This work presents a novel self-regulated toroidal continuously variable transmission (ART-CVT) that features a passive control of the speed ratio, achieved with no need for supplementary actuation system. The proposed transmission system is based on a full-toroidal CVT topology which combines a specially shaped geometry of the conjugate profiles with a pre-load system to create a correlation between the speed ratio and the input torque. Such a solution is conceived to reduce the complexity that is usually associated with active regulated systems and it is envisaged to be applicable to low-power/low-cost systems such as small wind turbines, powered-two-wheelers, or bicycles. We illustrate a simplified mathematical model that is able to describe the response of the proposed ART-CVT in quasi-static steady-state operational conditions. Additionally, we propose a case-study in a realistic scenario: a design for an ART-CVT that matches the requirements of a low-power wind turbine coupled with a synchronous generator directly connected to the grid without additional power converters. The achieved results show that an ART-CVT is able to reach working conditions close to the maximum theoretical aerodynamic performance without any active regulation.
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This research received funds from Tuscany Region (Italy) under the project EOLO no. 646436 (FAR FAS 2014-A).
Conflict of interest
AB and DM belong to ACTA, a company with a financial interest in the subject discussed in this manuscript. All the other authors declare no conflict of interest.
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Milazzo, M., Moretti, G., Burchianti, A. et al. A passively regulated full-toroidal continuously variable transmission. Meccanica 55, 211–226 (2020). https://doi.org/10.1007/s11012-019-01096-y