Energy Modes of the Pulse Linear Electromagnetic Motor with Effective Transformation of Magnetic Energy

The features of linear electromagnetic motors in the drive of impact machines are the impulsive and two-step nature of energy transformation. At the first stage, there is an electromagnetic transformation, that is, the accumulation of magnetic energy in working gaps. On the second stage, its transformation into mechanical work, that is, a magneto-mechanical transformation. Both these processes are separated in time they pass with varying degrees of restoration of the magnetic energy of the working gaps when the armature moves. During the working stroke of the armature, the trajectory of the motion of the operating point on the energy plane “current linkage - current” makes it ratio to establish the relationship between the mechanical operation of the engine and its residual magnetic energy. This ratio determines the magnetic efficiency. He, along with mechanical work, characterizes the efficiency of the magneto-mechanical energy conversion. The analysis shows that some of the energy regimes of the electromagnetic motor have low values of specific mechanical work. The urgency of the study is caused by the need to determine the magnitude of the magnetic efficiency for known energy modes and to find the best among them. For each of the regime known a mechanical method and residual magnetic energy per cycle were found by a known graphical method for determining the magnetic efficiency. This allowed us to compare the magnetic efficiency of each of the regime of the electromagnetic motor with the same residual magnetic energy. It is established that the magnetic efficiency of such an engine depends both on the design and mode parameters and on the coefficient of restoration of magnetic energy during the movement of the armature. Therefore, the twofold designs of the magnetic system of the electromagnetic motor make it possible to increase the efficiency of the magneto-mechanical transformation of such engines by 50 percent or more in comparison with single-gap engines. The best of the considered modes will be the energy regime with constant flux linkage while moving the armature and simultaneously decreasing the winding current of the motor. In this case, the magnetic efficiency approaches unity.