, variation of the friction coefficient on statically loaded radial journal bearing ( Chrysler connecting rod bearing) was determined theoretically and experimentally. In theoretical part, the effect of the bearing load, journal bearing clearance and oil viscosity to the friction coefficient was examined. In experimental part, the effect of the journal bearing parameters on the friction torque was measured by using TM 290 Hydrodynamic radial journal bearing apparatus. The friction coefficient was calculated using measured friction torque. Consequently, it was compared that obtained theorically and experimentally friction coefficient

An experimental investigation on frictional behavior of statically loaded micro-grooved journal bearing

WOS: 000297824800040Performances of plain and micro-grooved engine journal bearings were investigated in this study. Numerous experiments were performed under different static loads by using the purpose-built journal bearing test rig. Micro-grooves were made by cutting micro-channels both around and across the engine journal bearing surfaces. Stribeck curves for the micro-grooved and the plain journal bearings were then experimentally and theoretically generated while frictional torque versus angular velocity curves were also plotted. The results showed that the highest value of coefficient of friction as well as the frictional torque was obtained on the transversal micro-grooved journal bearings. (C) 2011 Elsevier Ltd. All rights reserved.Karadeniz Technical University [2002.112.003.03]This work was supported by the Research Fund of Karadeniz Technical University, Project number; 2002.112.003.03

Motor unit potential analysis of the palatal muscles in obstructive sleep apnea syndrome

Objectives: Among different theories about pathogenesis of obstructive sleep apnea syndrome (OSAS), dysfunction of upper airway muscles still awaits to be delineated. The aim of this study is to examine differences in motor unit potential (MUP) parameters of upper airway muscles between OSAS patients and healthy controls. Methods: Ten male patients diagnosed as OSAS by whole-night polysomnography were analyzed for MUP parameters of genioglossus (GG) muscle, palatoglossus muscle (PG), palatopharyngeus muscle, and uvular (U) muscle. Eight healthy volunteer men matched by age were enrolled as a control group. Results: In PG muscle parameters, the mean MUP area was significantly smaller (P = 0.040) in OSAS patients than those in controls. On the other hand, U muscle parameters showed a significantly larger mean MUP area (P = 0.022) in OUAS patients compared to those in the control group. In OSAS patients, the percentages of polyphasic MUPs of GG and PG muscles were significantly high (P < 0.001 and P = 0.05, respectively). Body mass index was positively correlated with number of phases of GG muscle (rs = 0.63, P < 0.05) and duration of U muscle (rs = 0.71, P < 0.05) in OSAS patients. Other MUP parameters of palatal muscles were similar between the two groups. Conclusion: Our results showed that, although mild in severity, structural neurogenic and myogenic changes characterized as mild and nonuniform MUP changes may co-exist in OSAS patients. These changes in palatal muscles may be attributed to compensatory adaptation of muscle fibers to other precipitating factors in OSAS