Determination of traction coefficient of driving wheels of the MTZ-82 tractor

There are various ways to control the value of normal responses of surface under tractor movers. One of them is to regulate the height of hitch point and the angle of drawbar power. The advantage of this method is that the necessary conditions are created for the automatic control of position of the center of pressure, which ensures the optimization of technical and economic indices of machine-tractor unit operation. To verify this method, it is necessary to carry out the tests determining the parameters of tractor operation, including the traction coefficient of driving wheels. Two variants of its determination are proposed: the towing of tractor with locked driving wheels and the drawbar tests. In both cases, the tractive effort at drawbar is applied at an angle. As a result of drawbar tests, an experimental tractive characteristic of tractor will also be obtained. In preliminary calculations, the weight distribution along the axes is determined depending on the value and the angle of drawbar power. The weight change on the rear axle is more intense than on the front one. It is necessary to use ballast weights on the tractor rear to compensate its unloading. As for tractors and agricultural implements under design, it is necessary to choose the rational component layout and design taking into account the weight redistribution during aggregation. The pre-calculated verification confirms the possibility of use of tractor towing in reverse gear with locked wheels to determine the traction coefficient of driving wheels. The applying of drawbar power at an angle allows to increase or decrease the responses of bearing surface on tractor movers during a particular operation and therefore has an advantage over conventional ballasting at the front of tractor. In combination with the ability to change the back tipping moment, this allows to optimize the traction characteristics of tractors.

tractor, pulling force, weight distribution, tractor tests, traction coefficient, drawbar tests