Yamaha MOTIV.e city car to use ultra-high-speed Zytek electric drive train
By Mike Hanlon
February 24, 2014
More details have emerged on the development of the Yamaha MOTIV.e city car concept which was shown at the Tokyo Motor Show last November. The MOTIV.e will be offered with several drivetrains, including an electric version, and EV specialist Zytek will supply a purpose-built ultra-high-speed motor for the project.
The 25 kW Zytek motor spins to 15,000 rpm and comes with advanced thermal management and control integration. The unit has been designed to cut cost, weight and size and this appears to have been achieved as the motor weighs just 13 kg (29 lbs), the gearbox just 11 kg (24 lbs) and the inverter just 7.5 kg (17 lbs).
The Yamaha MOTIV.e emanated from a partnership between Yamaha and Gordon Murray Design, using Murray’s iStream manufacturing technology and what appears to be a close relative of Murray's much-vaunted City Car – billed as an efficient electric vehicle at an affordable price. The car is Yamaha's first step into the automotive industry, and more cars will follow, though the aim is to produce cars of excellent drivability and with an emphasis on Yamaha's reputation for producing outstanding engines.
“Yamaha wanted the vehicle to reflect the company’s reputation for outstanding engines,” according to Zytek Marketing Director Steve Tremble. “Interpreting this in an electric vehicle has driven excellence in performance and driveability, as well as in weight reduction and efficiency, building on the potential of iStream to deliver an agile drivers’ car as well as maximizing the range.”
Zytek will supply Yamaha with the electric motor, Vocis single speed reduction gearbox, and an Electronic Vehicle Control Module (EVCM) which includes thermal management within the decision-making algorithms.
“This is a new generation of EVCM that integrates torque arbitration, temperature control and voltage management to allow better decision making,” Zytek’s engineering program manager, Neil Cheeseman explains. “It optimizes the driver’s torque request based on a broad range of parameters including battery charge and temperature and the grip available at the tires. By integrating these decisions, we can provide more with less to improve both the driving experience and the range while reducing the size, weight and cost of the power electronics and battery pack.”