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

  • Workzone safety can be economically viable
    October 24, 2014
    David Crawford looks how workzone safety can be ‘economically viable’. Highway maintenance is one of the most dangerous construction industry occupations in Europe. Research from The Netherlands on fatal crashes indicates that the risk facing road workzone operatives is ‘significantly higher’ than that for the general construction workforce. A survey carried out by the Highways Agency, which runs the UK’s motorway and trunk road network, has suggested that 20% of road workers have suffered injuries from pa
    Read More
  • The future of in-vehicle navigation systems
    February 3, 2012
    TRL's Alan Stevens looks at the evolution and future prospects of in-vehicle navigation devices. Human-Machine Interaction (HMI) plays a crucial role in the safety of vehicles on our roads. Until we achieve full automation (and that's a debatable prospect anyway) a driver's interaction with the vehicle - all the controls, information and systems - holds a pivotal role in safe driving.
    Read More
  • Elimination of electric vehicle systems
    June 24, 2016
    According to IDTechEx Research reports, Power Electronics for Electric Vehicles 2016-2026, Mild Hybrid 48V Vehicles 2016-2031 and Structural Electronics 2015-2025: Applications, Technologies, Forecasts”, el4ctric vehicles (EVs)have a cost challenge: hybrids have complexity problems meaning reliability and space issues. Extra power electronic units arrive for tasks such as a vehicle-to-grid, vehicle-to-house and inductive charging. Many more will be added in future such as regeneration modules - thermoelect
    Read More
  • Electric boats and ships 2017-2027: Large market emerging, says IDTechEx
    January 13, 2017
    Analysts at IDTechEx have issued a new report, Electric Boats and Ships 2017-2027 looking at this fragmented but often highly profitable and growing sector. It says there are already over 100 manufacturers of electric boats and ships. The report finds that the market for hybrid and pure electric boats and ships will rise rapidly to over US$20 billion worldwide in 2027 for non-military versions. The recreational boat market is the largest and fastest growing electric marine market in sales number, followe
    Read More

Highlighted Content