Articolele autorului Sevastian Liviu Bocîi
Link la profilul stiintific al lui Sevastian Liviu Bocîi

Estudio de las tensiones en válvulas biplanas tipo mariposa

This paper presents the study of tensions developed as a result of the static actuation developed in a biplane valve, butterfly type, with a 1.500 mm diameter, loaded with a pressure of 1 MPa, using the finite element method, experimentally verified using a resistive electrical tensiometrical method. The proper knowledge of those valve types is very important in order to control the admissible losses.

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Technological aspects of assembling and processing narrow tubes

The paper presents the assembling, welding and processing of narrow tubes made of austenitic stainless steel used for the manufacturing of syringes and of food industry parts. At the same time, the paper discusses the various phenomena occurring during the processing of the materials previous to assembling and welding as well as during the welding operation proper. Following these studies and experiments, a suitable welding technology has been homologated

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Study of the materials used in the manufacturing of a tubular camshaft

In this workshop we elaborated several heat treatment tests to a large number of cams in order to achieve better results of mechanical resistance of a tubular camshaft made for an internal combustion engine. The most important results of our tests are represented in a few graphics and tables in this workshop

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The influence of the braking time on heat flow through the friction surfaces of the friction elements of disk brakes for railway vehicles

Disk brakes were first introduced on the suburban and urban coaches and high speed freight cars (V > 120 km/h) for the following reasons: shoe brakes reached their potential limits, especially at high speeds; the maintenance of disc brakes is cheaper; greater comfort; the friction coefficient of disk brake elements (friction pad and brake disc) presents lower variation in velocity and pressure; disk brakes present lower temperatures of friction surfaces.

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Mathematical model of three-phase induction machine connected to advanced inverter for traction system for electric trolley

This paper establishes a mathematical model of induction machine connected to a frequency inverter necessary to adjust the electric motor drive. The mathematical model based on the Park’s theory allows the analysis of the whole spectrum (electric car – frequency inverter) to drive the electric trolley bus made on ASTRA Bus Arad (Romania). To remove higher order harmonics, the PWM waveform of supply voltage is used, set in the general case. Operating

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