The choice of a rational ballasting scheme and the angle of application of the traction force for a caterpillar tractor

A feature of the layout of modern tracked tractors is that the center of mass of the tractor is usually located with a forward shift from the center of the caterpillar support surface. Such a layout solution, in combination with the use of ballast weights placed most often in front of the tractor, makes it possible to provide its required traction and coupling properties when assembling with guns. However, since the tractor operates with a wide range of loads, when changing the gun with high traction resistance, for example, to a low-resistance trailer, it becomes necessary to adjust the weight of the ballast. In practice, this adjustment is often not carried out, i.e. Once installed, the front ballast is used throughout the operating life of the machine, worsening its fuel economy and not providing optimum traction and coupling properties. In this regard, the important task is to find solutions that would eliminate the need to adjust the mass of the ballast depending on the hook load. For this purpose, the article deals with the scheme of ballasting of a caterpillar tractor with the application of traction force at a positive angle. Also, for the Challenger MT865B tractor, with a number of assumptions about its geometric parameters, the calculated dependence of the ballasting coefficient on the coupling weight and the thrust angle was constructed. Dependence analysis allowed to come to the conclusion that it is possible to ensure the coincidence of the pressure center with the middle of the tractor's support surface over the entire range of its loads, with constant values of the ballasting factor and the angle of application of the traction force. To calculate the optimal values of these parameters, the paper presents the corresponding formulas.

caterpillar tractor, ballasting, pressure center, caterpillar bearing surface, traction force