Ðiñture 1 - Coal combine UKD 200-250
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Coal is the most significant power medium own Ukrainian reserves of which are able to provide it’s power safety. The government program of development of coal industry of Ukraine provides for continued increase of annual mining output volume that till 2010 reaches 110 ml. t. Increase of loading on cleaning coal-face is one of the terms of implementation program. Thank’s to the application of new intensive technologies of output of useful minerals and more accomplished technique.
One of the mainest point, determining the level of safety of combine on the a whole, there is the transmission to the executive branch. The promoted requirements to durability of its elements are determined by the high level of loading, and that a transmission of excavation machines is successive connections of large number of elements with the limited reliability, in this connection expenses on spare parts to the transmissions make greater part of cost of all spare parts.
The significant trend of perfection of constructions of created combines is averting of fatique destruction in transmission details. One of aspects of decision of this problem is further perfection of methods of calculation on endurance. That’s why, all questions, related to the further investigation of operationed strength of elements of transmission are actual.
Many scientific works are devoted to the questions of studying of dynamic process in drive of different types of cleaning combines and arisng up loads, calculation methods of bending strenghth of tooth gearing on the whole. Different project-construction organizations, scientific institutions, departments of high study organizations are studying problems of dynamic and creation of coal machines. The following organizations have been studying these aspects: Dongiproyglemach, DonYGI, DonNII, PNIUI, Avtomatgormash, IGD the name of A.A. Skochinskogo, UKRNII Ugleobogaschenie, Vniistroydormash, NIIkhimmash, MNTK «Mekhanobr» (Saint Petersburg), Mekhanobrchermet ( Krivoi Rog), Yasinovatskiy machine-building plant, NKMZ, DONGTU, NGA of Ukraine, Donbasskiy coal-metallurgical institute, Donbass state machine-building academy, DONGASA, MGGU et al.
The aim of this work – is the analysis of loadings, operating on shaft of reducing gear of the executive branch of cleaning combines and perfection of existing calculation methods of endurance and durability of reductor elements.
It is necessary to resolve some problems to achieve the purpose:
1) Analysis of existent methods of calculation on fatique durability;
2) Analysis of existent methods of schematizing of casual processes;
3) Conducting of mathematic design of expluatation of tooth-baals;
4) Processing of experimental data.
The given MM takes into account influencing of feeding network and change of parameters of electric motor because of ousting of current in a short-closed rotor with the difficult form of slots. The account of changing of parameters of AED is carried out replacement of the real cage of rotor fictitious double, in which resistances of overhead and lower cages do not depend on sliding. Parameters of chart of substituting for Xm, Xs, Xrâ, Xrí, Rs, Rrâ, Rrí are determined by calculation a way with the use of data of references of AED.
Further in the system :
ωñ – angular speed of the magnetic field ;
as, arâ, arí – are coefficients of relative reactance, depending on the parameters of scheme substitutions:
; 
;
;
where Xrs – is the resulted inductive resistance of stator:
;
Xm – inductive resistance mutual induction;
Xs – synchronous inductive resistance of stator;
Xrâ, Xrí – - inductive resistance of dispersion to according to overhead and lower cages of rotor;
bs, brâ, brí – are coefficients of relative active resistance, depending on the parameters of chart substitutions:
; 
;
;
Rs – is active resistance of phase of puttee of stator;
Rrâ, Rrí – is active resistance of phases to according to overhead and lower cages of rotor;
ΔUsα, ΔUsβ – are projections of vector of falling of tension of stator on an axis α and β, taking into account influencing of feeding network:
where Rc è Xc – accordingly active and reactive resistances a feeding network (connecting cables and transformer);
isα, isβ – are projections of currents of stator and rotor on an axis α and β:
Um – is amplitude of tension of phase:
,
Uí – is nominal phase tension of network;
t – is current time of process;
ð – is a number of pair of poles of electric motor;
–
- transmission relation of reductor.
Because of non-linearity of SDU and necessity of its decision numeral methods, the dependence of revolting forces on time in an obvious kind was not used, and SDU was examined as autonomous.
In future on the basis of it, MM will be executed calculation of gearings of subsystem of drive of executive branch of cleansing combine and the parameters of longevity of gearing have been.
List of literature:
© 2008 Zybovskaya Yuliya © 2008 DonNTU |
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