The electric vehicle business will approach a massive $500 billion in 2025 with the traction motors being over $25 billion.
Their design, location and integration is changing rapidly. Traction motors propelling land, water and air vehicles along can consist of one inboard motor or - an increasing trend - more than one near the wheels, in the wheels, in the transmission or ganged to get extra power. Integrating is increasing with an increasing number of motor manufacturers making motors with integral controls and sometimes integral gearing. Alternatively they may sell motors to the vehicle manufacturers or to those integrating them into transmission.
In a new report from IDTechEx called "Electric Motors for Hybrid and Pure Electric Vehicles 2015-2025: Land, Water, Air" these complex trends are explained with pie charts, tables, graphs and text and future winning suppliers are identified alongside market forecasts. There are sections on newly important versions such as in-wheel, quadcopter and outboard motor for boats.
Today, with the interest in new traction motor design there is a surge in R&D activities in this area, much of it directed at specific needs such as electric aircraft needing superlative reliability and power to weight ratio. Hybrid vehicles may have the electric motor near the conventional engine or its exhaust and this may mean they need to tolerate temperatures never encountered in pure electric vehicles.
Motors for highly price-sensitive markets such as electric bikes, scooters, e-rickshaws and micro EVs (car-like vehicles not homologated as cars so made more primitively) should avoid the price hikes of neodymium and other rare earths in the magnets.
In-wheel and near-wheel motors in any vehicle need to be very compact. Sometimes they must be disc-shaped to fit in. However, fairly common requirements can be high energy efficiency and cost-effectiveness, high torque (3-4 times nominal value) for acceleration and hill climbing and peak power twice the rated value at high speeds. Wide operating torque range is a common and onerous requirement. Overall energy saving over the drive cycle is typically critical. Usually winding and magnet temperature must be kept below 120C and then there are issues of demagnetisation and mechanical strength.