A novel vibration actuator based on active magnetic spring

•An actuator using a magnetic spring as elastic suspension, activated electromagnetically for generating vibratory forces, is proposed.•The differential magnetic spring can be very well modeled mathematically with a polynomial function of odd degree, 3 or 5.•The differential magnetic spring works practically linear for an interval that is about one third of the maximum allowable displacement.•Dynamic modeling of the vibration generator, considered as a damped harmonic oscillator, provides the necessary relations for its design.•The actuator generates sinusoidal vibrations, when is excited with a sinusoidal current in a linear domain of working (±3mm). The paper presents a theoretical study and experimental results regarding an original, low cost actuator, with a simple design, that uses an active magnetic spring in order to generate vibration. The analysis performed in the paper shows that the differential magnetic spring is the best solution for replacing the classical elastic suspensions in vibration generators. Mathematical modeling enables the determination of the parameters that characterize the actuator operation in the frequency domain. The experimental results show that the vibrator has, practically, a linear characteristic for oscillations of the order ±3mm in amplitude and has a resonance frequency of approximately 36.5Hz. The proposed model can generate dynamic forces of up to 15N for an input sinusoidal current of 0.1A (peak). The maximum force supported by the magnetic spring is 42N.