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a) b)
Figure 2. Powered magnetic field in the air gap of the synchronous generator of conventional design (a) and biaxial excitation synchronous generator (b) in a two-phase short circuit
Conclusion: In spite of the complexity of the constructive circuit, have a positive impact on the operating conditions of the execution of synchronous generator excitation biaxial they due to electrical system. the suppression of higher harmonics at the unsymmetrical short
References:
1. Ryudenberg R. Operating modes of electric power systems and installations. A,: Energy, - 1978. - 336 p.
2. Vazhnov A. I. Transients in AC machines. L.: Energy, Leningrad branch, - 1980. - 256 p., il.
3. Ahmatov M. G. Synchronous machines. Special course. - M.: Higher School, - 1984.
4. Pirmatov N. B., Ahmedov M. G. Disturbances are of synchronous machines biaxial excitation. Tashkent. Publisher TSTU, - 2003. -158 p.
5. Allaev K. R., Khaydarov S. D. Settlement - experimental study of short circuit modes of synchronous and asynchronous genera-tors.//Math. UzSSR series tehn. Sciences, - 1986, - No 5. - P. 23-26.
6. 6 Khaydarov S. D. Investigation of electromagnetic processes the electrical system of the methods of instantaneous values. Problems of energy - and resource, - Tashkent - No 1-2, - 2012. - P. 38-46.
7. Urusov I. D. The linear theory of oscillations of synchronous machine. - M.: Publishing the USSR Academy of Sciences, - 1960. -165 p., il.
8. Morsy M.S, Amer H. H., Bodr M.A, El-Serofi A. M. «Transient stebilegitg of synehronous generators with two-axis slip frequency excitation» England, - 1983.
DOI: http://dx.doi.org/10.20534/ESR-16-11.12-136-138
Urinova Sohiba Isroiljonovna, teacher of the Department"Theoretical and applied mechanics" Tashkent Institute of Textile and Light Industry, the Republic of Uzbekistan
Djuraev Anvar Djuraevich, technical sciences associate, professor of the Department "Theoretical and applied mechanics" Tashkent Institute of Textile and Light Industry, the Republic of Uzbekistan
E-mail: [email protected] Madrahimov Shavkat Halimovich, teacher of the Department"Theoretical and applied mechanics" Tashkent Institute of Textile and Light Industry, the Republic of Uzbekistan
E-mail: [email protected]
Reducing method of the redundant links in the kinematic pairs of batten lever mechanism of weaving looms
Abstract: In this article, new scheme of cam and lever battant mechanism with compound hinges, including elastic elements ofweaving looms are investigated. The technique ofliquidation and decrease in superfluous communications in kinematic steams of battant mechanism of the weaving looms are presented.
Keywords: weaving loom, beater, cam, lever, elastic element, inertiaforces, reactionforces, superfluous communications, mobility degree, and kinematic pair.
In practice of weavingindustry, thebattenmechanisms are battenmechanisms are easier on the device and have a high me-divided into two types, crank type and cam type. Crank type chanical efficiency, so on the shuttle weaving looms set mainly
Reducing method of the redundant links in the kinematic pairs of batten lever mechanism of weaving looms
the crank mechanisms. Cam batten mechanisms used on shuttle-less looms [1].
Battenloom mechanismis known in the form of the four-bar hinge mechanism [2]. Batten mechanism consists ofa body (frame), crank, connecting rod, rocker arm, the carrier and the top of the reed batten, connected to each other by hinges. The disadvantage of this design is a significant reaction forces in the joints between the connecting rod and the reed, as well as between the crank and
connecting rod at high-speed modes of fabric production. Also in the extreme positions of the sharp change kinematic and dynamic parameters are thread breakage, resulting in poor performance of the loom. Fig. 1 shows a diagram ofthe kinematic scheme ofthe linkage battenmechanism. During rotation of the crank 2, the connecting rod 3 makes flat — parallel movement, and Batten (lever) 4 swings about the pivot O2. In operation of the links in the kinematic pairs-reaction force occur due deflection.
c)
Fig.1 Scheme of the battenmechanisms of weaving looms; a - the existing mechanism of the batten; b - battenmechanism with two elastic hinges; c - battenmechanism with two elastic hinges and spring buffer redundant mechanism
The general theory of machines and mechanisms in the structural analysis part mainly detected number of mobile units, the kinematic pairs, the degree of mobility mechanism and redundant links. Determining the degree of mobility ofthe linkages carried out by Chebyshev, Ozola, Somov-Malyshev and Reschetov'sproposed methods [3; 4]. It also determined a redundant connection in lever mechanisms. In addition, consideration ofthe zero degree of mobility mechanisms are summarized in a special system, which is called the Assyrian groups [3; 4].
Battenmechanisms represent [5] planar-hinged four bar linkages. The degree of mobility of batten mechanism in Fig.1 deter-minedby method of Chebyshev [6].
W=3n-2P-P=3-3-2-4=1 (1)
where, n-number of links, P4, P5 — kinematic pairs of the fourth and fifth grades.
Kinematic analysis circuit indicates that the mobility of the mechanism is one, one is a generalized coordinate. Also known [7] that, the extra degree of freedom mechanism becomes in the case of the intersection of the axes of the two pairs of the fifth grade or location of these axes parallel. Therefore, in determining the degree of mobility of the linkages with the above conditions is considered appropriate account of redundant links in the mechanism, then, according to [3; 8], we have:
W=6n-5P—4P4+q (2)
where, q — the number of redundant links.
Given the fact that W=1, n=3, P=4, you can define
q=W-6n+5P+4P=3
1 5 4
(3)
The resulting number of redundant connections can also be determined using the Ozola'sformula [3].
q=W+6k-f=1+6-1-4=3 (4)
where, k — the number of independent loops in the mechanism, f — the total number of mobility, or the number of kinematic pairs of the fifth grade.
In the general theory of machines and mechanisms, each elastic mechanism unit available in the mobility increases by one. Effect of elastic links in the mechanisms of a certain degree of mobility does not take into account mechanisms. Thus, when using a composite rotational kinematic pairs, are not considered when determining the degree of mobility of the lever battenmechanism. It should be noted that the inclusion in the system of elastic elements reduce
It is therefore proposed a new formula for determining the degree of mobility of the lever mechanisms in view of elastic elements: W = 6n-5P5 + ny + q (5)
wherein, ny-elastic connections number between the components and the kinematic pairs, as well as elastic elements in composite kinematic pairs.
For lever mechanism of the batten of the weaving machine shown in Fig. 1 b, define the degree of mobility:
W = 3n-2P5-P4 = 1 (6)
As can be seen from Fig. 1 b, the mechanism have one degree of freedom. Therefore, from (5) can determine the amount of redundant links.
q = W-6n + 5P5-n = 1-18 + 20-2 = 1
y
So one elastic connection reduces the number of redundant connections to the unit. Therefore, to eliminate redundant links in the lever-hinge mechanism of the loom batten Prerequisites:
q = ny;
Then, taking into account the inclusion in the mechanism of the required number of elastic elements can eliminate redundant links, q = 0.
Wherein: W-6n + 5P5-ny = 0 and ny = W-6n + 5P5 (7)
For the reporting mechanism (see Fig. 1c) ny = 3.
Taking into account the proposed formulas (5) and (7) can be converted Ozola's formula [3] in the following form: q = W + 6k-f-n where, k — the number of independent paths in the shaft couplings, for this case, k = 1; f = 4; ny = 3; q = 0.
Therefore, for the complete elimination of redundant links in the kinematic pairs of hinged lever battenmechanism further including spring shock absorber — energy storage between the batten and the machine housing. At the same time in contact with the rocker springs in the mechanism are no redundant links, and apart from the rocker springs redundant connections is one.
Recommended method can be used for the hinged-lever mechanisms of any complexity.
References:
1. Surina N. F., Novikov A. K. "Equipment of flax weaving industry" Publisher "Light industry" - Moscow, - 1965, - P. 273-276.
2. Fundamentals of the theory, design and calculation of textile machinery, - M., "Mechanical Engineering", - 1975, - P. 217-221.
3. Artobolevsky I. I., Theory of mechanisms and machines, "Science", - 1975.
4. Baranov G. G. Course of theory of mechanisms and machines, - M., "Mechanical Engineering", - 1975.
5. Patent Rep. of Uzb. Batten mechanism of the loom. A. Juraev, Sh. Madrakhimov, IAP 20160154.
6. Juraev A. and others. The theory of mechanisms and machines. Ed. G. Gulyama, - Tashkent, - 2004, - P. 592.
7. Akulov V. J., Determination of redundant links and mobility in the mechanisms". "Engineering", - No 4, - 1977.
8. Portgiter F. M., Application of universal joints in agricultural machinery. Se of translations, "Agricultural Engineering" - 1954.
DOI: http://dx.doi.org/10.20534/ESR-16-11.12-138-140
Xudoyorov Anvarjon Nazirjonovich, Candidate of the technical sciences, assistant professor.
Mamadaliev Maxammadjon Xabibullayevich, Candidate of the technical sciences, assistant professor.
Muradov Rahimjon Xakimjonovich, Senior scientific employee researcher, PhD in Technique, Yuldasheva Matluba Ashuraliyevna, Researcher, assistant of the Faculty of Agro-engineering, Agricultural Institute of Andijan, the Republic of Uzbekistan.
E-mail: [email protected]
Motivation of the geometric form of looseners working surface of multifunction unit
Abstract: Results of the studies are brought in the article on motivation working surfaces of the geometric form of loosener multifunction unit. In the clause the results of the given researches on substantiation the geometrical form friableness working surface of the combined unit are given.
Keywords: geometric, multifunction, substantiation, friableness, cultivation, cotton plant, chisel-tillers, working organs, wedge-shape, compress, perpendicular, monolith, concave, protuberant, stretches, parameters, expenses, theoretical, experimental, contrast, velocity, fractions.
The destruction of the layer under influence working organ of ground can occur both because of the shift and take-off and a ground processing machines depending on their forms and pa- consequence of preliminary compression of ground by working rameters, depths of processing and physical-mechanical characters organ [1, 327-328].
