Force-displacement characteristics of linear stepping motors

A method for calculating the developed force of the hybrid linear stepping motor (LPM) is presented. The force equation is derived by use of design parameters, such as the magnetic flux or magnetic flux density produced by the permanent magnet. The relation between the force and the speed EMF induced in the coil when the forcer is moved externally at a constant velocity is obtained. It is found that disagreement between the theoretical and experimental force-displacement curves increases at large currents. Effects of the eddy currents in the stator core and magnetic saturation on the developed force are investigated. The acceleration characteristics of LPM are compared with those of a rotating type hybrid stepping motor