Abstract:The study considers the basic trends of development of modern mechanical transmissions of trucks and buses. It provides the developed various series of multispeed transmissions with automatic control and a number of transmissions from 6 to 16 for trucks and buses. The paper shows the basic parameters of the standard series of new transmissions received on the basis of innovative technical solutions. It provides the results of experimental studies of 16-speed transmissions on a special test stand and on the road as part of a truck transmission. Theoretical and experimental data on the gear change time are compared.
Key words:Multistage Transmission, Pneumatic Actuator, Synchronization Process, Automatic Control, Command Control
TRENDS OF DEVELOPMENT OF MANUAL TRANSMISSIONSThe transmissions of vehicles around the world most often have multispeed mechanical synchronized gearboxes with a friction clutch having such advantages as small weight and size, high reliability and service life, low cost, high energy performance as well as ease of maintenance and repair.In work (Crolla et al., 2009) the schemes and the general description of mechanical transmissions are presented, including with automated manual transmission (AMT), their advantages and disadvantages are described. It should be noted that at present AMT is widely used in vehicles, trucks, intercity buses and allterrain vehicles. Overview of the types of actuators and control systems of ATM is presented in the paper Ali et al. (2004). Electro-hydraulic (Lucente et al., 2007), electro-pneumatic (Jiang et al., 2011) and electro-mechanical (Kuroiwa et al., 2004, Karpukhin et al., 2015 actuators are the most used. Electro-hydraulic and electro-mechanical actuators are mainly used in cars and light commercial vehicles (Kuroiwa et al., 2004, Song et al., 2010. Medium and heavy-duty trucks, intercity buses and all-terrain vehicles have compressors that provide air compression and receivers -cylinders, which compressed air is stored, and that is why electro-pneumatic actuators are used there. As you know, the energy of compressed air is used to brake vehicles, control transmission, power take, remote tire inflation, etc. In this paper we consider AMT for trucks and buses. Clutch control systems for trucks with electro-pneumatic actuators are considered in the work (Langjord, 2011). The gearshift process and synchronization are discussed in detail in the works Lovas et al., (2006), Ivarsson et al., (2010), Junnarkar and Raibhole (2017). In some papers, the influence optimization of transmissions shift schedules on the traction performance and fuel consumption of vehicles is considered (Liao and Quail, 2011).For the majority of trucks, buses and road trains multispeed gearboxes are widely used. Their use ensures high traction and speed, reduced fuel consumption and improved environmental properties. Such gearboxes can be rationally used with automatic and command (semi-automatic) control (AMT), which allows us to realize the benefits of a wide range of gear rat...