This paper reports the results of an experimental study of the prototype rotary-piston air motor RPD-4,4/1,75 in the form of speed characteristics. The maxima of the air motor's performance effective indicators have been determined, as well as the rotation change ranges that correspond to them. It has been established that for the intake receiver's air pressure change range within 0.4...0.8 MPa the maximum value of effective power is 1.7...2.5 kW. In this case, the maximum value of the torque and mean effective pressure for a given pressure range in the intake receiver is 17.0...18.2 N•m and 0.13...0.18 MPa, respectively. The dependence has been derived of the hourly air consumption on the rotations and pressure in the intake receiver. Depending on the test mode, the hourly air consumption is within 25…226 kg/hour. It has been established that the minimum values of the specific effective air consumption correspond to 800...1,000 rpm. Thus, for a maximum value of air pressure in the intake receiver of 0.8 MPa, the specific effective consumption is 60.8...93.2 kg/(kW•h), for the minimum value of 0.4 MPa-49.7...81.3 kg/(kW•h). The potential of the adiabatic expansion capacity has been determined, brought to the air motor, as well as the effective adiabatic efficiency. The maximum efficiency of the air motor corresponds to 800...1,000 rpm. In this case, the maximum efficiency value was achieved at a pressure in the intake receiver of 0.4 MPa; it is 0.41. The dependences have been derived of the change in the pressure of spent air in the exhaust receiver, the maximum value of which does not exceed 0.

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A schematic diagram of a transport hybrid power plant using a new design RPE-4.4/1.75 rotary piston air engine is proposed. Its external speed characteristic is determined, according to which the maximum engine power is 8.75 kW at 850 rpm and the maximum torque is 127.54 N•m at 400 rpm. For various gears and speeds, all the components of the power balance were determined and the dynamic characteristic of the hybrid car was obtained when operated on an air engine. According to the dependences of the power balance, the total traction force from the rotary piston air engine on the driving wheels is 5 kN. The performance of acceleration of a hybrid car while working on an air engine is estimated, namely, the dependences of acceleration, time, and acceleration path are obtained. In urban traffic, the required time to accelerate the car to a speed of 60 km/h is 15.2 s and the path is 173 m. The possible drive range of the hybrid car on compressed air without additional recharging is analyzed. On one cylinder with compressed air with a volume of 100 liters, an initial pressure of 35 MPa, and a final pressure of 2 MPa, the hybrid car can travel about 26 km. O. Mytrofanov, A. Proskurin, A. PoznanskyiThe use of electric vehicles has a significant number of advantages and disadvantages. Thus, most of the disadvantages of electric cars are associated with batteries, namely, their significant cost, relatively low power reserve (especially at low ambient temperatures), a fairly long charging time, a small service life, and the cost of disposal. All these disadvantages are still compounded by an extremely undeveloped infrastructure of charging stations. Partially, these can be solved by using hybrid cars: for example, the problem of distance range or operation in winter.An alternative to electric and hybrid cars can be vehicles running on compressed air [10-13], or hybrid vehicles using an air engine instead of an electric one. Air engines, like electric engines, are environmentally friendly; in addition, the air engine power supply system has significant advantages compared to batteries, although it is somewhat more complicated. The advantages include the long service life of consumable cylinders, their quick refueling, and the fact that expensive and toxic disposal is not required. Thus, the frequency of inspection of cylinders for storing compressed air installed on mobile vehicles is 10 years (external and internal inspection and hydraulic tests with test pressure). The service life of supply cylinders with compressed air is set by the manufacturer. Usually, it is not limited, although in some countries, for example, in Russia, according to industrial safety requirements, it is limited to 20 years. Also, the advantages of using an air engine can be attributed to the fact that in summer, expanded and cooled air can be used in the car air conditioning system.The main element of a transport power plant is an air engine, where the technical and operational performance of the entire plant directly depends on its technical excell...

This paper reports an experimental study into the magnitude of the power of mechanical losses of the prototype of a rotary-piston engine with an articulated cam mechanism for transforming movement, which was aimed at resolving the issue related to improving the efficiency of energy conversion. It has been experimentally established that the greatest component of the power of mechanical losses in a rotary-piston engine with an articulated cam motion transformation mechanism is friction losses. Depending on the rotational speed, they are about 68.4...74.4 % of total losses. The influence of the rotor rotation frequency on the total change in the power of mechanical losses and its components has been determined (an increase in the rotations by 3.75 times leads to an increase in the power of mechanical losses by 3.3 times). It is established that the rotation frequency of the rotor does not have the same effect on the power components of mechanical losses. Thus, an increase in the rotations by 3.75 times leads to an increase in friction losses by 3.0 times, and the component of losses on pumping strokes by 4.1 times. It was found that an increase in the pressure of working body by 2.0 times contributes to an increase in the mechanical efficiency of the rotary piston engine by 1.1 times. At the same time, it was determined that the rational speed range, which corresponds to the maximum values of the mechanical coefficient of efficiency, regardless of the pressure of working medium, is 800...1200 min–1. The resulting experimental data on studying the magnitude of the power of mechanical losses in the form of an analytical model of the influence of the main operational parameters of the rotary-piston engine with an articulated-cam mechanism for converting movement into a mechanical coefficient of efficiency have been generalized. The results reported here could make it possible to preliminary assess losses at energy conversion at the design stage and to construct a rotary piston engine for different purposes

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