Tractor Front Axle Research Articles

Experimental Investigation of Plow-Chopping Unit

The article presents research results of a machine-tractor unit that performs two technological operations simultaneously: (i) chopping plant residues (sunflower stubble); (ii) covering the chopped stubble with the soil. The first operation is carried out with a front-mounted plant residues chopper, and the second one is carried out with a rear-mounted plough. The chopper’s working devices are rotated by the tractor’s front power take-off (PTO), which has two operating modes: 540 and 1000 rpm. It was determined that to reduce the dynamic load in the drive of the chopper’s plant residues working devices, to chop these residues qualitatively, and then to cover them with the soil, the tractor’s front PTO should be adjusted to a speed of 1000 rpm. With this mode of the chopper’s working device’s rotation, the difference in its vertical vibrations’ dispersion and the tractor front axle’s oscillations is insignificant. The variance of the plowing depth vibrations (1.44 cm2), changing aperiodically in the frequency range of 0–2.5 Hz, is not accidentally less than the variance of irregularities vibrations of the longitudinal field profile (2.75 cm2). The plough draft resistant oscillations of the plow-chopping unit had the least impaction at the plowing depth oscillations. The proof of this is the small value of the cross correlation function; for such oscillating processes as ‘plough draft resistance—plowing depth’, it was equal to 0.22, which is 3.4 times less than for oscillating processes ‘surface’s longitudinal profile—plowing depth’. The number of chopped particles less than 15 cm in length increased by 1.5 times, and the number of particles longer than 30 cm decreased by 3 times. With the complete incorporation of plant residues into the soil, their non-chopped part did not exceed 1%.

Strength evaluation of gears and bearings considering housing deformation of the tractor front axle

Strength evaluation of gears and bearings considering housing deformation of the tractor front axle

Power density based fatigue load spectrum editing for accelerated durability testing for tractor front axles

The fatigue load spectrum is one of the most important parts in accelerated durability testing of agricultural machinery; however, the traditional editing approach just focuses on influence of load amplitude on mechanical components, which is not suitable for the agricultural machinery, the loads of which are broad in frequency bandwidth and time-varying in stress amplitude. Therefore, considering the comprehensive influence of load amplitude and frequency on the fatigue life of materials, a power-density-based fatigue load spectrum editing (PD-LSD) approach for accelerated durability testing is proposed ensuring that fatigue load spectrum for accelerated durability testing of tractor components can reproduce operation load characteristics of components. The concept of power density is introduced, and a fatigue analysis method based on power density and short-time Fourier transform (STFT) is discussed. For the approach of this study, STFT and stress-life (S–N) curve were used to derive accumulative power density (AccPD) of the load signal. The AccPD identified and extracted high fatigue damage segments of original load signal and obtained reduced accelerated load spectrum of components. Based on the load signal of the 88-kW tractor front axle, this approach and the time damage editing approach were applied to edit the load signal. The results show that, the accelerated load Signal Ⅰ based on the PD-LSD approach with a shorter length of time contained almost same damage of the original load signal, and the statistical parameters (mean value, root mean square and kurtosis coefficient) and the signal amplitude domain of the accelerated load Signal Ⅰ were more consistent with the original load signal, which verifies the acceleration, accuracy and effectiveness of the approach. This research supports fatigue testing and durability analysis for a key component of agricultural machinery.

Assessment Study of the Design and Characteristic of Front-axle Hydro-pneumatic Spring of the Tractor

The paper discussed the improvement of design and characteristics of front-axle hydro-pneumatic spring of the tractor. For the experimental purposes, tractor with the model number of CF700 and the vibrational differential equation was established and also the three degrees of freedom vibration model of the front-axle suspension tractor was built up. According to the requirements of the tractor model number CF700 for front-axle suspension parameters, hydro-pneumatic spring with the controllable stiffness and damping was designed. The stiffness and damping non-linear mathematical model of hydro-pneumatic spring was established and the structural parameters of hydro-pneumatic spring were calculated. The performance of hydro-pneumatic springs was studied by simulation and the static and dynamic characteristics of the hydro-pneumatic spring were studied in the experiment. From the investigated results shows that the stiffness characteristics of hydro-pneumatic spring were studied and the static stiffness of hydro-pneumatic spring in equilibrium position was 72.6 kN.m-1. The influence of proportional valve current size, the opening of the throttle valve size and excitation frequency to the output force of hydro-pneumatic spring was studied by dynamic experiment. Further, from the results, it was showed that the designed hydro-pneumatic spring can adjust output force on a wide range of sizes. However, from the investigated results, it was concluded that the study provides an important basis for the later development of the semi-active hydro-pneumatic suspension of tractor front axle suspension.

Dependence of the agrotech-nical clearance under the front axle of a cotton tractor with a wheel arrangement 4K4a on the dimensions of the pivot pin, the size of the tires of the steered wheels and the angles of their installation

At present, the concept of the transition of cotton energy to a four-wheeled power plant is being worked out in the republic. And it has, in comparison with the existing one, an additional potential for increasing productivity due to increasing the ranks of agricultural machinery. Cotton refers to high-growth technical crops, as at the stage of maximum biological development plants reach a height of 800...1250 mm. Minimal traumatization of the above-ground part of the plants during the processing of row spacing and loss of harvest during harvesting is largely due to the increased agrotechnical clearance of cotton-growing tractors. The modern cotton tractor has a scheme of propulsors with axle configuration of 3K2 and clearance of 820...830 mm under tubes of shafts of rear axles, due to the installation of additional final gears. The front steer axle is single-wheeled, it does not prevent the safe passage of plants under the tractor's framework. When developing a four-wheeled cotton tractor, a major problem is the provision of the required agro-technical clearance under the tube of the front axle. Preliminary studies have established that it is possible to change the agrotechnical clearance under the portal structure of the front axle by changing the length of the pivots of the pivot pins to the dimensions that provide the four-wheeled tractor with satisfactory flotation above the row of cotton. At the same time, it is necessary to take into account the known effect of the linear and angular dimensions of the front axle on the kinematic characteristics of the steering and the operation of the propulsors, in connection with which the analytical interrelation of the agrotechnical clearance under the front axle of the tractor with axle configuration 4K4a, the dimensions of the pivots of pivot pins, the dimensions of the steered wheels and the angles of their settings, allowing to calculate the amount of agrotechnical clearance under the beam of the front axle for different combinations of arguments that are included in this dependence. For example, it is established that with the length of the pivot shaft of the experimental front driving axle of 435 mm and the installation of 11.2-20, 11.2R20 and 11.2R24 tires, an agro technical clearance is provided within 826...877 mm, which meets the requirements of the technical specification for the cotton tractor.

BRAKE OF THE FRONT DRIVE WHEELS OF THE TRACTOR "BELARUS"

The increase in the energy saturation of the new models of tractors "Belarus", as well as the mass of towed trailers and agro-technological tools that are mounted with them, required an increase in the efficiency of the tractor braking system. The purpose of the study is to increase the efficiency of the braking system of the wheeled tractor "Belarus MTZ" by creating wheel brakes for the front axle with minimal changes in its standard design. The developed drum brake with hydraulic drive of the front drive wheels of the tractor "Belarus MTZ-1221" does not require significant changes in the standard design of the front axle of the MTZ tractor and is adaptive to the anti-lock system, which operates on the basis of measurement and analysis of force factors. The design of the developed brake mechanism allows its adaptation to the anti-lock system, which operates on the basis of measuring and analyzing the forces that arise in the contact of the wheels of the front axle of the tractor with the supporting surface. The braking effect of the tractor "Belarus MTZ-1221" is provided by additional use of its coupling weight, which falls on its front axle. A set of design documentation for the drum brake for the front driving wheels of the tractor "Belarus MTZ-1221" was developed. The use of an additional traction weight of the tractor due to the wheel brakes of the wheels of the front axle of the tractor "Belarus MTZ-1221" will increase the efficiency of its braking, as well as increase the competitiveness of wheeled tractors produced by the JSC "Minsk tractor works". Bench tests confirmed the possibility of braking the calculated moments corresponding to the weight load on the front axle of the tractor "Belarus MTZ-1221". Consequently, the developed brake mechanism will ensure effective use of the tractive weight of "Belarus MTZ-1221" tractor.

Accelerated Life Test Design for Tractor Powertrain Front Axle

Accelerated Life Test (ALT) has been applied in the manufacturing for many years due to rapid changing technologies, more complex products, speedier product development, and more demanding customer requirements. These reasons have pushed the manufacturers to acquire reliability information faster. ALT allows reducing the time needed to show the reliability of the product. The purpose of this study is to design accelerated life testing which involved determination of normal test time, acceleration factor, acceleration test time, and finally experimental setup. This case study provides the basis for ALT designs for the tractor front axle based on customer usage and field failure analysis, which were conducted to estimate the current reliability, especially on the B10 life during the operational stage of the product. The accelerated life test conducted has guaranteed the B10 life of 4,000 hours with 90% confidence level for lesser time needed for testing to show the reliability of the front axle assembly.

Measurement of weight transfer in two wheel drive tractor by developed ring transducer

Weight transfer or weight shift is, in fact, reaction transfer or change in the reactions of front and rear wheels of the tractor. Weight transfer because of drawbar loading decreases soil reaction against the front wheels and increases reaction against the rear wheels. A study was done to measure the dynamic front wheel reaction of the tractor and thereby the weight transfer from front to the rear wheel. Developed ring transducer was attached below the tractor's front axle to measure the front wheel reaction. Field experiments were conducted using Ford-3630 tractor with three different implements viz., 3-bottom mould board plough, 9-tyne cultivator and offset disc harrow. For each operation, the parameters such as dynamic front wheel reaction, draft, slip and depth were measured. The instrumented link forces were used to calculate implement draft. Slip was calculated by measuring actual speed in the field at different depths and theoretical speed on a concrete surface in the same gear and throttle position. The dynamic front wheel reaction was measured by using the developed ring transducer and thus, the weight transfer from front to rear was calculated. Also the weight transfer for a given draft was calculated theoretically and compared with the experimentally determined weight transfer. The data indicated that weight transfer increased with increase in draft. The maximum variation between theoretical and experimental values of weight transfer was found to be 12.62 per cent. This variation may be due to some assumptions made in theoretical calculation as well as due to vibration of the front axle while operating the tractor in the field.

Design Optimisation of Four Wheel Drive Tractor Front Axle Housing

Design Optimisation of Four Wheel Drive Tractor Front Axle Housing

Advancement in Simulation of Front Axle of Tractor

Advancement in Simulation of Front Axle of Tractor

스파이럴과 스트레이트 베벨기어 가공 시 비용 및 생산성 비교연구

The tractor front axle has the lower standard for noise and vibration relatively and it increase the possibility to develop of the alternative straight bevel gear of the expensive spiral bevel gear. The purpose of this paper is to compare of the spiral vs. the straight bevel gear manufacturing process. The manufacturing cost and productivity are compared after the spiral bevel gear of the tractor front axle is replaced of to the straight bevel gear. If spiral bevel gear is replaced to straight bevel gear, the cost is reduce 4.6% and productivity is increase 18%.

Evaluation of dynamic load equations through continuous measurement of some tractor tractive performance parameters

In this research, a system was designed and constructed to measure dynamic load quantities based on the installation of two strain gauges on tractor front axle. The results of calibration tests on measurement system are a good evidence of suitable sensitivity and linearity of measuring system. Four predictive equations of dynamic load were compared by precise continuous measurement of dynamic load and other effective parameters through field experiments. The results showed that the Colvin et al. (1984) equation is the most appropriate equation in terms of measuring the dynamic load on tractor wheels in comparison with other equations.

Design of digital weight transfer display for agricultural tractors

A microcontroller based digital display unit was developed for 2WD agricultural tractors to measure and display the weight transfer from tractor front axle. The device includes a transducer for measuring the tractor front end reaction, an amplifier to amplify the transducer signal and a microcontroller to calculate and display the weight transfer from the front axle. The developed device can be mounted on any make and model of 2WD tractor. The digital display unit was rigorously tested in the laboratory as well as in the field. A maximum of + 3.5% variation in weight transfer was observed between the theoretically calculated and experimentally observed values. Key words: Microcontroller, weight transfer, ring transducer, tractor, front axle.

Design and Analysis of Front Axle for Two Wheel Drive Tractor

Fatigue failure has become a major concern in the automobile and aircraft industry, heavy machinery etc. Failures by fatigue are especially dangerous because they are unpredictable; giving no prior notification of the imminent failure they occur suddenly. Front axle of tractor is one of the major and very important components that undergo severe load conditions and it fails unexpectedly causes unrecoverable losses. The objective of this study is to analyze the existing design of the front axle of the tractor for service load conditions and redesign to its functional requirements and to increase its life expectations. Finite element simulation is carried out for the existing front axle using ANSYS. The critical location of the front axle has to be identified and redesigned to ensure the safety. The existing geometry of the front axle is modified to the optimum size which suits for functional requirements with increased life and minimum cost. In this analysis, the geometry of the front axle is modified and a new design is proposed. The life expectancy of the front axle was predicted for the dynamic load using ANSYS fatigue design module.

Finite Element Analysis of the Tractor Front Axle Housing Based on ANSYS

This paper shows the static strength analysis of the tractor front axle housing by using of the finite element analysis software ANSYS, visually shows equivalent stress and strain distribution and vertical displacement distribution of the front axle housing. At the same time it also shows the analysis results of the model processing, the results of accuracy and reliability, and the weak links of the structure. By analyzing the weakest link and the difference in strength between each node for the overall structure in the condition, it can provide a direction and theoretical basis for the design and optimization of geometric entities. And the results of the analysis may be as the basis for structural improvement. In this way, it can be verified that using computer virtual software for product development is positive.

Multi-objective-reliability-based optimisation of a farm tractor front axle suspension

This paper deals with the design and optimisation of a front suspension to be fitted on a standard low range farm tractor. The design process has been completed by using state-of-the-art robust multi-objective methods. Two complete, fully modular and parametric vehicle models of the farm tractor have been realised and experimentally validated. The inertia parameters and the tyres characteristics have been directly measured to get a good match between the response of models and of the actual vehicle. The models have then been modified to implement different suspension layouts. The described optimisation process has proved to be cost-effective and time-saving, and it can be generalised for complex vehicles and vehicle subsystems design.