Abstract. The article presents and analyses the reasons of the braking parameter in 4×4 tractor. It is noted that the wheeled tractors are working in transport, cargo, driving with implements and without them in the fields, etc. for most of the time. The contact area with the road surface during braking decreases when increasing the driving speed and the overall dynamic stiffness of the tire changing increases the rolling resistance. However, it is worth mentioning that the tire contact with the road surface area is also dependent on the tire air pressure and improperly selected or uneven tire air pressure to increase the vehicle rolling resistance, increasing the frontwheel lead, which reduces the braking efficiency. The change of the front-wheel lead increases kinematic discrepancy between the drive wheels. These factors have negative effect for the tractor performance parameters, the transmission is loaded heavily, the power losses are increased, tires wear faster, the fuel consumption is increased. This article shows and analyses tractor deceleration between different wheel drive (4×2 and 4×4) with different driving speed.Keywords: inflation pressure, deceleration, braking, agricultural tractor. IntroductionTractors are identified as MFWD (Mechanical Front-Wheel Drive) tractors, when the front axle is driven by a mechanical drive and the front drive wheels are smaller than the rear wheels. Today, MFWD tractors are extensively used for transportation work when connected to the tractor trailer or semi-trailer. The latter considerably increases the tractor rear wheel vertical load and the rear tire deformation, but reduces the front-wheel vertical load and tire deformation. Increasing and decreasing the rear of the front tire deformation increases the actual size of the front wheel advance. This change has no harmful effects on the tractor vehicle dynamics while working, because when running a good road and at higher speed, the front wheel drive is generally unplugged. However, front-wheel accelerates change effects of the MFWD tractor braking dynamics, since the braking front axle is always automatically enabled [1][2][3][4].Brake and steering systems in vehicles are the most effective gear, which directly affects the vehicle dynamics. In general, the brake system is running in the longitudinal vehicle dynamics and driving dynamics system running side. However, their effects combine when the vehicle is braked on uneven surfaces. The yaw moment braking compensates for steering control on the road. To avoid improper steering compensation vehicles have been equipped with the wheels being driven in rotation angle of the controller, designed to mitigate the impact of asymmetric braking forces and stabilize the angular deviation in vehicles [5][6][7].Freight transportation tractors are combined with various trailers or semi-trailers. Almost 75 % of kinetic energy of the tractor-trailer combination is acquired from the trailer, so it is very important that the brake system of the trailer is sufficient to defeat the e...
The transmission of mechanical front-wheel drive tractors normally has a front axle lead ratio, which is equal to 1.5…2.5%. Naturally, when ballast masses are added to the tractor or when inflation pressure in the tires is reduced, distortion of the tires is inevitable, which changes the lead of the front wheels. In this paper, we present the impact of tire inflation pressures on the lead front drive wheels and movement resistance force when the tractor travelled with a front drive axle enabled and was engine braking with the fuel supply off. It was found that the variation in front and rear tires inflation pressure combination can significantly change the lead of the front drive wheels. For the tested tractor up to 6.9%. The result is that when the tractor travelled with the front axle enabled and was engine braking, the engine-braking efficiency decreases with increasing lead of the front wheels. Front (slipping) wheels create the opposite-direction torque, which is transferred to the rear wheels through the tractor’s front-rear axle drive system. Additional losses of the engine braking occur in transmission due to power circulation, and the result is that the tractor wheels receive less braking torque from the engine.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.