EV motor and drivetrain manufacturer KersTech has developed a new motor for commercial EVs that combines electric and hydraulic functions, with the aim of maximizing efficiency and extending vehicle range and battery life.
According to KersTech, hydraulic motors are three times more energy-efficient than electric motors for launch acceleration and brake energy regeneration at lower vehicle speeds. Electric motors, conversely, are most efficient at higher speeds, but are inefficient at producing torque and recovering energy at low motor speeds due to heat losses generated in the windings.
The TwinTorq motor combines hydraulic and electric torque-producing elements in a single compact unit. It uses hydraulic torque during acceleration and regeneration phases, and electric torque for driving at cruising speeds. Control software manages torque sharing between the two systems to maximize efficiency and reduce energy demand on the battery.
The motor’s electric/hydraulic design shares common rotor and stator components, minimizing physical volume and cost, and the patent-pending coplanar architecture enables axial compactness, allowing the motor to be mounted low in the chassis for improved space utilization and low center of gravity.
KersTech says its simulations show a 25% to 45% improvement in efficiency compared to conventional electric motors of comparable power in lower-speed, frequent-start/stop drive cycles. The increased efficiency permits optimized battery design to reduce cost and extend battery life.