تحليل الاهتزاز في مولد منزلي بسيط

Abstract EN

This research presents an analysis for the vibration of a small electrical generator, which is widely used for domestic purposes.

This generator is of a type (ASTRA 3000) that gives an electrical power up to (2200 W), The analysis is achieved by using the method of the transfer matrices.

The generator consists of arotating system, abody cover (casing) and bearings so a mathematical model has been built accordingly.

The mathematical model consists of two beams connected to Each other with some springs and dampers where the rotating system has been represented by rotating beam under the gyroscopic moment effect, but the body cover is represented by a non-rotating beam.

And each bearing has two stiffness coefficients and two damping coefficients This model also considers the effect of supporting braces for the body cover which is represented by a flexible spring and damper.

The generated magnetic relucting force has been calculated and converted to flexible springs which are accounted for in the prepared model.

The current research studied the effects of the instantaneous changeable electrical load and the stiffness of the supported plastic pieces, on the critical speeds and over the rotating length and the casing with the existing of the exciting forces.

Also a comuter program has been developed by (New Fortran) language to embrace the theoretical work and from which the values of shear forces, the bending moments, deflections and slopes can be calculated over the entire length of the rotating system and casing.It is concluded that: the change of the electrical load affects the critical speeds values and the response of the generator.

It has also been found that the extreme values of the stiffness of the plastic pieces according to their original values decline the critical speed values.

However, there is a value little less than the original value, increasesthe critical speed values.