infinitely variable drive

Mechanical power split concept for gearbox industry


IVD is a mechanical solution for a stepless transmission comprised of epicyclic gear system with multi-input and one-way overrunning clutches combined with other mechanisms to convert translational motion to rotational motion. IVD is a substitute technology for currently wide spread used belt and hydrostatic CVTs which are complex and have efficiency issues which are due to friction based nature of belts and losses in liquid hydraulic fluids. IVD is a pure, complex and mechanical approach which can be used either directly or as a subsystem in larger gearbox.


Check out the concept video


We believe that our IVD concept will provide the transmission solution for the current and future needs of the gearbox manufacturing industry. Through initial analysis of our mainstream technology, we have identified following benefits of the IVD solution:



In comparison to belt systems, where efficiency is low at high speeds, IVD can achieve low friction loss at maximum speeds.


IVD concept maintains a direct contact without relying on friction based mechanisms. System simplicity and direct mechanical feedback offers continuous manual gear ratio selection.

Because of the solid structure, IVD requires less complicated controllers, which are needed in alternative solutions to improve system response.

Infinite ratio

In alternative systems, the infinite ratio is only achievable using friction based mechanism. Entirely mechanical IVD concept is thus reducing friction loss in the system.

Furthermore, for initiating a smooth output, a hydraulic torque actuator is used in some alternative solutions, resulting in a decrease in efficiency during operating conditions by about 15 percent. The achievable gear ratios are limited in alternative solutions, while infinite ratios are available with the proposed IVD concept.

Reverse ratio

Proposed IVD structure provides stepless gear ratios from forward to reverse in one complete purely mechanical setup with just one clutch or breaking mechanism which for example could be coupled to electric motor generator in hybrid setups.

Project description

Our dynamic team consists of both technical and commercial experts from Lappeenranta University of Technology, Saimaa University of Applied Science and our external resources which include research facilities and companies.

We aim to develop the IVD concept into a commercially viable solution that is ready for end-users and bring something new to transmission industry.
Based on the initial results obtained through research, our solution can be scaled to satisfy the global market potential, with the intent on producing customer tailored components for an optimal solution.

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