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This article studies the issues of digital simulation of physical operating processes in vehicles transmission. Simulation of dynamic processes is carried out in power transmissions at the design stage. The procedure for using the digital packages such as MATLab – Simulink and Simscape was considered for the numerical simulation of dynamic processes in mechanical systems based on the example of the theoretical calculation of K-744 tractor transmission dynamics. A digital model of K-744 tractor transmission is constructed, its calculation scheme is given, the initial characteristics are determined. A digital model of the tractor engine was created by means of the Simulink package. A nature of change in tractor engine torqueis determined by it. The calculated analysis of normal transmission frequencies is performed. Forced torsional vibrations are calculated in the tractor change gearbox generated by the vehicle engine operation. The conditions of resonance in the transmission are analyzed. The unfavorable modes of joint operation of the engine and the gearbox are determined for K-744 tractor.

The basic aspects of use of magnetic clutches and magnetic systems in sealed machine designs are examined. The investigation results are reported and recommendations are offered for their application.Magnetic clutches are used widely in sealed machines and apparatuses employed in nuclear and several other branches of the industry. In the nuclear industry, magnetic systems are used essentially in sealed transporting and lifting devices.Distinctive aspects of use of magnetic clutches and magnetic systems in sealed machines and apparatuses. 1. The transferring torque of a cylindrical magnetic clutch for a specific sealed machine or apparatus can be calculated by the formulas given in [1], but for making such a clutch, the active length of the magnet along its rotation axis is sometimes comprised of lengths of several magnets varying in length. At the junctions of the magnets, the operating magnetic induction is found to diminish, so it is necessary to perform a check calculation of the transferring torque of the cylindrical magnetic clutch with its component magnets, i.e., it is necessary to calculate the torque for each length of the magnets being components of the common active length and their summation. If the transferring torque of the clutch in the sum is less than the required, the magnets must be replaced by stronger ones, i.e., by magnets with greater residual magnetic induction.Let us examine this peculiar aspect with reference to the sealed pump of the trademark VGM-3/30 (Fig. 1) being operated at the Mayak Industrial Association. In principle of operation, the VGM-3/30 pump relates to vortex pumps with a closed-type impeller. The major components of the pump are an operating head 8, a plug 4 with an intermediate shaft passing through it, a casing 5 with a cylinder 12 supported on the inner projection of the casing, and a motor 1 (asynchronous or dc electric motor). The leak tightness of the pump is ensured by a magnetic clutch 7 that imparts rotary motion through a screen made from a weakly magnetic material, namely, 12Kh18N10T steel. The driving half-clutch of the magnetic clutch is fastened to the intermediate shaft and the driven half-clutch, to the shaft of the operating head. The operating head shaft rotates on sliding bearings made of siliconized graphite, which are lubricated by the fluid being pumped.The basic difference of the VGM-3/30 pump from other types of sealed pumps manufactured by Russian Federation plants is the presence of a magnetic clutch (Fig. 2) and a protective plug. The maximum torque transferable by the clutch must be greater than the torques acting during operation due to resistive forces (friction, load, and inertia), otherwise the magnetic link between the half-clutches may break, i.e., the magnetic clutch will not be able to transfer the torque.For making such a clutch, magnets with an active length l (Fig. 2a) are required, but sometimes there are magnets with a different length (fraction of l), i.e., the magnetic clutch is made with magnets of length l/2 (Fig. 2b) (the tot...