Optimization of the crankshaft bearings and investigation of the ball bearing usage in the compressor of the refrigerator
Creators: name: Bodur, Osman
Publisher: name: Yildiz Technical University
Year: 2014
Subjects: subject: Mechanical engineering
subject: FOS: Mechanical engineering

description: Increasingly depletion of fossil fuels in worldwide lead to increase the research and development activities on energy efficiency and usage of renewable energy in all countries. The usage of the energy efficiency in residences is also very important as much as in industry. When it comes to consumed energy in residences, 10-15% of this energy is consumed by refrigerators and freezers. Also, approximately 90% of the energy is consumed by refrigerator is consumed by the compressor. In addition, the effects of energy consumption labeling of refrigerators in the world market is forced to all manufacturers to produce more efficient refrigerators. The compressors are designed with high energy efficiency is utmost importance in order to produce refrigerators in high energy efficiency class.The thesis are created in this context, was examined in three different parts. In the first part, the friction losses which lead to energy cost in the radial journal bearing of the compressor, is calculated analytically according to the hydrodynamic lubrication theory. The kinematic and dynamic analysis of all the forces and moments, consist of the axial journal bearing on the crank-pressing surface and the radial journal bearings of the crankshaft due to the pressure force, was carried out in both the Matlab and Solidworks programs. Depending on the analysis results, the maximum eccentricity ratio in the present system and eccentricity ratio which may occur in the hydrodynamic lubrication conditions, were identified. Depending on the load-carrying capacity is known by the analysis consequences, dynamic viscosity of the system and the optimum bearing length required in order to achieve the maximum eccentricity ratio which will consist of minimum friction, were presented. The subject was supported by tests.In the second part of the study; the changing of the friction losses is specified by using axial ball bearing on the crankshaft pressing surface. After ball bearings characterizing parameters have been investigated in detail and examined, new axial ball bearing were designed. As well as custom designs, by using the existing standard ball bearings on journal bearings, the changing of the friction loss is calculated.In the third part, the energy gains on the crankshaft journal bearings in the case of ball bearings are shown in terms of power. About the suitability of the system were informed. In addition, Matlab Model which will reveal the frictional torques and power losses of the ball bearings are used in both the second and the third section subjects, was created at a basic level. The ball bearing usage are analyzed by the test results, the analysis results are evaluated.As result of the studies, around 10% the power gain was obtained on the radial journal bearing in the compressor and the friction losses in annual energy consumption of the refrigerator is reduced approximately 1.17 kWh in a year.