We’ve been waiting for some time now for electric motorcycles to take the next big leap towards the mainstream. Thanks to the longstanding efforts of manufacturers like Zero, and Harley-Davidson‘s new push toward electrification led by the LiveWire, we’re getting closer to seeing that happen. Kawasaki, meanwhile, may be looking in a different direction, having filed a patent application for a hybrid motorcycle.
The newly published patent application was originally filed with Japan’s patent office in December 2017 and subsequently filed with the U.S. Patent and Trademark Office a year later. It describes a motorcycle equipped with both an electric motor and an internal combustion engine. The patent illustrations show a parallel hybrid system, meaning the engine and the motor work together to deliver power to the rear wheel. The patent explains, however that the concepts can also work in a series hybrid mode, where only the electric motor provides driving power and the gas guzzling engine acts as a range extender. A split hybrid system where either the motor or engine produces motive power is also described.
The patent addresses one of the key concerns about hybrid motorcycles: how to arrange all the various parts in a compact form. Hybrid cars offer multiple options for engineers to position the engine, motor, transmission, fuel tank and batteries; on a motorcycle, the options are rather limited.
According to the patent, the AC electric motor (#4 in the diagrams) and combustion engine form a single unit along with the transmission, all sharing the same casing. The battery (#21) is located above the engine between the frame spars where a conventional fuel tank would normally be found. In this configuration, the tank (#15) can be mounted to the side of the seat or, alternatively, outside the frame beside the battery. In either case, the fuel tank is kept to the left side of the motorcycle, balanced with a coolant tank on the right side. In theory, this keeps all the heaviest parts close to the center of gravity.
While the patent proves that Kawasaki has been working on a hybrid motorcycle, it doesn’t necessarily mean we’ll see one any time soon. Kawasaki has also filed multiple different patents for electric motorcycles over the years, and none have seen the light of day as yet, so don’t hold your breath for a production hybrid from Kawasaki.