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The work is devoted to the analysis of the transmission of a special vehicle (SV) for moving on various surfaces, in particular on stepped ones, designed for people with disabilities. Based on the analysis of various vehicles for the movement of people with disabilities, a model of a SV was created. The main difference of proposed SV is the possibility of using the movement of the passenger՚s center of mass relative to the chassis of a SV for stabilization of the movement. A kinematic scheme of the SV transmission which includes the planetary reducer was created. The reducer provides movement of SV at various modes. Also SV transmission was modeled in the Solidworks software. The analysis of the performance of this transmission when moving a SV on various surfaces was made on base of created 3D-model. Based on the analysis, the efficiency of the transmission of a SV was proved both when moving on a straight surface, and in walking mode when overcoming steps.

The system of special vehicle (SV) motion stabilization during moving on a straight surface is modeled on the base of dynamic equations of the mathematical model. The movement is stabilized by using a PID controller, the angular displacement of the mass is selected to ensure a given speed of movement, and the deflection angle is stabilized by controlling the engine torque.

Problem of loading and unloading of tracked vehicles on a rail flatcar can origin during the transportation of construction machinery, for example in case of reconstruction works near railways when using of cranes is impossible. Current solutions are based on use of ramps connected to a rail flatcar. These ramps are lowered on rails for moving out of a vehicle. At this protection of rails and railway elements during vehicle turning is provided by preliminary stacking of sleepers and automotive rubber tires on place for vehicle movement. This article describes automated method and appropriate mechanism for loading and unloading of self-propelled tracked machines on a rail flatcar. This method provides reduced labor intensity and process duration by exception of hand operations and also avoidance of damages of railway elements.

The description of multifunctional test bench construction to determine the basic operational characteristics of transmissions of automobiles and trucks designed in Volgograd State Technical University is provided. The description of its mathematical model created on the basis of the spatial dynamic schema is given and the results of calculation of test bench mass and inertia parameters are provided. The models of moving masses are the masses of transmission rotating elements, which transmit torque, transmission housing, test bench frame, that consists of two subframes, two hubs, DinaPack loading device, including a hydraulic machine. The values of parts inertia moments and stiffness of its joints are obtained by DASP software package and SolidWorks 3D CAD system. On the first stage to carry out the simulation capabilities at various loading conditions and forecast their results without a long-term field tests, on the basis of the structural scheme of test bench the flat dynamic model was created, which besides the data on composition and communication of the masses, contains data on elastic, inertial and dissipative parameters of its elements. On the next stage the spatial structural test bench scheme was created, on the basis of which in “Universal mechanism” program the spatial dynamic model was made. The dynamic model of test bench includes 31 inertial masses influenced by linear, contact, bipolar and special forces. To check the adequacy of the created model at the initial stage the calculation of fundamental frequencies of its masses in the range from 0 to 10000 Hz was made. The comparison of its values with the results of processing of experimental digital oscillograms of test bench masses oscillations showed sufficient for the solution of engineering problems convergence of results.

This article describes the original method proposed by authors that provides decreasing of the dynamic loading of tractor transmission by means of change of the reactive element torsional stiffness. One of the most loaded elements in tracked vehicles is the final drive unit which is loaded by high dynamic modes. The tractor Chetra 6C-315 has an epicyclic final drive with a stopped ring gear. Authors propose use of a strictly resilient mount of the ring gear instead of a rigid connection. To analyze efficiency of the proposed method, a 3D-model of transmission was created in the “Universal Mechanism” software. Also, the model of a caterpillar mover was created in the same software for analysis of influence on transmission loads of the complex of kinematic and dynamic factors impacting on the forming of torque on driving sprockets. This article presents results of modeling of loading processes in transmission elements with the elastic coupling and without it during the longitudinal motion at various speeds and in turns with various radii. The results show that element dynamic load at high loading dynamic modes decreases by 20-30% in case the coupling is installed.

The paper provides information about design of made in Volgograd State Technical University multi-functional test bench for determination of the basic operational characteristics of automobiles and automotive trucks transmissions. The test bench allows evaluating the level of vibration load of transmission elements in a wide range of operating modes. It also allows investigating modes of propagation of torsional vibrations on the shaft lines, determining overall efficiency of the transmission, noise intensity and vibration of units. The test bench allows receiving characteristics of the fields of thermal loading, investigating influence of lubrication system parameters on changing operational parame- ters. It also allows conduct life cycle testing of transmissions or their components.