scholarly journals ESTIMATION OF THE EFFICIENCY OF THE REGENERATIVE HY-DRAULIC DRIVE FORESTRY TRACTOR WITH DISCOVER TRAILER

2021 ◽  
Author(s):  
V.I. Posmetev ◽  
Keyword(s):  
Hydraulic Drive ◽  
Road Transport ◽  
Working Fluid ◽  
Preliminary Assessment ◽  
Compressed Gas ◽  
Actual Direction

Substantiated the actual direction of increasing the efficiency of timber road transport, which consists in the development and use in its design of recuperative mechanisms based on various methods of conversion and accumulation of compressed gas energy. A promising recuperative hydraulic drive of a timber tractor with a dismantling trailer has been proposed. A preliminary assessment of the operation of the mechanism for converting the energy of the working fluid into the energy of compressed gas has been carried out on the basis of simulation.

Improving the Performance of the Hydraulic Drive of an All-Terrain Vehicle in Low Temperature Conditions

2021 ◽  
pp. 9-16
Author(s):  
M.V. Tsvetkov ◽  
A.A. Nikitin
Keyword(s):  
Low Temperature ◽  
Ambient Temperature ◽  
Transport System ◽  
Soil Cover ◽  
Hydraulic Drive ◽  
Road Transport ◽  
Working Fluid ◽  
Mechanical Transmission ◽  
Northern Regions ◽  
Weak Surface

Currently, 70 % of Russian localities with a population of 9 million people are not connected to the transport system of the country by paved roads, especially in the northern regions, where the ambient temperature in winter does not rise above -500C. Road transport accounts for the largest number of transported goods. One of the vehicles of this type is an all-terrain vehicle Trackol, designed to move on roads with a weak surface: on snow, swamp and soil cover of thawed taiga. The analysis of the vehicle Trackol operation has shown insufficient reliability of its transmission. Analysis of of using the vehicle Trackol showed insufficient reliability of its transmission. To improve the situation the mechanical transmission has been replaced with a hydraulic one, taking into account the main disadvantages associated with maintaining the cleanliness of the working fluid. A system for regulating the temperature of the working fluid in the hydraulic drive of an all-terrain vehicle has been developed. The design of the working fluid filter is proposed, allowing capturing not only dirt, but also moisture due to the use of polyvinylformal of the TPVF brand as the filter element material.

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.

scholarly journals ENERGY-EFFICIENT TECHNICAL SOLUTIONS FOR THE OPERATIONAL CHARACTERISTICS OF THE HYDRAULIC DRIVE OF THE TRACTOR

2021 ◽  
Author(s):  
R.V. Yudin ◽  
◽  
R.N. Puzakov ◽  
Keyword(s):  
Energy Saving ◽  
Energy Efficient ◽  
Hydraulic System ◽  
Hydraulic Drive ◽  
Working Fluid ◽  
Uneven Terrain ◽  
Operational Characteristics ◽  
High Dynamic ◽  
Hydraulic Accumulator ◽  
Technical Solutions

During the movement of the tractor on the uneven terrain, there are fluctuations that cause jumps of the working fluid in the hydraulic system and high dynamic loads. The solution to this problem is the use of an energy-saving hydraulic drive with a hydraulic accumulator and a system of aggregates this leads to increased efficiency and increased productivity of skidding grippers. A mathematical model of working processes with an energy-saving hydraulic drive is compiled.

scholarly journals Justification of the Kinematic Diagrams for the Distribution System of a Planetary Hydraulic Motor

2018 ◽  
Vol 7 (4.3) ◽  
pp. 6 ◽  
Author(s):  
Angela Voloshina ◽  
Anatolii Panchenko ◽  
Oleg Boltynskiy ◽  
Igor Panchenko ◽  
Olena Titova
Keyword(s):  
Distribution System ◽  
Hydraulic System ◽  
Hydraulic Drive ◽  
Fluid Distribution ◽  
Working Fluid ◽  
Hydraulic Motor ◽  
Hydraulic Motors ◽  
Output Characteristics ◽  
Kinematic Diagram ◽  
The Impact

The output characteristics of a planetary (orbital) hydraulic motor could be significantly improved if the kinematic diagrams for its working fluid distribution system are chosen correctly and substantiated. Fluctuations in the flow of the power fluid cause pulsation in the cavity of the input pressure of the hydraulic motor. This results to vibration of the hydraulic system elements. Thus, the hydraulic motor can be considered as a source of pulsation which leads to functional failures of the hydraulic system. As they run at low rotational speeds with high torque, planetary hydraulic motors are commonly applied for a hydraulic drive in active working tools of self-propelled machinery. It has been established that one of the main components of a planetary hydraulic motor, which causes pressure pulsations, is its distribution system. The frequency and amplitude of these pulsations depends on the kinematic diagram for the distribution system of the power fluid. Therefore, we studied how the kinematic diagram for the distribution system effects on the output characteristics of a planetary motor. Since the change in the capacity of a distribution system with various kinematic diagrams influences on the output characteristics of a planetary motor, the impact was investigated. The kinematic diagrams, which improve the output characteristics of planetary hydraulic motors, were justified. 

scholarly journals MATHEMATICAL MODEL OF THE INTERACTION OF THE SCREW WORKING BODIES OF FOREST FIRE GROUND-THROWING MACHINES WITH THE GROUND COVER

2021 ◽  
Vol 11 (1) ◽  
pp. 163-171
Author(s):  
Petr Popikov ◽  
Anton Pozdnyakov
Keyword(s):  
Mathematical Model ◽  
Forest Fire ◽  
Forest Fires ◽  
Hydraulic Drive ◽  
Ground Cover ◽  
Forest Litter ◽  
Working Fluid ◽  
Hydraulic Motor ◽  
Working Bodies ◽  
Fire Ground

The paper provides an overview of research on the working processes of screw working bodies of technological machines. It is noted that at present such important issues in the theory of auger working bodies as the required number of auger turns, the required position of the auger spiral in relation to the center, etc. have not been fully resolved, since the solution of these issues can provide an increased productivity of the tool. A structural and technological scheme of a forest fire machine with multifunctional modules is proposed, which consists of auger working bodies, which can be changed modularly with a screw metal thread for a brush, depending on the area and type of soil, the rotor of the thrower, with the ability to drive the cutters-throwers and auger working bodies both from the power take-off shaft of the tractor, and using a hydraulic motor, a guide casing. A mathematical model of an auger working body with a hydraulic drive has been compiled for removing the ground cover with forest litter when extinguishing forest fires with a ground gun, so that combustible materials do not fall into the fire zone together with the soil flow from the rotor-thrower. The working process of the hydraulic drive of the auger working bodies of a forest fire ground-sweeping machine is described by a system of differential equations, including the equations of translational and rotational movements of the auger working body and the equation of the flow rate of the working fluid. The problem of optimization of kinematic and dynamic parameters of auger working bodies of forest fire ground-sweeping machine is set

scholarly journals Hydraulic plunger pump contamination sensitivity evaluation

2018 ◽  
Vol 48 (1) ◽  
pp. 371-383
Author(s):  
Leszek Ułanowicz ◽  
Grzegorz Jastrzębski ◽  
Michał Jóźko ◽  
Ryszard Sabak ◽  
Paweł Szczepaniak
Keyword(s):  
Hydraulic Drive ◽  
Research Paper ◽  
Working Fluid ◽  
Sensitivity Factor ◽  
Hydraulic Pump ◽  
Correct Operation ◽  
Plunger Pump ◽  
Sensitivity Evaluation ◽  
Contamination Sensitivity

Abstract The correct operation of the hydraulic pump and achieving the assumed durability depends on the purity of the used working fluid. The research paper discusses a method for evaluating the contamination sensitivity of a hydraulic plunger pump. The theoretical grounds for evaluating the contamination sensitivity of hydraulic plunger pumps of a hydraulic drive based on the contamination sensitivity factor were presented. An example of evaluating contamination sensitivity of an NP-34M hydraulic plunger pump was discussed.

scholarly journals SELF-CLEANING FILTER FOR CLOSED HYDROSYSTEMS OF AGRICULTURAL EQUIPMENT

2021 ◽  
Vol 295 (2) ◽  
pp. 130-138
Author(s):  
M. STADNIK ◽  
◽  
А. VIDMYSH ◽  
S. SHARGORODSKIY ◽  
V. RUTKEVYCH ◽  
...  
Keyword(s):  
Pressure Drop ◽  
Pressure Pulsation ◽  
Experimental Studies ◽  
Hydraulic Drive ◽  
Operating Mode ◽  
Working Fluid ◽  
Hydraulic Systems ◽  
Agricultural Equipment ◽  
Self Cleaning ◽  
Special Stand

The issue of increasing the reliability and durability of hydraulic units of closed hydraulic systems of agricultural equipment is considered, due to better cleaning of the working fluid by filtration units. The design of a self-cleaning filter with hydraulic automatic control of backwashing of slotted filtration elements with a counterflow of the working fluid is proposed. A special stand has been developed for simulating the operation of a self-cleaning filter of closed hydraulic systems of agricultural equipment. Experimental studies on a special stand confirmed the efficiency of the proposed design and made it possible to identify its main advantages in comparison with domestic and foreign counterparts. Based on the analysis of transient processes with increased pressure pulsation of agricultural equipment of a closed hydraulic drive, the actual pressure drop at which automatic flushing is triggered was established, compared with the calculated one, in which it was impossible to take into account such real factors as friction in the sealing units, the characteristics of the springs, distortions, tightness of valve pairs, fluctuations in dimensional chains. The most optimal operating mode of auto-washing equipment with a choke diameter of 1.0 mm has been determined. The auto-washing equipment was switched on at a pressure drop of 1.5 MPa (15 atm) and in an improved mode – pressure pulsations with an amplitude of 2 MPa (20 atm) when the auto-wash was turned off decreased in time to 0.12 s. It is noted that the developed self-cleaning filter for closed hydraulic systems of agricultural equipment will improve the reliability and increase the service life of the elements of hydraulic units and the machine itself as a whole.

scholarly journals Measuring system for monitoring the polydimensional deformation of superstructures of bridges and over-bridges improvement of volume hydraulic drive construction and road machines using flow shareholders

2021 ◽  
pp. 7
Author(s):  
Igor Pimonov
Keyword(s):  
Service Life ◽  
Hydraulic Drive ◽  
Road Construction ◽  
Measuring System ◽  
Working Fluid ◽  
Return Flow ◽  
Flow Divider ◽  
Working Volume ◽  
Hydraulic Machines ◽  
Hydraulic Motors

Due to its advantages, the hydraulic drive is widely used in road construction machines. Depending on its design, the share of the hydraulic drive, which is the most expensive unit of a road construction machine, accounts for thirty to eighty percent of all failures. Reliable hydraulic drive, provides, to a large extent, the reliability of the whole machine and the efficiency of the construction organization as a whole. The efficiency of the hydraulic drive of construction machines, and, as a consequence, the machines themselves, is ensured by a set of measures, among which the most important is the quality design, manufacture and operation, combined into a single structural system. Depending on the quality of cleaning of the working fluid, the service life of hydraulic machines can be increased or decreased several times. Accumulation of pollutants in the hydraulic drive, the hardness of which is significantly higher than the hardness of metals, causes rapid wear of the surfaces of hydraulic units and the service life is rapidly reduced. Cavitation in the pump is accompanied by a pulsation of fluid pressure and noise. These pulsations are due to the return flow of fluid from the discharge cavity of the pump, which is accompanied by hydraulic shocks and as a result of alternating shocks, a pressure pulsation in the discharge line of the pump. The amplitude of these pulsations can, under known conditions, reach a value that causes the destruction of the pump. The possibility of cavitation can be reduced by rational choice of modes of operation of the hydraulic system and the correct design of its units, but this phenomenon can be completely eliminated only by using auxiliary pumping pumps, as well as increasing the pressure in the suction line of the pump. On the basis of the analysis of perspective directions of improvement of the hydraulic drive of the excavator the following improved scheme of it is developed. Usually only high-flow hydraulic motors can be used in flow dividers. But in our case it is necessary that the device had, first of all, small mechanical losses and small cost, and accuracy of division of working liquid which follows on filters can be small. In the volume flow divider, hydraulic motors are used: gear, piston, vane, screw, roller. The simplest dividers of volume type are paired (connected by shafts) hydraulic motors of lamellar (vane) and roller types. Hydraulic motors in this scheme are flow measuring devices (dispensers), which supply for one revolution the volume of liquid, equal without taking into account the leaks in the hydraulic motor, its working volume. The use of a flow divider as a source of hydraulic energy makes it possible to improve the hydraulic drive by combining in a single system the purification of the working fluid and the ejector feed of the pump. The most promising, in terms of cost, are flow dividers based on vane and rotary hydraulic motors..

scholarly journals Analysis of the Throttle Speed Control Efficiency in Volumetric Hydraulic Drives

2019 ◽  
pp. 13-33
Author(s):  
K. D. Efremova ◽  
V. N. Pilgunov
Keyword(s):  
Control Method ◽  
Hydraulic Drive ◽  
Hydraulic Cylinder ◽  
Movement Speed ◽  
Working Fluid ◽  
Total Efficiency ◽  
Control Methods ◽  
Output Link ◽  
Hydraulic Cylinders ◽  
Load Characteristics

To control a movement speed of the output link of an executive hydraulic engine (hydraulic cylinder or hydraulic motor), volumetric hydraulic drives traditionally use volumetric and throttle control methods. Under volumetric control, a supply unit employs a pressure-regulated positive displacement pump, as a result of which it is impossible or difficult to separate and independently control the movement speed of the output links of the hydraulic cylinders. In case of throttle control, there is a significant dependence of the speed of the output link on the load it overcomes, a low efficiency of the hydraulic drive and hereto related active heating of the working fluid, as well as large energy losses. However, in embodiment, due to lack of an expensive variable pump, this method of control is much cheaper and can be used in a multi-channel hydraulic drive with a centralized supply unit.Depending on the throttling device localization in the hydraulic drive circuit, there are series (primary or secondary control) and parallel (working fluid bypass adjustment) throttle connection schemes. The secondary control scheme, which generates a pressure in the outlet of the executive hydraulic engine, is preferable due to the fact that it provides an increased pressure in both cavities of the executive hydraulic engine and, accordingly, a lack of combined air bubbles in the working fluid. Heat released in the throttle is discharged directly into the tank, and the pressure in the outlet reduces the danger level of the emergency situation consequences in the event of an unauthorized change in the sign of the load to be overcome. The quality of control is, mainly, assessed by the type of load characteristics, i.e. dependences of the output link speed and its developed power on the load to be overcome, as well as by the control efficiency (the total efficiency value of the regulating and executive subsystems of the hydraulic drive). The dependence of the dynamics and kinematics of the hydraulic drive on the control methods are of particular interest.The proposed paper, based on the developed mathematical models and their testing for specific sizes of hydraulic cylinders presents the numerical values of the load characteristics and dependences of the total efficiency on the load value to be overcome. Shows that the speed load characteristic steepness of an executive hydraulic cylinder and the sign of its derivative are determined by the throttle control method. The greatest power developed by the output link of the hydraulic engine is shifted to the loads that are 50 ... 70% of their maximum value.As a result of theoretical studies using numerical calculation methods, a technique has been developed for selecting a throttle control method with an assessment of its quality and efficiency. The results of the conducted studies expand the capabilities to forecast the dynamics and kinematics of the output link of the hydraulic drive at the stage of its engineering design.

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.

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