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This study focuses on the oil flow, supplied from the oil hole in plain bearings; the oil flow in bearings that were statically loaded was measured precisely using a test rig. In the case that oil was supplied through an oil hole, experimental results showed that the bearing oil flow depended largely on the circumferential angle of the oil feed hole in relation to the loading direction. When compared with the results of conventional theoretical analysis, it became obvious that the conventional analysis method could not make an exact prediction. The authors have assumed that such difference would come from the oil film extent. Using a transparent bearing so that the behavior of the oil film within the bearing clearance could be visible, the oil film extent for different circumferential positions of the oil feed hole were observed. The bearing oil flow was calculated based on the actually measured oil film extent. The calculated result was compared with the experimental one.

The recent trend toward the compact and light-weight construction of automotive engines with high power output has been imposing higher requirements of fatigue strength, anti-seizure property and conformability on bearings. In order to meet these requirements, the authors analyzed the property of each layer of multi-layer Al-Si-Sn bearings and investigated its influence on bearing performance. Improvement was achieved as to the bearing alloy and the intermediate bonding layer based on the results of the investigation. As a result, this newly improved bearing has been concluded to provide better fatigue strength than conventional bearings. It has thus become possible to apply it as a bearing for the recent engines used under harsh conditions.

Recent automotive engines for high performance vehicles have been designed for higher speeds and outputs. Not only the combustion load but also the inertia force applied on the connecting rod has been increasing. Automotive engines have also become compact and lighter in weight for needs of lower fuel consumption. For these reasons, the rigidity of the connecting rod has been reduced in comparison with the increasing inertia force. As a result, fretting damage may occur between two surfaces of the connecting rod big end bore and the bearing outer surface, causing breakage of the connecting rod itself. Countermeasures for fretting such as a tighter bearing fit ( interference ) and higher rigidity of the connecting rod big end are generally adopted. But the details for these countermeasures can not be easily predicted at the design stage. Rather they are obtained only by durability tests on the actual engines.

The Rankine cycle using ammonia-water mixture as a working fluid has been studied theoretically by several researches. Analytically, its plant efficiency is higher than that of a conventional steam Rankine cycle operating at relatively low temperatures. Typical applications are gas turbine combined cycles, geothermal power plants and ocean thermal power plants. The purpose of this study is to investigate experimentally the applicability of this cycle to a bottoming cycle of a gas turbine combined plant. Authors' major concerns are plant efficiency, durability of materials and stability of ammonia-water at relatively high temperature region, as well as plant economy. This paper describes the results of the experimental studies on the above problems.

As the recent automotive engines are designed for higher performance, the rotating speed of the engines have been increased drastically. Therefore the engine bearings should be further improved to have better anti-seizure and wear properties under the high temperature at the high rotating speed. The authors have analyzed the necessary functions of the three layers copper-lead bearings at such operating conditions, and then improved and developed the overlay and the copper based bearing alloy with steel back. Physical and chemical properties for this new bearing were studied. Then the bearing performance tests were carried out including the high speed seizure tests and engine tests. From these test results, it was confirmed that this new bearing could be applied for the recent very high speed automotive engines.

The recent trend toward the compact and light-weight construction of diesel engines with high power output has been imposing higher requirements of fatigue strength and antiseizure characteristics on bearings. In order to meet these requirements, the authors developed a new bearing alloy of higher fatigue strength for use in heavy load engines, through the analysis of the Al-Zn-Si alloy which has high corrosion resistance. Experimental results of this new alloy to study its physical properties and bearing performances indicate that it can be applied to bearings in diesel engines which operate in harsh conditions.

Friction loss of bearings under dynamic load is often measured by motoring on an actual engine. Motoring, however, is not capable of reproducing the bearing load during the firing. The authors developed a dynamic load simulating machine, which applies variable load corresponding to one engine load cycle by means of a hydraulic pressure controlled with servo valves. Friction loss and the shaft center locus were measured under the static load and the dynamic load simulating to the main bearing load of V-engine. The variation was studied while changing various dimensions of a bearing such as clearance, bearing length, revolution speed, shaft diameter, and presence of a circumferential groove. By comparing the test results with theoretical values, good agreement in the basic tendency was obtained.