THEORETICAL STUDY OF THE VIBRATION EXCITATION AND NOISE GENERATION PROCESSES OF THE GRINDING WHEELS OF THREAD- AND SPLINE GRINDING MACHINES

Akustika ◽  
2021 ◽  
pp. 173
Author(s):  
Aleksandr Shashurin ◽  
Zhenish Razakov ◽  
Alexander Chukarin
Keyword(s):  
Surface Layer ◽  
Theoretical Study ◽  
Machine Building ◽  
Noise Generation ◽  
Sound Emission ◽  
Noise Levels ◽  
Grinding Wheels ◽  
Standard Values ◽  
Grinding Machines ◽  
Grinding Operations

The competitiveness of machine-building products is largely determined by the accuracy of mechanical processing of the manufactured parts and the state of the surface layer. The condition of the surface layer is carried out by finishing operations, such as grinding. The volume of grinding operations is from 25 to 60 % of various technological operations. Working conditions in the grinding areas are considered harmful and dangerous. [1]. The noise levels at the workplaces of these machines’ operators exceed the standard values. The sound emission from the part during grinding is a particular feature of this process. A theoretical study of the noise generation processes on such machines was carried out to develop the recommendations.

New Active Online Balancing Method for Grinding Wheel Using Liquid Injection and Free Dripping

2017 ◽  
Vol 140 (3) ◽  
Author(s):  
Xining Zhang ◽  
Xu Liu ◽  
Huan Zhao
Keyword(s):  
Grinding Wheel ◽  
Time Varying ◽  
Residual Liquid ◽  
Grinding Wheels ◽  
Abrasive Particles ◽  
Balance Condition ◽  
Liquid Injection ◽  
Grinding Machines ◽  
The Relationship

Grinding is a vital method in machining techniques and an effective way to process materials such as hardened steels and silicon wafers. However, as the running time increases, the unbalance of grinding wheels produce a severe vibration and noise of grinding machines because of the uneven shedding of abrasive particles and the uneven adsorption of coolant, which has a severe and direct impact on the accuracy and quality of parts. Online balancing is an important and necessary technique to reduce the unbalance causing by these factors and adjust the time-varying balance condition of the grinding wheel. A new active online balancing method using liquid injection and free dripping is proposed in this paper. The proposed online balancing method possesses a continuous balancing ability and the problem of losing balancing ability for the active online balancing method using liquid injection is solved effectively because some chambers are full of liquid. The residual liquid contained in the balancing chambers is utilized as a compensation mass for reducing rotor unbalance, where the rotor phase is proposed herein as a target for determining the machine unbalance. A new balancing device with a controllable injection and free dripping structure is successfully designed. The relationship between the mass of liquid in the balancing chamber and the centrifugal force produced by liquid is identified. The performance of the proposed method is verified by the balancing experiments and the results of these experiments show that the vibration of unbalance response is reduced by 87.3% at 2700 r/min.

scholarly journals INVESTIGATION OF THE PROCESS OF DOUBLE-SIDED GRINDING OF TORCHES OF PUSHERS WITH DIFFERENT DIAMETRERS

2018 ◽  
pp. 86-93
Author(s):  
Oleksandr Lytvyn ◽  
Kalchenko Dmytro Kalchenko
Keyword(s):  
Large Scale ◽  
Maximum Diameter ◽  
Grinding Wheel ◽  
Universal Method ◽  
Grinding Wheels ◽  
Processing Efficiency ◽  
Agricultural Engineering ◽  
Grinding Machines ◽  
Precision Of Processing ◽  
Different Diameters

Urgency of the research. In machine tools, automotive, agricultural engineering, manufacturing, where it is necessary to ensure high accuracy of surfaces of parts with different diameters of faces, it is required to adhere to high requirements for the quality of geometric sizes, roughness and accuracy of molding. Target setting. Grinding of end surfaces of parts with different diameters of faces, is carried out on two-sided end-grinding machines. The specific gravity of grinding in the total complexity of mechanical processing is constantly increasing and at the present stage it is about 30 % in the machine tool industry, in the automotive industry more than 38% of the total complexity of processing. Actual scientific researches and issues analysis. On the two-sided end-grinding machines of the Saturn company (Germany) the processing of round ends of parts is done with a circular feed to the processing area. Abrasive wheels are used without calibrating plots, which requires a lot of processing to obtain the required precision, which reduces the productivity of grinding. The disadvantage of the method is that the processing of parts with different face diameters is not considered. Uninvestigated parts of general matters defining. It is necessary to improve the processing efficiency of parts by developing the methods of two-sided polishing of the ends of pushers with different diameters oriented grinding wheels with and with-out calibrating sections, and also the rotation or without rotation of the workpiece on the calibration section, at least one revo-lution. The research objective. Improving the accuracy of finishing the end surfaces of parts of various diameters with grinding wheels, is achieved by the fact that the shaping of the ends of the smaller diameter is performed by the maximum diameter of the flat end of one circle, and the shaping of the end face of a larger diameter – the calibration section of the second circle, the length of which is equal to the diameter of the larger end and filled with diamond pencil, which moves along a radius, which coincides with the radius of the location of the axes of the parts in the feed drum. The statement of basic materials. In order to ensure the processing of parts in one pass and the necessary precision of processing, in large-scale and mass production, a grinding method oriented circles with calibrated sections with one-sided arrangement of ends of one diameter is used. The calibration sections are then made of different lengths, depending on the diameter, respectively, larger and smaller. Conclusions. The universal method of practical application of model of accuracy of shaping of ends of parts of different diameters, oriented grinding circles with and without calibration plots has been suggested. The presented method simplifies the grinding of the grinding wheel. It does not require special editing and allows to use regular editing.

Vibrations and Waterborne Noise on Fishery Vessels

1988 ◽  
Vol 32 (02) ◽  
pp. 112-133
Author(s):  
W. Ojak
Keyword(s):  
United Nations ◽  
Noise Generation ◽  
Noise Levels ◽  
Structural Vibrations ◽  
Mechanical Vibrations ◽  
Noise Propagation ◽  
Research Institutes ◽  
Fishery Research ◽  
Elastically Supported ◽  
Agricultural Organization

The Food and Agricultural Organization of the United Nations granted a fellowship to the author to study, at several European ship research institutes, the problem of noise generation and propagation on fishery vessels. He later took part in the design of the fishery research vessel Prof. Siedlecki, which included the implementation of a series of antivibration and antinoise precautions. This paper compares vibration and noise levels on two fishery research vessels—the conventional RV G.O.Sars and RV Prof. Siedlecki. The paper is divided into two parts. In the first part, mechanical vibrations of the elastically supported propeller are dealt with and conditions for minimum vibration response are determined. In the second part, structural vibrations in the ships and noise propagation from the ships to the water are described. The paper concludes with data on structural vibrations and waterborne noise propagation. This paper, and the paper published in the June 1984 issue of JOURNAL OF SHIP RESEARCH [1],2 completes the author's approach to propeller vibrations.

On the Modelling of Noise Generation in Corrugated Pipes

2009 ◽  
Author(s):  
Hugh Goyder
Keyword(s):  
Vortex Shedding ◽  
Oil And Gas ◽  
Natural Frequencies ◽  
Oil And Gas Industry ◽  
Noise Generation ◽  
Noise Levels ◽  
Eigenvalue Approach ◽  
Gas Industry ◽  
Offshore Oil And Gas ◽  
Offshore Oil

The offshore oil and gas industry uses pipes which are made flexible by means of a corrugated construction. Those pipes that run from a platform to the seabed are known as risers while those that connect two pipes on the seabed are known as jumpers. Gas flowing within the pipe interacts with the corrugations and generates noise. This noise is of concern because it is of sufficient amplitude to cause pipework vibration with the threat of fatigue and pipe breakages. This paper examines the conditions that give rise to the large noise levels. The conditions for the onset of noise are investigated using an eigenvalue approach which involves the effect of damping due to losses from the pipe boundaries and pipe friction. The investigation which is conducted in terms of reflection conditions shows why only few of the very many possible natural frequencies are selected. The conditions for maximum noise response are also investigated using a non-linear model of vortex shedding. Here an approach is developed in which the net power generated along a single wavelength is calculated.

scholarly journals A Review on Acoustic and Skid Resistance Solutions for Road Pavements

2021 ◽  
Vol 6 (3) ◽  
pp. 41 ◽  
Author(s):  
Sergio Copetti Callai ◽  
Cesare Sangiorgi
Keyword(s):  
Surface Layer ◽  
Traffic Accidents ◽  
Asphalt Mixtures ◽  
Skid Resistance ◽  
Noise Generation ◽  
Road Noise ◽  
Pavement Surface ◽  
Acoustic Impact ◽  
Resistance Performance

As cities grow in size, traffic also increases, thus making the population more exposed to road noise and traffic accidents. It is therefore important to study and understand which properties of the pavement influence its acoustic impact and skid resistance performance. The pavement texture plays a major role in generating noise and friction, and it can be engineered in order to control both of them at the same time. The phenomena regulating skid resistance are well understood today. The same applies for noise generation and propagation; the literature contains methods of designing the pavement surface layer to achieve consistent results. Several types of solutions can be found for asphalt mixtures, most of them derived from decades of studies and research. They use different approaches to be effective for noise and friction, but all have in common the control of the surface’s macro and microtexture. Finally, some considerations are made regarding novel paving solutions with artificial aggregates instead of natural ones to address noise and skid resistance.

On the Modelling of Noise Generation in Corrugated Pipes

2010 ◽  
Vol 132 (4) ◽  
Author(s):  
Hugh Goyder
Keyword(s):  
Vortex Shedding ◽  
Oil And Gas ◽  
Natural Frequencies ◽  
Oil And Gas Industry ◽  
Noise Generation ◽  
Noise Levels ◽  
Eigenvalue Approach ◽  
Gas Industry ◽  
Offshore Oil And Gas ◽  
Offshore Oil

The offshore oil and gas industry uses corrugated pipes because of their flexibility. Gas flowing within these pipes interacts with the corrugations and generates noise. This noise is of concern because it is of sufficient amplitude to cause pipework vibration with the threat of fatigue and pipe breakages. This paper examines the conditions that give rise to the large noise levels. These conditions, for the occurrence of noise, are investigated using an eigenvalue approach, which involves the effect of damping due to losses from the pipe boundaries and pipe friction. The investigation is conducted in terms of reflection conditions and shows why only few of the very many possible natural frequencies are selected. The conditions for maximum noise response are also investigated by means of a nonlinear model of vortex shedding. Here, an approach is developed in which the net power generated by each wavelength is calculated.

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