The electric rim motor that Rémi Champeaux of Hy-Generation in Breton, France, has been developing since 2016 is now ready for pre-order, with two of the Rim6 motors built and already in use.
A rim motor is so-named because instead of having a propeller and blades fixed to a central axis, the blades are attached to the outside rim of the motor casing. The technology is commonly used in thrusters to maneuver large boats in tight waters. A rim motor is also used in the Pulse 58 RIB that RS Electric boats introduced at Boot Dusseldorf.
The original concept of M. Champeaux took the rim motor one step further. In the first prototypes he designed the propeller blades to be self-adjusting to automatically optimize the torque and power consumption at different speeds. As he progressed, however, he decided to set that feature aside and develop the more basic elements of the motor and introduce the ingenious blade design in a future iteration.
Electric rim motor won innovation awards
Champeaux has a degree in engineering and it was while working on construction ships at sea that he began to think about how to make the huge rim thrusters that they use more energy efficient.
He received support and some research money from French seed funds, and his first designs for the adjustable propeller blades (which could also be easily swapped out for alternate shape blades) won a regional Trophée d’Innovation 56 award. (The video at the bottom of this page shows the original adjustable blades).
It was prototype tests, though, that led him to rethink the pace of development. He told Briag Merlet of of Boat Industry News “We wanted to make too many innovations all at once and it was difficult to interpret the results. So we’re going to split up the stages, in particular with fixed blades, for the first series of motors.”
The first two electric rim motors built by Hy-Generation are now at work as a twin propulsion system on a riverboat in Breton, and the next stage is to offer that motor model to the public and start to industrialize the production.
With a power rating of 6kW • 8HP, the Rim6 is designed for small, light dinghies and for maneuvering sailboats in harbours and marinas. The company also sees a specific market opportunity in rental boats, because the motor is under the power rating that requires an operator to have a license.
The motor casing, or ‘nozzle’ is made of carbon fibre, and the motor technology is brushless permanent magnet with a nominal voltage of 48 volts. The height of the motor is 630mm • 25″, with a diameter of 400mm • 16″, depth of 200mm • 8: and the weight of the system is 12kg • 26lbs.
LiFePo batteries, chargers and mountings
Hy-Generation has matched the motor with a LiFePo (Lithium Iron Phosphate) battery with a fully integrated battery management system and 6.14kW capacity. The battery weighs in at 37.5kg • 82lbs. Extra batteries can be added in parallel to extend range.
There are three charging options: the Standard system (650W) has a charging time of 7 hours and the Fast system can recharge a single battery in 2 hours.
There are three fittings available with the RIM6. One is similar to the type of mechanism commonly used with electric trolling motors, there is a set up as a through-hull pod for sailboats, or using a configuration that extends the electric rim motor out form the boat so it can be mounted as a side thruster or on a sloped transom.
Because of the various battery and mounting options, there is not a set price for the Rim6. You can get complete information on the Hy-Generation site. Motors ordered now will be ready for the spring of 2021.