ZF has unveiled the High Revolution Drive, a compact 3-in-1 electric drive that spins its motor at up to 30,000 rpm. The company says this allows the unit to be almost 25 percent smaller and lighter than a comparable drive running at 18,000 rpm, and to cut the magnet mass in the motor by half.
The higher speed is central to the design. At the same power output, a faster-spinning motor needs less torque, and because torque is closely tied to rotor volume, the motor can be made smaller. A two-stage spur gearbox with a ratio of about 18:1 delivers the necessary torque to the wheels. The version shown peaks at 200 kW and 3,500 Nm.
Lower Costs and Reduced Supply Chain Dependence
Reducing magnet use lowers production costs and reduces reliance on critical supply chains, which is a growing concern for drive system suppliers. ZF says the system still achieves an efficiency of nearly 93 percent, on par with its existing SELECT system despite the higher speed and gearing. The lighter design should also help extend driving range.
Managing Noise and Vibration
Higher rotational speeds make noise and vibration harder to control. ZF says it addressed this by designing the electric motor, gearing, bearings and tooth geometry as a single integrated system. Thomas Meiser, Head of the E-Mobility Business Unit at ZF, said that “robustness and low noise and vibration levels were stringent development targets from the outset.” He added that “for the configuration presented, 30,000 rpm is the economic and technical sweet spot.”
Platform and Market Plans
The High Revolution Drive is a variant of ZF’s modular SELECT platform and uses existing technologies, which the company says keeps product costs predictable. The drive is aimed at high-volume passenger cars and covers roughly 150 kW to 200 kW. It is designed to work with both 400-volt and 800-volt electrical architectures. ZF plans to begin production by 2030.
Because the system builds on SELECT technology, automakers may be able to bring new vehicles to market faster and with lower development costs. Several manufacturers are already in discussions with ZF about the drive.
