The power unit of universal tractors of traction class 1,4 with an integrated starter generator

Abstract

The technical development of tractor designs is characterized by an increase in the power of consumers, the use of electric drive units. The load on the electric system of a modern tractor is constantly growing and exposes the existing 12-volt systems to excessive loading. To date, with the relatively low efficiency of traditional generators it is impossible to meet the growing needs of tractors and its systems. The solution of the problem of increasing the power simultaneously with increasing the efficiency (up to 85...90 %) could become an integrated starter-generator. Possessing sufficient power in the propulsion mode (up to 8 kW), the starter generator makes it possible to improve the starting and energy characteristics of the internal combustion engines of the tractor. The proposed design of electrical machines is located between the engine cylinder assembly and the tractor clutch. The adopted configuration allows to transfer considerable power in both directions, improves the starting qualities of diesel engines of tractors, and also realize the functions of damping the torsional oscillations of the crankshaft, which significantly reduces the noise and vibration of the engine. Based on the results of the study, the choice of a starter-generator device based on a valve motor is justified in connection with diesel engines of universal tractors of traction class 1,4 and a scheme for its placement in the clutch housing without changing its basic design has been developed. The advantage of the proposed design is the use of electric machines to start the engine, which in this case is switched to the electric motor mode and switches to the generator mode during operation, providing power to the on-board network. In addition, combining the starter and generator in a single unit simplifies the design, reduces the cost of manufacturing and assembly, which is an advantage in terms of production costs, replacing the starter and generator and on some tractors the starting piston engine.