Three-Dimensional Motion Analysis of an Actuator (TR)

	Trial Version
	Video Tutorials

Overview

Three-dimensional relative motion is essential to analyzing characteristics of actuators and solenoid valves. JMAG provides a patch meshing feature as a solution. You have only to model the object, and the mesh is filled automatically by the program between the parts each time the object moves. Figure 1 shows the vibrator to be analyzed in this example. In this model, the plunger moves longitudinally (Z-direction), with vibration generated by the righting force occurring in the gap with the stator. There is no mechanical friction, but because the plunger is made of magnetic material, the motion generates eddy currents, causing losses that damp the motion.

Figure 1 - Analysis model of plunger and stator Enlarged View

Figure 2 - Data to be prepared by the user Enlarged View

Figure 2 shows the data to be prepared by the user. Figure 3 shows a sample mesh automatically generated by JMAG during the analysis process. Figure 4 shows the distribution of magnetic flux and eddy currents while in motion. It can be seen that lines of magnetic flux flow in an orderly fashion, and eddy currents occur on the part of the conductor surface where the magnetic flux is concentrated.

Figure 3-1 - Mesh automatically generated during the analysis process Enlarged View	Figure 3-2 - Mesh automatically generated during the analysis process Enlarged View

Figure 5 shows the time history for the plunger displacement. The situation where kinetic energy is consumed due to the eddy currents and damping vibration is well captured. Figure 6 shows the response with eddy currents ignored (electric conductivity 0) and mechanical friction applied. As the coefficient of friction, c, increases, simple vibration becomes damped vibration. Figure 7 shows an animation of the magnetic flux distribution. Here, the same analysis was run with the permanent magnet on the stator replaced by an electromagnet.

Figure 4 - Distribution of magnetic flux and eddy currents while in motion Enlarged View

Figure 5 - Time history for the plunger displacement Enlarged View	Figure 6 - Response with coefficient of friction changed Enlarged View

Animation of analysis run with permanent magnet changed to an electromagnet The same analysis was run with the permanent magnet on the stator replaced with an electromagnet. This is an animation of the magnetic flux density distribution. For a more detailed view, see the full animation file (111 kB).