Zeroshift unveils new clutchless multi-speed transmission for EVs

By Editors on August 12, 2010 6:26 AM

The UK-based transmission specialist firm Zeroshift has come up with a new clutchless multi-speed gearbox designed specifically for use in electric vehicles. A variation on its existing Automated Manual Transmission design, Zeroshift says this EV-specific component would make it possible for a given vehicle to be fitted with better-scaled motors and battery packs. It also would permit the vehicle's motor to operate at 95-percent or higher efficiency levels, a factor it contends would deliver better performance and longer range as well as help extend the usable life of the battery pack itself.

Zeroshift's managing director Bill Martin sums up the potential scale of the benefit by noting: "Our studies suggest that by using a compact, multi-speed transmission and a smaller electric motor, manufacturers can gain an operating efficiency of up to 10 percent. You can use that 10 percent to improve EVs' range or reduce the size, weight and cost of battery packs."

Like its Automated Manual Transmission, Zeroshift's EV transmission does not require the use of a clutch to facilitate uninterrupted and virtually seamless ratio changing. Instead, it relies on Zeroshift's unique arrangement of internal dampers inside of the gear hubs and integrates their operation using electronic controls on the motor. By eliminating the need for a clutch, this bespoke EV transmission sidesteps one of the most challenging mechanical aspects faced by automakers attempting to make a multi-speed transmission live a long and happy life when matched with a high-torque power source. Although there's no word as to when or where we might see a first use of Zeroshift's EV transmission, the company admits that it's currently engaged in discussions with several manufacturers.