Full-metal vibroinsulators with circular elements are widely spread and effectively reduce a harmful impact of vibration in mechanical systems. However, in a contemporary literature an issue of a regulation of that kind of vibroinsulators and their study, considering non-linearity of the characteristics, is addressed insufficiently. In the presented study by a joint implementation of Mohr's method and finite element method the method of a calculation of loading characteristics of adjustable full-metal vibroinsulators with elastic elements in the form of an ellipse and a system of two ellipses was developed. Broad (in a few hundreds of times) capabilities to regulate their rigidity characteristics were demonstrated. The presence of zone of quasi-zero rigidity is detected. The method allows to accurately determine parameters of a vibroinsulator, which increases quality of final products.

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An implementation of full-metal vibroinsulators is one of the most effective measures for an elimination of harmful effects of vibration in mechanical systems. However, in a contemporary literature an issue of an analytical calculation of vibroinsulators of that type, considering a non-linearity of the characteristics, is addressed insufficiently. In the presented study, by an implementation of exact theory of bending of elastic rods, the methodology of load characteristics calculation of full-metal vibroinsulators with elastic elements of rectilinear and circular shape of initial axial lines was developed. A groundlessness of Euler equation's implementation was demonstrated in a case of large displacement of linear rods, commensurable with their length. The method allows to increase designer's capabilities, to improve an accuracy of the calculation and to reduce time spent for a final adjustment of a product, which will ultimately lead to cost reduction final products.

The roof mounted boiler house is one of the perspective kinds of autonomous heat supply. Boiler houses are located on the building roofs or on a special substructure, mounted over the roof. New apartment blocks are usually equipped with the roof mounted boiler houses thanks to the high cost effectiveness of this solution. However, vibration isolation is often neglected when boilers are installed directly to the substructure. As a result, residents of the upper floor apartments suffer from the constant noise exposure. Experimental studies of various boiler equipment operation modes were conducted in order to determine the main sources of noise and their frequency spectrum. It was shown that the main source of the noise increase in residential areas was the boiler combustion process. The noise has a structural character. The vibration protection system, based on the rope isolators (VMT), has been developed in order to reduce the noise levels in residential areas. We have carried out necessary calculations, taking into account the weight of the boiler, the water in it and all associated elements. Also, the isolator samples were a statically tested. The vibration protection system implementation provides the achievement of sanitary noise norms in residential areas. Key words: Noise; isolator; vibration protection system; vibration; roof boiler

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