Parametrical series method presents greatest effect with machines of mass application, possessing wide range of changes of indexes.
Correct choice of machine type, number of members of a series and intervals between them !s of prime importance in designing parametrical series.
As an example fig.2.8. shows possible parametrical series of 3-phase alternative current engine /6/.At it is seen at fig,2.8., neither arithmetic, nor geometric progression corresponds to usability curve. Rational series is rarefied in the sphere of the least usability and is concentrated in the sphere of the greatest one. It allows to answer demands of the large range of users. Subdivision of engines in this field provides increase of degree of their usage and cost increase.
One of the main conditions, providing economic effect of parametrical series, is duration of their application. That's why in designing present state and perspectives of development of corresponding fields must be taken into account.
Translate the following words into Russian, use them in your rendering of the text:
Specification, possessing, indexes, index gradation, to put into basis, alteration, dimensions, alongside, geometrical similarity, dimension-similar, standard size series, serve, smaller overall dimensions, concentration of power, mixed series, modification, one-type or geometrical similar, application, reduce, limitation, hence effective, production of machines, increase, scale of, technological gain, parametrical series, presents, mass application, possessing wide range, correct choice, is of prime importance, duration.
Find corresponding English equivalents for the following word combinations:
Параметрические ряды, одинаковое, назначение, регламентирд-вать, конструкция, показатели, градация, случай, целесообразно, основа, единый, необходимые, пособия, модификация, размерно-подобные, размерные, установить, типоразмерными, служить, двигатель, применяют, такт, обладающие, равная, габариты, газотурбинные, способные, обусловлен, сокращение, централизованное, следовательно, масштаб, массовое применение, диапазон, показатель, проектирование, фаза; электродвигатель, ток, прогрессия, соответствуют, кривая применяемости, рациональный, разряжён, сгущен, позволяет удовлетворить потребность, дробность, обеспечивает, условие, учитывать, перспектива, отрасль.
Questions to the text and subjects for discussion :
l.What do you understand under parametrical series?
2.Why is it advisable to put a common type of a machine into the basis?
3.What series are called demension series?
4.1n what cases is it advisable to set a type of a machine with its own dimension for each gradation? Give examples.
5.What are mixed series?
6.Why do standard size and mixed series not reduce productivity of parametrical series method?
7.Can the centralized production be considered to be a tethnological gain?
8.Why does parametrical series method present a great effect with machines of mass application?
9.What do you think is jf prime importance in designing parametrical series?
10.What allows to answer demands of a large range of users?
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