ZF develops High Revolution Drive, an e-drive that spins at up to 30,000 rpm

ZF has developed the High Revolution Drive, a 3-in-1 electric drive that spins at up to 30,000 rpm and is designed for high-volume passenger cars. It is a variant of the company’s modular SELECT e-drive platform.

At the same power output, a higher rotational speed reduces the required motor torque. Since torque is closely linked to rotor volume, the motor can be designed to be smaller and lighter. A two-stage spur gear transmission with a ratio of about 18:1 delivers the required torque at the wheels. The version ZF has shown delivers a peak output of 200 kW and peak wheel torque of 3,500 Nm.

ZF says the High Revolution Drive is nearly 25% smaller and nearly 25% lighter than a comparable SELECT drive running at 18,000 rpm. It needs 50% less magnet mass, which lowers costs and reduces dependence on critical supply chains. Efficiency is nearly 93%, on par with the comparable SELECT system, even at high rotational speed and a high gear ratio.

ZF is focusing on drive outputs of about 150 to 200 kW. The architecture can be scaled to different power ratings and to both 400 V and 800 V systems. ZF says it is in talks with several automakers and aims to start production by 2030.

ZF says that because the drive uses existing SELECT technologies, automakers can bring it into new vehicles faster and at lower development cost. “With SELECT, we do not have to start from scratch for every new drive variant,” said Thomas Meiser, Head of the E-Mobility Business Unit at ZF. “We use our modular system to tailor new concepts to different customer requirements.”

Higher speeds make noise and vibration harder to control. “Robustness and low noise and vibration levels were stringent development targets from the outset,” said 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.”

Source: ZF