Pneumatic device of the preload and dynamic loads balancing to reduce the intensity of thermal processes in the metal cutting process

Improved reliability of the technological system "machine-tool-instrument-detail" is an important current task. Backlashes and insufficient stiffness of technological system lead to intensive wear of the cutting tool, increasing the heat in the cutting zone. Due to high temperature in the thin surface layers of the workpiece and tool thermal processes may occur which are similar to release and can cause the structural changes of the material. The current article presents the final design of the device which has been developed to reduce the intensity of thermal processes in metal cutting

Radial-piston pump for drive of test machines

The article reviews the development of radial-piston pump with phase control and alternating-flow mode for seismic-testing platforms and other test machines. The prospects for use of the developed device are proved. It is noted that the method of frequency modulation with the detection of the natural frequencies is easily realized by using the radial-piston pump. The prospects of further research are given proof

Quench propagation and protection analysis of the ATLAS Toroids

The ATLAS superconducting magnet system consists of the Barrel Toroid, two End Cap Toroids and the Central Solenoid. However, the Toroids of eight coils each are magnetically separate systems to the Central Solenoid. The Toroids are electrically connected in series and energized by a single power supply. The quench protection system is based on the use of relatively small external dump resistances in combination with quench-heaters activated after a quench event detection to initiate the internal dump of stored energy in all the coils. A rather strong quench-back effect due to eddy-currents in the coil casings at the transport current decay is beneficial for the quench protection efficiency in the event of heater failures. The quench behaviour of the ATLAS Toroids was computer simulated for normal operation of the quench protection system and its complete non-operation (failure) mode. (3 refs)

Quench propagation and detection in the superconducting bus-bars of the ATLAS magnets

The ATLAS superconducting magnet system comprising Barrel (BT) and End-Cap Toroids (ECT) and also Central Solenoid (CS) will store more than 1.5 GJ of magnetic energy. The magnet system will have many superconducting busbars, a few meters long each, running from the current leads to Central Solenoid and Toroids as well as between the coils of each Toroid. Quench development in the busbars, i.e., the normal zone propagation process along the busbar superconductors, is slow and exhibits very low voltages. Therefore, its timely and appropriate detection represents a real challenge. The temperature evolution in the busbars under quench is of primary importance. Conservative calculations of the temperature were performed for all the magnets. Also, a simple and effective method to detect a normal zone in a busbar is presented. A thin superconducting wire, whose normal resistance can be easily detected, is placed in a good thermal contact to busbar. Thus, the wire can operate as straightforward and low-noise quench-detector. (4 refs)

Reduction of a fan vibration activity in a life support system of oil and gas stations

Relevance. Electromechanical fans are widely used in life support systems of oil and gas stations, operate in conditions of vibration, high rotational speeds and loads. Design, technological and operational reasons influence vibration activity of an electromechanical device. The greatest "contribution" to the existing vibrations, according to the frequency spectrum, is made by the imperfection of the design elements of the ball bearing. They are: separator movement, variable stiffness under the action of radial load, interaction of micro-dimensions of working surfaces, facet and waviness of working surfaces of rings and balls. In addition, the resulting vibrations negatively affect both the reliability and durability of the fan. Since it is technically impossible to completely eliminate the vibration activity of an electromechanical device, it is advisable to reduce it with the help of a technical solution by introducing a damping element into a kinematic circuit of the vibration source. In this regard, the development of a damping device is an integral technical task that helps to reduce the vibration activity of technical life support systems of oil and gas stations, as well as to improve the quality of environmental conditions of human life. To reduce vibration activity, a damper design is proposed that takes into account various types of energy dissipation. However, given the dense spectrum of vibration frequencies from ball bearings, a viscous friction element is introduced into the damper design. To determine the effectiveness of reducing vibration activity, a model of the damper in question was made based on the developed 3D model. For tests in determining the effectiveness of applying a viscous friction element, two variants of the damper design were used. In the first version of the damper design, there was no viscous friction element, and in the second version there was one. According to the test results of the damper layouts, it can be seen that the developed technical solution to reduce the vibration activity of the electromechanical device has practical confirmation. The studies underlying the developed design of the damper with a viscous friction element allows for reduction in the vibration amplitude. Object. Electromechanical device in operating mode. Aim. To describe the vibration activity in the operating mode of an electromechanical device in the entire spectrum of disturbing effects acting along the axes, taking into account the imperfect geometry of ball bearing parts; to develop a damper for reducing the vibration activity level in the electromechanical device. Methods. Vibration diagnostics, computational mathematics, measuring instruments, software "Vibration recorder-F", "Vibration Recorder-M2", "Logger"-recorder and "Bearing". Results. The paper demonstrated the effectiveness of the proposed technical solution to reduce the vibration amplitude in the operating frequency range of the electromechanical device rotor up to 4 times compared with the corresponding maximum amplitude value without its use

Solid-state damper for reducing vibration activity of an electromechanical device of a life support system of oil and gas stations

Relevance. Mechanical vibrations are a common and technically important process that has a negative acoustic effect on human health and in some cases is a harmful production factor. In devices, the presence of vibration is caused by exciting influences of various physical nature: mechanical, electromagnetic, aerodynamic. The reason for their occurrence are defects in parts and assemblies, the technical principle of the ball bearing device, as well as the coincidence of the operating frequency of the device with natural frequency of the structural elements. Since it is technically impossible to completely eliminate the vibration activity of an electromechanical device, the actual topic of scientific research is the technical task of developing a damping device with determining its effectiveness to reduce the vibration activity of an electromechanical device, thereby minimizing the effects of concomitant harmful production factors on humans. To study this problem, a 3D model of the construction of a solid-state damper based on aluminum foam has been developed, according to which two layouts are made with different depths of cylindrical ducts used to install screws. The results of measuring vibration characteristics showed that the material used as a vibration dampener has damping properties and can be used to reduce the level of vibration activity of an electromechanical device. A comparison of the test results of the solid-state damper layouts showed that using layout No. 1 reduces the vibration amplitude up to 3 times compared with layout No. 2. Object. Fragment of the damping element of the vibration damper of a solid-state damper based on aluminum foam. Aim. To develop a design for a solid-state damper based on aluminum foam and determine the effectiveness of its use to reduce the level of vibration activity of an electromechanical device of the life support system of oil and gas stations. Methods. Modern approaches of vibration diagnostics, computational mathematics and measuring instruments. Results. There is a possibility of creating a solid-state damper based on aluminum foam to solve the problems of reducing the amplitude of vibration in the operating frequency range of the rotor of an electromechanical device compared with the corresponding vibration characteristics without damping elements