scholarly journals DETERMINATION OF VIBRATION POWER OF VIBRATION SOURCES OF SPINDLE UNITS OF METAL CUTTING MACHINES

2021 ◽  
Vol 23 (3) ◽  
pp. 55-61
Author(s):  
A.F. Denisenko ◽  
◽  
V.V. Mikhailov ◽  
Keyword(s):  
Metal Cutting ◽  
Center Of Mass ◽  
Spindle Assembly ◽  
Vibration Field ◽  
Spindle Unit ◽  
Urgent Task ◽  
Parametric Reliability ◽  
Calculated Model ◽  
Spindle Assemblies

Monitoring the state of spindle assemblies of modern metal-cutting machines using CIP methods implies the possibility of installing control sensors in places with maximum vibration information content. In this regard, the assessment of the informativeness of the vibration field of the spindle assembly, which can be carried out in advance, taking into account the design features, geometric and dimensional characteristics, is an urgent task. Based on the energy approach, using the example of the spindle assembly of a universal lathe, a computational model is proposed, built along the median planes of the walls. On the basis of the calculated model, the equations of the energy balance were compiled taking into account the conditions for the transfer of vibration power between the walls of the housing. The method for determining the vibration power of the main sources in the spindle assemblies is given: a spindle with residual unbalance, a drive gear and bearings. It has been established that the most significant factors determining the vibration power introduced into the spindle unit housing are the operation of the bearings, the weight of the spindle and the location of its center of mass. The result obtained makes it possible to detect incipient defects in the bearings, which, as practice shows, are the defining elements of the parametric reliability of spindle assemblies. The resulting model of the vibration field can be used to determine the reference values of vibration velocities that are formed from sources in the absence of defects.

scholarly journals Informativity of the Vibration Signal of the Spindle Unit of the Metal Cutting Machine

2021 ◽  
Vol 346 ◽  
pp. 03043
Author(s):  
Alexander Denisenko ◽  
Viktor Mikhailov
Keyword(s):  
Energy Balance ◽  
Power Flow ◽  
Metal Cutting ◽  
Early Stage ◽  
Vibration Signal ◽  
Balance Equations ◽  
Vibration Field ◽  
Spindle Unit ◽  
Urgent Task ◽  
Vibration Power Flow

Monitoring the condition of the spindle units of modern metal-cutting machines by methods of non-selective diagnostics involves the possibility of installing monitoring sensors in places with maximum vibration information. In this regard, the assessment of the informative value of the vibration field of the spindle unit, which can be carried out in advance, taking into account the design features, geometric and dimensional characteristics, is an urgent task. Based on the energy approach, a computational model based on the median planes of the walls is proposed using the example of a universal lathe spindle unit. On the basis of the calculated model, the energy balance equations are drawn up taking into account the conditions for the transmission of vibration power between the walls of the housing. The dependences that allow us to calculate the coefficients that take into account the absorption of vibration energy by the walls of the housing are given. The solution of the energy balance equations made it possible, based on the level of the vibration power flow, to rank the walls of the spindle unit body by information content,. The resulting model of the vibration field can be used to determine the reference values of vibration velocities that are formed from sources in the absence of defects. This will allow for non-selective diagnostics to detect the occurrence of a defect at an early stage, and in the presence of a defect to assess the level of its development.

scholarly journals Dynamics of Spindle Assembly of Metal-Cutting Machine

2020 ◽  
Vol 9 (3) ◽  
pp. 3121-3125
Keyword(s):  
Dynamic Characteristics ◽  
Metal Cutting ◽  
Experimental Studies ◽  
Spindle Assembly ◽  
Metal Cutting Machine ◽  
Method Of Calculation ◽  
Cutting Machine ◽  
Spindle Unit

The methods of conducting an experiment to study the dynamic characteristics of the elements of the spindle assembly are considered. The results of experimental studies of the dynamics of the spindle assembly of a cutting machine are presented. The method of calculation of dynamic characteristics, and the own frequencies of fluctuation of spindle node of the metal cutting machine «НТ-250М» are described. The design of the features of the spindle unit was carried out in the software «АРМ WINMACHINE».

MEASURING OF THE MINIMUM VALUE OF TENSION PRELOAD IN A BEARING TO ENSURE THE RIGIDITY OF A SPINDLE UNIT DURING REPAIR OF THE “BEARING OUTER RING–CASE” JOINT

2021 ◽  
pp. 36-40
Author(s):  
V. Yu. Fedchenko ◽  
A. A. Fedchenko ◽  
I. V. Burjanov
Keyword(s):  
Metal Cutting ◽  
Lower Boundary ◽  
Spindle Assembly ◽  
Intersection Point ◽  
Outer Ring ◽  
Polymer Composition ◽  
Main Task ◽  
Minimum Value ◽  
Spindle Unit ◽  
Bearing Stiffness

The article proposes a method for determining minimum tension preload when restoring stiffness of a joint between a case and an outer ring of a bearing. Stiffness is essential prerequisite for functioning of a spindle assembly in a metal-cutting machine. To large extent, stiffness of an assembly is affected by deformation of its supports, mainly the frontal one. During work, this influence increases due to weakening and displacement of “outer ring of a bearing–case” fit. Fretting corrosion wear is believed to be the main cause of this phenomenon. Usage of polymer compositions in restoration of joints increases stiffness due to contact area enlargement. Main task is to determine required minimum value of tension preload to fully restore stiffness of a fit. This experimental study includes finding stiffness of “outer ring of a bearing–case” joint directly and finding stiffness of a spindle assembly as a whole. Method proposed helps to define minimum tension preload in an adjustable front bearing with different values of hole wear in a case which have been restored with polymer composition. Minimum tension preload is defined at the intersection point of a bearingʼs stiffness-tensile curve with the lower boundary of the stiffness parameter range. This method can be used for fit and for a spindle assembly as a whole.

scholarly journals Measuring the quartic Higgs self-coupling at a multi-TeV muon collider

2020 ◽  
Vol 2020 (9) ◽  
Author(s):  
M. Chiesa ◽  
F. Maltoni ◽  
L. Mantani ◽  
B. Mele ◽  
F. Piccinini ◽  
...  
Keyword(s):  
Higgs Boson ◽  
Center Of Mass ◽  
Mass Energy ◽  
Simple Analysis ◽  
Proton Proton ◽  
Coupling Interaction ◽  
Center Of Mass Energy ◽  
Muon Collider ◽  
Better Than

Abstract Measuring the shape of the Higgs boson potential is of paramount importance, and will be a challenging task at current as well as future colliders. While the expectations for the measurement of the trilinear Higgs self-coupling are rather promising, an accurate measurement of the quartic self-coupling interaction is presently considered extremely challenging even at a future 100 TeV proton-proton collider. In this work we explore the sensitivity that a muon collider with a center of mass energy in the multi-TeV range and luminosities of the order of 1035cm−2s−1, as presently under discussion, might provide, thanks to a rather large three Higgs-boson production and to a limited background. By performing a first and simple analysis, we find a clear indication that a muon collider could provide a determination of the quartic Higgs self-coupling that is significantly better than what is currently considered attainable at other future colliders.

Spindle assembly with adjustable output characteristics

2021 ◽  
pp. 21-23
Author(s):  
Keyword(s):  
Spindle Assembly ◽  
Performance Characteristics ◽  
Taper Angle ◽  
Gas Bearings ◽  
Output Characteristics ◽  
Experimental Bench ◽  
Spindle Assemblies

A method for controlling the output characteristics of spindle assemblies based on the use of tapered gas bearings with a small taper angle is proposed. An experimental bench for studying the performance characteristics of these bearings is described. The results of researches of gas-static bearings with a small taper angle are presented. Keywords: spindle assembly, gas-static support, small taper angle, experiment. [email protected]

scholarly journals Research of the activities of the enterprises of the perfume and cosmetic industry of Ukraine

2021 ◽  
pp. 44-55
Author(s):  
Iryna Kazakova ◽  
Viacheslav Lebedynets ◽  
Svitlana Kovalenko ◽  
Viktoriya Kazakova
Keyword(s):  
Economic Activity ◽  
Cosmetic Products ◽  
Economic Activities ◽  
Research Production ◽  
Urgent Task ◽  
Cosmetic Industry ◽  
Business Entities ◽  
Individual Success ◽  
Further Development

The perfumery and cosmetic industry of Ukraine is distinguished by its dynamic development and makes a significant contribution to the country's economy. Several types of economic activities are involved in its functioning, including the development, research, production and sale of perfumery and cosmetic products, as well as the provision of cosmetic services to the population. The economic activity of each sector in the chain of creation, production and sale of cosmetic products / services determines both their individual success and the efficiency of the entire system as a whole. In this regard, the systematization and analysis of the indicators of economic activity of enterprises of each type of activity of the national cosmetic industry is an urgent task, the solution of which will reasonably determine the prospects for both the further development of this industry and the export potential of the Ukrainian economy as a whole. The aim of this work was to conduct a comprehensive study of the dynamics of the main indicators of Ukrainian enterprises of perfumery, cosmetic and related industries economic activity for the period 2010–2019 and determination of their development trends. The available data of the State Statistics Service of Ukraine, the Patent Office of Ukraine, as well as a database of scientific and professional publications publications were used as materials and methods. Retrospective, logical, research methods, as well as the method of content analysis were used. The results of a comparative analysis of the main indicators of the economic activity of business entities in the studied industry made it possible to establish trends in the development of this sector of the economy and substantiate the patterns observed at the present stage. Conclusions. The results of the study indicate that the production potential of the perfumery and cosmetic industry in Ukraine is promising, as well as significant opportunities for further development of the trade in these products and the provision of cosmetic services to the population.

Development of a 6-DOF Testing Platform for Multirotor Flying Vehicles with Suspended Loads

Aerospace ◽  
2021 ◽  
Vol 8 (11) ◽  
pp. 355
Author(s):  
Saad M. S. Mukras ◽  
Hanafy M. Omar
Keyword(s):  
Degrees Of Freedom ◽  
Center Of Mass ◽  
Performance Testing ◽  
Flight Performance ◽  
Testing Platform ◽  
Six Degrees Of Freedom ◽  
Mass Properties ◽  
Test Platform ◽  
Suspended Loads

The development of multirotor vehicles can often be a dangerous and costly undertaking due to the possibility of crashes resulting from faulty controllers. The matter of safety in such activities has primarily been addressed through the use of testbeds. However, testbeds for testing multirotor vehicles with suspended loads have previously not been reported. In this study, a simple yet novel testing platform was designed and built to aid in testing and evaluating the performances of multirotor flying vehicles, including vehicles with suspended loads. The platform allows the flying vehicle to move with all six degrees of freedom (DOF). Single or three-DOF motions can also be performed. Moreover, the platform was designed to enable the determination of the mass properties (center of mass and moments of inertia) of small multirotor vehicles (which are usually required in the development of new control systems). The applicability of the test platform for the in-flight performance testing of a multirotor vehicle was successfully demonstrated using a Holybro X500 quadcopter with a suspended load. The test platform was also successfully used to determine the mass properties of the vehicle.

COVID-19 diagnostic laboratory strategies: modern technologies and development trends (review of literature)

2020 ◽  
Vol 65 (12) ◽  
pp. 757-766
Author(s):  
Boris Georgievich Andryukov ◽  
I. N. Lyapun
Keyword(s):  
Research Result ◽  
Simple Device ◽  
Epidemiological Surveillance ◽  
Serological Tests ◽  
Diagnostic Laboratory ◽  
Urgent Task ◽  
Polymerase Chain ◽  
Device Free ◽  
Modern Technologies

The COVID-19 pandemic, associated with the new coronavirus SARS-CoV-2, has caused a surge in incidence worldwide, as well as a severe crisis in global health and economy. Therefore, fast and accurate diagnosis of infection is key to timely treatment and elimination of the spread of the virus. Currently, the standard method for detecting coronavirus is reverse transcription polymerase chain reaction (RT-PCR). However, this method requires expensive equipment and trained personnel, which limits the conduct of mass testing and lengthens the time to obtain a research result. Serological tests for antibodies against SARS-CoV-2 and the determination of protective immunity in various populations are used to retrospectively identify patients with asymptomatic and mild forms of infection, monitor the course of infection in hospitalized patients, and also track contacts and epidemiological surveillance. The use of standard methods for diagnosing COVID-19 in conditions of mass morbidity, especially in conditions of insufficient resources and lack of appropriate infrastructure, is associated with a number of limitations. Therefore, the search and development of new, fast, inexpensive, simple, device-free and no less sensitive and specific tests is an urgent task. Therefore, the search and development of new, fast, inexpensive, simple, device-free and no less sensitive and specific tests is an urgent task. The review examines new laboratory technologies for diagnosing a new infection - loop isothermal amplification (LAMP) and immunochromatographic analysis (ICA), which can become a real alternative to the used molecular and enzyme immunoassay methods. The dynamic development of these methods in recent years expands the prospects for their use both for diagnosing COVID-19 and monitoring a pandemic.

Study on Determination of Friction Model at the Tool-Chip Interface of Titanium Alloy Ti6Al4V Based on Orthogonal Cutting

2011 ◽  
Vol 117-119 ◽  
pp. 1788-1791
Author(s):  
Yue Feng Yuan ◽  
Wu Yi Chen
Keyword(s):  
Titanium Alloy ◽  
Cutting Force ◽  
Metal Cutting ◽  
Orthogonal Cutting ◽  
Cutting Speed ◽  
Friction Model ◽  
Carbide Tool ◽  
Orthogonal Turning ◽  
Titanium Alloy Ti6al4v

It is necessary for cutting simulation to determine the friction model at the tool-chip interface suitable for metal cutting process. Cutting force experiments in orthogonal turning titanium alloy TI6AL4V are carried out with cement carbide tool KW10. The Coulomb frictions at the tool-chip interface are calculated based on measured cutting force, and the friction model is regressed, where cutting speed and feed rate are presented.

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