Magnet circuit optimization design of giant magnetostrictive actuator

Abstract

To optimize the electromagnetic performance of giant magnetostrictive actuator(GMA), equivalent magnet circuit equation was proposed, and effects of magnetic circuit components gap's magnetic permeability and the evenness of driving magnetic field on the magnetic field characteristics were analyzed based on the equation. the driving coil's structure was designed, and its shape was optimized based on G-factor; with the electromagnetic field analysis function available in ANSYS program, several different magnetic circuits and their field distribution are analyzed. As a result, a kind of magnetic circuit structure with more even magnetic field is found out. The actuator prototype was made and tested, and result shows the optimal method proposed in the paper can greatly improve performance of GMA.

Numerical Evaluation and Experimental Test on a New Giant Magnetostrictive Transducer with Low Heat Loss Design

“…Equation (10) shows that when the magnetic line propagates on the interface of two media, it usually changes its direction and forms a certain refraction angle. If the medium 1 is ferromagnetic material and the medium 2 is air, then µ 2 << µ 1 , θ 2 << θ 1 .…”

“…Actually, some remarkable achievements have been obtained by taking a panoramic view of the GMT. As the most important heating part of the transducer, the excitation coil is optimized by Liu to reduce the heating and obtain a better coil shape [10]. However, the coil with the high power shape factor has a limited effect on reducing heat loss.…”

New Type of Linear Magnetostrictive Motor Designed for Outer Space Applications, from Concept to End-Product

“…The ring (6), made of a material with low magnetic remanence, grips the active GMM core (1) so that the lower magnet ( 4) is in its immediate vicinity. The ring ( 6) is split (a gap of 0.8 mm) to not short-circuit the coil, as is the rod (13), which aims to fix the components of (A). The plate (7) is fastened to the pusher rod (2) using the fixing screw (8).…”

“…The magnetic bias coil ( 12) is also wound with CuEm, with N B = 5600 turns and a diameter of Φ = 0.35 mm (measured without Em insulation). The brass rod (13) is made of CuZn37. The two coils are impregnated with 525Ez electro-insulating varnish.…”

“…Using an optimal design method, Dehui et al [13] proposed, designed, and tested a GMA prototype with improved performance: a displacement in the range of 70 µm, a precision of 0.05 µm, and a driving force of 500 N. Terfenol-D, one of the most used GMMs, has a low relative permeability of about four, which is responsible for leakage flux. In this regard, to ensure a homogeneous magnetic field along the rod, the flux leakage at the rod ends has to be compensated for [14].…”