ZF presents new electric drives

The German supplier ZF presented a new generation of electric drives for passenger cars and light commercial vehicles. With numerous innovations at the component and system level, these are to “set standards with outstanding power density and energy efficiency”.

According to the company’s press release, these standards include the compact design of the drives, the so-called “discrete approach” to power electronics, and the resource-saving use of materials, which should also make the production of the drives more sustainable.

Modular concept

The new ZF drives for passenger cars and light commercial vehicles are based on a modular overall concept with an electric motor, an inverter, a transmission, and software.

ZF intends to offer the components individually and overall systems that are fully integrated drivelines. “We are focusing on three basic systems that meet our customers’ main requirements, namely efficiency, performance, and cost, even in the standard version,” says Markus Schwabe, Product Line Manager of Electrified Powertrain Systems. “On this basis, we can optimally implement further individual customer requirements in e-vehicles of all segments.”

“Thanks to sophisticated internal interfaces, the new, extremely compact design allows system or component adaptations to be made with little effort,” says Otmar Scharrer, head of development for electric drive technologies at ZF. “The design has high structural rigidity, enabling superior noise behavior.”

‘Discrete package technology’

With the so-called “discrete package technology”, ZF wants to balance a high degree of component uniformity and high adaptability in power electronics. As a result, individualization occurs at the chip level, and the individual power semiconductor switches can be combined to form power modules.

In the electric drive itself, the focus is on the cooling concept to increase the power density. In the stator, the copper rods of the braided winding technology developed by ZF have oil flowing directly around them – precisely at the point where most heat is generated during operation.

With the more efficient cooling concept, it should be possible to increase the power with the same weight and installation space or deliver a smaller and lighter electric drive with the same power.

For the new coaxial reduction gearbox, ZF relies on its know-how in planetary gearboxes for combustion engines. Two planetary gearboxes integrated into each other are intended to achieve the desired axle ratio and include the fully integrated differential function.

In addition, the system includes a direct current to direct current converter, specially developed for fuel cell drives. The converter is supposed to compensate for the low output voltage and the strong voltage drop at a high load of the fuel cells. As a result, ZF claims an efficiency of 99,6%.

Stepped introduction

The new generation of electric drive systems from ZF should be available on the market from 2025 as a complete system. However, ZF will bring individual components into series production earlier.

“The great interest of manufacturers in our products in both the passenger car and commercial vehicle sectors is confirmed by our high order backlog in the high-voltage business,” says ZF Board of Management member Stephan von Schuckmann, who is responsible for e-mobility in the Group. “With the next generation of electric drives, we are consistently continuing our strategy of developing sustainable and efficient mobility for the future.”