- TITLE:
TORSIONAL VIBRATIONS OF A SHAFT CAUSED BY IMPRECISIONS IN THE TRANSMISSION
- AUTHOR(S):
S. Pulev, G. Tonkova
- ABSTRACT:
This work investigates the influence of a possible defect in electric motors - eccentricity in the transmission between the rotating shaft
and the motor. Kinematic disturbance is used to describe the imprecision. A mechano-mathematical model with two degrees of freedom is
used. The differential equations describing the vibrations are derived with methods from analytical mechanics. The law of the torsional
vibrations is derived analytically. Values are obtained for the periodically changing dynamic twisting moments of the shaft's sections. A
numerical example is provided along with diagrams and amplitude-frequency response charts of the vibrations.
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TORSIONAL VIBRATIONS OF A SHAFT CAUSED BY IMPRECISIONS IN THE TRANSMISSION
- TITLE:
ON THE APPLICATION OF THE FUNCTIONAL APPROACH TO THE METHODS OF PROCESSING LAYERED SUPERHARD COMPOSITES
- AUTHOR(S):
E. Lashko, O. Salenko, V. Shchetynin, S. Klimenko, S. Melnichuk
- ABSTRACT:
Layered superhard composites are widely used in the manufacture of tool components, special products of aviation and space technology.
Typically, these products are a plates of regular geometric shape, the final shaping of which is made by diamond grinding. Proposed finish
processing of composite materials is to implement hybrid methods based on laser-jet technologies, with use the functional approach. In
terms of composite materials processing laser-jet is a hybrid, capable of a certain way to influence the components of the composite at
different levels – from nanozone to macrovolume. The hybridization process, which is consist of scribing, water-jet cutting, smoothing of the
surface will allow according to the structure of the processed composite plates get high quality cuts. Field experiments were performed on
laser-jet complex of LSK-400-5, equipped with a abrasive-jet head with water nozzle d c=0,22 mm and calibration tube Dk=1,05 mm, and
also a system of combining a laser jet with the liquid stream by means of flying optics. Process of cutting the plates was performed using a
Nd: YAG laser with a power of 400 W, and operating at a frequency of 50 Hz. Composite plate is a layered system coated with base layer of
cubic boron nitride with 2,8 mm, common plate thickness – 4,5 mm. Using a functional approach allowed us to obtain high-quality cut (the
roughness of the end is 3,2 μm, the width of the slot is 0,12 mm), while the time to perform the operation of cutting at a specified contour
made up only 1,8 min.
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ON THE APPLICATION OF THE FUNCTIONAL APPROACH TO THE METHODS OF PROCESSING LAYERED SUPERHARD COMPOSITES
- TITLE:
3D MODELING OF CUTTING-DEFORMING TAPS
- AUTHOR(S):
M. Nikolova- Pencheva, I. Alexandrova, J. Mitev
- ABSTRACT:
The paper presents the methodology and the algorithm for a construction of a 3D model of cutting-deforming taps with new design,
forming the threads by combining cutting and plastic deformation methods. Formulas for calculation of the structural elements of the
cutting-deforming taps have been presented using the threads parameters as input data for tools design. Autodesk Inventor system has been
used. The stages of the 3D model construction have been presented. The created 3D model is a basis for a strengt h-strain study of cutting-
deforming taps and for a generation of a program for the production of CNC machines using CAM module.
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3D MODELING OF CUTTING-DEFORMING TAPS
- TITLE:
A DESIGN METHODOLOGY FOR A BIDIRECTIONAL SERIES RESONANT DC-DC CONVERTER
- AUTHOR(S):
A.S. Vuchev, A. A. Lichev, P. N. Georgiev
- ABSTRACT:
Results from an approximate analysis of a bidirectional series resonant DC-DC converter
operating above the resonant frequency are discussed. The converter control technique is taken into
consideration. A methodology for design of the converter is proposed. Calculations for a 200W
converter are made. The obtained results are verified by simulation investigations.
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A DESIGN METHODOLOGY FOR A BIDIRECTIONAL SERIES RESONANT DC-DC CONVERTER
- TITLE:
STRESS ANALYSIS OF SINUSOIDAL CURVED GEAR PROFILES
- AUTHOR(S):
G. IRSEL, O. AYER, M. ARDA
- ABSTRACT:
A gear with sinus curved profile was presented in this paper. The tooth profile was designed
according to sinus function for 2π and 4π period. The trace of the gear was chosen as involute
profile. Proposed gear types was built and simulated in CATIA software and the results compared
with spur gear form simulation results. The stress distribution was investigated for the contact
surfaces and tooth root region. It was aimed to obtain optimized gear profile with less stress values.
It was concluded that the gear built with 2π period function gave the less stress values because of
having bigger contact surface comparing to spur gear.
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STRESS ANALYSIS OF SINUSOIDAL CURVED GEAR PROFILES
