scholarly journals Proper Technical Maintenance of Combine Harvester Rolling Bearings for Smooth and Continuous Performance for Grain Crop Agrotechnical Requirements

2021 ◽  
Vol 11 (18) ◽  
pp. 8605
Author(s):  
Eglė Jotautienė ◽  
Antanas Juostas ◽  
Shankar Bhandari
Keyword(s):  
Rolling Bearing ◽  
Frequency Interval ◽  
Vibration Source ◽  
Condition Evaluation ◽  
Technical Maintenance ◽  
Qualitative Work ◽  
Grain Crop ◽  
Combine Harvester ◽  
Main Component ◽  
Vibration Parameters

The threshing mechanism is the main component of the combine harvester on which the grain separation and cleaning qualitative work indicators depend. It is important to ensure that all threshing mechanism components, including the threshing drum bearings and all other bearings of the combine, are working properly and reliably. There are many places in the combine where it is not possible to measure bearing vibrations directly without dismounting them, since there is no suitable spot to mount a sensor. The paper investigates the threshing drum rolling bearing condition of combines, which are difficult to access, by using a vibration diagnostics technique utilizing a newly manufactured steel bracket. The vibration measurements and analysis were conducted by the Adash A4900 Vibrio M analyzer (Adash spol. s.r.o., Ostrava, Czech Republic). The vibration source measurement was based on the fast Fourier transform (FFT) spectrum analysis. Analysis of the experimental results showed that average squared velocity values (in the frequency interval of 10–1000 Hz), together with other measured vibration parameters, can be used for the combine threshing drum‘s bearing condition evaluation.

scholarly journals Methods of identifying grain production cost when threshing grain crops in view of the need in combine harvesters and combine operators

2019 ◽  
Vol 49 (2) ◽  
pp. 85-93 ◽  
Author(s):  
G. E. Chepurin ◽  
A. P. Tsegelnik
Keyword(s):  
Crop Yield ◽  
Production Cost ◽  
High Performance ◽  
Operating Speed ◽  
Grain Crops ◽  
Grain Crop ◽  
Combine Harvester ◽  
Definition Of ◽  
Combine Harvesters

The paper presents substantiation of the rational use of combine harvesters’nominal throughput when threshing grain crops with the yield ranging from 0.8 to 5.0 t/ha and over. The main factors that determine nominal throughput of combine harvesters and their operational indicators are identified. The structure andcontents of thetechnological passport of combine harvesters are substantiated, and the algorithm of effective determination of their key operational indicators, based on the passport, are developed. These indicators depend on harvesting technology, grain crop yield, the share of non-grain part in the threshed grain bulk, the coverage of swath headers and direct-cut headers, and the operating speed of combine harvesters. The definition of the term “technological passport of the combine harvester” is given. Maximum and minimum allowable grain crop yield is established for the rational load of combine harvesters threshing at the standard operating speed of7.5 km/hrecommended by the Ministry of Agriculture of theRussian Federation. The existing methods make it possible to determine the operational efficiency of high-performance machinery by operational costs. However, they do not take into account the shortage of human resources when determining production cost of the threshed grain. As a result of the research conducted, the algorithm and techniques of determination of actual grain cost when harvesting grain crops by direct combining and swath harvesting methods are developed taking into account the need in combines of an i-class and combine operators. Production cost of grain threshed on the area of1000 hectarescalculated by the techniques developed, allows to define the minimum estimated and actual grain cost for an i-class combine harvester by direct combining and swath harvesting methods.

The Research on the Methodology of Diagnosing the Fault of Bearing in Warships Based on NS-EMD

2013 ◽  
Vol 711 ◽  
pp. 352-357
Author(s):  
Jin E Huang ◽  
Dong Xu ◽  
Yan Lei Wang ◽  
Yang Zhang ◽  
Shuang Wang
Keyword(s):  
Signal Processing ◽  
Vibration Signal ◽  
Rolling Bearing ◽  
Processing Method ◽  
Image Method ◽  
Vibration Source ◽  
Rolling Bearings ◽  
Average Value ◽  
Signal Processing Method ◽  
Emd Method

EMD is now a commonly used nonlinear and instable signal processing method, but it has boundary runaway and modal aliasing. The single disunited IMF cannot well reflect the characteristics of the respective vibration source. Therefore, in order to suppress the boundary runaway that will appear in the process of EMD, the image method is used to extend the length of signal data. To solve the modal aliasing, it is necessary to decompose the extended data by the EMD method, to distinguish the IMF that produces modal aliasing after decomposition, to integrate it according to the integrity of the EMD and then to re-decompose it after adding broadband white noise with the average value of zero. On the basis of that, it is better to improve NS-EMD method and realize the AM-FM demodulation by standardized method. By the spectrum analysis, we extract the fault characteristics of rolling bearings and propose a method to diagnose faults of rolling bearing. The results of analyzing the simulation and the vibration signal of fault rolling bearing shows that the method can effectively extract fault characteristics of rolling bearing.

scholarly journals Vibration Response of the Crawler Combine Chassis Frame Excited by the Engine

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Taibai Xu ◽  
Dongju Gao ◽  
Yi Chen ◽  
Weiwei Zhang ◽  
Fei Xu ◽  
...  
Keyword(s):  
Excitation Frequency ◽  
Firing Frequency ◽  
Vibration Response ◽  
Vibration Source ◽  
Theoretical Derivation ◽  
Response Characteristics ◽  
Engine Vibration ◽  
Vibration Mechanism ◽  
Combine Harvester ◽  
Engine Excitation

There are many problems of vibration and noise in combine working. As the main power source and excitation source of a combine, the working state of an engine directly affects the reliability and stability of the whole harvester. In order to analyze the vibration response characteristics of a chassis frame under engine excitation, the vibration mechanism and theoretical excitation characteristics of an engine vibration source on a crawler combine harvester are analyzed in this paper, and the vibration response of chassis under engine excitation is tested and analyzed. After theoretical derivation, a two-degree-of-freedom dynamic model of an engine and chassis is established. The experimental results show that the up and down vibration generated by the engine is the main vibration source in the Z direction, and the main excitation frequency is the second-order firing frequency. This paper provides a theoretical reference and experimental basis for vibration reduction and noise reduction of combine and vibration characteristics of the chassis frame.

A Framework to Determine the Upper Bound on Extractable Power as a Function of Input Vibration Parameters

2016 ◽  
Vol 3 (1) ◽  
Author(s):  
John D. Heit ◽  
Shad Roundy
Keyword(s):  
Upper Bound ◽  
Time Dependent ◽  
Mathematical Framework ◽  
Vibration Source ◽  
Viscous Damping ◽  
Damping Force ◽  
Dependent Frequency ◽  
Sinusoidal Input ◽  
Linear Spring ◽  
Vibration Parameters

AbstractThis paper outlines a mathematical framework to determine the upper bound on extractable power as a function of the forcing vibrations. In addition, the method described provides insight into the dynamic transducer forces required to attain the upper bound. The relationship between vibration parameters and transducer force gives a critical first step in determining the optimal transducer architecture for a given vibration source. The method developed is applied to three specific vibration inputs: a single sinusoid, the sum of two sinusoids, and a single sinusoid with a time-dependent frequency. As expected, for the single sinusoidal case, the optimal transducer force is found to be that produced by a resonant linear spring and a viscous damping force, with matched impedance to the mechanical damper. The resulting transducer force for the input described by a sum of two sinusoids is found to be inherently time dependent. The upper bound on power output is shown to be twice that obtainable from a linear harvester centered at the lower of the two frequencies. Finally, the optimal transducer force for a sinusoidal input with a time-dependent frequency is characterized by a viscous damping term and a linear spring with a time-dependent coefficient.

scholarly journals THE STRUCTURE AND CONTENT OF THE TECHNOLOGICAL PASSPORT AND OPERATION PROCESS CHARTS OF GRAIN HARVESTERS

2018 ◽  
Vol 48 (3) ◽  
pp. 50-57 ◽  
Author(s):  
G. E. Chepurin ◽  
A. P. Tsegelnik
Keyword(s):  
Combine Method ◽  
Weather Conditions ◽  
Production Environment ◽  
Two Phase ◽  
Grain Crops ◽  
Regulatory Standards ◽  
Operation Process ◽  
Grain Crop ◽  
Standard Value ◽  
Combine Harvester

The work describes how parameters of grain crop stalk mass, combine harvester speed, coverage of swath headers and fi eld size infl uence the actual throughput of a grain harvester and the feasibility of its nominal throughput at threshing. The nominal throughput of a grain harvester is usually taken as the delivery of corn bulk in kilograms her second to a thresher with the level of grain loss of 1.5 percent and the standard moisture of grain and straw. In a production environment, the throughput of a grain harvester of the classical scheme increases by 1.45 times when the straw content in corn bulk goes down from 1.5 to 0.7 in unit fraction and decreases by 1.16 times when the straw content goes up from the standard value to 2.3. By regulatory standards the actual throughput of a grain harvester can only be 10 percent lower than its nominal throughput. When choosing harvesting strategy and tactics in the farm conditions, the technological passport of the 7 kg/s class grain harvester may be represented as a nomogram consisting of four quadrants. The procedure of using a technological passport was developed by harvesting grain crops with the yield of 1 to 2 tons per hectare by the 7 kg/s class grain harvester. According to the calculations for the normal weather conditions and the yield range mentioned above, such harvester will be fully loaded only at two-phase harvesting, threshing double swaths cut by reapers with the coverage of 10 and 6 m, and at the maximum allowable operating speed of the grain harvester. The coverage of the swath headers for the straight combine method is from 9 to 11 m, so the effi cient load of the 7 kg/s class grain harvester at maximum allowable operating speeds is achieved only at threshing grain crops with the yield capacity of over 2 tons per hectare. These fi ndings can be used to develop operation process charts for grain crop threshing in each fi eld by the straight or two-phase methods.

scholarly journals Study on Mechanical Law of Vibration Abscission of Camellia Oleifera Fruit Based on High-Speed Camera Technology

2019 ◽  
Vol 10 ◽  
pp. 1713-1725
Author(s):  
Yang Cheng ◽  
Wang Qi
Keyword(s):  
High Speed ◽  
Mechanical Characteristics ◽  
Vibration Source ◽  
High Speed Camera ◽  
Camellia Oleifera ◽  
Binding Force ◽  
Harvesting Process ◽  
Pulling Force ◽  
Vibration Parameters ◽  
Low Amplitude

The movement and mechanical characteristics of oil-tea camellia fruit coupling with flower simultaneously during the harvest period were studied to provide an indispensable theoretical guideline for the mechanized picking machine. The mechanical properties of Camellia oleifera were obtained by investigating its flowers and fruits, and the vibration harvesting of Camellia oleifera was studied by using dynamic vibration device. The i-Speed3 high-speed camera was used to record the harvesting process, and the image analysis and calculation were carried out by its own Control-Pro software. The results showed that different varieties of Camellia oleifera had different flowering periods, ranging from 30 to 55 days; their weight also varied among varieties; there was no inevitable relationship between the binding force (pulling force and torque) of fruit stalks and their varieties, locations and diameter of fruit stalks. More importantly, during the vibration process, the fruit peeling speed is related to the vibration source clamping position and vibration parameters. Under the condition of short clamping distance and high frequency and low amplitude, the fruit is more likely to fall off.

scholarly journals Electromagnetic Vibration Energy Harvesting for Railway Applications

2018 ◽  
Vol 148 ◽  
pp. 12004 ◽  
Author(s):  
S. Bradai ◽  
S. Naifar ◽  
C. Viehweger ◽  
O. Kanoun
Keyword(s):  
Energy Harvesting ◽  
Excitation Frequency ◽  
Laser Sensor ◽  
Vibration Source ◽  
Efficient Design ◽  
Vibration Energy Harvesting ◽  
Railway Traffic ◽  
Electromagnetic Vibration ◽  
Vibration Parameters ◽  
German Cities

Safe localization of trains via GPS and wireless sensors is essential for railway traffic supervision. Especially for freight trains and because normally no power source is available on the wagons, special solutions for energy supply have to be developed based on energy harvesting techniques. Since vibration is available in this case, it provides an interesting source of energy. Nevertheless, in order to have an efficient design of the harvesting system, the existing vibration needs to be investigated. In this paper, we focus on the characterization of vibration parameters in railway application. We propose an electromagnetic vibration converter especially developed to this application. Vibration profiles from a train traveling between two German cities were measured using a data acquisition system installed on the train’s wagon. Results show that the measured profiles present multiple frequency signals in the range of 10 to 50 Hz and an acceleration of up to 2 g. A prototype for a vibration converter is designed taking into account the real vibration parameters, robustness and integrability requirements. It is based on a moving coil attached to a mechanical spring. For the experimental emulation of the train vibrations, a shaker is used as an external artificial vibration source controlled by a laser sensor in feedback. A maximum voltage of 1.7 V peak to peak which corresponds to a maximum of 10 mW output power where the applied excitation frequency is close to the resonant frequency of the converter which corresponds to 27 Hz.

scholarly journals THE MODELING OF CONSTRUCTIONS OF SHIPS LOADER’S ENGINE ROOM FOR THE IDENTIFYING THE CAUSE OF INCREASED VIBRATION

2021 ◽  
Vol 30 (1) ◽  
pp. 88-99
Author(s):  
V. Popov ◽  
◽  
A. Popova ◽  
Keyword(s):  
Spur Gear ◽  
Technical Condition ◽  
Normal Operation ◽  
Vibration Velocity ◽  
Vibration Source ◽  
Natural Oscillations ◽  
Term Operation ◽  
Engine Room ◽  
Support Frame ◽  
Vibration Parameters

The article contains a finite element modeling of the stress-strain state of metal constructions of the foreign manufactured ships loader’s engine room, located in the seaport of Yuzhny’s town under the jibs lifting and lowering drive vibration source. The model have been developed taking into account the technical condition of the structure, which were determined after visual and instrumental examination. Have been researched the rotating structures of jibs lifting and lowering drive, means of ensuring smooth start and soft stop of the drive, have been increased the specific drive imperfections. Have been done the cinematic and dynamic calculations on a subject of definition of vibration parameters of rotation components of drive (electric motor, spur gear, gear, brace and rope drums). Have been offered the effective methods of experimental research, which including the scheme of installations of sensors at the structure of support frame of engine room, experimental measurements of vibration characteristics (vibration, amplitude, vibration velocity, vibration acceleration) and its mathematical processing. Have been done the comparison of the theoretical forced vibrations frequency of structural units of ships loader with experimentally determined data and localization of the most dangerous source of vibration. Have been revealed the main reason of excess vibration the structure of ships loader which are reduced rigidity of drive support frame which has been damaged from corrosion and consequently, resonance of rotational drive components with natural oscillations of ships loader structures. Have been developed the method of strengthening of structures of engine room, which have been damaged from corrosion during long term operation for the reduction of vibration intensity and for the further normal operation.

ROLLING BEARING TECHNICAL CONDITION FORECASTING USING VIBRATION ACCELERATION OVERALL LEVEl

2020 ◽  
pp. 12-19
Author(s):  
Yu. V. Sarapulov ◽  
V. A. Sidorov ◽  
A. E. Sushko ◽  
R. A. Khasanov
Keyword(s):  
Practical Importance ◽  
Rolling Bearing ◽  
Technical Condition ◽  
Normal Operation ◽  
Threshold Values ◽  
Vibration Acceleration ◽  
Extensive Experience ◽  
Corporate System ◽  
Vibration Parameters ◽  
Bearing Damage

Traditionally, the assessment of changes in the technical condition of individual components and mechanisms of rotation machines in industry is associated with trends analysis of various vibration parameters. Over the decades of using vibration analysis, we have accumulated extensive experience in faults locating and critically determining, however, it is the assessment of the remaining life that regulates the timing of maintenance and repair activities that is of great practical importance. This article uses the example of a pump unit rolling bearing to consider approaches to predicting the growsup stage of defects based on the analysis of values of vibration acceleration levels. The stages of normal operation and other stages of bearing damage are highlighted, threshold values are calculated and dependences of changes in diagnostic criteria for each stage of the life cycle are constructed. The obtained dependencies show results that are similar in general, but individual in their values, therefore, the accumulation of possible scenarios of events allows creating a knowledge base for predicting the behavior of a mechanical system. The necessary tools for multifactor forecasting were implemented within the SAFE PLANT software platform (LLC SPA DIATECH, Moscow) and are successfully applied at Uralkali PJSC for monitoring the technical condition of all technological equipment and managing MRO processes by integrating the results of diagnostics and forecast assessments into the ORACLE corporate system.

Total etch dentin bonding systems: scanning electron microscopy of the resin-dentin hybrid layer

1992 ◽  
Vol 50 (2) ◽  
pp. 1092-1093
Author(s):  
Jorge Perdigao
Keyword(s):  
Composite Resin ◽  
Mechanical Interlocking ◽  
Hybrid Layer ◽  
Agent Based ◽  
Dentin Bonding ◽  
Acid Agent ◽  
Bond Strengths ◽  
Main Component ◽  
Bonding Systems ◽  
New Generation

In 1955, Buonocore introduced the etching of enamel with phosphoric acid. Bonding to enamel was created by mechanical interlocking of resin tags with enamel prisms. Enamel is an inert tissue whose main component is hydroxyapatite (98% by weight). Conversely, dentin is a wet living tissue crossed by tubules containing cellular extensions of the dental pulp. Dentin consists of 18% of organic material, primarily collagen. Several generations of dentin bonding systems (DBS) have been studied in the last 20 years. The dentin bond strengths associated with these DBS have been constantly lower than the enamel bond strengths. Recently, a new generation of DBS has been described. They are applied in three steps: an acid agent on enamel and dentin (total etch technique), two mixed primers and a bonding agent based on a methacrylate resin. They are supposed to bond composite resin to wet dentin through dentin organic component, forming a peculiar blended structure that is part tooth and part resin: the hybrid layer.

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