Clutchless multi-speed transmission for EVs

Transmission specialist Zeroshift has devised a multi-speed gearbox for electric vehicles (EVs) that needs no clutch.
February 1, 2012 Read time: 1 min
Zeroshift's multi-speed transmission concept changes gear without interrupting the torque, allowing EVs to run for longer at peak efficiency.

Transmission specialist 1994 Zeroshift has devised a multi-speed gearbox for electric vehicles (EVs) that needs no clutch. A damper inside the gear hubs and electronic control of the motor make ratio changes seamless. The company claims the innovation could enable manufacturers to downsize EVs’ electric motors, keeping them running longer at the medium loads and speeds where peak efficiency of over 95 per cent is possible. For drivers, that could mean more performance, greater range and longer lasting batteries.

Zeroshift’s managing director Bill Martin says: “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 per cent. You can use that 10 per cent to improve EVs’ range or reduce the size, weight and cost of battery packs.”

Zeroshift’s concept prevents any torque interruptions during ratio changes and does not require a clutch, issues that have so far deterred EV manufacturers from fitting multi-speed gearboxes. Current EVs instead use a single-speed transmission, but the motor then spends more of its time outside of its optimum efficiency range.

Related Content

  • May 31, 2013
    Temporary traffic monitoring with Bluetooth and wi-fi
    David Crawford reviews developments in temporary ITS. Widespread take-up of technologies such as Bluetooth and wi-fi are encouraging the emergence of more sophisticated, while still cost effective, ITS responses to the traffic issues posed by temporary road situations such as work zones and special events. Andy Graham of traffic solutions specialists White Willow Consulting says: “A machine-to-machine radio link is far easier and cheaper than reading characters on a plate.” There can be other plusses. Tech
    Read More
  • December 16, 2014
    Do satellites provide a heavenly view of tolling’s future?
    Satellite-based tolling opens up new options for authorities and can be integrated with DSRC systems as David Crawford discovers. As the proud custodian of the European Union (EU)’s longest road network covered by a single (truck) charging scheme – and the only one to include all major roads - Slovakia has become the continent’s poster-nation for the virtues of GNSS/CN (Global Navigation Satellite System/Cellular Network)-based tolling. It is also proved to be a very fast implementer. Speaking at the 2014 I
    Read More
  • December 5, 2013
    Vehicle manufacturers and local authorities seek satnav solutions
    The increasing capability of satellite navigation is helping vehicle manufacturers and local authorities as well as individual drivers and fleets. In comparison to the physical ITS infrastructure in towns and cities and on motorways and highways, satellite navigation (satnav) systems have come a long way in a short time. Many (if not the majority) individual drivers and fleets use or have access to a satnav and now the vehicle manufacturers and even local authorities are beginning to utilise satnav derived
    Read More
  • March 27, 2020
    California e-dreaming with ABB
    Data can unlock the costs and benefits of converting commercial fleets to electric vehicles.
    Read More

Highlighted Content