Ultra-high-speed 30,000-rpm EV motor unleashes 3,500 Nm of torque at wheels

German automotive supplier ZF has developed a compact electric vehicle drive that spins at up to 30,000 rpm and delivers 3,500 Nm of peak torque at the wheels. It uses a two-stage gearbox to turn the motor’s high speed into usable wheel torque, allowing it to shrink the drive while maintaining the same power output as a comparable unit. The 3-in-1 system combines an electric motor, power electronics, and a transmission. The version ZF presented delivers 200 kW of peak power and is nearly 25% smaller and lighter than a comparable drive that runs at 18,000 rpm. ZF is in talks with several automakers and is targeting production by 2030. How a smaller motor delivers 3,500 Nm At a given power output, an electric motor spinning faster needs to generate less torque. Since motor torque is closely tied to rotor volume, the higher speed allows ZF to use a smaller rotor and build a lighter motor. The transmission then reduces rotational speed and multiplies torque before it reaches the wheels. ZF uses a two-stage transmission with helical gears and a reduction ratio of about 18:1. That setup gives the High Revolution Drive its peak wheel torque of 3,500 Nm while letting the motor run at speeds well above those of the 18,000-rpm unit ZF used for comparison. “The High Revolution Drive draws on ZF’s full systems expertise,” said Thomas Meiser, head of ZF’s E-Mobility Business Unit. “Rather than optimizing individual components in isolation, we systematically coordinate the electric motor, power electronics and transmission,” he added. Half the magnet mass at nearly 93% efficiency Higher motor speeds make noise and vibration harder to control. ZF designed the motor, gears and bearings together and accounted for the shape of the gear teeth to manage those effects. Meiser said 30,000 rpm offered the best balance of cost and technical performance for the version presented. The new drive requires half the magnet mass of the comparable 18,000-rpm unit. ZF said the reduction lowers costs and reduces its dependence on critical supply chains. Despite the higher motor speed and gear reduction, the system achieves nearly 93% efficiency, matching the comparable drive. ZF also expects the lower weight to help extend vehicle range. A modular drive for 400- and 800-volt EVs ZF developed the High Revolution Drive as a variant of its existing SELECT platform. Its initial focus is on high-volume passenger cars with drive outputs of about 150 to 200 kW. The architecture can be adapted for different power ratings and for both 400- and 800-volt electrical systems. The smaller package gives automakers more room to work with when laying out a new vehicle. By reusing technology from SELECT, ZF also aims to cut the time and development cost of integrating the drive into future models and give manufacturers more flexibility in how they produce it. “With SELECT, we do not have to start from scratch for every new drive variant,” Meiser said. “We use our modular system to tailor new concepts to different customer requirements,” he added. Get the latest in engineering, tech, space & science - delivered daily to your inbox.Atharva is a full-time content writer with a post-graduate degree in media & amp; entertainment and a graduate degree in electronics & telecommunications. He has written in the sports and technology domains respectively. In his leisure time, Atharva loves learning about digital marketing and watching soccer matches. His main goal behind joining Interesting Engineering is to learn more about how the recent technological advancements are helping human beings on both societal and individual levels in their daily lives.