A Belleville-spring-based electromagnetic energy harvester

Abstract

Energy harvesting from kinetic ambient energy is particularly effective to power autonomous sensors. This work proposes an innovative energy converter based on two counteracting Belleville springs and exploiting their peculiarity, for a height to thickness ratio equal to 1.414, of nearly zero stiffness over a wide deflection range. After analytical and numerical modelling a prototype is developed and experimentally investigated. The sub-optimal geometry of the commercial springs used in the prototype, together with a non-ideal response makes the operating frequency for the prototype higher than analytical and numerical predictions. Nevertheless, the harvester exhibits a significantly large bandwidth, together with a high output power, compared to similar solutions in the literature, for all the examined configurations and input excitations.

Design and experimental assessment of an electromagnetic energy harvester based on slotted disc springs

“…Starting from the encouraging results obtained in a previous work, 24 this paper improves the design and validation of an innovative electromagnetic energy converter with a multi-frequency response. Compared to the previous work, 24 the present solution uses two counteracting slotted conical disc springs to implement a low stiffness elastic system.…”

“…[4][5][6][7][8][9][10][11][12][13][14] Thus, it is important to develop energy harvesters working in the low frequency range and with a multi-frequency response: to this aim, piezoelectric and electromagnetic transducers provide a simple and effective way. 8,9 Many solutions have been proposed in the literature, both relying on piezoelectric and on electromagnetic transducers: these systems exhibit either a linear response [15][16][17][18][19][20][21][22][23][24] or a non-linear one. [25][26][27][28][29][30][31] Two main drawbacks can be traced in the solutions from the literature.…”

“…32 In particular, for a given ratio between the diameter and the height of the spring, the spring stiffness becomes nearly zero along a significant stroke across the flat configuration. 24 The second step presents a conceptual solution of a low stiffness elastic system relying on counteracting and preloaded conical disc springs, which is devoted to the development of an energy harvester. The third step describes the dynamic response of this elastic system.…”

“…Many solutions have been proposed in the literature, both relying on piezoelectric and on electromagnetic transducers: these systems exhibit either a linear response 15–24 or a non-linear one. 25–31 Two main drawbacks can be traced in the solutions from the literature.…”

3-Degree-of-freedom electromagnetic vibration energy harvester with serially connected leaf hinge joints

“…The frequencies of ambient vibration sources are variable in the low frequency range within 100 Hz (Khan and Ahmad, 2016; Roundy et al, 2003). Many researchers have developed some interesting designs of the structures of harvesters to locate a number of target resonant frequencies in the low frequency range (Castagnetti, 2012, 2015b; Li et al, 2013; Wang and Tang, 2017; Zhou et al, 2012).…”