ZF’s High Revolution Drive is a 3-in-1 passenger car electric drive running at up to 30,000rpm. Nearly 25% smaller and lighter than a comparable 18,000rpm SELECT drive, it halves magnet mass, reaches nearly 93% efficiency and, in the version shown, delivers 200kW and 3,500Nm wheel torque. Production is targeted by 2030.
ZF has developed a compact 3-in-1 electric drive that runs at up to 30,000 revolutions per minute (rpm), allowing it to use a smaller, lighter electric motor with half the magnet mass of a comparable drive.
The High Revolution Drive from the Friedrichshafen, Germany-based supplier is a variant of its modular SELECT electric drive platform. ZF says it is nearly 25% smaller and nearly 25% lighter than a comparable SELECT drive running at 18,000rpm while delivering the same power. The version shown has a peak output of 200kW and peak wheel torque of 3,500Nm.
The concept is based on the relationship between speed and torque. At the same power output, a higher rotational speed reduces the torque the motor must produce. Because torque is closely linked to rotor volume, the motor can be made smaller and lighter. A two-stage helical cylindrical gear transmission with a ratio of about 18:1 then converts the high speed into the torque required at the wheels.
According to Thomas Meiser, head of the E-Mobility Business Unit at ZF, the approach depends on developing the components together. “The High Revolution Drive draws on ZF’s full systems expertise,” he says. “Rather than optimising individual components in isolation, we systematically coordinate the electric motor, power electronics and transmission.”
Higher speeds make noise and vibration harder to control. ZF says it addressed this through the coordinated design of the components, drawing on its gear and transmission experience. “Robustness and low noise and vibration levels were stringent development targets from the outset,” says Meiser. “To achieve this, we considered the electric motor, gearing, bearings and tooth geometry as an integrated system. For the configuration presented, 30,000 rpm is the economic and technical sweet spot.”
According to the company, the 50% reduction in magnet mass lowers costs and reduces dependence on critical supply chains. Despite the high rotational speed and gear ratio, the system achieves efficiency of nearly 93%, in line with the comparable SELECT system. ZF adds that the lower weight helps increase electric range.
The drive is aimed at the high-volume passenger car market, with outputs of approximately 150-200kW. The architecture can be scaled to different power ratings and is suitable for both 400-volt and 800-volt systems.
Because it uses existing SELECT technologies, ZF says automakers can bring the drive into new vehicles faster and at lower development cost, with predictable product costs. “With SELECT, we do not have to start from scratch for every new drive variant,” says Meiser. “We use our modular system to tailor new concepts to different customer requirements.”
ZF is in talks with several automakers and is targeting production by 2030.
