# 2(27) 2007



Dynamic investigation of the hinged mechanism of a needle of sewing-machines by taking into account clearances. N. Davitashvili, G. Sharashenidze, A. Sharvashidze, S. Sharashenidze. “Problems of Mechanics”. Tbilisi, 2007, ¹ 2(27), pp. 7 - 20, (Engl.).

The dynamic investigation of the hinged mechanism of a needle of sewing-machines by taking into account clearances in two kinematic pairs is given. The number of differential equations describing complementary and basic motions of the mechanism is set. The values of kinetic energy for four forms of motions are obtained and differential equations for complementary and basic motions of the mechanisms received. The reduced moment, generalized forces, reaction and friction forces are determined. Using the obtained results, a comparative analysis for the parameters of ideal and real mechanisms, which allows choosing optimal dimensions of clearances for durable work of the mechanism, is given. 6 ill. Bibl. 10. Engl.; summ in Russ.


SYNTHESIS OF MECHANISMS WITH ADJUSTABLE LINKS USING LEAST SQUARES OPTIMIZATION. Ozgun Selvi, Hakki Erhan Sevil, Serhan Ozdemir. “Problems of Mechanics”. Tbilisi, 2007, ¹ 2(27), pp. 21 - 25, (Engl.).

In this paper the least squares optimization method is utilized for tuning structural and mechanical errors that occur in the design stage of linkage mechanisms. The output errors are assumed to be normally distributed. For a normal distribution, the output error could be minimized when the standard deviation is minimized. A spatial four-bar mechanism (RSSR) with adjustable links is given as an example to explain synthesis procedure. 2 ill. Bibl. 15. Engl.; summ. in Russ.


Testing of drill-injection piles for static load with the use of quick-setting cement. V. Japaridze, G. Kipiani, T. Garsevanishvili. “Problems of Mechanics”. Tbilisi, 2007, ¹ 2(27), pp. 26 - 33, (Engl.).

The need for reconstruction and strengthening of foundation of buildings are frequently caused by errors made in the planning, the neglect of construction standards and rules, and also by errors being the result of poor quality geological engineering investigation. This happens when the cleavage of soil and its physicomechanical characteristics are conducted with a little accuracy, such are as: the level of surface and ground water, the regime of their flow and the degree of aggressiveness, and also when in the geological cut are not taken into account the lenses of soft ground, is not taken into account the pressure of actually effective wind on the building and so forth. The experiment was intended for testing the drill-injection piles on driving in, static axial loads, the purpose of which was to determine their actual calculated endurance; moreover, the drill-injection piles were prepared not on the base of portland cement, traditional in building, but on the base of quick-setting portland cement, which is today extremely vital. 3 ill. Bibl. 3. Engl.; summ. in Russ.


ROTATIONAL METHOD SPHERE  FOR THE SOLUTION OF GEOMETRY TASKS IN SPACE. Z. Natsvlishvili, G. Namgaladze, G. Eradze, M. Abulashvili. “Problems of Mechanics”. Tbilisi, 2007, ¹ 2(27), pp. 34 - 38, (Russ.).

The paper et al deals with graphic and analytical methods of the evaluation of the geometrical figure movement on the spherical surface. It has been shown the practical application of the developed methods  to the solution of the problems connected with kinematic investigation the four-linked spherical stank-slide gear. 3 ill. Bibl. 2. Russ.


RESONANT FLUCTUATIONS OF THE REGULATOR OF TRANSPORT  DIESEL ENGINE WITHOUT INFLUENCE ON ITS HIGH-SPEED MODE. A. Muchaidze, T. Natriashvili,  Kh. Mgebrishvili. “Problems of Mechanics”. Tbilisi, 2007, ¹ 2(27),
pp. 39 - 43, (Russ.).

Process of automatic control of the diesel engine is analysed in view of its cyclicities. It is shown, that if in structure of a periodic component of the twisting moment, the composing harmonic dominates over frequency equal or multiple to frequency injection submissions of fuel system the diesel engine - regulator can have an operating conditions when in a regulator resonant fluctuations as in independent system without influence for angular speed raise rotation of a shaft of a diesel engine. Process is analysed theoretically and results are approved experimentally. 3 ill. Bibl. 3. Russ.


DEFINITION OF QUALITY OF TRACTOR UNIT OPERATION CONTROLED BY AUTOMATIC DRIVING OPTICAL UNIT. O. Margvelashvili, A. Nozadze. “Problems of Mechanics”. Tbilisi, 2007, ¹ 2(27), pp. 44 - 48, (Russ.).

The process of motion of the tractor unit controlled by the automatic driving optical system is considered and it is shown that the system, according to motion accuracy, satisfies agricultural techniques demands. 5 ill. Bibl. 2. Russ.


The new type thermo-dynamical cycle with energy regeneration and new construction of engine for drawing near the Carnot cycle. A. Aptsiauri. “Problems of Mechanics”. Tbilisi, 2007, ¹ 2(27), pp.  49 - 55, (Russ.).

The theoretical basis of new type thermo-dynamical cycle and construction of principally new type of engines were worked up. The new type engine has very compact construction and contains the pistons, which move parallel of the shaft. The new construction gives possibility to create the light piston internal combustion engine with high efficient capacity and good efficiency. (Efficiency of Diesel cycle). At the same time, on the basis of new construction may be realized   bi-temperature cycle. New type engine with the bi-temperature cycle has the working medium, which contains two separated volumes of the gas with different temperature, but with equal pressure. Because of the internal regeneration of the thermal energy  of combustion gas, coefficient of efficiency of the new cycle approaches to the coefficient of efficiency of the ideal cycle of Carnot. 3 ill. Bibl. 3. Russ.


QUANTITATIVE ASSESSMENT OF MILLING CUTTER COGS BEATING AND   ITS INFLUENCE ON THE WORKING PROCESS STABILITY. M. Iremadze, L. Zivzivadze. “Problems of Mechanics”. Tbilisi, 2007, ¹ 2(27), pp. 56 - 59, (Russ.).

The possibilities of getting mathematical models for preliminary qualitative estimation of beating teeth is considered in this article, which provides the increase of the stability of milling process. 2 ill. Bibl. 5. Russ.


Methods of diagnosis of technological processes and machines and tools. J.  Bakhtadze, M. Tsikarishvili, I. Charakashvili, T. Otarashvili. “Problems of Mechanics”. Tbilisi, 2007, ¹ 2(27), pp. 60 - 63, (Russ.).

Methods of diagnosis (vibro-diagnosis of accurate failure, methods of wear control, oprical-fiber methods), their characteristics and modern solution are presented. With the use of the presented acceletometer the vibration record which shows sharacteristics of the developed vibration process can be written down. Also original diagrams of optical-fiber sensors of wear control are presented. 3 ill. Bibl. 6. Russ.


ON ONE PROBLEM OF THE PLANE THEORY OF ELASTICITY FOR INFINITE STRIP WEAKENED BY PERIODIC FULL-STRENGTH HOLES. G. Kapanadze, K. Kakhaia. “Problems of Mechanics”. Tbilisi, 2007, ¹ 2(27), pp. 64 - 71, (Russ.).

The problem of elastic equilibrium for an infinite strip weakened by periodic fill-strength holes in considered. We assume that the boundaries of holes are free from outer loads and on the boundary of the strip are applied absolutely smooth rigid stamps with straight-line bases and on the stamps are applied the same normal squeezing forces. The problem consists in determination of the stressed condition of the strip and analytical forms of boundaries of full-strength holes when a tangential normal strain is constant. According to Kolosov-Myskhelishvili formulas the problem is reduced to the mixed problem of the theory of analytical functions. The unknown complex potentials and the equations of full-strength contours are constructed effectively (in analytical form). 1 ill. Bibl. 12. Russ.


To the analysis of the compelled motions of a Rotary profile-Grinding Machine. B. Navrozashvili, A. Asatiani, M. Lomidze. “Problems of Mechanics”. Tbilisi, 2007, ¹ 2(27), pp. 72 - 76, (Russ.).

On the basis of carried out investigations it is obtained new approximate model of a rotary profile-grinding machine, representing by itself a basis for the subsequent analysis of the compelled motions. Bibl. 3. Russ.


THE TECHNICAL UNITS OF SMALL MECHANIZATION FOR WORKS IN THE TEA PLANTATIONS. Z. Makharoblidze, R. Khazhomia, I. Dzirkvadze, B. Shavishvili. “Problems of Mechanics”. Tbilisi, 2007, ¹ 2(27), pp. 77 - 80, (Russ.).

The work deals with the small mechanization adaptive technical units made on the base of motoblock in order to work in the tea plantations. Foreseeing the mutual-touching surface contractive deformations, using the strike theory, it is made the strike-power calculating formula which foresees the kinematic and dynamic parameters of cutting-knife and the physical-mechanical properties of plant stuff. 3 ill. Bibl. 2. Russ.


Mathematical model for projecting and producing combined tools equiped with changeable multisurface plates. A. Magradze. “Problems of Mechanics”. Tbilisi, 2007, ¹ 2(27), pp. 81 - 83, (Engl.).

In this article it is considered the possibility of getting mathematical models between shaping surface and geometry of cutting tool (taking into account the installation of a tool on the machine) which can be used at automated projecting and producing of a tool on the second level machine. 1 ill. Bibl. 3. Russ.