ENSURING QUALITATIVE-ACCURACY CHARACTERISTICS DURING RESTORING OF VEHICLE PARTS

2021 ◽  
Vol 3 (144) ◽  
pp. 116-121
Author(s):  
Nikita A. Pen’kov ◽  
◽  
Oleg A. Sidorkin ◽  
Sergey Yu. Zhachkin ◽  
Anatoliy I. Zavrazhnov ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Current Density ◽  
Hydraulic Drive ◽  
Research Purpose ◽  
Working Fluid ◽  
Agricultural Machinery ◽  
Servo Valve ◽  
Contact Points ◽  
Drive Systems

One of the most common reasons for the failure of hydraulic drive systems for agricultural machinery is the working fluid leak in the contact points of the rubbing surfaces of hydraulic blocks. The application of composite coatings based on chromium on the contacting surfaces allows you to restore the defect in the shape of the part caused by wear, as well as reduce the friction coefficient at the contact points, which positively affects the wear resistance of the part. (Research purpose) The research purpose is in developing technologies for restoring parts of agricultural machinery with predetermined operational properties. (Materials and methods) A servo valve, widely used in various hydraulic drive systems, was used as an experimental sample. Its working surface was restored with a composite coating applied by electroplating to increase the wear resistance of the servo valve. (Results and discussion) Authors conducted a series of direct measurements under the same conditions. The article presents the de-pendence of the microhardness on the parameters of the electrolysis mode and the thickness of the applied coating using the method of least squares. The nature of changes in microhardness and residual stresses was evaluated to determine the quality of the coatings. The article presents the dependences of these indicators on various control parameters (current density, temperature, tool pressure). The equations of the regression of the main qualitative and accuracy characteristics of the parts were deter-mined using the apparatus of the theory of experimental planning. (Conclusions) The article presents the method for predicting coatings of a given quality, taking into ac-count the influence of the current density and the temperature of the electrolyte during electrolysis on the nature of the precipitation obtained. The influence of the tool pressure on the depth of deformation of the formed layers was estimated. This approach allows us to evaluate the nature of the stress distribution in the formed coating and the quality of the restored parts.

METHODS AND RESULTS OF MICROMETER STUDIES OF HYDRAULIC SYSTEM SEALING UNITS OF AGRICULTURAL MACHINERY

2020 ◽  
Vol 4 (141) ◽  
pp. 12-19
Author(s):  
MIKHAIL BEREZIN ◽  
Keyword(s):  
Cross Section ◽  
Hydraulic Drive ◽  
Research Purpose ◽  
Working Fluid ◽  
Initial Contact ◽  
Thickness Gauge ◽  
Agricultural Machinery ◽  
Oil Pipeline ◽  
Compression Deformation ◽  
The Cross

End-type sealing units based on round-section rubber rings are the most common types of seals for volumetric hydraulic drive units of various agricultural machinery. Its service life depends on the correspondence of the geometric dimensions of the elements that make them up, as well as on the combination of limit deviations of the specified elements. (Research purpose) The research purpose is in studying deviations and identifying statistical distribution of the cross-section diameters of new rings and the depth of grooves under them in order to determine the number of connections that meet the requirements of the standard. (Materials and methods) Author examined the sealing joints of the oil pipeline and the valve cover of the hydraulic distributor of the MTZ 80/82 tractor and new rubber rings that are part of repair kits intended for repair. Micrometric studies were performed using the GM-50 micrometer depth gauge and the TN 1060T thickness gauge. (Results and discussion) About 90 percent of the examined compounds do not meet the requirements of the standard, which explains to a large extent the low level of their reliability. At the same time, a significantly higher level of inconsistencies is in the metal parts of these connections. The vast majority of nonconforming joints have a combination of ring and groove sizes, which provides increased initial compression deformation of the ring in the groove. (Conclusions) Inconsistencies in the dimensions of the groove and the cross-section of the ring, which lead to an increase in the initial compression deformation of the seal, and thus the initial contact stresses, cause a certain increase in the theoretical life of the connection. To predict the connection reliability more accurate, it is necessary to study the influence on leaks not only of the geometric dimensions of the mating elements, but also other factors: surface roughness, as well as the actual operating temperature of the node and the aggressiveness of the hydraulic working fluid.

EVALUATION OF TRIBOTECHNICAL PROPERTIES OF THE COATING OBTAINED BY ELECTRIC SPARK HARDENING

2020 ◽  
Vol 4 (141) ◽  
pp. 157-163
Author(s):  
IL’YA ROMANOV ◽  
◽  
ROMAN ZADOROZHNIY
Keyword(s):  
Wear Resistance ◽  
Reference Sample ◽  
Optical Microscope ◽  
Research Purpose ◽  
Tribotechnical Properties ◽  
Uncoated Surface ◽  
Before And After ◽  
Materials Used ◽  
Friction Track

When applying coatings using various methods on the surfaces of moving parts that work in joints, it is important to make sure that the coatings are strong and wear-resistant in order to return them to their original resource. All existing hardening technologies and materials used to perform coatings have their own characteristics, therefore, the quality of the resulting coatings can be judged only after specific tests. (Research purpose) The research purpose is in evaluating the properties of the coating obtained by the method of electric spark hardening, and its ability to resist friction and mechanical wear. (Materials and methods) Authors conducted tests on the basis of the "Nano-Center" center for collective use. A coating was applied on the BIG-4M unit with a VK-8 hard alloy electrode, tribological properties were evaluated on a CSM Instruments TRB-S-DE-0000 tribometer, the width of the friction track was measured after the test using an inverted OLYMPUS gx51 optical microscope, and samples were weighed before and after the test on a VLR-200 analytical balance. Conducted research in accordance with GOST 23.224-86 and RD 50-662-88 guidelines. (Results and discussion) The article presents performed tests on the run-in and wear resistance of the coating. The samples were worked on with a step-by-step increase in the load. During the tests, the friction force was drawed on the diagram. Authors compared the results with the reference sample, an uncoated surface. (Conclusions) The resulting coating has better run-in and wear resistance compared to the standard, and the increase in wear resistance in dry friction conditions is very significant.

INCREASING THE WEAR RESISTANCE OF THE WORKING BODIES OF AGRICULTURAL MACHINES BY THE HDTV METHOD WITH ADDING POWDER OF THE EED METHOD

2020 ◽  
Vol 4 (141) ◽  
pp. 123-131
Author(s):  
IL’YA ROMANOV ◽  
Keyword(s):  
Wear Resistance ◽  
Abrasive Wear ◽  
High Frequency ◽  
Machine Building ◽  
Abrasive Wear Resistance ◽  
Research Purpose ◽  
Powder Materials ◽  
Agricultural Machinery ◽  
Resource Saving ◽  
Working Bodies

The development of energy and resource-saving methods and technologies for strengthening and restoring the working bodies of agricultural machinery will increase their abrasive wear resistance and durability by using materials from machine-building waste and reduce the cost by 10-30 percent without reducing operational characteristics. (Research purpose) The research purpose is in increasing the abrasive wear resistance and durability of cultivator legs by surfacing powder materials obtained by electroerosive dispersion from solid alloy waste by high-frequency currents. (Materials and methods) Authors obtained a powder for research on their own experimental installations of the CCP "Nano-Center" of electroerosive dispersion from waste of sintered hard alloys of the T15K6 brand. The microhardness of powders and coatings on microshifts was measured using the PMT-3 device, and the hardness of coatings with the KMT-1 microhardometer was measured using the Rockwell method according to GOST 9013-59. The microwave-40AV installation was used to assess the wear resistance of materials of working bodies of tillage machines. (Results and discussion) In the course of laboratory wear tests the relative wear resistance of samples hardened by high-frequency surfacing currents significantly exceeds the wear resistance of non-hardened samples made OF 65g steel, accepted as the reference standard. (Conclusions) Based on the results of experimental studies, the article proposes a new resource-saving technological process for strengthening the working bodies of agricultural machinery through the use of materials from machine-building waste, which allows increasing the abrasive wear resistance of working bodies by 1.5-2 times due to the use of tungsten-containing materials.

scholarly journals Agricultural machine parts quality control by dynamic non-destructive methods

2018 ◽  
Vol 226 ◽  
pp. 04034 ◽  
Author(s):  
Alexey N. Beskopylny ◽  
Viktor B. Rykov ◽  
Elena M. Zubrilina ◽  
Andrey D. Chistyakov
Keyword(s):  
Quality Control ◽  
Wear Resistance ◽  
Manufacturing Process ◽  
Mechanical Characteristics ◽  
Point Of View ◽  
Agricultural Machinery ◽  
Machine Parts ◽  
Non Destructive ◽  
Destructive Methods

The problem of quality control of agricultural machinery parts by means of dynamic non-destructive methods of impact indentation of conical shape indenters is considered. Quality of the crucial parts is considered from the point of view of a set of mechanical characteristics that determine the strength, hardness, wear resistance and deformability. These characteristics must be known and be able to control on all the details promptly and accurately both in the manufacturing process and in operation. The mechanical characteristics of metals are stochastic in nature. For this purpose, an impact indentation device was developed, and the method based on probabilistic laws of dispersion of mechanical characteristics is obtained.

scholarly journals EXPERIMENTAL RESOURCE STAND RESEARCH OF THE GOLDEN DIVISION DISTRIBUTOR

2019 ◽  
pp. 80-86
Author(s):  
Volodymyr Rutkevych
Keyword(s):  
Hydraulic Drive ◽  
Operating Conditions ◽  
Working Fluid ◽  
Stable Operation ◽  
Initial Stage ◽  
Flow Divider ◽  
Main Components ◽  
Working Bodies ◽  
Cost Characteristics

The article discusses and analyzes the operating conditions of a modern hydraulic drive. Despite the difficult operating conditions of modern agricultural machinery (difficult working conditions, frequent changes in the technological load on the working bodies, low quality of the working fluid, increased dust content and temperature fluctuations), the hydraulic drive is its main reliable element. The basis of hydraulic drives is hydraulic spool type devices, they remain the main components of a modern hydraulic drive, are able to increase energy, dynamic, cost characteristics and increase the reliability and durability of this drive. The advantages, disadvantages and directions of improvement of this drive are noted. The modern directions of development of the hydraulic drive aimed at increasing the reliability, durability and adaptability to changing the technological load on the working bodies are considered. A booth design is proposed that allows to investigate a resource study of the developed spool splitter of a forage stem feeder. As a result of the research at the initial stage, some shortcomings in the structural implementation of the developed spool of the flow divider at the time up to 2·104 cycles were revealed. After analyzing the operating conditions and making changes to the design of the stem feeder spacer spacer and retesting, the spacer spacer showed stable operation, with more than 6.6·105 load cycles.

INCREASING THE RELIABILITY OF HYDRAULIC DRIVE PARTS OF AGRICULTURAL MACHINES

2021 ◽  
Vol 3 (144) ◽  
pp. 49-55
Author(s):  
Aleksey A. Solomashkin ◽  
◽  
Azamat F. Il’mukhametov
Keyword(s):  
Wear Rate ◽  
Hydraulic Drive ◽  
Technical Condition ◽  
Research Purpose ◽  
Agricultural Machinery ◽  
Maintenance Strategies ◽  
Machine Parts ◽  
Current Value ◽  
Specific Part ◽  
Agricultural Machines

The article identifies the existing types of troubleshooting of self- propelled agricultural machinery. Taking into account the wear rate of the same type of parts from the group of parts of the same name when determining the permissible wear during their resource diagnostics is an urgent problem. The article presents the resource parameter and its influence on the reliability indicators of machine parts. (Research purpose) The research purpose is in determining the basic principles of the strategy of maintenance and repair of agricultural machinery in order to ensure control of the technical condition of machine parts, in particular, to increase the reliability of hydraulic drive parts. (Materials and methods) The article presents the options for maintenance strategies, the disadvantages and advantages of each of them. (Results and discussion) The article presents standard maintenance strategies: according to the need, planned preventive, according to the condition and justifies the optimal type of maintenance, taking into account the wear rate of each specific part. Authors performed an analysis of the algorithm for carrying out maintenance in each case individually. The tolerance is set based on the condition: if the current value of the controlled resource parameter during the next diagnosis turns out to be less than the set value, then such a part at the current value of the wear rate will be able to refine it until the next inter-control check. (Conclusions) The choice of a maintenance strategy has an important role in increasing the reliability of hydraulic drive parts of agricultural machines. A strategy has been developed that takes into account the wear rate of each specific part and the culling is carried out taking into account the wear rate of each part individually. Parts with a high wear rate are rejected first, and parts with a low wear rate are the last.

Comparative analysis of hardening methods of the lancet cultivator shovel

2020 ◽  
pp. 68-78
Author(s):  
Natal’ya S. Kryukovskaya
Keyword(s):  
Wear Resistance ◽  
Traction Force ◽  
Research Purpose ◽  
Labor Intensity ◽  
High Productivity ◽  
Advantages And Disadvantages ◽  
Hardening Process ◽  
Working Surface ◽  
Cost Of Materials

The lancet cultivator shovels wear out intensively under the action of abrasive soil particles, which degrades the quality of cultivation, violates agricultural requirements and leads to an increase in traction force and fuel consumption. Strengthening of lancet shovels allows increasing their wear resistance and durability. (Research purpose) The research purpose is in analyzing the methods of strengthening the lancet cultivator shovels and identifying their main advantages and disadvantages. (Materials and methods) The article reviews the methods of strengthening the lancet cultivator shovels described in domestic and foreign literature and specialized magazines. (Results and discussion) It was found that the issue of strengthening the working parts of tillage tools and the cultivator shovels in particular is given much attention and the problem of their wear is currently relevant. There are many methods of strengthening that differ from each other in the principle of strengthening, as well as in the labor intensity, cost of materials and equipment for performing strengthening. The article presents a diagram for a visual comparison of methods for strengthening the lancet cultivator shovel. (Conslusion) Analysis of methods for strengthening lancet shovels showed that it is possible to increase their wear resistance up to 5.8 times. However, the methods of hardening that provide the greatest increase in wear resistance of working parts of tillage tools require large amount of time, labor and material costs. It was found that the method of hardening by surfacing individual wear-resistant rollers on the working surface of the arrow legs of the cultivator becomes the most promising. This method provides an increase in wear resistance up to three times with high productivity and simplicity of the hardening process, and it’s relatively cheap.

PROSPECTS FOR THE USE OF CERAMIC MATERIALS FOR THE NEEDS OF THE AGRO-INDUSTRIAL COMPLEX

2021 ◽  
Vol 2 (143) ◽  
pp. 91-102
Author(s):  
Anatoliy V. Fedotov ◽  
◽  
Aleksey S. Dorokhov ◽  
Dmitriy A. Kovalev
Keyword(s):  
Wear Resistance ◽  
Crack Resistance ◽  
Porous Ceramic ◽  
Ceramic Materials ◽  
Porous Ceramics ◽  
Production Costs ◽  
Research Purpose ◽  
Industrial Complex ◽  
Highly Porous

As a result of poor quality, parts of tillage equipment have to be replaced 3-7 times a year. One of the reasons is the lack of attention to the possibility of using technical ceramics in agricultural engineering to improve the wear resistance and durability of machine parts. (Research purpose) The research purpose is in assessing the state of research and prospects for the use of ceramic materials in the Russian Federation for the needs of the agro- industrial complex. (Materials and methods) For the experiments has been used nanostructured boehmite obtained by hydrothermal synthesis to improve the properties of materials and coatings. The crack resistance was determined by the indentation method, and the methane content in the biogas was determined by the chromatographic method. (Results and discussion) The article presents the results of the use of aluminum oxide ceramics for the manufacture of parts of tillage equipment, which allows increasing the resource of parts for processing loamy soils by 2.4-4.5 times. The creation of nanocomposites is promising to increase the strength, wear resistance and crack resistance of the material. In the composition of the non-stick coating, the addition of boehmite increases the abrasion strength of the coating and the compressive strength of the samples by 2.2-2.7 times, and improves the quality of casting. The use of highly porous ceramic materials in the gating system helps to reduce waste, reduce production costs, and improve the quality of foundry products. (Conclusions) Ceramic materials due to their high hardness, wear resistance and corrosion resistance are becoming promising for use in the agro-industrial complex. The widespread use of modern ceramic materials as parts of tillage equipment, non-stick coatings and for the filtration of melts will improve the quality of casting, the durability of products, and reduce the cost of their production. Positive results on wastewater treatment with the use of highly porous ceramics allow us to consider it an innovative material for such purposes and it is advisable to continue research in this direction.

scholarly journals Devising quality control criteria for manufacturing control valves of the type «nozzle-flap»

2021 ◽  
Vol 1 (1 (109)) ◽  
pp. 27-34
Author(s):  
Oleksandr Lytviak ◽  
Sergii Komar ◽  
Oleksandr Derevyanko ◽  
Viacheslav Durieiev
Keyword(s):  
Flow Rate ◽  
Hydraulic Drive ◽  
Relative Length ◽  
Control Valve ◽  
Automatic Regulation ◽  
Working Fluid ◽  
Control Valves ◽  
Quality Of Control ◽  
Technical Requirements

This paper is a continuation of research into the causes and ways to eliminate the generation of self-oscillations in the system of automatic regulation of rotations of the free turbine in the turboshaft gas turbine engines of helicopters. The study of dynamic processes in the system of automatic regulation of free turbine’s rotations in a turboshaft GTE has shown that one of the reasons for the development of self-oscillations is the poor performance of the control valve of the type «nozzle-flap» in the rotation regulator’s hydraulic drive. At a pump-regulator plant, the criterion for the quality of control valve execution or repair implies that the geometric size of the valve parts and the flow rate of working fluid through the valve when the flap is closed meet the technical requirements. As practice shows, this is not enough. With this approach, valve defects manifest themselves only during the tests of assemblies as part of the engine. This paper proposes a method to examine the characteristics of control valves such as «nozzle-flap», as well as criteria for assessing the quality of their execution. Experimental characteristics of control valves such as «nozzle-flap» for an actual regulator of free turbine rotation frequency are given. New data on the outflow of liquid from the nozzle with a flap have been obtained. It is shown that the destruction of the stagnation zone in the nozzle tip could result in that the valve flow rate increases, which negatively affects the characteristics of the hydraulic drive and regulator in general. A technique has been proposed to improve the stability of the valve’s performance by increasing the relative length of the nozzle. It is shown that the most informative characteristic of the valve is the dependence of flow rate on the position of the flap. Based on this characteristic, it is possible to determine the criteria for rejecting valves without testing them as part of the assembly

STUDY OF THE EFFECT OF PRESSURE ON THE PERFORMANCE AND DURABILITY OF THE SAUER DANFOSS 90 SERIES VOLUMETRIC HYDRAULIC DRIVE

2020 ◽  
Vol 4 (141) ◽  
pp. 54-63
Author(s):  
PAVEL IONOV ◽  
◽  
ALEKSANDR ZEMSKOV ◽  
ALEKSEY STOLYAROV ◽  
SERGEY TIMOKHIN ◽  
...  
Keyword(s):  
Control System ◽  
Design Research ◽  
Hydraulic Drive ◽  
Research Purpose ◽  
Working Fluid ◽  
Level Of Knowledge ◽  
Increase In Productivity ◽  
Pumping Unit ◽  
The Difference ◽  
Experimental Values

During operation, there are occur failures of the Sauer-Danfoss 90 series hydraulic drive, resulting in downtime of equipment and losses to operating companies. It is not always possible to determine the true cause of the loss of performance of an imported hydraulic drive due to its low level of knowledge and complexity of the design. (Research purpose) The research purpose is in studying the influence of pressure in the control system on the performance and durability parameters of the Sauer Danfoss 90 series volumetric hydraulic drive. (Materials and methods) An analysis of the design and works devoted to the study of the failures of volumetric hydraulic drives allows proposing a new scheme for loss of performance and outlining ways to improve the durability of the Sauer Danfoss 90 series. (Results and discussion) The pressure values in the control system were calculated for the pumping unit of the 90R100, at which the pumping unit moves from the minimum to the maximum position, which was confirmed experimentally using bench equipment. The difference between the calculated and experimental values is 0.04-0.07 megapascals. The increase in productivity in the control system leads to an increase in the performance parameters and to an increase in the pre-repair life of the Sauer Danfoss 90 series hydraulic drive. (Conclusions) To improve pre-repair life of a Sauer Danfoss hydraulic drive it is required the use of more powerful feed pump, as at the same values of the clearances in the joints, he is able to compensate for leakage of working fluid longer, while maintaining the performance above the limits.

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