Electromagnetic drive system with integral position detector

Abstract

An electromagnetic drive system includes a motor having a first motor section movable relative to a second motor section along a motion axis. The second motor section has three excitation coils. The first motor section includes a magnetic circuit generating a magnetic field in the excitation coils. The first motor section also includes a short-circuit winding for only high-frequency induction currents. This short-circuit winding is magnetically coupled to the excitation coils. The degree of electromagnetic coupling of at least one excitation coil depends on the position of the first motor section relative to the second motor section. The short-circuit winding provides a position-dependent electromagnetic coupling between the center excitation coil and the two outer excitation coils. The position-dependent coupling can be detected by superimposing a high-frequency detection signal on the excitation system for the center coil and by detecting currents induced in the two outer coils by the high-frequency detection signal. Thus, a compact drive system with a built-in position detector is obtained.

Dependencies are inferred from the claim text.