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In the design of gearboxes and transfer boxes of heavy-duty vehicle`s transmissions, sliding bearings are often used as supports for gear wheels. Analysis of the results of statistical processing of gearbox parts failures and transfer boxes of wheeled tractors with a pulling force of 30 kN indicates the need to improve the reliability of the sliding bearings of the gear wheels. Such plain bearings ensure free rotation of the gear wheels in case of the torque transmission absence, and when locked by a clutch, the radial load of the gear wheel is sensed, while operating in the slipping rolling mode. Such units are poorly understood and in the technical literature sources there are no recommendations for their engineering, which often leads to errors when selecting operation gaps and press fitted in gear wheels. The manufacturers of the transmissions assemblies replaced the plain bearings, which in this case are made of metal-ceramic bushes, for roller bearings.

Plane bearings are used as rotating bearings for gear wheels of vehicles transmissions. The design of these units provides for the operation of bearings in two main loading modes: sliding mode (without load transfer) and rolling mode with slipping motion (with load transfer). The mode of sliding bearings operation in the rolling and slipping mode is not sufficiently studied, which makes it impossible to quantify at the design stage the influence of the operating conditions of the vehicle on wear processes, and, therefore, on their reliability. It is necessary to take into account the fact that the condition of the bearing coupling affects the conditions of the gearing. The results of statistical studies of wear and accelerated wearing tests of sliding bearings of gears of a wheeled tractor show the low reliability values of both gear wheels and sliding bearings.

This article describes experimental research results of the electropneumatic clutch control device for the mechanical transmission. The aim is to assess electropneumatic clutch control device characteristics to regulate both mechanical and robotic transmission. The feature of the clutch control system having the electropneumatic actuator on the basis of a power cylinder is the use of a control module that consists of an acceleration valve and two electropneumatic valves. A new structural relationship between the electropneumatic clutch control device elements on the basis of the new acceleration valve design is suggested. The assessment of mass and dimension parameters of well-known devices and this electropneumatic clutch control device is provided. A new approach to choose automated clutch control system parameters taking into account the relay electropneumatic control system operation features is suggested.

Diagnosis of the car is a necessary means for early detection of developing malfunctions. A technique for diagnosing on a short road based on the acceleration in the second and third gears and coasting from 50 or 40 to 20 km/h is proposed. The results should be compared with the reference values calculated, taking into consideration the speed rolling resistance dependence, described by the square trinomial, the speed air resistance dependence with the variable exponent, the losses of the transmission idling mode and the progressive total resistances decrease at speeds below 25 km/h. The general speed dependence of the total resistance is described by a sixth-degree polynomial but not the second-degree one, as many researchers believe. The experimental check was performed on a subcompact sedan with 1.6 atmo engine. Weight of 1370 kg. First class road with an average rise of 0.0182, asphalt in good condition. There was no wind.

The article deals with the analysis of one of the methods of selecting rational parameters of automated clutch control system for robotic transmission. The objective is to select rational parameters of automated clutch control system for robotic transmission, equipped with electropneumatic actuating mechanism on the basis of mathematical simulation. The depicted mathematical simulation of the clutch control system is characterized by the possibility to coordinate the algorithm of control unit with the dynamic processes in the execution device. The new functional interrelations between the elements of the electro-pneumatic actuator are mathematically described. The way to the selection of rational parameters of an automated control system for clutch is recommended; the selection taking into account the features of the electro-pneumatic actuator. Using the mathematical modeling method, rational control parameters of the automated clutch control system are determined.