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V.2(46), 2021
2-13He method of researching the dynamic properties of the railway crew in the action on it harmonic parametric perturbation, caused by the changing rigidity of the base of the rail, is set out. For such differential equations there are no regular methods of solving them, moreover, their exact solutions are not known at present, so they are used by approaching methods. A two-degree mechanical system with a harmonic parametric perturbation described by a system of ordinary homogeneous differential equations is considered. One of the hard-bone parameters is a function of time and varies from 2000 to 3000 N/m. To calculate the boundaries of dynamic instability (parametric resonance) a method of generalized Hill definers is used, which does not require the introduction of small parameters. The area of interaction of parametrically excited and forced vibrations has been determined. -
V.3(47), 2021
78-89The article is devoted to the development of a methodology for monitoring the alignment and radial runout of the inner cylindrical seating surfaces of locomotive motor-axle bearings. The main reasons for the wear of the working surfaces of the bearings and the consequences of the influence of the clearances in the interfaces of the plain bearings and the axles of the wheelsets on the increase in the intensity of wear of the parts and the deterioration of the dynamic characteristics of the running gear of the locomotive are listed. The paper presents a basic diagram of the basing and control of deviations from alignment and radial runout of the inner cylindrical surfaces of bearings, describes the design and principle of operation of a special control device for measuring these deviations. The purpose of the work is to substantiate the feasibility of monitoring deviations from the shape and location of surfaces during the repair of motor-axial bearings. The paper describes the sequence of steps for measuring the alignment and radial runout of bearings and the interpretation of the measurement results. The features of the design of the control device are considered, the advantages of its use are listed in comparison with the existing analogues of the devices used to control the alignment of the holes of the body parts located on the same axis. At the same time, it was found that the control of alignment and radial runout must be carried out in order to assess the possible degree of misalignment of the traction motor frame and the axle of the wheelset of the locomotive after repair. Thus, the conclusions obtained confirm the need to tighten quality control of the restoration of locomotive motor-axle bearings by introducing into the production process the operations to control the alignment and radial runout of motor-axle necks and motor-axle bearing liners made of lead bronze, tin or lead-tin babbits.