Contents of Journal of Mechanical Engineering 60, 2 (2009)




HARIHARAN, V., SRINIVASAN, P. S. S.: Experimental investigations on bearing 
housing vibration signatures caused by shaft rub                              61

PAVLENKO, I.: Dynamic analysis of the locking automatic balancing device 
of the multistage centrifugal pump                                            75

GUŽELA, Š., FEKETE, R.: Velocity of the particulate material outflow from 
the storage                                                                   87

GUŽELA, Š., JURIGA, M., FEKETE, R.: The influence of particle size 
of particulate material on the internal friction angle                       105






Abstracts



Experimental investigations on bearing housing vibration signatures caused by shaft rub

VAGGEERAM HARIHARAN, P. S. S. SRINIVASAN


Identifying vibration signature caused by rub on bearing housing is very critical in preventing rub related machinery failure. Also, the effect of rub material and speed on vibration signature associated with rub are two other key issues. In this paper, an effort has been made to answer the above questions by simulating rub in a controlled way. The vibration signature on bearing housing caused by shaft rub was studied by applying a rub on rotating machinery. Full annular rub was simulated with two types of rub material, namely mild steel and aluminium. Experiments were carried out at three speeds 740, 1150 and 1600 rpm. Time domain and frequency domain signals on bearing housing with and without rub were collected and analysed. Several observations on the effects of rub on bearing housing vibration are presented.



Dynamic analysis of the locking automatic balancing device of the multistage centrifugal pump

IVAN PAVLENKO

The reliability of automatic balancing device of centrifugal pumps can be decreased in case of intensive wear of cylindrical throttle before and after the unloading device of the balancing disk. Therefore, the locking automatic balancing device is offered, operating as the axial hydrostatic bearing with hyper bearing capacity and, simultaneously, as the non-contact consolidation with self-adjustable leaking. The dynamic calculation is based on the equations of pump rotor and regulator rod axial movement and also on equations of fluid flow balance through throttles taking into consideration compression and displacement flow. The methodology of dynamic calculation gives the opportunity to select the main parameters of hydro-mechanical system engineering based on providing the transient processes quality and stability conditions.




Velocity of the particulate material outflow from the storage

ŠTEFAN GUŽELA, ROMAN FEKETE

There is often a need to stock the particulate materials in industry. These materials can be stocked by several manners: by means of the unit covers (paper bag, barrel, box...), extensively (heap of bulk cargo) and intensively (bunker and silo). Various requests are made by the demands on the storage design. One of them is the sluice size, which has to provide the continuous particulate material outflow. If the conveyance for the particulate material transfer from storage has to be correctly projected there is a need to know the outflow velocity of the material from the sluice. The paper deals with the influence of the sluice size on the asked velocity of the particulate material outflow from the storage.



The influence of particle size of particulate material on the internal friction angle

ŠTEFAN GUŽELA, MARTIN JURIGA, ROMAN FEKETE

Particulate materials are processed in various industrial equipments. It is necessary to know the basic mechanical and physical properties of the particulate materials for the correct design of such equipment. The angle of internal friction is one of the most important properties of a material, and its identification is necessary for determination of the pressure rate in the particulate material. Jenike's shearing apparatus determines the angle of internal friction experimentally. The paper deals with the influence of the particle size on the angle of internal friction. Its exact knowledge is necessary for the correct design and construction of equipment for the processing of particulate materials.