Research of the problem of optimization and development of a calculation method for two-stage chain drives used in heavy industrial vehicles in conditions of economic efficiency

The article is dedicated to the problem of optimization of chain drives of the drilling unit. At present, increasing the power per machine to the optimal limits, reducing the material and energy consumption per unit capacity of the machine, as well as operating costs are considered topical issues. The machines that are designed and constructed to optimal limits must be very powerful and productive. The machines that are applied to perform drilling works in the oil and gas industry must be easy to operate, reliable and have ability to operate for a long time. When constructing such machines, their being lightweight, economical, as well as their preparation in a short time and at low cost should be taken into account in advance. In order to ensure the reliable operation of drilling rigs, it is more expedient to apply chain drive in their mechanical transmission. First of all, the application of chain drive in drilling units and hoisting mechanisms is considered. Then a calculation method was developed for the chain drives of the drilling unit used in deep exploration wells and the exploitation of wells, and, accordingly, the calculation of the chain drive was carried out. The chain drive consists of drive and driven sprockets and a chain that encompasses the sprockets and engages in their teeth. Chain drives with several driven sprockets are also used. In addition to the basic listed elements, chain drives include tensioners, lubricating device and guards. The chain consists of hinged links that provide mobility or “flexibility” of the chain. Chain drives can be performed in a wide range of parameters. The calculation took into account the quality of the material, the service life and durability of the chain drive constructio

A Retrieval Queueing Model With Feedback

A multi-server retrial queuing model with feedback is considered in this paper.Input flow of calls is modeled using a Markovian Arrival Process (M AP) and the service time is assumed to follow an exponential distribution. An arriving call enters into service should there be a free server. Otherwise, in accordance to Bernoulli trials, the call will enter into an infinite orbit (referred to as a retrial orbit) to retry along with other calls to get into service or will leave the system forever. After obtaining a service each call, independent of the others, will either enter into a finite orbit (referred to as a feedback orbit) for another service or leave the system forever. The decision to enter into the feedback orbit or not is done according to another Bernoulli trial. Calls from these two buffers will compete with the main source of calls based on signals received from two independent Poisson processes.The rates of these processes depend on the phase of the M AP. The steady-state analysis of the model is carried out and illustrative numerical examples including economical aspects are presented

COMPARATIVE ANALYSIS OF LANDSCAPE FEATURES OF THE MINOR CAUCASUS (INCLUDING NAKHCHIVAN IN THE AZERBAIJAN TERRITORY) AND THE STATE OF CALIFORNIA, USA (DEATH VALLEY AND THE MOJAVE DESERT) FOR DEVELOPMENT OF TOURISM ECONOMY

In this report authors describe similar peculiarities of landscapes of Azerbaijan and the State of California, USA. Authors present natural features of these territories in order to analyze similarities of landscapes or their elements