Engineer interview

Toyota Industries corporation, world’s top manufacturer of forklift, adopts high efficient Toyota Super Drive AC motor on many models of the forklift truck. Mr. Kosaki, Engineering Manager responsible for motor design, was a member of the new motor development team and explained background and story of the motor development.

Toyota set the target of new forklift truck, GENEO Ecore 3wheel counter balance forklift truck launched in 2015, as 20% longer operating hours which is the industrial top level.
Because electric motors consume the largest percentage of electric power in forklifts, to achieve the target, the motor efficiency is very important and we decided to develop low loss and high efficient motor.

In this motor development, efficiency improvement was the most important development theme. Permanent magnet motors using rare earth permanent magnets, which are easier to increase efficiency, were an option, but by the cost reason we decided our direction not to use rare earth magnet.

The goal was not simply to increase the maximum efficiency, but to achieve high efficiency at a wide range of operating points (speed / torque points) required for traction motors. Also, as an effect of improving efficiency, heat generation due to loss is reduced and output density is increased. As a result, it was expected to improve acceleration and lifting performance.
This motor development was very big challenge how to improve efficiency that balances costs.

Realizing high efficiency with a wide range of operating points (speed / torque points) required new motor structure. It was very tough development to find the optimal balance by selecting motor cores and slot shapes from over a thousand combinations and analyzing them in large quantities.
In actual development process, the structure is selected by combining the simulation and prototype evaluation results, and efficiency and power density were improved by the very steady and repeated work.
The newly developed motor is the 5th generation structure of our forklift motor by own design, and it achieves high efficiency in a wide range of operating points through generations by utilizing the design assets developed by seniors so far. We are proud to have developed the best motor for forklifts.

By this development we contributed to actually achieve the 20% improvement in operating hours of the forklift truck, which was the original development goal, and I heard that the motor was one of the reasons for Rinova reach truck to win the METI Award for Excellence. In overseas improved acceleration and operability has been well received by forklift operators with motor feature of high output density.

Electrification is big wave in the world wide. Now I’m working to expand the high efficient motor lineup and contribute to the realization of a sustainable society, not only with forklifts but also with other applications in the world, especially in Europe where the electrification market is expanding ahead.